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Summary Background We hypothesised that combining zanubrutinib with obinutuzumab and venetoclax (BOVen) as an initial therapy for chronic lymphocytic leukaemia and small lymphocytic lymphoma would lead to high rates of undetectable minimal residual disease (MRD), and we explored MRD as a biomarker for directing treatment duration. Methods This multicenter, investigator-initiated, single-arm, phase 2 trial took place at two two academic medical centres in the USA. Patients were eligible for the primary cohort if they had treatment-naive chronic lymphocytic leukaemia or small lymphocytic lymphoma, required therapy, and were at least 18 years of age with an Eastern Cooperative Oncology Group performance status up to 2. BOVen was administered in 28 day cycles (oral zanubrutinib at 160 mg twice per day starting in cycle 1 on day 1; intravenous obinutuzumab at 1000 mg on day 1 [split over day 1 with 100 mg and day 2 with 900 mg for an absolute lymphocyte count >25 000 cells per μL or lymph nodes >5 cm in diameter], day 8, and day 15 of cycle 1, and day 1 of cycles 2–8; and oral venetoclax ramp up to 400 mg per day starting in cycle 3 on day 1) and discontinued after 8–24 cycles when prespecified undetectable MRD criteria were met in the peripheral blood and bone marrow. The primary endpoint was the proportion of patients that reached undetectable MRD in both the peripheral blood and bone marrow (flow cytometry cutoff less than one chronic lymphocytic leukaemia cell per 10 000 leukocytes [ clinicaltrials.gov ( NCT03824483 ). The primary cohort is closed to recruitment, and recruitment continues in the TP53-mutated mantle cell lymphoma cohort. Findings Between March 14, 2019, and Oct 10, 2019, 47 patients were screened for eligibility, and 39 patients were enrolled and treated. Median age was 62 years (IQR 52–70) with 30 (77%) of 39 male participants and nine (23%) of 39 female participants. 28 (72%) of 39 patients had unmutated immunoglobulin heavy-chain variable-region and five (13%) of 39 had 17p deletion or TP53 mutation. After a median follow-up of 25·8 months (IQR 24·0–27·3), 33 (89%) of 37 patients (95% CI 75–97) had undetectable MRD in both blood and bone marrow, meeting the prespecified undetectable MRD criteria to stop therapy after a median of ten cycles (IQR 8–12), which includes two cycles of zanubrutinib and obinutuzumab before starting venetoclax. After median surveillance after treatment of 15·8 months (IQR 13·0–18·6), 31 (94%) of 33 patients had undetectable MRD. The most common adverse events were thrombocytopenia (23 [59%] of 39), fatigue (21 [54%]), neutropenia (20 [51%]), and bruising (20 [51%]), and the most common adverse event at grade 3 or worse was neutropenia (seven [18%]) in the intention-to-treat population. One death occurred in a patient with intracranial haemorrhage on day 1 of cycle 1 after initiating intravenous heparin for pulmonary emboli. Interpretation BOVen was well tolerated and met its primary endpoint, with 33 (89%) of 37 previously untreated patients with chronic lymphocytic leukaemia or small lymphocytic lymphoma reaching undetectable MRD in both peripheral blood and bone marrow despite a median treatment duration of only 10 months, owing to our undetectable MRD-driven treatment discontinuation design. These data support further evaluation of the BOVen regimen in chronic lymphocytic leukaemia and small lymphocytic lymphoma with treatment duration guided by early MRD response kinetics. Funding Beigene, Genentech (Roche), Grais-Cutler Fund, Lymphoma Research Fund, Lymphoma Research Foundation, American Cancer Society, Farmer Family Foundation, and the National Instititutes of Health and National Cancer Institute.

Although patients with bronchus-associated lymphoid tissue (BALT) lymphoma show an indolent clinical course, appropriate disease management at diagnosis is not well defined. This study aimed to compare 3 treatment strategies for patients with BALT lymphoma: active surveillance, systemic chemotherapy or immunotherapy at diagnosis, or complete surgical resection at diagnosis. We conducted a retrospective study of all patients with new diagnoses of marginal zone lymphoma (MZL) involving the lung who were treated at the Memorial Sloan Kettering Cancer Center between 1995 and 2017. Primary BALT lymphoma was defined as disease confined to the lungs and adjacent lymph nodes. Active surveillance was defined as a documented observation plan and ≥3 months of follow-up before initiating treatment. Overall survival (OS) and event-free survival (EFS) were compared between treatment groups. We reviewed 200 consecutive patients with MZL involving the lung; 123 met the inclusion criteria and were managed by active surveillance (47%), complete surgical resection (41%), or systemic chemotherapy or immunotherapy (11%). With a median follow-up of >60 months, surgical resection was associated with a superior EFS compared with active surveillance and systemic treatment (6-year EFS: 74% vs 65% vs 62%, respectively; P = .013). Larger lesions and thrombocytopenia were associated with shorter EFS. All groups had excellent OS at 6 years (93%), albeit with a slight superiority for surgical resection (100%) over active surveillance (91%) and systemic treatment (76%) (P = .024). BALT lymphoma is an indolent disease that can often be managed expectantly and not require therapy for many years.

Mature B cell neoplasms, previously indolent non-Hodgkin lymphomas (iNHLs), are a heterogeneous group of malignancies sharing similar disease courses and treatment paradigms. Most patients with iNHL have an excellent prognosis, and in many, treatment can be deferred for years. However, some patients will have an accelerated course and may experience transformation into aggressive lymphomas. In this review, we focus on management concepts shared across iNHLs, as well as histology-specific strategies. We address open questions in the field, including the influence of genomics and molecular pathway alterations on treatment decisions. In addition, we review the management of uncommon clinical entities including nodular lymphocyte-predominant Hodgkin lymphoma, hairy cell leukemia, splenic lymphoma and primary lymphoma of extranodal sites. Finally, we include a perspective on novel targeted therapies, antibodies, antibody–drug conjugates, bispecific T cell engagers and chimeric antigen receptor T cell therapy.

The prognosis of patients with relapsed or refractory (R/R) diffuse large B-cell lymphoma (DLBCL) is poor. Chimeric antigen receptor (CAR) T-cell therapy has been approved for R/R DLBCL after 2 prior lines of therapy based on data from single-arm phase 2 trials, with complete responses (CRs) in 40% to 60% of patients. However, a direct comparison with other treatments is not available and, moreover, its true efficacy in real-world patients is unknown. In this single center, retrospective, observational study of 215 patients, we compared outcomes in patients treated with CAR T-cell therapy (n = 69) with a historical population treated with alternate therapies (n = 146). Patients treated with CAR T cell vs alternate therapies demonstrated a CR rate of 52% vs 22% (P < .001), median progression-free survival (PFS) of 5.2 vs 2.3 months (P = .01), and median overall survival (OS) of 19.3 vs 6.5 months (P = .006), and this advantage appeared to persist irrespective of the number of lines of prior therapy. After adjusting for unfavorable pretreatment disease characteristics, superior overall response rate in the CAR T cohort remained significant; however, differences in PFS and OS between cohorts did not. In addition, patients who responded to alternate therapies demonstrated prolonged remissions comparable to those who responded to CAR T therapy. We contend that in select clinical scenarios alternate therapies may be as efficacious as CAR T therapy; thus, additional study is warranted, ideally with randomized prospective trials.

PURPOSE We conducted a phase II study evaluating pembrolizumab plus gemcitabine, vinorelbine, and liposomal doxorubicin (pembro-GVD) as second-line therapy for relapsed or refractory (rel/ref) classical Hodgkin lymphoma (cHL) (ClinicalTrials.gov identifier: NCT03618550 ). METHODS Transplant eligible patients with rel/ref cHL following first-line therapy were treated with two to four cycles of pembrolizumab (200 mg intravenous [IV], day 1), gemcitabine (1,000 mg/m2 IV, days 1 and 8), vinorelbine (20 mg/m2 IV, days 1 and 8), and liposomal doxorubicin (15 mg/m2, days 1 and 8), given on 21-day cycles. The primary end point was complete response (CR) following up to four cycles of pembro-GVD. Patients who achieved CR by labeled fluorodeoxyglucose-positron emission tomography (Deauville ≤ 3) after two or four cycles proceeded to high-dose therapy and autologous hematopoietic cell transplantation (HDT/AHCT). HDT/AHCT was carried out according to institutional standards, and brentuximab vedotin maintenance was allowed following HDT/AHCT. RESULTS Of 39 patients enrolled, 41% had primary ref disease and 38% relapsed within 1 year of frontline treatment. 31 patients received two cycles of pembro-GVD, and eight received four cycles. Most adverse events were grade 1 or two, whereas few were grade 3 and included transaminitis (n = 4), neutropenia (n = 4), mucositis (n = 2), thyroiditis (n = 1), and rash (n = 1). Of 38 evaluable patients, overall and CR rates after pembro-GVD were 100% and 95%, respectively. Thirty-six (95%) patients proceeded to HDT/AHCT, two received pre-HDT/AHCT involved site radiation, and 13 (33%) received post-HDT/AHCT brentuximab vedotin maintenance. All 36 transplanted patients are in remission at a median post-transplant follow-up of 13.5 months (range: 2.66-27.06 months). CONCLUSION Second-line therapy with pembro-GVD is a highly effective and well-tolerated regimen that can efficiently bridge patients with rel/ref cHL to HDT/AHCT.

Patients with chronic lymphocytic leukemia (CLL) have an increased risk for severe COVID-19 disease and mortality. The goal of this study was to determine the efficacy of COVID-19 vaccine in patients with CLL. We evaluated humoral immune responses to the BNT162b2 messenger RNA (mRNA) COVID-19 vaccine in patients with CLL and compared responses with those obtained in age-matched healthy control subjects. Patients received 2 vaccine doses, 21 days apart, and antibody titers were measured by using the Elecsys Anti-SARS-CoV-2 S assay after administration of the second dose. In a total of 167 patients with CLL, the antibody response rate was 39.5%. A comparison between 52 patients with CLL and 52 sex- and aged-matched healthy control subjects revealed a significantly reduced response rate among patients (52% vs 100%, respectively; adjusted odds ratio, 0.010; 95% confidence interval, 0.001-0.162; P < .001). The response rate was highest in patients who obtained clinical remission after treatment (79.2%), followed by 55.2% in treatment-naive patients and 16.0% in patients under treatment at the time of vaccination. In patients treated with either Bruton’s tyrosine kinase inhibitors or venetoclax ± anti-CD20 antibody, response rates were considerably low (16.0% and 13.6%). None of the patients exposed to anti-CD20 antibodies

Context Tafasitamab+LEN, a chemotherapy-free, novel treatment for R/R DLBCL, demonstrated efficacy in ASCT-ineligible patients in the single-arm Phase II L-MIND study (NCT02399085). Objective To compare outcomes in patients treated with tafasitamab+LEN in the L-MIND study with matched patient populations treated with commonly administered NCCN-/ESMO-recommended therapies for non-transplant-eligible patients with R/R DLBCL in routine clinical practice. Design RE-MIND2 (NCT04150328) is an observational, retrospective cohort study. The L-MIND tafasitamab+LEN cohort was matched with RE-MIND2 patients using estimated propensity score-based 1:1 nearest neighbor matching balanced for nine patient and disease baseline characteristics: age ( 9 /L), anemia (cut-off upper limit of normal). Setting Academic, public, and private hospitals in Europe, North America, and Asia-Pacific. Patients Age: ≥18 years old with histologically confirmed DLBCL. Prior systemic therapy for DLBCL: ≥1, including ≥1 anti-CD20 therapy. Interventions Data are presented for tafasitamab+LEN vs all (pooled) systemic therapies, tafasitamab+LEN vs bendamustine+rituximab (BR), and tafasitamab+LEN vs rituximab+gemcitabine+oxaliplatin (R-GemOx). Main Outcome Measures The primary endpoint was overall survival (OS). Secondary endpoints included objective response rate, complete response rate, progression-free survival, event-free survival, duration of response, and time to next treatment. Results In RE-MIND2, 3,454 patients were enrolled from 200 centers. For the comparative analysis, 76 patients from the L-MIND tafasitamab+LEN study were included in the full analysis set. Strictly matched pairs of patients (standardized mean difference ≤0.2) included: tafasitamab+LEN vs pooled therapies, n=76 pairs; tafasitamab+LEN vs BR, n=75 pairs; and tafasitamab+LEN vs R-GemOx, n=74 pairs. Tafasitamab+LEN was associated with longer OS compared with pooled therapies (HR: 0.55; p=0.0076), BR (HR: 0.42; p Conclusions Results of this analysis suggest that tafasitamab+LEN has improved OS vs commonly used regimens. Funding This study was funded by MorphoSys AG.

Patients with follicular lymphoma (FL) frequently require multiple treatments during their disease course; however, survival based on lines of treatment remains poorly described in the post-rituximab era. Also, the Follicular Lymphoma International Prognostic Index (FLIPI) score was developed to predict survival at diagnosis, yet it remains unknown whether increase in FLIPI score following an initial observation period is associated with less-favorable outcomes. To address these knowledge gaps, we retrospectively studied 1088 patients with FL grade 1–3A managed between 1998 and 2009 at our institution. Median overall survival (OS) and progression-free survival (PFS) after first-line treatment were not reached and 4.73 years, respectively. Following successive lines of treatment, years of median OS and PFS were, respectively: after second-line, 11.7 and 1.5; third-line, 8.8 and 1.1; fourth-line, 5.3 and 0.9; fifth-line, 3.1 and 0.6; sixth-line, 1.9 and 0.5. In initially observed, subsequently treated patients, FLIPI score increase after observation was associated with inferior survival following first-line treatment. The reduced survival we observed after second-line and later therapy supports the development of new treatments for relapsed patients and benchmarks historical targets for clinical endpoints. This study also highlights the utility of changes in FLIPI score at diagnosis and after observation in identifying patients likely to have worse outcomes.

We reviewed pre-diagnosis clinical data of 420 patients with pathologically confirmed myelodysplastic syndromes (MDSs) presenting with anemia. In 232 patients with yearly pre-diagnosis complete blood counts (CBCs), we also analyzed CBC kinetics in respects to a standardized timepoint in which all patients had similar levels of hemoglobin (Hgb). At the standardized timepoint (last documented 12 > Hgb ≥ 11 g/dL), occurring months-years before diagnosis, median CBC values were Hgb 11.4 g/dL, absolute neutrophil count (ANC) 2.7 × 103 (k)/mcl, and platelets (PLTs) 181 k/mcl. Gradual changes in CBC could be observed years prior to this timepoint, for the most part while within normal/near-normal limits. During this time, most patients had a coexisting alternative etiology for anemia. Patients with high-risk cytogenetic/blast features had a rapid and steeper decrease in counts in the last year before developing a concerning anemia (decrease in: Hgb 0.75 g/dL vs 0.55 g/dL; PLT 29.5 vs 4.5 k/mcl; ANC 0.86 vs 0.4 k/mcl, P = .03). Low-risk patients had a high rate of longstanding mild anemia (31% vs 16%, P = .05). Rate of development of cytopenia and number of involved hematopoietic lines were prognostic. In 65% of patients, with near normal CBC at the standardized timepoint, but in whom there was a decrease in multiple hematopoietic lines over the preceding year, the 5-year overall survival (5yOS) was 53% compared to 71% in patients with isolated slowly progressing anemia (20% of patients). In 15% of patients with mild cytopenia developing after both a rapid decrease and multiple involved lines, prognosis was dismal (5yOS 34%). In conclusion, kinetics of pre-MDS CBC values correlate with disease risk and survival.

This retrospective study aimed to better define the characteristics and outcomes of extranodal stage I diffuse large B-cell lymphoma (DLBCL) in the rituximab era. Patients diagnosed with stage I DLBCL from 2001 to 2015 treated with rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone (R-CHOP) or R-CHOP–like regimens with or without radiation (RT) were included. We identified 1955 patients with newly diagnosed DLBCL, of whom 341 had stage I and were eligible for this analysis. Extranodal presentation was observed in 224 (66%) patients, whereas 117 (34%) had nodal involvement. The most common extranodal sites were as follows: bone, 21%; stomach, 19%; testis, 9%; intestine, 8%; breast, 8%. Overall, 69% extranodal patients and 68% nodal patients received RT. Median follow-up was 5.5 years (interquartile range, 4.3-8.2). Ten-year overall survival (OS) and disease-free survival were 77% (95% confidence interval [CI], 67%-83%) and 77% (95% CI, 68%-85%). In the multivariable analyses, extranodal involvement was associated with worse OS (hazard ratio [HR], 3.44; 95% CI, 1.05-11.30) and progression-free survival (PFS; HR, 3.25; 95% CI, 1.08-9.72) compared with nodal involvement. Consolidation RT was associated with better OS (HR, 0.26; 95% CI, 0.12-0.49) and PFS (HR, 0.35; 95% CI, 0.18-0.69) in the extranodal population; however, the benefit was no longer observed in patients that were positron emission tomography (PET) negative at the end of immunochemotherapy. Relapses occurred usually late (median, 37 months), and the most common sites were the lymph nodes (31%) and the central nervous system (27%). Extranodal stage I DLBCL had a worse outcome than nodal stage 1 DLBCL. End of immunochemotherapy PET results may help select extranodal patients for consolidation RT.

High-grade B-cell lymphoma (HGBL) with translocations involving MYC and BCL2 or BCL6 comprises ∼10% of cases of diffuse large B-cell lymphoma (DLBCL) and carries a poor prognosis. The incidence, prognosis, and optimal therapy for DLBCL harboring extra copies of the genes MYC, BCL2, and BCL6, rather than their genetic translocations, are unknown. In this retrospective, single-center study we identified 144 DLBCL cases including 46 patients with classic HGBL with double-hit or triple-hit chromosomal translocations (DHL), 55 with extra copies of MYC in addition to aberrations (extra copies or translocations) of BCL2 and/or BCL6 but did not meet the criteria for HGBL (EC group), and 43 without any aberrations of MYC, BCL2, or BCL6 (wild type [WT]). Unfavorable baseline characteristics had similar frequency in the EC and WT groups, but were significantly more prevalent in the DHL group. With a median follow-up of 36 months, the 2-year event-free survival (EFS) was similar between the WT and EC groups at 77% (95% confidence interval [CI], 65-90) and 82% (95% CI, 72-93), respectively. In contrast, the 2-year EFS of the DHL group was 63% (95% CI, 51-79). The 2-year overall survival in the WT, EC, and DHL groups was 86% (95% CI, 76-97), 89% (95% CI, 81-98), and 74% (95% CI, 62-88), respectively. Among patients treated with R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone), the EC group had outcomes similar to those of the WT group. Our results indicate that patients with DLBCL with extra gene copies of MYC, BCL2, and BCL6 fare differently from those with HGBL and respond well to standard R-CHOP therapy.

Objectives To ascertain the relevance of bone marrow cellularity (BMC) to the interpretation of blast percentage (blast%) in MDS prognostication. Methods We compared survival prediction based on blast% adjusted to different levels of cellularity, compared to the survival based on the original IPSS-R blast% grouping. Results We analyzed 355 consecutive MDS patients. Cellularity, in and of itself or its interaction with blast%, was not associated with overall survival (OS). In a small subset of patients with a hypercellular marrow (15%; n = 26), dismal prognosis was observed at lower levels of blast%. For these cases OS was similar to higher IPSS-R blast groups. For example, within the Intermediate group (blast% 5%-10%), those with a hypercellular marrow and >6% blasts had an OS of 10 m similar to 16 m in the High (blast% 10%-19%) blast group. These changes did not translate into a significant improvement in overall prognostic power of a cellularity-adjusted IPSS-R (C index 0.71 vs. 0.70). Conclusion Adjusting blast% to cellularity did not improve prognostication. However, within IPSS-R-defined blast groups, a small subset of patients with relatively higher blast% and hypercellularity may have a worse prognosis than expected.

OBJECTIVE To evaluate disease characteristics and long-term outcomes in patients requiring second-line treatment following fludarabine, cyclophosphamide, and rituximab (FCR), for relapsed/refractory disease (R/R), or following discontinuation due to toxicities. METHOD A retrospective analysis of 126 chronic lymphocytic leukemia patients treated with frontline FCR: 63 received second-line treatment (41 relapsed, nine refractory [SD/PD], 13 prior toxicity). Time to next treatment (TTNT) was calculated from beginning FCR to initiation of second-line therapy. Overall and event-free survival was calculated from initiation of salvage treatment (OS2/EFS2). RESULTS Median follow-up for the entire cohort was 67 and 37 months from second-line therapy. TTNT

A non-invasive myelodysplastic syndromes (MDS) diagnostic model would allow for care while avoiding invasive bone marrow examinations (BME). BME-established MDS patients were compared to non-MDS (BME-excluded) patients. Variables (gender, age, hemoglobin (Hb), mean red blood cell corpuscular volume (MCV), platelet (PLT), and white blood cell (WBC)) were combined with multivariate logistic regression; a probability score (Y) was calculated. MDS (n = 48) and non-MDS (n = 63) patients were used to establish the model. The ROC was drawn, giving an AUC of 0.748 (95% CI: 0.656-0.84). Two cutoff values were used for Y. Y ≥ 0.633: high likelihood (positive predictive value (PPV) = 85%); Y ≤ 0.288: low likelihood (negative predictive value (NPV) = 81%) of MDS. The first group is defined as probable MDS (pMDS); the second, probably not MDS (pnMDS). The model was validated with 40 additional patients (20 with and 20 without MDS). Using clinical and lab data, we could diagnose or exclude MDS in about half of the patients, avoiding BME. Future work will use larger cohorts of patients to improve and further validate the model.

Background Several therapies are recommended by NCCN/ESMO guidelines for autologous stem cell transplant (ASCT)-ineligible patients with relapsed/refractory (R/R) diffuse large B-cell lymphoma (DLBCL). In the single-arm, Phase II L-MIND study (NCT02399085), the chemotherapy-free regimen tafasitamab + lenalidomide (LEN) demonstrated efficacy for this patient population. In the absence of randomized clinical trial data, RE-MIND2 (NCT04697160), an observational, retrospective cohort study, compared patient outcomes from L-MIND with matched patient populations treated with NCCN/ESMO recommended therapies for ASCT-ineligible patients with R/R DLBCL. Methods Data were retrospectively collected between 1 April and 13 November 2020 from academic and public hospitals, as well as private practices in North America, Europe and Asia Pacific. To ensure consistency with L-MIND I/E criteria, patients aged ≥18 years with histologically confirmed DLBCL and who had received ≥2 systemic therapies for DLBCL (including ≥1 anti-CD20 therapy) were enrolled. For the main analysis, patients from the L-MIND tafasitamab + LEN cohort were matched with patients from the RE-MIND2 observational cohort using estimated propensity score-based 1:1 nearest neighbor matching, balanced for six baseline characteristics: age ( A sensitivity analysis was performed using an inverse probability of treatment weighting method calculating the average effect of the treatment on the treated, to generate balanced cohorts based on nine baseline characteristics: age, refractoriness to last line of therapy, number of previous lines of therapy, history of primary refractoriness, prior ASCT, Ann Arbor Stage (I/II vs III/IV), elevated LDH (yes vs no), neutropenia (yes vs no), and anemia (yes vs no). Additional sensitivity analyses accounting for missing baseline characteristics using multiple imputation technique were performed. Data are presented for tafasitamab + LEN versus polatuzumab vedotin + bendamustine + rituximab (pola-BR), rituximab + LEN (R2), and CD19 CAR-T therapies (CAR-T). The primary endpoint was overall survival (OS). Secondary endpoints included objective response rate (ORR), complete response rate, progression-free survival and duration of response. Results Of 3,454 patients enrolled from 200 sites, 106, 106, and 149 patients were treated with pola-BR, R2, and CAR-T, respectively. For the comparative analysis, matched patient pairs were created using 1:1 nearest neighbor matching with a caliper. Matched pairs consisted of: tafasitamab + LEN vs pola-BR, n=24 pairs; vs R2, n=33 pairs; and vs CAR-T, n=37 pairs. A significant OS benefit was associated with tafasitamab + LEN compared to pola-BR (HR: 0.44, 95% confidence interval [CI]: 0.20-0.96; p=0.038) and R2 (HR=0.44, 95% CI: 0.22-0.84; p=0.014) (Figure 1A-B). There was no significant difference in OS benefit between tafasitamab + LEN and CAR-T (HR=0.95, 95% CI: 0.47-1.91; p=0.891) (Figure 1C). ORR was 62.5% (15/24) for tafasitamab + LEN vs 58.3% (14/24) for pola-BR (p=1.000), 63.6% (21/33) vs 30.3% (10/33) for R2 (p=0.013), and 59.5% (22/37) vs 75.7% (28/37) for CAR-T (p=0.214). Improved outcomes were also observed with tafasitamab + LEN for other secondary endpoints (Table 1). Results are consistent with those obtained in the sensitivity analyses. Conclusions The results of this retrospective cohort analysis suggest that the novel tafasitamab + LEN combination may significantly improve health outcomes, with a prolonged survival benefit for ASCT-ineligible R/R DLBCL patients, relative to NCCN/ESMO recommended therapies. Tafasitamab + LEN improved survival outcomes compared with pola-BR and R2 in closely matched patient populations. Comparable outcomes were observed for tafasitamab + LEN vs CAR-T. Although based on limited patient numbers, these data may be clinically relevant in the context of emerging therapies for R/R DLBCL. While this study design does not replace randomized data, it remains more rigorous than inter-trial comparison. The limitations of comparing clinical trial and matched retrospective real-world data will be discussed. Funding: MorphoSys AG. Figure 1 Figure 1. Disclosures Nowakowski: Celgene, MorphoSys, Genentech, Selvita, Debiopharm Group, Kite/Gilead: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene, NanoString Technologies, MorphoSys: Research Funding. Joffe: AstraZeneca. Epizyme: Consultancy. Fleury: Abbvie, Astrazeneca, BMS, Celgene, Janssen, Kite-Gilead, Merck, Novartis, Roche, Seattle Genetics: Other: conference and advisory role. Peters: AbbVie, Incyte: Consultancy, Honoraria. Greil: Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses, Research Funding; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses, Research Funding; Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses, Research Funding; BMS: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses, Research Funding; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses, Research Funding; AstraZeneca: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses, Research Funding; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses; MSD: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses, Research Funding; Gilead: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses, Research Funding; Daiichi: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses, Research Funding; Sankyo: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses, Research Funding; Sanofi: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Merck: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Honoraria, Other: Travel, Accommodations, Expenses, Research Funding; Sandoz: Honoraria, Research Funding. Ku: Roche: Consultancy; Antegene: Consultancy; Genor Biopharma: Consultancy. Marks: Kite/Gilead: Membership on an entity's Board of Directors or advisory committees; AbbVie: Other: Meeting attendance; Kite/Gilead: Honoraria; Merck: Consultancy. Kim: AstraZeneca: Research Funding. Zinzani: BeiGene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Bristol Myers Squibb: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; EUSA Pharma: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; ADC Therapeutics: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Merck Sharp & Dohme: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celltrion: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Kyowa Kirin: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Verastem: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Sandoz: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Incyte: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; TG Therapeutics Inc: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Servier: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen-Cilag: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Gilead: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; ImmuneDesign: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Portola: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Sanofi: Consultancy, Membership on an entity's Board of Directors or advisory committees; Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Trotman: Beigene: Research Funding; Celgene: Research Funding; Bristol Myers Squibb: Research Funding; Roche: Research Funding; Janssen: Research Funding; PCYC Pharmacyclics: Research Funding. Sabatelli: Incyte: Current Employment, Current equity holder in publicly-traded company. Huang: MorphoSys: Current Employment. Waltl: MorphoSys: Current Employment. Winderlich: MorphoSys: Current Employment, Current equity holder in publicly-traded company. Ambarkhane: MorphoSys: Current Employment, Other: Support for attending meetings/travel. Kurukulasuriya: MorphoSys: Current Employment, Current equity holder in publicly-traded company, Other: Support for attending meetings/travel. Cordoba: Pfizer: Research Funding; Kyowa-Kirin: Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; AbbVie: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; ADCTherapeutics: Membership on an entity's Board of Directors or advisory committees; BMS: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Incyte: Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Kite: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Hess: Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Research Funding; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Incyte: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Gilead/Kite: Research Funding; AstraZeneca: Honoraria, Membership on an entity's Board of Directors or advisory committees; Genmab: Honoraria, Membership on an entity's Board of Directors or advisory committees; Gilead: Honoraria, Membership on an entity's Board of Directors or advisory committees; EUSA: Honoraria, Membership on an entity's Board of Directors or advisory committees. Salles: Miltneiy: Consultancy; Novartis: Consultancy; Morphosys: Consultancy, Honoraria; Janssen: Consultancy; Genentech/Roche: Consultancy; Kite/Gilead: Consultancy; Regeneron: Consultancy, Honoraria; Velosbio: Consultancy; Takeda: Consultancy; Allogene: Consultancy; Ipsen: Consultancy; Loxo: Consultancy; Rapt: Consultancy; Genmab: Consultancy; Incyte: Consultancy; Epizyme: Consultancy, Honoraria; Debiopharm: Consultancy; BMS/Celgene: Consultancy; Beigene: Consultancy; Abbvie: Consultancy, Honoraria; Bayer: Honoraria.

Background: Venetoclax (Ven; BH3 mimetic) and Obinutuzumab (O; CD20 antibody) is an approved, fixed-duration regimen (one year) that induces undetectable minimum residual disease (uMRD) and durable remissions in treatment naïve patients (pts) with chronic lymphocytic leukemia (CLL; Fischer NEJM 2019). In the CLARITY trial of venetoclax-ibrutinib (BTK inhibitor; BTKi) in relapsed or refractory CLL, peripheral blood (PB) MRD response kinetics predicted bone marrow (BM) uMRD and were associated with progression-free survival (Rawstron EHA 2020). We explored MRD as a biomarker to direct treatment duration in an investigator-initiated phase 2 trial of Zanubrutinib (BTKi) and O-Ven (BOVen). We hypothesize that early MRD kinetics will identify a defined cohort of pts with delayed BM MRD clearance, and early recurrent detectable MRD after discontinuation of treatment in pts attaining uMRD. Methods: In this multicenter, phase 2 trial (NCT03824483), eligible pts had previously untreated CLL requiring treatment (iwCLL), ECOG PS ≤2, absolute neutrophil count (ANC) ≥1,000/ul, platelets (PLT) ≥75,000/ul (ANC ≥0/ul, PLT ≥20,000/ul if due to CLL). Informed consent was obtained from all pts. BOVen was administered in 28-day (D) cycles (C): Zanubrutinib 160 mg by mouth (PO) twice daily starting D1; Obinutuzumab 1000 mg IV D1 (split D1-2 if lymphocyte count ≥25,000/ul or lymph node ≥5cm), D8, D15 of C1, and D1 of C2-8; Venetoclax ramp up initiated C3D1 (target 400 mg PO daily). MRD was evaluated by flow cytometry (MRD-FC) and immunosequencing (MRD-IS; Adaptive ClonoSEQ) with uMRD defined as ≤10 -4 for flow and ≤10 -5 for IS. Treatment consisted of 8-24 cycles with duration determined by prespecified MRD criteria. Beginning on C7D1 then every 2 cycles, pts with PB uMRD-FC had BM within 14 days. If BM uMRD, PB MRD was repeated after two additional cycles. Pts with confirmed uMRD-FC in PB and BM discontinued therapy and entered posttreatment surveillance. Response was assessed per iwCLL. Adverse events (AE) were assessed per CTCAE v5. MRD-IS failure free survival (FFS) was calculated from end-of-treatment (EOT) to the date of detectable MRD-IS (≥10 -5) using the Kaplan-Meier method. Results: The study accrued 39 pts (03/19-10/19): median age 59 years (23-73), 3:1 male predominance, 28/39 (72%) IGHV unmutated, 5/39 (12.8%) del(17p)/TP53M. All pts were evaluable for toxicity with 37 evaluable for efficacy. At a median follow up of 26+ months (mo; 4.5-30.5+), 95% (35/37) pts achieved uMRD-FC in PB, among whom 33 (94%) also achieved uMRD-IS. BM uMRD-FC was seen in 89% (33/37) at a median time of 8 mo (6-16), all of whom met prespecified MRD criteria and discontinued therapy after a median of 10 mo (8-18). Three pts discontinued therapy with persistent detectable BM MRD after 24 cycles. The most common AEs were neutropenia (51%), thrombocytopenia (44%), diarrhea (44%), infusion related reaction (41%) and bruising (41%). The most common grade ≥3 AE was neutropenia (15%). No laboratory or clinical TLS occurred (Howard definition). A ≥400-fold reduction in PB MRD-IS after 4 cycles (ΔMRD400) was selected using the Youden Index and was highly predictive of attaining BM uMRD in ≤8mo (sensitivity 88% [21/24], specificity 100% [11/11], PPV 100% [21/21], NPV 79% [11/14]. As a result, the median duration of therapy was shorter among patients who achieved ΔMRD400 (8 vs 13 mo). Of 33 pts who met prespecified uMRD criteria and stopped therapy, 31 (94%) remain uMRD-FC following a median 15 mo (0-20) from EOT, and 2 pts had recurrent MRD (1 with PD recaptured PB uMRD with retreatment). Of 33 pts who discontinued therapy after achieving the prespecified MRD endpoint, MRD-IS was evaluated every 3 months in 31 pts for a median of 12 mo (range, 3-18) from EOT. MRD-IS FFS was longer in pts who achieved ΔMRD400 (log rank p Conclusion: BOVen achieved frequent, durable uMRD. All pts completed therapy (median 10 mo treatment), including 89% (33/37) who met the prespecified PB/BM uMRD endpoint. With a median posttreatment follow-up of 15 mo, 31 (94%) remain uMRD-FC. ΔMRD400 identified a cohort of pts (40%) with delayed BM MRD clearance and earlier MRD recurrence, despite longer treatment duration. ΔMRD400 warrants further study as a predictive biomarker for treatment duration. Figure 1 Figure 1. Disclosures Soumerai: Seattle Genetics: Consultancy; AstraZeneca: Consultancy; BeiGene: Consultancy, Research Funding; BMS: Consultancy; Adaptive Biotechnologies: Consultancy, Research Funding; AbbVie: Consultancy; TG Therapeutics: Consultancy, Research Funding; BostonGene: Research Funding; GlaxoSmithKline: Research Funding. Mato: Janssen: Consultancy, Research Funding; LOXO: Consultancy, Research Funding; Johnson and Johnson: Consultancy, Research Funding; Acerta/AstraZeneca: Consultancy, Research Funding; DTRM BioPharma: Consultancy, Research Funding; Genmab: Research Funding; AstraZeneca: Consultancy; MSKCC: Current Employment; Genentech: Consultancy, Research Funding; Sunesis: Consultancy, Research Funding; Nurix: Research Funding; AbbVie: Consultancy, Research Funding; Adaptive Biotechnologies: Consultancy, Research Funding; Pharmacyclics LLC, an AbbVie Company: Consultancy, Research Funding; TG Therapeutics: Consultancy, Other: DSMB, Research Funding; BeiGene: Consultancy, Research Funding. Dogan: Seattle Genetics: Consultancy; Peer View: Honoraria; Takeda: Consultancy, Research Funding; Roche: Consultancy, Research Funding; Physicians' Education Resource: Honoraria; EUSA Pharma: Consultancy. Joffe: Epizyme: Consultancy; AstraZeneca: Consultancy. Hochberg: Leuko: Consultancy; Intervention Insights: Consultancy. Abramson: Bluebird Bio: Consultancy; Morphosys: Consultancy; Bristol-Myers Squibb Company: Consultancy, Research Funding; Kymera: Consultancy; BeiGene: Consultancy; Novartis: Consultancy; C4 Therapeutics: Consultancy; Genmab: Consultancy; EMD Serono: Consultancy; Kite Pharma: Consultancy; Incyte Corporation: Consultancy; Astra-Zeneca: Consultancy; Allogene Therapeutics: Consultancy; Seagen Inc.: Research Funding; AbbVie: Consultancy; Karyopharm: Consultancy; Genentech: Consultancy. Batlevi: TouchIME: Honoraria; BMS: Current holder of individual stocks in a privately-held company; Medscape: Honoraria; GLG Pharma: Consultancy; Dava Oncology: Honoraria; Kite Pharma: Consultancy; Juno/Celgene: Consultancy; ADC Therapeutics: Consultancy; Life Sciences: Consultancy; Moderna: Current holder of individual stocks in a privately-held company; Regeneron: Current holder of individual stocks in a privately-held company; Viatris: Current holder of individual stocks in a privately-held company; Pfizer: Current holder of individual stocks in a privately-held company; Karyopharm: Consultancy; TG Therapeutics: Consultancy; Memorial Sloan Kettering Cancer Center: Current Employment; Seattle Genetics: Consultancy; Bayer: Research Funding; Xynomic: Research Funding; Roche/Genentech: Research Funding; Novartis: Research Funding; Epizyme: Research Funding; Janssen: Research Funding; Autolus: Research Funding. Matasar: Rocket Medical: Consultancy, Research Funding; Merck Sharp & Dohme: Current holder of individual stocks in a privately-held company; Juno Therapeutics: Consultancy; Merck: Consultancy; Genentech, Inc.: Consultancy, Honoraria, Research Funding; Bayer: Consultancy, Honoraria, Research Funding; IGM Biosciences: Research Funding; GlaxoSmithKline: Honoraria, Research Funding; F. Hoffmann-La Roche Ltd: Consultancy, Honoraria, Research Funding; Memorial Sloan Kettering Cancer Center: Current Employment; Teva: Consultancy; TG Therapeutics: Consultancy, Honoraria; Pharmacyclics: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Takeda: Consultancy, Honoraria; Seattle Genetics: Consultancy, Honoraria, Research Funding; ImmunoVaccine Technologies: Consultancy, Honoraria, Research Funding; Daiichi Sankyo: Consultancy. Noy: Rafael Parhma: Research Funding; Morphosys: Consultancy; Targeted Oncology: Consultancy; Medscape: Consultancy; Pharmacyclics: Consultancy, Research Funding; Janssen: Consultancy, Honoraria; Epizyme: Consultancy. Palomba: Ceramedix: Honoraria; Seres: Honoraria, Other: Stock, Patents & Royalties, Research Funding; Notch: Honoraria, Other: Stock; Novartis: Consultancy; Kite: Consultancy; PCYC: Consultancy; BeiGene: Consultancy; Lygenesis: Honoraria; Nektar: Honoraria; Juno: Patents & Royalties; Wolters Kluwer: Patents & Royalties; Rheos: Honoraria; Magenta: Honoraria; Pluto: Honoraria; WindMIL: Honoraria; Priothera: Honoraria. Kumar: Abbvie Pharmaceuticals: Research Funding; Pharmacyclics: Research Funding; Kite Pharmaceuticals: Other: advisory board , Research Funding; Celgene: Honoraria, Other: advisory board, Research Funding; Astra Zeneca: Honoraria, Other: Advisory Board, Research Funding; Adaptive Biotechnologies, Celgene, Abbvie Pharmaceticals, Pharmacyclics, Seattle Genetics: Research Funding; Seattle Genetics: Research Funding. Roeker: AbbVie, AstraZeneca, Janssen, LOXO, Pharmacyclics, TG Therapeutics, Vaniam Group, Verastem: Consultancy; Pfizer: Consultancy, Research Funding; Pharmacyclics: Consultancy; TG Therapeutics: Consultancy; Loxo Oncology: Consultancy; Abbot Laboratories: Current equity holder in publicly-traded company. Thompson: VJHemOnc: Honoraria; MJH Life Sciences: Honoraria; Curio Science: Honoraria. Roshal: Physicians' Education Resource: Other: Provision of services; Auron Therapeutics: Other: Ownership / Equity interests; Provision of services; Celgene: Other: Provision of services. Huang: BeiGene: Current Employment, Current equity holder in publicly-traded company, Current holder of individual stocks in a privately-held company, Current holder of stock options in a privately-held company, Divested equity in a private or publicly-traded company in the past 24 months, Other: Travel, Accommodations, Expenses; Protara Therapeutics: Current holder of individual stocks in a privately-held company, Membership on an entity's Board of Directors or advisory committees, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company). Biondo: Roche: Current holder of individual stocks in a privately-held company; Genentech, Inc.: Current Employment. Wu: Genentech, Inc.: Current Employment; Roche/GNE: Current equity holder in publicly-traded company, Current holder of individual stocks in a privately-held company, Current holder of stock options in a privately-held company. Jacob: Adaptive Biotechnologies: Current Employment. Abdel-Wahab: H3B Biomedicine: Consultancy, Research Funding; Foundation Medicine Inc: Consultancy; Merck: Consultancy; Prelude Therapeutics: Consultancy; LOXO Oncology: Consultancy, Research Funding; Lilly: Consultancy; AIChemy: Current holder of stock options in a privately-held company, Membership on an entity's Board of Directors or advisory committees; Envisagenics Inc.: Current holder of stock options in a privately-held company, Membership on an entity's Board of Directors or advisory committees. Zelenetz: Novartis: Honoraria; Genentech/Roche: Honoraria, Research Funding; BMS/Celgene/JUNO: Honoraria, Other; AstraZeneca: Honoraria; MethylGene: Research Funding; Pharmacyclics: Honoraria; Amgen: Honoraria; MEI Pharma: Honoraria, Research Funding; Gilead: Honoraria, Research Funding; Verastem: Honoraria; Beigene: Honoraria, Other, Research Funding; Abbvie: Honoraria, Research Funding; SecuraBio: Honoraria; Janssen: Honoraria; Gilead: Honoraria; MorphoSys: Honoraria; NCCN: Other; LFR: Other. OffLabel Disclosure: Zanubrutinib is administered off-label in combination with venetoclax and obinutuzumab for patients with CLL/SLL.

Introduction Histone deacetylase (HDAC) inhibitors have single agent activity in various types of lymphoma. They restore antigen-specific immune recognition in B-cell lymphoma cells and modulate programmed cell death (PD)-1 expression on circulating T-lymphocytes. Pembrolizumab (PEM) is highly active in Hodgkin Lymphoma (HL) and demonstrates a 12-month PFS of 46% in patients with R/R HL. Preclinical studies have shown synergism of this combination in mouse models of various tumors. We present the interim efficacy analysis from the first stage of our phase II trial investigating the combination of the HDAC inhibitor Entinostat (ENT) and the PD-1-blocking antibody PEM in patients with R/R HL. Methods Patients with R/R HL received ENT 5-7 mg orally once weekly and PEM 200 mg intravenously once every three weeks. Prior use of anti-PD-1 or HDAC inhibitor was allowed if there had been clinical benefit. Tumor assessment was evaluated using the RECIL criteria. The primary endpoint is the 12-month progression-free survival (PFS). Using a Simon two-stage minimax design to power the study, 21 patients were to be enrolled in the first stage with a 12-month PFS rate of 40% considered undesirable and 60% desirable. Results At time of data censoring on 7/24/21, 22 patients with HL have been enrolled. The median number of prior therapies was 5 (2-17). 7 (32%) were refractory to the most recent therapy, 13 (59%) had received autologous stem cell transplant (ASCT), 12 (55%) prior anti-PD1 antibody therapy, and 3 (14%) prior HDAC inhibitor therapy. Out of 22 evaluable patients, the overall response rate (ORR) was 86% and the complete response (CR) rate was 45%. Responding patients included 9 with prior anti-PD-1 antibody and 3 with prior HDAC inhibitor therapy. With median duration of follow-up among survivors of 8.4 months (2-26), the 12-month PFS was 72% (44%-87%). Reasons for treatment discontinuation included: progression (n=6), toxicities (n=5) consolidation with transplant or radiation (n=3), withdrawal of consent (n=3), and completion of study protocol (n=2). Severe toxicities resulting in study discontinuation were pleural effusions, pericarditis, pneumonitis and peripheral neuropathy. Out of the 22 total patients with HL enrolled in this study, 50% of patients had grade ≥3 (41%) and thrombocytopenia (32%). 41% exhibited grade ≥3 non-hematologic AEs, which included pericardial or pleural effusions (n=2, 9%), as well as fatigue, musculoskeletal pain, abdominal pain, pneumonitis, elevated lipase, hyperglycemia, and peripheral neuropathy. AEs that were potentially immune-related included hypothyroidism (n=2, 9%), elevated transaminases (n=4, 18%), diarrhea (n=3, 14%) and pneumonitis (n=2, 8%). Conclusions Interim results following stage I of this phase 2 trial demonstrates a 12-month PFS rate of 74%, meeting the primary endpoint of the study and justifying continued investigation of the combination of PEM and ENT. In this heavily pretreated patient population, responses were seen in the majority of patients despite prior exposure to anti-PD-1 agents. Figure 1 Figure 1. Disclosures Vardhana: Immunai: Membership on an entity's Board of Directors or advisory committees. Moskowitz: Bristol-Myers Squibb: Research Funding; Seattle Genetics: Consultancy, Research Funding; ADC Therapeutics: Research Funding; Beigene: Research Funding; Miragen: Research Funding; Janpix Ltd.: Consultancy; Merck: Consultancy, Research Funding; Imbrium Therapeutics L.P./Purdue: Consultancy; Takeda: Consultancy; Incyte: Research Funding. Joffe: AstraZeneca. Epizyme: Consultancy. Khan: Seattle Genetics: Research Funding. Kumar: Seattle Genetics: Research Funding; Astra Zeneca: Honoraria, Other: Advisory Board, Research Funding; Kite Pharmaceuticals: Other: advisory board , Research Funding; Pharmacyclics: Research Funding; Abbvie Pharmaceuticals: Research Funding; Celgene: Honoraria, Other: advisory board, Research Funding; Adaptive Biotechnologies, Celgene, Abbvie Pharmaceticals, Pharmacyclics, Seattle Genetics: Research Funding. Zelenetz: Gilead: Honoraria; Genentech/Roche: Honoraria, Research Funding; AstraZeneca: Honoraria; MorphoSys: Honoraria; Novartis: Honoraria; Pharmacyclics: Honoraria; Verastem: Honoraria; SecuraBio: Honoraria; BMS/Celgene/JUNO: Honoraria, Other; MethylGene: Research Funding; Abbvie: Honoraria, Research Funding; Gilead: Honoraria, Research Funding; MEI Pharma: Honoraria, Research Funding; Janssen: Honoraria; Beigene: Honoraria, Other, Research Funding; Amgen: Honoraria; NCCN: Other; LFR: Other. Horwitz: Affimed: Research Funding; ADC Therapeutics, Affimed, Aileron, Celgene, Daiichi Sankyo, Forty Seven, Inc., Kyowa Hakko Kirin, Millennium /Takeda, Seattle Genetics, Trillium Therapeutics, and Verastem/SecuraBio.: Consultancy, Research Funding; Aileron: Research Funding; Acrotech Biopharma, Affimed, ADC Therapeutics, Astex, Merck, Portola Pharma, C4 Therapeutics, Celgene, Janssen, Kura Oncology, Kyowa Hakko Kirin, Myeloid Therapeutics, ONO Pharmaceuticals, Seattle Genetics, Shoreline Biosciences, Inc, Takeda, Trillium Th: Consultancy; Celgene: Research Funding; C4 Therapeutics: Consultancy; Crispr Therapeutics: Research Funding; Daiichi Sankyo: Research Funding; Forty Seven, Inc.: Research Funding; Kura Oncology: Consultancy; Kyowa Hakko Kirin: Consultancy, Research Funding; Millennium/Takeda: Research Funding; Myeloid Therapeutics: Consultancy; ONO Pharmaceuticals: Consultancy; Seattle Genetics: Consultancy, Research Funding; Secura Bio: Consultancy; Shoreline Biosciences, Inc.: Consultancy; Takeda: Consultancy; Trillium Therapeutics: Consultancy, Research Funding; Tubulis: Consultancy; Verastem/Securabio: Research Funding. Noy: Janssen: Consultancy, Honoraria; Epizyme: Consultancy; Morphosys: Consultancy; Rafael Parhma: Research Funding; Medscape: Consultancy; Targeted Oncology: Consultancy; Pharmacyclics: Consultancy, Research Funding. Batlevi: Memorial Sloan Kettering Cancer Center: Current Employment; Moderna: Current holder of individual stocks in a privately-held company; Viatris: Current holder of individual stocks in a privately-held company; BMS: Current holder of individual stocks in a privately-held company; Autolus: Research Funding; Pfizer: Current holder of individual stocks in a privately-held company; Dava Oncology: Honoraria; Bayer: Research Funding; Medscape: Honoraria; ADC Therapeutics: Consultancy; Regeneron: Current holder of individual stocks in a privately-held company; TouchIME: Honoraria; TG Therapeutics: Consultancy; Karyopharm: Consultancy; Seattle Genetics: Consultancy; Life Sciences: Consultancy; Kite Pharma: Consultancy; Juno/Celgene: Consultancy; GLG Pharma: Consultancy; Xynomic: Research Funding; Roche/Genentech: Research Funding; Novartis: Research Funding; Janssen: Research Funding; Epizyme: Research Funding. Matasar: Pharmacyclics: Honoraria, Research Funding; Juno Therapeutics: Consultancy; TG Therapeutics: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; Rocket Medical: Consultancy, Research Funding; Genentech, Inc.: Consultancy, Honoraria, Research Funding; Merck: Consultancy; Merck Sharp & Dohme: Current holder of individual stocks in a privately-held company; GlaxoSmithKline: Honoraria, Research Funding; ImmunoVaccine Technologies: Consultancy, Honoraria, Research Funding; Seattle Genetics: Consultancy, Honoraria, Research Funding; Memorial Sloan Kettering Cancer Center: Current Employment; IGM Biosciences: Research Funding; Bayer: Consultancy, Honoraria, Research Funding; Teva: Consultancy; Janssen: Honoraria, Research Funding; F. Hoffmann-La Roche Ltd: Consultancy, Honoraria, Research Funding; Daiichi Sankyo: Consultancy. Palomba: Nektar: Honoraria; Notch: Honoraria, Other: Stock; PCYC: Consultancy; Kite: Consultancy; Ceramedix: Honoraria; Novartis: Consultancy; Priothera: Honoraria; Juno: Patents & Royalties; Wolters Kluwer: Patents & Royalties; Lygenesis: Honoraria; Pluto: Honoraria; Rheos: Honoraria; BeiGene: Consultancy; Seres: Honoraria, Other: Stock, Patents & Royalties, Research Funding; WindMIL: Honoraria; Magenta: Honoraria. Lee: Intellisphere, LLC: Consultancy. Dogan: EUSA Pharma: Consultancy; Takeda: Consultancy, Research Funding; Roche: Consultancy, Research Funding; Peer View: Honoraria; Seattle Genetics: Consultancy; Physicians' Education Resource: Honoraria. Salles: Abbvie: Consultancy, Honoraria; BMS/Celgene: Consultancy; Kite/Gilead: Consultancy; Ipsen: Consultancy; Janssen: Consultancy; Genmab: Consultancy; Takeda: Consultancy; Morphosys: Consultancy, Honoraria; Rapt: Consultancy; Genentech/Roche: Consultancy; Epizyme: Consultancy, Honoraria; Beigene: Consultancy; Debiopharm: Consultancy; Regeneron: Consultancy, Honoraria; Loxo: Consultancy; Miltneiy: Consultancy; Novartis: Consultancy; Incyte: Consultancy; Bayer: Honoraria; Velosbio: Consultancy; Allogene: Consultancy. Younes: AZ: Current Employment, Other: Senior Vice President, Global Head of Haematology (Early and Late Stage) Oncology R&D at AstraZeneca. von Keudell: Pharmacyclics: Consultancy, Honoraria; AbbVie: Research Funding; Janssen: Research Funding; Merck: Consultancy, Honoraria; Merck: Research Funding; Incyte: Consultancy, Honoraria; BMS: Research Funding.

Background: In untreated Hodgkin lymphoma (HL), metabolic tumor volume (MTV) significantly declined following pembrolizumab monotherapy, regardless of baseline MTV, and may serve as a better measure of treatment response to PD-1 blockade than the Lugano Classification (Allen, et al. Blood 2021). Furthermore, standard PET evaluation can fail to differentiate between malignancy, pseudoprogression and physiological background in patients (pts) receiving PD-1 blockade. The predictive power and prognostic significance of MTV in patients with relapsed or refractory (RR) HL receiving PD-1 blockade is unknown. We sought to examine the role of MTV in HL pts treated with PD-1 blockade. Methods: We identified 30 pts who received pembrolizumab or nivolumab-based therapy off-study for RR HL between July 2015 and May 2021. In the PET/CT analysis, all lesions were visually identified, and all measurable lesions were selected for the analysis. Responses were assessed by Lugano Classification. Indeterminant response (IR) was defined as evidence of progression on PET without clinical deterioration as per the Lyric Criteria. MTV was obtained by summing the metabolic volumes of all measurable lesions, using the 41% SUVmax threshold to measure each lesion MTV using Beth Israel plugin. MTV was evaluated at baseline (MTV0) and at first reassessment (MTV1) after initiation of PD-1 blockade. Δ (delta) MTV was calculated as % change in MTV from MTV0 to MTV1. Receiver operating characteristic (ROC) curve was performed for ΔMTV and best overall response rate (BOR) to determine the optimal cut-off value. Overall survival (OS) was measured from PD-1 blockade initiation to death or last follow-up. We examined the association between MTV and clinical factors, PET-1 response, and overall survival using Cox proportional hazards model and Fisher exact test, respectively. Results: 25 patients had complete clinical data and PET/CT analysis (Table 1). The median age at first relapse was 39 years (range: 18-81); 64% were male. 6 pts previously received PD-1 blockade on clinical trials and discontinued treatment due to study completion or toxicity. The median time between PET0 and PET1 was 3.4 months (range 2.0-7.3). Median MTV0 and MTV1 values were 39.8 ml and 17.1 ml, respectively. With a median follow up from initiation of PD-1 blockade among survivors of 38.7 months, 5 pts (19%) died. The median OS of the entire cohort was not reached (95%CI: 76.4-NR) (Figure 1). The best response to PD-1 blockade included 15 (60%) with complete metabolic response (CMR), 5 (20%) with partial metabolic response (PMR), and 5 (20%) with progression of disease (POD). Median ΔMTV was -70% (range -100 to +909%). MTV0 was not predictive of OS, PET1 response, or BOR. However, ΔMTV predicted for PET1 response (p=0.004) and BOR (p=0.004). 18 (72%) pts had a reduction in ΔMTV (range: -100, -22), while 7 (28%) pts had an increase in ΔMTV (range: 33-909). The optimal ΔMTV threshold for prediction of BOR was 120% (Figure 1). ΔMTV Among pts with IR on PET-1, ΔMTV Conclusions: Quantitative change in MTV from baseline to first reassessment may aid in predicting treatment response and long-term outcomes in patients with RR HL receiving PD-1 blockade, particularly those initially characterized as achieving indeterminate response. Further prospective clinical trials are needed to validate the role of ΔMTV in predicting response and long-term outcomes for RR HL pts receiving PD-1 blockade. Figure 1 Figure 1. Disclosures Moskowitz: Merck & Co., Inc.: Research Funding. Matasar: Seattle Genetics: Consultancy, Honoraria, Research Funding; TG Therapeutics: Consultancy, Honoraria; Bayer: Consultancy, Honoraria, Research Funding; Genentech, Inc.: Consultancy, Honoraria, Research Funding; Memorial Sloan Kettering Cancer Center: Current Employment; Juno Therapeutics: Consultancy; Merck: Consultancy; Pharmacyclics: Honoraria, Research Funding; Rocket Medical: Consultancy, Research Funding; Daiichi Sankyo: Consultancy; GlaxoSmithKline: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; ImmunoVaccine Technologies: Consultancy, Honoraria, Research Funding; Merck Sharp & Dohme: Current holder of individual stocks in a privately-held company; Teva: Consultancy; F. Hoffmann-La Roche Ltd: Consultancy, Honoraria, Research Funding; IGM Biosciences: Research Funding; Takeda: Consultancy, Honoraria. Zelenetz: Amgen: Honoraria; MorphoSys: Honoraria; Novartis: Honoraria; MEI Pharma: Honoraria, Research Funding; Beigene: Honoraria, Other, Research Funding; Gilead: Honoraria, Research Funding; Pharmacyclics: Honoraria; SecuraBio: Honoraria; Genentech/Roche: Honoraria, Research Funding; Abbvie: Honoraria, Research Funding; Verastem: Honoraria; BMS/Celgene/JUNO: Honoraria, Other; MethylGene: Research Funding; AstraZeneca: Honoraria; Janssen: Honoraria; NCCN: Other; LFR: Other; Gilead: Honoraria. Joffe: AstraZeneca. Epizyme: Consultancy. von Keudell: Merck: Research Funding; Janssen: Research Funding; BMS: Research Funding; Incyte: Consultancy, Honoraria; AbbVie: Research Funding; Merck: Consultancy, Honoraria; Pharmacyclics: Consultancy, Honoraria. Batlevi: Medscape: Honoraria; Memorial Sloan Kettering Cancer Center: Current Employment; Moderna: Current holder of individual stocks in a privately-held company; Pfizer: Current holder of individual stocks in a privately-held company; ADC Therapeutics: Consultancy; Regeneron: Current holder of individual stocks in a privately-held company; TG Therapeutics: Consultancy; Kite Pharma: Consultancy; Seattle Genetics: Consultancy; TouchIME: Honoraria; BMS: Current holder of individual stocks in a privately-held company; Bayer: Research Funding; Viatris: Current holder of individual stocks in a privately-held company; Karyopharm: Consultancy; Juno/Celgene: Consultancy; Life Sciences: Consultancy; Dava Oncology: Honoraria; GLG Pharma: Consultancy; Xynomic: Research Funding; Roche/Genentech: Research Funding; Novartis: Research Funding; Epizyme: Research Funding; Janssen: Research Funding; Autolus: Research Funding. Caron: Astra-Zeneca: Current holder of individual stocks in a privately-held company; bristol myers: Current holder of individual stocks in a privately-held company; GlaxoSmithKlein: Current holder of individual stocks in a privately-held company; Johnson and Johnson: Current holder of individual stocks in a privately-held company; Novartis: Current holder of individual stocks in a privately-held company; pfizer: Current holder of individual stocks in a privately-held company; Teva: Current holder of individual stocks in a privately-held company. Noy: Rafael Parhma: Research Funding; Morphosys: Consultancy; Medscape: Consultancy; Pharmacyclics: Consultancy, Research Funding; Targeted Oncology: Consultancy; Epizyme: Consultancy; Janssen: Consultancy, Honoraria. Salles: Velosbio: Consultancy; Morphosys: Consultancy, Honoraria; Regeneron: Consultancy, Honoraria; Novartis: Consultancy; Epizyme: Consultancy, Honoraria; Allogene: Consultancy; Rapt: Consultancy; Genentech/Roche: Consultancy; Takeda: Consultancy; Miltneiy: Consultancy; Loxo: Consultancy; Kite/Gilead: Consultancy; Genmab: Consultancy; Incyte: Consultancy; Ipsen: Consultancy; Janssen: Consultancy; Debiopharm: Consultancy; BMS/Celgene: Consultancy; Beigene: Consultancy; Abbvie: Consultancy, Honoraria; Bayer: Honoraria. Moskowitz: ADC Therapeutics: Research Funding; Takeda: Consultancy; Incyte: Research Funding; Merck: Consultancy, Research Funding; Beigene: Research Funding; Seattle Genetics: Consultancy, Research Funding; Bristol-Myers Squibb: Research Funding; Miragen: Research Funding; Janpix Ltd.: Consultancy; Imbrium Therapeutics L.P./Purdue: Consultancy.

Introduction: The prognostic significance of immunoglobulin heavy-chain variable region gene (IGHV) mutational status in chronic lymphocytic leukemia (CLL) is well established. Previous studies have shown that CLL patients with mutated IGHV (M-IGHV) have a better prognosis, manifested in a longer time-to first treatment (TTFT) and overall survival (OS). Here we present an analysis on the impact of IGHV mutational status in an Israeli cohort of patients with CLL. Methods: A total of 254 patients with CLL (diagnosed from 1991 to 2020), followed at the Tel-Aviv Sourasky Medical Center were included. The IGHV mutational status has been determined by next-generation sequencing (NGS) or cDNA Sanger. The sequences with a germline homology 98% or higher were considered unmutated, and those with a homology less than 98% as mutated CLL. IGHV subsets were analyzed using the ARResT/AssignSubsets website. All data were statistically analyzed by IBM SPSS Statistics 27 (IBM Corporation, Armonk, NY, USA), P-values were two-sided, and the significance level was determined at a Results: Out of 254 patients, 132 (52.0%) had an unmutated IGHV gene (UM-IGHV), and 122 (48.0%) were mutated (M-IGHV). At diagnosis, most patients (Table 1) were ≤65 years of age (n=157, 61.8%), males (n=160, 63.0%) and had an absolute lymphocytic count equal to or less than (≤)15.0 x10 9/L (n=115, 52.5%). Advanced Binet stage was more commonly associated with UM-IGHV (n=44, 57.9%) (P=0.033). Among 240 patients (94.1%), the most frequently used VH gene segments (Figure 1) included; VH1-69 (n=35, 14.6%), VH4-34 (n=24, 10.0%), VH1-2 (n=17, 7.1%), and VH3-23 (n=16, 6.7%). Six major B-cell receptors (BCR) subsets (Figure 2) were identified in 21/180 of patients (11.7%), which most commonly included: CLL#1 (n=6, 28.6%), CLL#4 (n=5, 23.8%), and CLL#2(n=3, 14.3%). Patients with M-IGHV had a longer time to first treatment (TTFT) (P In multivariate analyses of the entire cohort; for TTFT (Table 2A), males (P=0.002, HR=1.9, [1.3-2.9]), >65 years of age at diagnosis (P=0.008, HR=1.8, [1.2-2.7]), advanced Binet stage (P65 years of age at diagnosis (P=0.010, HR=2.6, [1.3-5.5]) and UM-IGHV mutational status (P=0.004, HR=2.9, [1.4-5.9]) were found to be significant factors for shorter OS. In multivariate analyses performed separately for each IGHV mutational status group; males (P=0.021, HR=2.1, [1.1-4.0]), age >65 years (P=0.002, HR=3.2, [1.5-6.4]) and advanced Binet stage (P65 years at diagnosis (P=0.039, HR=4.3, [1.1-17.0]) was the only independent predictor in M-IGHV patients, while no variable maintained its statistical significance in UM-IGHV cases. Conclusion: As previously studied, our cohort demonstrates that M-IGHV CLL patients have better TTFT and OS. However, the rate of BCR subsets in Israel appears to be lower than expected. A separated multivariate analysis for M-IGHV and UM-IGHV patients revealed different independent predictors for TTFT and OS to each of the IGHV mutational status groups. Further studies with larger cohorts are required to deeply study these differences and provide further clinical insight into the pathophysiology of CLL. Figure 1 Figure 1. Disclosures Joffe: AstraZeneca: Consultancy; Epizyme: Consultancy. Herishanu: AbbVie: Honoraria, Research Funding; Janssen: Honoraria; Roche: Honoraria; Medison: Honoraria.

Introduction Central nervous system relapse (secondary central nervous system lymphoma -SCNS) is an uncommon but devastating complication of aggressive B-cell lymphoma. Patients (Pts) with CNS-IPI 4-6 are at greatest risk (10.2% at 2 years). Intravenous high-dose methotrexate (HD-MTX) is widely used to mitigate SCNS risk but data supporting this practice are limited. Methods We performed a multicentre, retrospective study at 21 sites in Australia, Asia, North America and Europe. Chart or registry review was performed for consecutively diagnosed pts with diffuse large B-cell lymphoma (DLBCL) and CNS-IPI 4-6, high grade B-cell lymphoma (HGBL) with rearrangements of MYC+BCL2 and/or BCL6 and primary breast/testicular DLBCL irrespective of CNS-IPI. Pts were diagnosed between 2000-2020, 18-80 years at diagnosis, and treated with curative intent anti-CD20 based chemo-immunotherapy. Pts with CNS involvement at diagnosis were excluded. HD-MTX was defined as at least one cycle of intravenous MTX at any dose. Time to SCNS was calculated from date of diagnosis (all-pts), and from the end of frontline systemic lymphoma therapy, defined as 6x21 days from diagnosis (complete response (CR-pts)), until SCNS, systemic relapse, death, or censoring, whichever came first. Cumulative risk of SCNS was computed using the Aalen-Johansen estimator treating death and systemic relapses as competing events. Adjusted cumulative risks were obtained by using an inverse probability of treatment weighting approach. The average treatment effect was computed as the difference in adjusted 5-year risk of SCNS. Results - 2300 and 1455 pts were included in the all-pts and CR-pts analyses, respectively. Baseline demographics and details of therapy are summarised in Table 1. Except for a predominance of males, pts ≤60 years and pts with ECOG 0-1 in the HD-MTX vs no HD-MTX groups, the demographics and treatments were well balanced. At a median follow up of 5.9 years (range 0.0-19.1) and 5.5 years from diagnosis (range 0.0-18.7), 201/2300 and 84/1455 pts experienced CNS events in the all-pts and CR-pts analyses respectively. For all-pts(n=2300), CNS-IPI was 4-6 in 2052(89.2%), with R-CHOP-like therapy given to 93.8%. 410 pts (17.8%) received HD-MTX (265 HD-MTX alone, 145 in combination with intrathecal methotrexate (IT-MTX);435 received IT-MTX alone;1455 received neither. There were 32/410 and 169/1890 SCNS events, with median time from diagnosis to SCNS of 8.8 and 6.7 months in the HD-MTX and no HD-MTX groups respectively. 5-year OS was 70% (95% CI, 65-76%) and 55% (95% CI 53-57%) in HD-MTX and no HD-MTX groups respectively. There was no difference in the adjusted 5-year risk of SCNS between the HD-MTX and no HD-MTX groups (8.4% vs 9.1%, adjusted hazard ratio [HR] 0.71, p=0.100) (Figure 1). For CR-pts(n=1455), CNS-IPI was 4-6 in 1267(87.0%), with R-CHOP-like therapy given to 93.3%. 284 pts (19.5%) received HD-MTX (170 HD-MTX alone, 114 with IT-MTX);298 received IT-MTX alone;873 received neither. There were 16/284 and 68/1171 SCNS events, with median time from diagnosis to SCNS of 11.0 and 10.3 months in the HD-MTX and no HD-MTX groups respectively. 5-year OS was 74%(95% CI 67-81%) and 75%(95% CI 72-78%) in the HD-MTX groups and no HD-MTX groups respectively (adjusted HR 1.08, p=0.622). There was no difference in the 5-year risk of CNS relapse between the HD-MTX and no HD-MTX groups 5.0% vs 6.0% (adjusted HR 1.03, p=0.903) (Figure 2). Exploratory analysis of the impact of HD-MTX among the highest risk groups CNS IPI 5 (n=368), CNS-IPI 6 (n=59) and CNS-IPI 6 plus all pts with testicular, renal or adrenal involvement (n=349) did not reveal differences in SCNS rates in HD-MTX treated pts. Additional subgroup analyses will be presented at the meeting. Conclusions To our knowledge, this is the largest study of the efficacy of HD-MTX in reducing SCNS events focusing exclusively on high-risk pts. The overall incidence of CNS relapse observed was consistent with previous reports in similar patient cohorts at 9%. The use of HD-MTX did not lower SCNS rates overall or when analysis was confined to CR pts at completion of curative intent therapy to compensate for potential immortal bias associated with HD-MTX therapy. Despite the limitations of the non-randomized and retrospective design, it appears unlikely that HD-MTX is associated with a clinically meaningful reduction in SCNS rates in pts with high risk for SCNS. Figure 1 Figure 1. Disclosures Lewis: AstraZeneca: Consultancy, Honoraria; Novartis: Patents & Royalties: Conference attendance; Janssen: Honoraria, Patents & Royalties: Conference attendance; Roche: Consultancy, Honoraria. Villa: Janssen: Honoraria; Gilead: Honoraria; AstraZeneca: Honoraria; AbbVie: Honoraria; Seattle Genetics: Honoraria; Celgene: Honoraria; Lundbeck: Honoraria; Roche: Honoraria; NanoString Technologies: Honoraria. Bobillo: F. Hoffmann-La Roche Ltd: Consultancy, Speakers Bureau; Gilead: Speakers Bureau. Ekstroem Smedby: Takeda: Consultancy; Janssen Cilag: Research Funding. Savage: Merck: Consultancy, Honoraria, Other: Institutional clinical trial funding; BMS: Consultancy, Honoraria, Other: Institutional clinical trial funding; AbbVie: Consultancy, Honoraria; Roche: Research Funding; Takeda: Other: Institutional clinical trial funding; Servier: Consultancy, Honoraria; Seattle Genetics: Consultancy, Honoraria; Astra-Zeneca: Consultancy, Honoraria; Beigene: Other: Institutional clinical trial funding; Genentech: Research Funding. Eyre: Beigene: Honoraria, Research Funding; Incyte: Consultancy; Secura Bio: Consultancy, Honoraria; Janssen: Honoraria; Gilead/KITE: Honoraria, Other: Travel support for conferences, Research Funding, Speakers Bureau; Loxo Oncology: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Abbvie: Consultancy, Honoraria, Other: Travel to conferences; AstraZeneca: Honoraria, Research Funding; Roche: Consultancy, Honoraria. Cwynarski: Incyte: Consultancy, Speakers Bureau; Gilead: Consultancy, Speakers Bureau; Atara: Consultancy; Celgene: Consultancy; Takeda: Consultancy, Other: travel to scientific conferences, Speakers Bureau; Kite, a Gilead Company: Consultancy, Other: travel to scientific conferences, Speakers Bureau; Janssen: Consultancy, Other: travel to scientific conferences; Roche: Consultancy, Other: travel to scientific conferences, Speakers Bureau; BMS/Celgene: Other: travel to scientific conferences. Stewart: Teva: Honoraria; Sandoz: Honoraria; Amgen: Honoraria; AstraZeneca: Honoraria; Novartis: Honoraria; Celgene: Honoraria; Gilead: Honoraria; Abbvie: Honoraria; Janssen: Honoraria; Roche: Honoraria. Bishton: Gilead: Honoraria, Other: Travel grants; AbbVie: Honoraria, Other: Travel grants; Celgene/BMS: Honoraria, Other: travel grants; Celltrion: Honoraria, Other: Travel grants; Takeda.: Honoraria, Other: Travel grants . Fox: F. Hoffmann-La Roche Ltd: Consultancy, Membership on an entity's Board of Directors or advisory committees. Joffe: Epizyme: Consultancy; AstraZeneca: Consultancy. Eloranta: Janssen Pharmaceutical NV: Other: NV. Sehn: Genmab: Consultancy; Novartis: Consultancy; Debiopharm: Consultancy. Manos: Bristol-Myers Squibb: Other: Travel and meetings. Hawkes: Specialised Therapeutics: Consultancy; Gilead: Membership on an entity's Board of Directors or advisory committees; Merck Sharpe Dohme: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees; Antigene: Membership on an entity's Board of Directors or advisory committees; Regeneron: Speakers Bureau; Bristol Myers Squib/Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Merck KgA: Research Funding; Astra Zeneca: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Roche: Membership on an entity's Board of Directors or advisory committees, Other: Travel and accommodation expenses, Research Funding, Speakers Bureau; Janssen: Speakers Bureau. Minson: Novartis: Research Funding; Hoffman La Roche: Research Funding. Dickinson: Celgene: Research Funding; Amgen: Honoraria; Takeda: Research Funding; Gilead Sciences: Consultancy, Honoraria, Speakers Bureau; MSD: Consultancy, Honoraria, Research Funding, Speakers Bureau; Janssen: Consultancy, Honoraria; Bristol-Myers Squibb: Consultancy, Honoraria; Roche: Consultancy, Honoraria, Other: travel, accommodation, expenses, Research Funding, Speakers Bureau; Novartis: Consultancy, Honoraria, Research Funding, Speakers Bureau. Øvlisen: Abbvie: Other: Travel expenses. Gregory: Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel fees, Speakers Bureau; Janssen: Consultancy; Novartis: Consultancy. Ku: Roche: Consultancy; Antegene: Consultancy; Genor Biopharma: Consultancy. Talaulikar: Roche: Honoraria, Research Funding; Jansenn: Honoraria, Research Funding; Amgen: Honoraria, Research Funding; Takeda: Honoraria, Research Funding; EUSA Pharma: Honoraria, Research Funding. Maurer: Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene: Research Funding; Genentech: Research Funding; Kite Pharma: Membership on an entity's Board of Directors or advisory committees; Morphosys: Membership on an entity's Board of Directors or advisory committees, Research Funding; Nanostring: Research Funding. El-Galaly: Abbvie: Other: Speakers fee; ROCHE Ltd: Ended employment in the past 24 months. Cheah: Roche: Consultancy, Honoraria, Other: advisory and travel expenses, Research Funding; Janssen: Consultancy, Honoraria, Other: advisory; MSD: Consultancy, Honoraria, Other: advisory, Research Funding; Gilead: Consultancy, Honoraria, Other: advisory; Ascentage pharma: Consultancy, Honoraria, Other: advisory; Beigene: Consultancy, Honoraria, Other: advisory; AbbVie: Research Funding; Celgene: Research Funding; AstraZeneca: Consultancy, Honoraria, Other: advisory; Loxo/Lilly: Consultancy, Honoraria, Other: advisory; TG Therapeutics: Consultancy, Honoraria, Other: advisory.

Purpose/Objective(s) Indolent non-Hodgkin lymphomas (iNHL), such as follicular lymphoma (FL) and marginal zone lymphoma (MZL) are highly radiosensitive. Previously untreated patients with localized disease are potentially curable (PC) with RT. While standard of care remains 24Gy, de-escalation to very low dose radiotherapy (VLDRT) of 4Gy reduces toxicities and treatment duration. Use of VLDRT outside of palliation remains controversial, however, we hypothesize it may be sufficient for most lesions. Materials/Methods We present the largest single institution VLDRT experience of adults with FL/MZL treated between 2005-2018 with modern principles including PET staging and involved site radiotherapy (ISRT). Outcomes include best clinical/radiographic response using Lugano criteria between 1.5-6 months post-VLDRT, and cumulative incidence of local progression (LP), distant progression and overall progression, all using death as competing risk. Outcomes were stratified by VLDRT intent; lesions considered PC were localized sites without prior treatment. All other sites were considered non-curable. Competing risk regression was used to identify potential histologic/clinical predictors of LP. Results In total, 250 patients were treated to 299 lesions including 52 potentially curative (PC) sites (Table 1). Post-VLDRT, overall response rate was 90% for all treated sites with 68% achieving complete response (CR). With median follow-up of 2.4y, the 2y cumulative incidence of LP was 25% for the entire cohort. PC patients had considerably lower 2y-LP of 9% (95% CI 3-19%) compared to 29% (95% CI 23-34%) for the non-curable. Lesion size > 6cm was associated with lower odds of CR and greater risk of LP relative to lesions 0-2cm. There was no suggestion of inferior outcomes for PC patients relative to non-curable. The probability of receiving additional RT to the same site 2y post VLDRT is 15% (95% CI 11-19%), and subsequent response after additional RT was 68% CR (n = 30/45), 18% partial response (n = 8), and 14% non-response (n = 6). Conclusion We demonstrate that modern VLDRT approaches utilizing PET staging and ISRT result in excellent ORR with nearly 70% CR. Importantly, the cumulative incidence of LP at 2 years post VLDRT is low at 25%, highlighting the possibility of durable remissions. Given clinical versatility and apparent efficacy for PC patients, we support an adaptive ISRT stepwise strategy where patients will be treated initially with VLDRT, reserving full dose treatment for those with suboptimal response. A prospective, multicenter study by ILROG has been developed to compare PC patients randomized to standard 24 Gy versus this proposed response-adapted approach.

Decreased absolute lymphocyte counts (ALCs) following frontline therapy for chronic lymphocytic leukemia may be associated with disease control, even in patients without evidence of minimal residual disease. We studied the prognostic significance of ALCs during the first year following treatment with fludarabine, cyclophosphamide, and rituximab (FCR). We evaluated 99 patients who achieved a partial response without lymphocytosis ( 1.8 vs not reached for ALC ≤ 0.7 at 9 months, P

Background: With the incorporation of positron emission tomography (PET) imaging as part of the standard staging evaluation of follicular lymphoma (FL), it is generally recommended to obtain the diagnostic biopsy from a lesion with the highest standardized uptake value (SUV) to rule out de novo histologic transformation (HT). In some cases such an approach might be impractical, while in other cases a biopsy from a diseased area with a high SUV may still demonstrate an indolent histology. To date, there is no data to guide treatment choices in patients (pts) with FL with high SUVmax but with no documented evidence of HT. Specifically, it remains unclear whether anthracycline-containing regimens, such as R-CHOP, provide a better outcome than R-Bendamustine (BR). Furthermore, it is unknown whether rituximab (R) maintenance is beneficial in this setting. Therefore, we aimed to compare the efficacy of R-CHOP vs BR in newly diagnosed FL pts with high SUVmax at baseline PET and to clarify the role of maintenance. Patients and Methods: We retrospectively identified 261 consecutive pts with newly diagnosed biopsy-proven FL1-3A and a SUVmax≥13 on baseline PET, who were treated with frontline R-CHOP (n=183) or BR (n=78) at 7 US cancer centers based on the physician's choice. Progression-free survival (PFS) was calculated from starting treatment until progression, relapse or death. Cut-offs of SUVmax ≥13≤18 and SUVmax>18 were used for sub-analysis (Haematologica;2020;105:1907-1913). Results: Median age was 59 years. The baseline characteristics of the two groups differed significantly for a younger age (58 vs 62 years, p=0.009), a higher rate of B-symptoms (26% vs 10%, p=0.005) and baseline SUVmax>18 (49% vs 36%, p=0.04) in the R-CHOP group. A diagnostic biopsy was obtained from the site at the highest SUV in 129 (71%) and 43 (55%) pts, respectively (p=0.01). These suggest a potential selection of R-CHOP in pts with adverse features. At the end of therapy (EoT), R-CHOP treated pts achieved higher PET-CT complete response rates (CR 82% vs 69%, p=0.02). This superiority held in pts with diagnostic biopsy at the highest SUV site (CR 83% vs 67%, p=0.03), but not in the others (CR 80% vs 71%, p=0.37). Progression occurred at EoT in 11 and 14 pts receiving R-CHOP and BR (6% vs 18%, p=0.02), with a higher rate of HT in the BR group (13% vs 4%, p=0.006). After a median follow-up of 76 months (range, 4-208 months), there was no significant difference in PFS between R-CHOP and BR treated pts (hazard ratio [HR] 1.22, p=0.34). PFS was strongly associated with FLIPI 2 (HR 2.32, p=0.01) and 3-5 (HR 2.69, p=0.003) in the univariate as well as in the multivariate analysis (FLIPI 2 HR 2.19, p=0.02; FLIPI 3-5 HR 2.51, p=0.01). There was a trend toward overall survival (OS) benefit in the R-CHOP group (Fig.1A). In the univariate analysis for OS, BR regimen (HR 2.12, p=0.03), age >60 (HR 2.54, p=0.006), FLIPI 3-5 (HR 5.13, p=0.03) and biopsy at the highest SUV site (HR 0.44, p=0.01) were prognostic, however none of those remained significant in the multivariate analysis (BR regimen HR 1.84, p=0.09; age >60 HR 1.92, p=0.08; FLIPI 3-5 HR 3.11, p=0.14; biopsy at the highest SUV site HR 0.60, p=0.13; SUVmax>18 HR 1.87, p=0.055). Among pts with EoT response after R-CHOP or BR (n=170 and n=64, respectively), one third in each group (36% vs 41%, respectively) received R-maintenance for a median of 8 administrations (range, 2-12). A significant PFS advantage (landmark analysis) was observed with R-maintenance (Fig.1B; HR 0.53, p=0.02); however, this did not translate in survival benefit (HR 0.67, p=0.49). In a multivariable model, R-maintenance (HR 0.53, p=0.02), FLIPI 2 (HR 2.47, p=0.03) and 3-5 (HR 2.79, p=0.01) remained independent prognosticators of PFS, while no parameters significantly affected OS. The 2-year HT rate (10% vs 17%) and cumulative incidence did not statistically differ between R-CHOP and BR groups (Fig.1C, p=0.159). Early progression (POD24) occurred in 43 and 22 pts who received R-CHOP and BR, respectively (24% vs 28%) and resulted in a significantly higher risk of death (HR 4.12, p=0.006). Conclusion: In newly diagnosed FL pts with SUVmax≥13 at baseline PET, R-CHOP was more effective in achieving CR and reducing the risk of early HT compared with BR, and it was associated with a trend toward survival advantage. Rituximab maintenance significantly prolonged PFS. A prospective evaluation with a larger population will be needed to confirm our findings. Disclosures Joffe: Epizyme: Membership on an entity's Board of Directors or advisory committees; AstraZeneca: Membership on an entity's Board of Directors or advisory committees. Ruella:Abclon, BMS, NanoString: Consultancy; Abclon: Consultancy, Research Funding; UPenn/Novartis: Patents & Royalties. Svoboda:Adaptive: Consultancy; Astra-Zeneca: Consultancy, Research Funding; BMS: Consultancy, Research Funding; Imbrium: Consultancy; Incyte: Research Funding; Pharmacyclics: Consultancy, Research Funding; Merck: Research Funding; Seattle Genetics: Consultancy, Research Funding; TG: Research Funding; Genmab: Consultancy; Atara: Consultancy. Witzig:Immune Design: Research Funding; Spectrum: Consultancy; Karyopharm Therapeutics: Research Funding; Acerta: Research Funding; Celgene: Consultancy, Research Funding; AbbVie: Consultancy; MorphSys: Consultancy; Incyte: Consultancy. Smith:TG Therapeutics: Consultancy, Research Funding; Janssen: Consultancy; BMS: Consultancy; Celgene: Consultancy, Research Funding; Pharmacyclics: Research Funding; Karyopharm: Consultancy, Research Funding; FortySeven: Research Funding; Acerta: Research Funding; Genentech/Roche: Consultancy, Other: Support of parent study and funding of editorial support, Research Funding. Armand:Affimed: Consultancy, Research Funding; Otsuka: Research Funding; Bristol-Myers Squibb: Consultancy, Honoraria, Research Funding; IGM: Research Funding; Infinity: Consultancy; Genentech: Research Funding; Sigma Tau: Research Funding; Celgene: Consultancy; Adaptive: Consultancy, Research Funding; Tensha: Research Funding; Roche: Research Funding; Merck & Co., Inc.: Consultancy, Honoraria, Research Funding; Pfizer: Consultancy; ADC Therapeutics: Consultancy. Nastoupil:Janssen: Honoraria, Research Funding; LAM Therapeutics: Research Funding; Gilead/KITE: Honoraria; Gamida Cell: Honoraria; TG Therapeutics: Honoraria, Research Funding; Merck: Research Funding; Novartis: Honoraria, Research Funding; Genentech, Inc.: Honoraria, Research Funding; Karus Therapeutics: Research Funding; Bayer: Honoraria; Celgene: Honoraria, Research Funding; Pfizer: Honoraria, Research Funding. Ansell:Takeda: Research Funding; Regeneron: Research Funding; Bristol Myers Squibb: Research Funding; Seattle Genetics: Research Funding; Trillium: Research Funding; Affimed: Research Funding; AI Therapeutics: Research Funding; ADC Therapeutics: Research Funding. Zelenetz:Novartis: Consultancy; Adaptive Biotechnology: Consultancy; Genentech/Roche: Consultancy; Gilead: Consultancy; Gilead: Research Funding; Celgene: Consultancy; Roche: Research Funding; Amgen: Consultancy; BeiGene: Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy; Sandoz: Research Funding; Celgene: Research Funding; MorphoSys: Research Funding; MEI Pharma: Research Funding. Younes:BioPath, Xynomic, Epizyme, and F. Hoffmann-La Roche: Consultancy; Janssen, Curis, Merck, Bristol-Myers Squibb, Syndax Pharmaceuticals, F. Hoffmann-La Roche, Curis (Inst), Johnson & Johnson (Inst), Novartis (Inst): Research Funding; Janssen, AbbVie, Merck, Curis, Epizyme, F. Hoffmann-La Roche, Takeda, Bristol-Myers Squibb, Bayer HealthCare Pharmaceuticals, Celgene, Incyte, Janssen Pharmaceuticals, Merck, Sanofi, Seattle Genetics, Takeda Millennium: Honoraria; AstraZeneca: Current Employment; MSKCC: Ended employment in the past 24 months.

Introduction Marginal Zone Lymphoma (MZL) includes three subtypes of indolent lymphoma: splenic MZL, extranodal MZL of mucosa-associated lymphoid tissue (MALT) and nodal MZL. The diagnosis of MZL is often made by exclusion of other lymphoma subtypes based on phenotype. One of the markers that are often involved in this discernment is CD5. The CD5 is not expressed in most of the cases of MZL, probably independently of the subtype, while it is usually expressed in different diseases such as Mantle Cell Lymphoma and Small Lymphocytic Lymphoma/Chronic Lymphocytic Leukemia. A subgroup of MZL, however, unequivocally expresses CD5, and very little is known about the characteristics and outcomes of these patients compared to their CD5 negative counterparts. Methods From our pathology database, we collected all the reports of indolent lymphoma containing the words "marginal zone" and/or "MALT" diagnosed or reviewed at MSKCC. We reviewed the text of the selected pathology reports to identify all cases that were unequivocally MZL and reported positivity or negativity of the CD5 marker in the lymphoma cells. From the electronic medical records, we collected all the relevant clinical information for all CD5+ MZL cases, and for a subset of CD5- MZL cases with a 1:2 match for age at diagnosis and sex. The survival and baseline characteristics analyses only included patients that were followed by our lymphoma group. We report differences between groups with the chi-squared test. Overall survival (OS) was estimated using the cumulative incidence method, and time to treatment (TTT) was estimated using the subdistribution function to adjust for semi-competing risk of death on treatment initiation. A modified proportional hazards model was used to compare the subdistribution hazard between groups, and a standard Cox proportional hazards model was used to compare the hazard of death between groups. Results From 03/1998 to 09/2019, 64 patients were diagnosed with CD5+ MZL and followed by the Lymphoma Service at MSKCC. The control group of CD5- MZL included 137 patients that matched the CD5+ positive patients for age at diagnosis and sex. 20.3% of the CD5+ vs 14.6% of the CD5- MZL were nodal (p=0.30); Extra-nodal (EN) localizations included: GI tract - other than stomach (5.9% CD5+, 9.4% CD5-), stomach (17.7% CD5+, 17.1% CD5-), skin (7.8% CD5+, 12.0% CD5-), lung (9.8% CD5+, 12.0% CD5-), eye (9.8% CD5+, 7.7% CD5-), spleen (25.5% CD5+, 18% CD5-), multiple sites (13.7% CD5+, 10.3% CD5-), other single EN sites (9.8% CD5+, 13.7% CD5-). IPI score was low in 52% CD5+ vs 61% CD5-; low intermediate in 28% CD5+ vs 19% CD5-; high intermediate in 21% CD5+ vs 13% CD5-; no CD5+ had high IPI, while 7% of CD5- did (chi-square p=0.04). Transformation to DLBCL was similar in the 2 groups with 7% events in CD5+ and 4% in CD5- (p=0.42). Bone marrow involvement seemed to be more prevalent in the CD5+ MZL (67.5% vs 47.2% of the CD5-; p=0.04). IGHV was mutated in 80% of the CD5+ and 64% of the CD5- (p=0.24). OS analysis was performed first considering death by any cause: median OS was not reached for CD5+ MZL (95% C.I. 8.8 years - NE) and it was 27 years for CD5- (95% C.I. 14.3 years - NE). No difference was observed between CD5+ vs CD5- (p=0.9, Figure 1A). We also calculated MZL related survival, including deaths related to transformation to high grade lymphoma. No difference was observed between CD5+ vs CD5-, (p=0.3, Figure 1B). Median time to 1st treatment (including topical treatment and radiation therapy) was 1.4 years (95% C.I. 0.4 - 2.3) for CD5+ and 0.4 years (95% C.I. 0.3 - 0.9). No difference was observed between CD5+ vs CD5- (p=0.2, Figure 1C). Median time to first systemic treatment was 4.3 years (95% C.I. 1.6 - 12.9) for CD5+ and 7 years (95% C.I. 3.1 - 15.4) for CD5- MZL. No difference was observed between CD5+ vs CD5- (p=0.6, Figure 1D). Conclusions In this retrospective case-control analysis assessing the differences between CD5+ and CD5- MZL in terms of clinical presentation, survival, transformation occurrence and time to first topical or systemic treatment, we demonstrate that the two subgroups might have some differences in terms of bone marrow involvement but probably no difference in terms of outcome. Our sample size is small, and larger studies on a population with more events might clarify, with multivariate analysis, if these differences are real. Figure Disclosures Joffe: Epizyme: Membership on an entity's Board of Directors or advisory committees; AstraZeneca: Membership on an entity's Board of Directors or advisory committees. Palomba:Pharmacyclics: Honoraria; Celgene: Honoraria; Merck: Honoraria; Novartis: Honoraria; Regeneron: Research Funding; Juno Therapeutics, a Bristol-Meyers Squibb Company: Honoraria, Research Funding; Genentech: Research Funding. Noy:Rafael Pharma: Research Funding; Janssen: Consultancy; Pharmacyclics: Consultancy; Medscape: Consultancy; Targeted Oncology: Consultancy; Morphosys: Consultancy; Pharmacyclics: Research Funding; NIH: Research Funding. Matasar:Daiichi Sankyo: Consultancy; Immunovaccine Technologies: Honoraria, Research Funding; Pharmacyclics: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; IGM Biosciences: Research Funding; GlaxoSmithKline: Honoraria, Research Funding; Rocket Medical: Consultancy, Research Funding; Seattle Genetics: Consultancy, Honoraria, Research Funding; Genentech, Inc.: Consultancy, Honoraria, Research Funding; Merck: Consultancy; Bayer: Consultancy, Honoraria, Research Funding; Teva: Consultancy; F. Hoffmann-La Roche Ltd: Consultancy, Honoraria, Research Funding; Juno Therapeutics: Consultancy; Takeda: Consultancy, Honoraria. Hamlin:J&J Pharmaceuticals: Research Funding; Portola Pharmaceutics: Consultancy; Portola: Research Funding; Molecular Templates: Research Funding; Incyte: Research Funding; Celgene: Consultancy; Karyopharm: Consultancy; Juno Therapeutics: Consultancy. Kumar:Kite Pharmaceuticals: Honoraria, Other: Honoraria for Advisory Board; Astra Zeneca: Honoraria, Other: Honoraria for Advisory Board; Celgene: Honoraria, Other: Honoraria for Advisory Board; Seattle Genetics: Research Funding; Pharmacyclics: Research Funding; Celgene: Research Funding; Adaptive Biotechnologies,: Research Funding; AbbVie: Research Funding. Moskowitz:Seattle Genetics: Consultancy; Miragen Therapeutics: Consultancy; Imbrium Therapeutics, L.P.: Consultancy; Merck: Research Funding; Bristol-Myers Squibb: Research Funding; Incyte: Research Funding; Seattle Genetics: Research Funding; Merck: Consultancy. Falchi:Genmab: Research Funding; Roche: Research Funding. von Keudell:Merck: Consultancy, Honoraria. Straus:Targeted Oncology: Consultancy, Speakers Bureau; Seattle Genetics: Consultancy, Membership on an entity's Board of Directors or advisory committees; ASH: Other: Conference in December 2019 on HL to other physicians during ASH; Elsevier: Membership on an entity's Board of Directors or advisory committees, Other: CME writer; OncLive: Speakers Bureau; Takeda Pharmaceuticals: Research Funding, Speakers Bureau; NY Lymphoma Rounds: Consultancy; Imedex, Inc.: Speakers Bureau; Karyopharm Therapeutics: Membership on an entity's Board of Directors or advisory committees. Horwitz:Aileron: Consultancy, Research Funding; ADCT Therapeutics: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Forty Seven: Consultancy, Research Funding; Infinity/Verastem: Research Funding; Kyowa Hakka Kirin: Consultancy, Research Funding; Millenium/Takeda: Consultancy, Research Funding; Seattle Genetics: Consultancy, Research Funding; Trillium: Consultancy, Research Funding; Corvus: Consultancy; Innate Pharma: Consultancy; Mundipharma: Consultancy; Portola: Consultancy, Research Funding; Beigene: Consultancy; C4 Therapeutics: Consultancy; Daiichi Sankyo: Research Funding; GlaxoSmithKline: Consultancy; Janssen: Consultancy; Kura Oncology: Consultancy; Miragen: Consultancy; Myeloid Therapeutics: Consultancy; Verastem: Consultancy, Research Funding; Vividion Therapeutics: Consultancy; Affirmed: Consultancy; ASTEX: Consultancy. Dogan:Takeda: Consultancy; Roche: Consultancy, Research Funding; Physicians Education Resource: Consultancy; Corvus Pharmaceuticals: Consultancy; Seattle Genetics: Consultancy; EUSA Pharma: Consultancy; AbbVie: Consultancy; National Cancer Institute: Research Funding. Zelenetz:BeiGene: Membership on an entity's Board of Directors or advisory committees; Adaptive Biotechnology: Consultancy; Novartis: Consultancy; Amgen: Consultancy; Janssen: Consultancy; Celgene: Consultancy; Gilead: Consultancy; Genentech/Roche: Consultancy; Gilead: Research Funding; Roche: Research Funding; Celgene: Research Funding; Sandoz: Research Funding; MorphoSys: Research Funding; MEI Pharma: Research Funding.

Introduction: Interleukin-1 receptor-associated kinase 4 (IRAK4) is essential for toll-like receptor (TLR) and interleukin-1 receptor (IL-1R) signaling in immune cells including B lymphocytes. It forms the Myddosome complex with the MYD88 adaptor protein, with IRAK4 being essential for downstream signaling, maximal activation of NFkB with inflammatory and immune response and tumor promotion [Treon 2012; Rhyasen 2015]. CA-4948 is a novel small molecule, oral inhibitor of IRAK4, first-in-class and only suppressor of the TLR pathway currently tested in hematological malignancies. When combined with the BTK inhibitor ibrutinib that blocks parallel BCR signaling and NF-kB activating pathway, it has shown synergy in in-vivo B-cell NHL models, providing strong rationale for clinical evaluation [Booher 2018]. Recent preclinical studies demonstrated the role of IRAK4 activation as a driver of secondary, adaptive tumor resistance and survival mechanisms of hematological and solid tumor malignancies [Melgar 2019] that could be blocked by CA-4948 to delay or reverse resistance. Study Design and Methods: This is a multicenter, open-label trial of oral CA-4948 combined with ibrutinib in adult patients with relapsed or refractory hematologic malignancies. (NCT03328078). It has 2 parts: a dose escalation (Part A2), and expansion basket of 4 cohorts (Part B). Part A2: Is a truncated 3+3 design: CA-4948 starting is 200 mg BID with subsequent escalation to 300 mg BID. Both dose are safe and active against NHL as seen in the nearly completed monotherapy Part A1 of this trial Patients will receive CA-4948 with ibrutinib at the labeled dose for the respective NHL subtype (560 mg or 420 mg) until toxicity or progression. Primary objectives are safety/tolerance (MTD, RP2D); 2nd objectives are pharmacokinetics and preliminary efficacy; exploratory objectives include biomarker correlations (e.g., MYD88-L265P mut, IRAK4 pathway, NFκB inhibition). Part B basket has four cohorts: 1 -MZL, 2 - ABC-DLBCL, 3 - PCNSL, and 4 - NHL with adaptive ibrutinib resistance. Cohorts 1-3 must be BTK-inhibitor naïve. Cohort 4 includes ibrutinib treated NHLs after developing adaptive, secondary resistance. All will receive the combination of ibrutinib and CA-4948. Cohort 4 patients will be allowed a Samples sizes, statistical considerations: Approx. 18 patients in Part A2. In Part B, a Simon 2-Step design will be applied to each cohort. Early stopping rule for futility after approx. 20 patients in Stage 1: full accrual with Stage 2 will add about 25 patients. Successful signal efficacy identification in a cohort may support further expansion or a subsequent controlled trial. The safety population will include all patients in the study who received any test dose. The efficacy population will have a valid baseline and post-baseline disease assessment. Safety assessments include TEAEs, safety labs, vitals, physical exams, PK, and ECGs; efficacy assessments: tumor imaging, para-protein determination, and histo/cyto-morphologic examinations. Part A2 inclusion: Histopathologically confirmed B-cell NHL as per the WHO 2016 classification. Eligible NHL subtypes: FL, MZL, MCL, DLBCL (including extranodal lymphomas of leg, testicle, or other sites, excluding mediastinal lymphoma), CLL/SLL, primary or secondary CNS lymphoma, and WM/LPL. Patients with FL, MCL, MZL, WM/LPL, or CLL/SLL should meet clinical treatment criteria. Part B inclusion: Cohorts 1-3 include patients with MZL, ABC-DLBCL, or PCNSL who are BTK-inhibitor naïve. Cohort 4 will include ibrutinib pre-treated MCL, MZL, CLL/SLL, WM/LPL, ABC-DLBCL, or PCNSL with adaptive resistance. Exclusions for both Parts A2 and B: Significant acute or chronic toxicity from prior anti-cancer therapy that has not resolved to Grade ≤ 1, as determined by NCI CTCAE v 4.03 within 7 days prior to start of study or serious co-morbidities. Disclosures Nowakowski: NanoString: Research Funding; Seattle Genetics: Consultancy; Curis: Consultancy; Kymera: Consultancy; Kite: Consultancy; Celgene/BMS: Consultancy, Research Funding; MorphoSys: Consultancy, Research Funding; Ryvu: Consultancy, Membership on an entity's Board of Directors or advisory committees. Leslie:TG Therapeutics: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene/BMS: Speakers Bureau; Seattle Genetics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; KitePharma: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; BeiGene: Speakers Bureau; Pharmacyclics/Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; AstraZeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Epizyme: Speakers Bureau; Karyopharm: Speakers Bureau; Bayer: Consultancy, Membership on an entity's Board of Directors or advisory committees; ADC therapeutics: Consultancy, Membership on an entity's Board of Directors or advisory committees; AbbVie: Consultancy, Membership on an entity's Board of Directors or advisory committees. Joffe:AstraZeneca: Membership on an entity's Board of Directors or advisory committees; Epizyme: Membership on an entity's Board of Directors or advisory committees. Lunning:Kite: Consultancy, Honoraria; Novartis: Consultancy, Honoraria; TG Therapeutics: Research Funding; Verastem: Consultancy, Honoraria; Acrotech: Consultancy; ADC Therapeutics: Consultancy; Legend: Consultancy; Janssen: Consultancy, Honoraria; Karyopharm: Consultancy, Honoraria; Curis: Research Funding; Gilead: Consultancy, Honoraria; Beigene: Consultancy, Honoraria; Aeratech: Consultancy, Honoraria; Bristol Meyers Squibb: Consultancy, Honoraria, Research Funding; AstraZeneca: Consultancy, Honoraria. Patel:Adaptive Biotechnologies: Consultancy; Kite: Consultancy; BeiGene: Consultancy; AstraZeneca: Consultancy, Research Funding, Speakers Bureau; Pharmacyclics: Consultancy, Speakers Bureau; Celgene/BMS: Consultancy, Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy, Speakers Bureau; Genentech: Consultancy, Speakers Bureau. Landsburg:Takeda: Research Funding; Triphase: Research Funding; Seattle Genetics: Speakers Bureau; Morphosys: Membership on an entity's Board of Directors or advisory committees; Karyopharm: Membership on an entity's Board of Directors or advisory committees; Curis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees. Fenske:Medical College of Wisconsin: Current Employment. Ramchandren:Merck, Seattle Genetics, Janssen, Genentech: Research Funding; Seattle Genetics, Sandoz-Novartis, Pharmacyclics, an AbbVie Company, Janssen, Bristol-Myers Squibb: Consultancy. Skarbnik:Alexion: Consultancy; Beigene: Speakers Bureau; Verastem: Speakers Bureau; CLL Society: Membership on an entity's Board of Directors or advisory committees; AstraZeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Gilead: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Seattle Genetics: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Speakers Bureau; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Kite Pharma: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Jazz Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Pharmacyclics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Tun:Bristol-Myers Squibb: Research Funding; Celgene: Research Funding; Mundipharma: Research Funding; Curis: Research Funding; TG Therapeutics: Research Funding; Acrotech: Research Funding; DTRM Biopharma: Research Funding.

Nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) is a rare subtype of lymphoma that, like other Hodgkin lymphomas, has historically been treated aggressively. However, in most cases, NLPHL has an indolent course, which raises the question of to what extent these patients require aggressive upfront treatment. We describe the management and outcomes of consecutive NLPHL patients diagnosed at Memorial Sloan Kettering Cancer Center (MSK), with a focus on evaluating active surveillance. All patients aged 16 years or older diagnosed and followed at MSK between 1974 and 2016 were included. Treatment outcomes were compared between management with active surveillance and other strategies. We identified 163 consecutive patients who were treated with radiotherapy alone (46%), active surveillance (23%), chemotherapy (16%), combined modality (12%), or rituximab monotherapy (4%). Median follow-up was 69 months. Five-year progression-free survival (PFS), second PFS (PFS2), and overall survival (OS) estimates were 85% (95% confidence interval [CI], 78-90), 97% (95% CI, 92-99), and 99% (95% CI, 95-100), respectively. Only 1 of 7 deaths was lymphoma related. Patients managed with active surveillance had slightly shorter PFS than those receiving any active treatment, with 5-year PFS of 77% (95% CI, 56-89) vs 87% (95% CI, 79-92; P = .017). This difference did not translate into better PFS2 or OS. Only 10 patients managed with active surveillance (27%) eventually required treatment, after a median of 61 months, and none died. NLPHL has an excellent prognosis. Within the limitations of a retrospective analysis, active surveillance is a viable initial management strategy for selected NLPHL patients.

Multiple myeloma (MM) is a multi–subclonal malignancy with relatively high heterogeneity. Patients who initially presented with both monoclonal-protein (MP) and free light chain (FLC) secretion but then relapsed with a light chain escape pattern have been shown to reflect disease clonal evolution and to bare a worse prognosis. We hypothesized that a discordant MP/FLC pattern at diagnosis may reflect a similar clonal evolution that had occurred prior to diagnosis of active myeloma, conferring a worse outcome. We analyzed 255 consecutive newly diagnosed MM patients who received first line bortezomib-based therapy between 2007 and 2014, hypothesizing that their MP/FLC fingerprint at diagnosis reflects clonal heterogeneity and, therefore, affects outcome. An involved FLC level ≥ 700 mg/L and MP ≥ 2.5 g/L were used as cutoffs for low vs high FLC and MP levels, respectively. Patients were divided into 4 subgroups according to their involved FLC and MP blood levels at diagnosis: HiLC and HiMP for patients with either a predominant FLC or a predominant MP, respectively, and HiLC-MP and LoLC-MP when both FLC and MP were increased or decreased, respectively. There were 68 (27%) patients with HiLC, which presented more often with International Staging System-3 stage (P

e20017 Background: FDG avidity above liver on interim PET (PET2) during frontline ABVD is considered a marker of impending treatment failure and an indication to switch to an intensified regimen. However, in clinical practice the utility of PET2 for treatment decisions is less clear. We describe outcomes of patients with positive PET2 who continued treatment with ABVD in the clinical setting. Methods: A retrospective study of all patients with newly diagnosed advanced-stage Hodgkin lymphoma treated with frontline ABVD at Memorial Sloan Kettering Cancer Center between 2008-2017. Eligibility criteria were set to correspond with the RATHL inclusion criteria (stage IIB - IV, or IIA bulky or ≥ 3 involved sites). We identified all PET2 reports indicating suspected residual uptake. All positive PET2 images were then reviewed by a single study radiologist. To increase reproducibility and avoid selection of borderline cases, we defined as PET2 positive only those cases with a lesion-to-liver (mean) SUV ratio ≥ 1.3. We also used a recently published stringent criterion of lesion-to-liver (max) ratio ≥ 1.4 (mPET2+). Progression-free and overall survival (PFS, OS) were calculated from the date of initial treatment until progression or death of any cause. Consolidative radiation was not considered a PFS event, and all progressions were verified by biopsy. Results: We identified 227 patients fitting RATHL inclusion criteria treated with ABVD. Median age was 34, with 25% (58) ≥ 45 years, 12% (26) had an IPS ≥ 4; 28% (64) stage II (5% II-X) and 38% (87) with extranodal involvement. 57 (25%) patients had a PET2 report indicating suspected residual lymphoma (PET2+), however, only 32 (14%) met the more stringent mPET2+ criterion. Most patients with PET2+ continued ABVD (84%, 48), and 9 switched to escBEACOPP (this subset of patients had substantially worse disease and are not the focus of this analysis). 21 (9%) patients received consolidative radiation. With a median follow-up of 47 months (42-54m), PET2+ patients who continued ABVD had a 3yPFS of 70% (58-85%, n = 48); mPET+ had a 3yPFS of 71% (55-92%, n = 24). Overall survival was excellent regardless of PET2 status (5yOS 97%). Conclusions: The outcome of PET2+ patients in this analysis was better than previously reported and the continuation of ABVD was appropriate for most patients. Use of a confirmatory biopsy is important for identifying true progressions. Patients with PET2+ had an excellent OS. Evaluation of the superiority of alternative regimens in PET2+ patients requires an ABVD comparator arm.

8006 Background: Venetoclax (Ven)-Obinutuzumab (O) is approved for chronic lymphocytic leukemia (CLL) achieving frequent undetectable minimum residual disease (uMRD; Fischer NEJM 2019). Ven-Ibrutinib is synergistic with frequent uMRD but with grade >3 neutropenia in 33-48% patients (pts; Tam ASH 2019; Jain NEJM 2019). Zanubrutinib (B) is a highly specific BTK inhibitor that demonstrated 100% occupancy in lymphoid tissues, so may be preferred to combine with OVen. We hypothesize that treatment (tx) with BOVen using an MRD driven discontinuation strategy will achieve frequent uMRD and durable responses. Methods: In this multicenter, investigator initiated phase 2 trial (NCT03824483), eligible pts had previously untreated CLL requiring tx per iwCLL, ECOG PS 1, PLT >75 (ANC >0, PLT >20 if due to CLL). BOVen was administered in 28D cycles: B 160 mg PO BID starting D1; O 1000 mg IV D1 or split D1-2, 8, 15 of C1, D1 of C2-8; Ven ramp up initiated C3D1 (target 400 mg QD). Tx duration was determined by a prespecified uMRD endpoint (min 8 cycles). MRD was assessed in peripheral blood (PB; flow cytometry, sensitivity >10−4) starting C7D1 then every 2 cycles. Once PB uMRD was determined and confirmed in bone marrow (BM), tx continued 2 additional cycles. Adverse events (AE) were assessed per CTCAE v5. Median (med) time to uMRD (primary endpoint) was estimated using the Kaplan-Meier method. Results: The study accrued 39 pts (3-10/19): med age 59 years (23-73), 3:1 male, CLL IPI >4 26/39 (67%), unmutated IGHV 28/39 (72%), 17p del/ TP53 mutated 4/39 (10%), all pts were evaluable for toxicity with 37 evaluable for efficacy. At a med follow up of 8 months (mo; 3-10), 25/37 (68%) pts achieved PB uMRD. Med time to PB uMRD is 6 mo (4-8+). Another 8/37 (22%) had PB MRD < 0.1%. Of 25 with PB uMRD, 19 had BM uMRD with 10/19 completing 2 additional cycles and discontinued; 3 had BM MRD (all

The risk of developing non-Hodgkin lymphoma increases with age, yet elderly patients are under-represented in clinical trials. Here, we evaluate a combination regimen including ifosfamide, carboplatin and etoposide with or without rituximab (ICE ± R) in 32 fit elderly patients (median age 75.6 years) with relapsed or refractory diffuse large B-cell lymphoma. ICE ± R was generally administered in reduced doses and was well tolerated. The overall response rate (ORR) was 53.1% with a complete response (CR) rate of 40.6%. The median progression free survival (PFS) and overall survival (OS) were 3.9 and 17.0 months, respectively. Patients who responded to ICE ± R achieved median PFS of 47.2 months and OS of 78.9 months. Patients ineligible for autologous transplantation who responded to ICE ± R were treated with additional cycles, and achieved a median PFS of 18.9 months and OS of 21.7 months. Previous response to first-line therapy was the strongest predictor of response, PFS and OS to second-line treatment.

This study aimed to evaluate the efficacy and safety of the fludarabine-cyclophosphamide-rituximab regimen for young physically fit patients with chronic lymphocytic leukemia in the "real-life" setting. We specifically focused on the impact of dose reduction on patient outcomes. The patient cohort consisted of 128 patients with chronic lymphocytic leukemia (≤ 70 years) treated at 10 Israeli centers with front-line fludarabine-cyclophosphamide-rituximab. We defined reduced chemotherapy as two-thirds or less of the total indicated dose. Patients treated with rituximab were divided into two groups and compared: those who received full dosages of 375 mg/m(2) or 500 mg/m(2), and patients given less than six cycles with either dose. Overall and clinical complete response rates (92.8% and 70.4%), as well as toxicities and overall survival (median not reached at 6 years), were similar to other reported clinical trials, but progression-free survival was shorter (42.5 months). Almost 50% of patients had some dose reduction of chemotherapy, 21% receiving less than two-thirds of the indicated dose, while close to 30% did not complete six cycles of rituximab. Reduced doses of chemotherapy and rituximab were independently associated with shorter progression-free survival (hazard ratio 3.6, P0.0001 for reduced chemotherapy; hazard ratio 2.5, P=0.003 for incomplete-treatment with rituximab). Achieving a complete response was associated with longer overall survival but was not linked to the given dose of chemoimmunotherapy. In younger physically fit patients, front-line fludarabine-cyclophosphamide-rituximab therapy in the "real-life" setting achieves long remissions (albeit shorter than in clinical trials) and prolonged overall survival. However, dose reductions are commonly administered and may impact outcome.

Little is known about the prognosis associated with statin therapy and its gender differences in older adults aged ≥80 years. To study the mortality and survival associated with statin therapy and their gender differences in older adults aged ≥80 years. This was a historical prospective study conducted at a tertiary medical center. The medical charts of all older adults aged ≥80 years who had been admitted to a single internal medicine department during 1 year were reviewed. All-cause 3‑year mortality and survival rates following hospital admission in men and in women using statins were investigated. The final cohort included 216 patients: 122 (56.5%) women, mean age 85.3 ± 3.9 years. Overall, 66 (53.2%) women and 58 (46.8%) men used statins for 3 years or more following hospital admission. During this time 48 (39.3%) women and 48 (51.1%) men died. The all-cause 3‑year mortality rates were significantly lower only in women who had used statins compared with women who had not used statins (24.2% vs. 57.1%; relative risk = 0.2; 95% confidence interval 0.1–0.5; p < 0.0001). The 3‑year cumulative survival rates were significantly higher in women who had used statins as part of primary as well as secondary cardiovascular prevention (p < 0.0001 and p = 0.014, respectively). A Cox regression analysis showed that statin therapy was independently associated with low 3‑year cumulative mortality rates in women (hazard ratio=0.3; 95% confidence interval=0.1–0.6; p = 0.001). In older adults aged ≥80 years, statin therapy is associated with high 3‑year cumulative survival rates only in women.

Recurrent hospitalizations with hyponatremia are commonly encountered in older adults admitted to Internal Medicine wards. However, the incidence and the prognostic implication of this phenomenon have never been studied.Medical charts of all older adults (≥75 years) admitted to Internal Medicine wards at a tertiary medical center during 2009-2010 with symptomatic moderate to severe hyponatremia (blood sodium ≤130 meq/l) upon admission were reviewed. The study group included patients with one or more hospitalizations with hyponatremia in the year following the first hospitalization with hyponatremia. The control group included patients with a single hospitalization with hyponatremia. Mortality rates were studied one year following the second hospitalization with hyponatremia in the study group and one year following the single hospitalization with hyponatremia in the control group. Regression analysis was used to study the association between recurrent hospitalizations with hyponatremia and 1-year mortality while controlling for demographics, chronic co-morbidities, albumin serum levels, and the number of hospitalizations.The cohort included 431 older adults: 301 (69.8%) women; mean age of 84.6±5.6 years. Overall, 120 (27.8%) patients had recurrent hospitalizations with hyponatremia and 125 (29.0%) patients died within a year. 1-Year mortality rates were higher in patients with recurrent hospitalizations with hyponatremia than in patients with a single hospitalization with hyponatremia (42.5% vs. 23.8%; p0.0001). Regression analysis showed that recurrent hospitalizations with hyponatremia were independently associated with 1-year mortality (odds ratio 1.9; 95% confidence interval 1.1-3.2; p=0.018).Recurrent hospitalizations with hyponatremia in older adults are common and associated with 1-year mortality.

Introduction: Gemcitabine/oxaliplatin (GemOx), with or without rituximab, is a frequently used treatment of relapsed or refractory (r/r) aggressive B-cell non-Hodgkin lymphoma (B-NHL), and is NCCN compendium-listed for both transplant-eligible and ineligible patients based upon results in small phase II clinical trials. Increasingly, GemOx is being accepted as a comparator arm for clinical trials in these populations. However, there is a paucity of observational data describing the effectiveness of R-GemOx in the treatment of r/r aggressive B-cell lymphoma. Methods: We conducted a retrospective analysis of the use of the GemOx regimen (with or without rituximab) in patients with r/r aggressive B-NHL at Memorial Sloan Kettering Cancer Center between January 2007 and January 2018, with a data cutoff of July 1, 2019. Data were extracted from the electronic medical record. Eligible diagnoses included diffuse large B-cell lymphoma and its subtypes (DLBCL); high-grade B-cell lymphomas (HGBL); transformed indolent B-cell lymphoma (tNHL) and grade 3B follicular lymphoma (FL3B). The primary objective of the study was to evaluate the activity of GemOx-based treatment in this patient population, as measured by overall response rate (ORR), complete response (CR) rate, progression-free survival (PFS), and overall survival (OS). CR was defined by a qualitatively negative 18-FDG-PET scan following completion of GemOx. PFS was defined as the time from start of therapy to disease progression or death, censoring patients at the time of initiation of any consolidative treatment. Similarly, OS was defined as the time from the start of GemOx until death or loss to follow-up. Results: Data were collected for 140 consecutive patients that received GemOx with (n=81) or without (n=59) rituximab in the treatment of a qualifying diagnosis (Table 1). Those treated had a median age at initiation of therapy of 69 (range, 30-92) and were predominantly male (58%). The median number of prior lines of therapy was 1 (range, 1-7), and the majority (97%) had received prior rituximab; few had received either prior autotransplant (11%) or allotransplant (1%). Regarding treatment delivered, the median number of cycles of therapy was 2 (range 1-12) with a mode of 2 (n=44, 31%). The ORR was 26% (n=37) with a CR rate of 15% (n=21). When evaluated by diagnosis, the ORR was 22% (n=19/88) in DLBCL, 40% (n=4/10) in HGBL, 35% (n=14/40) in tNHL, and 0% (n=0/2) in FL3B. Of the patients that responded to GemOx, 11 were successfully bridged to transplant (7 auto; 4 allo); two of those who went on to allotransplant had previously undergone autotransplant. Additionally, 3 patients went on to subsequently receive CAR-T therapy. Assessing the cohort overall, with a median follow-up of 48.1 months, PFS was only 1.4 months (95% CI: 1.3, 1.8), and median OS was 7.8 months (95% CI: 5.5, 12.0) (Figure 1). OS was longest for patients with tNHL at 10.2 months followed by DLBCL (7.5), HGBL (6.8) and FL3B (4.1) (Figure 2). Patients that received GemOx without rituximab in the setting of rituximab-refractory disease had a median OS of 4.1 months, less than that of 10.7 months for those receiving rituximab (p=0.052). However, there was no difference observed in PFS by inclusion of rituximab (1.6 months vs. 1.3 months, p=0.166). Patients with disease that was primary refractory following first-line therapy had a median OS of 4.5 months from initiation of GemOx, less than that of 10.8 months for patients that had achieved complete remission with first-line therapy (p=0.024). Patients that received GemOx as second-line therapy did not have a statistically significantly higher ORR (31% vs. 19%), OS (10.8 vs. 6.0 months), or PFS (1.7 vs, 1.4 months; all p=NS). In the subset of patients with DLBCL, there was again no significant difference in ORR (21% vs. 22%, p=NS), OS (8.5 vs. 6.1 months), or PFS (1.6 vs. 1.4 months; all p=NS). Conclusion: Despite compendium listing for both transplant-eligible and ineligible patients, and despite its adoption as a comparator arm in current and planned trials in r/r DLBCL, the real-world activity of GemOx with or without rituximab in the treatment of relapsed or refractory aggressive B-cell lymphoma is poor. Ongoing analysis is being conducted to seek clinical and histopathologic features associated with improved outcomes with GemOx. Disclosures Batlevi: Juno Therapeutics: Consultancy, Membership on an entity's Board of Directors or advisory committees. Colbourn:GILD: Other: Stock; LLY: Other: Stock; JNJ: Other: Stock; SGEN: Other: Stock; MRK: Other: Stock; SNY: Other: Stock; BIIB: Other: Stock; ABBV: Other: Stock; CELG: Other: Stock. Horwitz:Infinity/Verastem: Consultancy, Research Funding; Trillium: Research Funding; Infinity/Verastem: Consultancy, Research Funding; Kyowa Hakko Kirin: Consultancy; Corvus Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Millennium/Takeda: Consultancy, Research Funding; Mundipharma: Consultancy; Portola: Consultancy; Celgene: Consultancy, Research Funding; Portola: Consultancy; Innate Pharma: Consultancy; Seattle Genetics: Consultancy, Research Funding; Infinity/Verastem: Consultancy, Research Funding; Seattle Genetics: Consultancy, Research Funding; Kura: Consultancy; Aileron: Research Funding; Corvus Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Corvus Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Forty-Seven: Research Funding; Celgene: Consultancy, Research Funding; ADCT Therapeutics: Research Funding; Kyowa Hakko Kirin: Consultancy; ADCT Therapeutics: Research Funding; Astex: Consultancy; Mundipharma: Consultancy; Miragen: Consultancy; Portola: Consultancy; Mundipharma: Consultancy; Seattle Genetics: Consultancy, Research Funding; Innate Pharma: Consultancy; Innate Pharma: Consultancy; Affimed: Consultancy; Affimed: Consultancy; Innate Pharma: Consultancy; Aileron: Research Funding; Kyowa Hakko Kirin: Consultancy; Forty-Seven: Research Funding; Kura: Consultancy; Millennium/Takeda: Consultancy, Research Funding; Forty-Seven: Research Funding; ADCT Therapeutics: Research Funding; Seattle Genetics: Consultancy, Research Funding; Astex: Consultancy; Aileron: Research Funding; Portola: Consultancy; Astex: Consultancy; Celgene: Consultancy, Research Funding; Trillium: Research Funding; Miragen: Consultancy; Trillium: Research Funding; Kyowa Hakko Kirin: Consultancy; Mundipharma: Consultancy; Millennium/Takeda: Consultancy, Research Funding; Trillium: Research Funding; Aileron: Research Funding; Affimed: Consultancy; Corvus Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Millennium/Takeda: Consultancy, Research Funding; Astex: Consultancy; Miragen: Consultancy; Miragen: Consultancy; Affimed: Consultancy; Celgene: Consultancy, Research Funding; Kura: Consultancy; Kura: Consultancy; ADCT Therapeutics: Research Funding; Forty-Seven: Research Funding; Infinity/Verastem: Consultancy, Research Funding. von Keudell:Bayer: Consultancy; Genentech: Consultancy; Pharmacyclics: Consultancy; Pharmacyclics: Consultancy; Bayer: Consultancy; Genentech: Consultancy. Kumar:Seattle Genetics: Research Funding. Noy:Medscape: Honoraria; Prime Oncology: Honoraria; NIH: Research Funding; Janssen: Consultancy; Pharamcyclics: Research Funding; Raphael Pharma: Research Funding. Palomba:Merck & Co Inc.: Other: Immediate Family Member, Consultancy (includes expert testimony); Seres Therapeutics: Other: Immediate Family Member, Equity Ownership and Membership on an entity's Board of Directors or advisory committees; Hemedicus: Other: Immediate Family Member, Speakers Bureau ; Kite Pharmaceuticals: Other: Immediate Family Member, Membership on an entity's Board of Directors or advisory committees; Pharmacyclics: Membership on an entity's Board of Directors or advisory committees; STRAXIMM: Other: Immediate Family Member, Membership on an entity's Board of Directors or advisory committees; Noble Insights: Consultancy; Evelo: Other: Immediate family member, Equity Ownership; MSK (IP for Juno and Seres): Other: Immediate Family Member, Patents & Royalties - describe: intellectual property rights . Rodriguez-Rivera:Memorial Sloan Kettering Cancer Center: Employment. Sauter:Juno Therapeutics: Consultancy, Research Funding; Sanofi-Genzyme: Consultancy, Research Funding; Spectrum Pharmaceuticals: Consultancy; GSK: Consultancy; Novartis: Consultancy; Genmab: Consultancy; Precision Biosciences: Consultancy; Kite/Gilead: Consultancy; Celgene: Consultancy. Straus:Seattle Genetics: Consultancy, Honoraria; Hope Funds for Cancer Research: Membership on an entity's Board of Directors or advisory committees; Elsevier (PracticeUpdate): Consultancy, Honoraria. Vardhana:ADC Therapeutics: Consultancy; Rheos Pharmaceuticals: Honoraria; Agios Pharmaceuticals: Honoraria. Younes:Roche: Consultancy, Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Curis: Honoraria, Research Funding; Merck: Honoraria, Research Funding; Abbvie: Honoraria; Takeda: Honoraria; Pharmacyclics: Research Funding; AstraZeneca: Research Funding; Genentech: Research Funding; Biopath: Consultancy; Xynomics: Consultancy; Epizyme: Consultancy, Honoraria; Celgene: Consultancy, Honoraria; HCM: Consultancy; BMS: Research Funding; Syndax: Research Funding. Zelenetz:Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Beigene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Genentech/Roche: Consultancy, Membership on an entity's Board of Directors or advisory committees; Bayer: Consultancy, Membership on an entity's Board of Directors or advisory committees; MEI Pharma: Consultancy, Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Astra-Zeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; Gilead: Consultancy, Membership on an entity's Board of Directors or advisory committees; DAVA Oncology: Consultancy, Membership on an entity's Board of Directors or advisory committees; Verastem: Consultancy, Membership on an entity's Board of Directors or advisory committees; Gilead: Consultancy, Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Karyopharm: Consultancy, Membership on an entity's Board of Directors or advisory committees; DAVA Oncology: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees; Karyopharm: Consultancy, Membership on an entity's Board of Directors or advisory committees; Genentech/Roche: Consultancy, Membership on an entity's Board of Directors or advisory committees; Morphosys: Consultancy, Membership on an entity's Board of Directors or advisory committees; Bayer: Consultancy, Membership on an entity's Board of Directors or advisory committees; Beigene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Astra-Zeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees; Pharmacyclics/AbbVie: Consultancy, Membership on an entity's Board of Directors or advisory committees; Morphosys: Consultancy, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; Pharmacyclics/AbbVie: Consultancy, Membership on an entity's Board of Directors or advisory committees; Verastem: Consultancy, Membership on an entity's Board of Directors or advisory committees; MEI Pharma: Consultancy, Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees. Matasar:GlaxoSmithKline: Honoraria, Research Funding; Daiichi Sankyo: Consultancy; Juno Therapeutics: Consultancy; Teva: Consultancy; Rocket Medical: Consultancy, Research Funding; Seattle Genetics: Consultancy, Honoraria, Other: Travel, accomodation, expenses, Research Funding; Janssen: Honoraria, Research Funding; Bayer: Other: Travel, accommodation, expenses; Genentech, Inc.: Consultancy, Honoraria, Other: Travel, accommodation, expenses , Research Funding; Bayer: Consultancy, Honoraria, Other; Roche: Consultancy, Honoraria, Other: Travel, accommodation, expenses , Research Funding; Merck: Consultancy, Equity Ownership; Pharmacyclics: Consultancy, Honoraria, Research Funding.

Introduction: Central nervous system (CNS) relapse in patients with diffuse large B-cell lymphoma (DLBCL) is an uncommon yet often fatal complication with an overall survival (OS) of less than 6 months. According to the clinical risk model CNS-IPI, patients with 4-6 risk factors have a 2-year rate of CNS relapse of 10%. Involvement of certain extranodal sites such as testes or breast also confers increased risk, even with low-CNS-IPI. In high-risk patients, CNS prophylaxis is usually recommended, although the optimal regimen remains unclear. In this study, we examined the efficacy of different regimens on preventing CNS relapse in high-risk patients. Methods: We reviewed all newly diagnosed patients (pts) with DLBCL at Memorial Sloan Kettering Cancer Center from 2001 to 2017 treated with frontline rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone (RCHOP) or RCHOP-like regimens. Patients with primary mediastinal lymphoma, HIV-positive or known CNS disease at diagnosis were excluded. High risk for CNS (HR-CNS) relapse was defined by high-CNS IPI (4-6 risk factors) or low-CNS IPI with testicular, breast, kidney/adrenal and/or bone marrow (BM) involvement. CNS prophylaxis was administered per physician preference. Results: We identified 2002 pts treated with RCHOP or RCHOP-like regimens. Among them, 569 (28%) were classified as HR-CNS relapse and were included in the study. Median age was 68 years (range 21-91) and 290 (51%) were male. The high-risk extranodal sites were: BM, n=118 (20%); kidney/adrenal, n=106 (18%); testes, n=51 (9%) and breast, n=47 (8%). 158 pts (28%) had more than 2 extranodal sites. Cell or origin determined by Hans algorithm was non-germinal center (GCB) (non-GCB) in 40%, GCB in 39% and missing in 21%. 284 pts (50%) received CNS prophylaxis: intrathecal (IT) methotrexate (MTX) and/or IT cytarabine, n= 245 (86%); or high-dose intravenous MTX (HD-MTX), n=40 (14%). Pts's characteristics are shown in Table 1. After a median follow-up of 5.6 years, CNS relapse was observed in 36 out of 569 pts with HR-CNS relapse (5-year risk 6.4%), of whom 14 (39%) had received prophylaxis (IT, n=12; HD-MTX, n=2). The risk of CNS relapse at 5 years in pts who received IT prophylaxis was 5.6% compared with 5.2% in pts who received intravenous HD-MTX. Pts with HR-CNS relapse who did not receive prophylaxis had a 5-year risk for CNS relapse of 7.6% (p=0.34) (Figure 1). Pts with non-GCB phenotype had a higher risk of CNS relapse compared with patients with GCB subtype (5-year risk of 10% vs. 2%) (p=0.03). The median time to CNS relapse was 9 months (range 6-110 months). Pts who received prophylaxis, (either IT or HD-MTX), relapsed later than patients who did not receive prophylaxis, with a median time to relapse of 19 months (range 7-55) vs. 8 months (range 6 to 110), respectively. The risk of CNS relapse at 1 year was lower for pts who received prophylaxis (IT or HD-MTX) compared to pts who did not, 1% vs. 3.2%, risk ratio (RR) 0.30 (95% CI; 0.07,0.68). However, over time the risk of CNS relapse became similar between prophylaxis and non-prophylaxis groups, with a 5-year risk of 5.8% vs. 7.6% (RR 0.76, CI 95%; 0.37, 1.55), respectively (Figure 2). CNS relapses were confined to the CNS (n=26, 72%) or included systemic relapsed in addition to CNS (n=10, 28%). CNS sites of relapse are detailed in table 2. Overall survival (OS) in patients with CNS relapse was worse than in pts who relapsed outside the CNS, with a 2-year OS of 24% (95% CI, 12%-40%) vs. 40% (95% CI, 31%-48%), respectively (p=0.002). Conclusion: In the era of chemoimmunochemotherapy, CNS prophylaxis tended to delay relapse rather than effectively preventing it. Although we did not detect differences in the efficacy between intrathecal and intravenous HD-MTX, larger studies are needed to better compare the efficacy of these two preventive modalities. Disclosures Noy: Medscape: Honoraria; Janssen: Consultancy; Prime Oncology: Honoraria; NIH: Research Funding; Pharamcyclics: Research Funding; Raphael Pharma: Research Funding. Horwitz:Corvus Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Corvus Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Mundipharma: Consultancy; Affimed: Consultancy; ADCT Therapeutics: Research Funding; Astex: Consultancy; Innate Pharma: Consultancy; Seattle Genetics: Consultancy, Research Funding; Miragen: Consultancy; Miragen: Consultancy; Kura: Consultancy; Kura: Consultancy; Innate Pharma: Consultancy; Infinity/Verastem: Consultancy, Research Funding; Trillium: Research Funding; Celgene: Consultancy, Research Funding; Portola: Consultancy; Millennium/Takeda: Consultancy, Research Funding; Millennium/Takeda: Consultancy, Research Funding; Portola: Consultancy; Trillium: Research Funding; Celgene: Consultancy, Research Funding; Astex: Consultancy; Infinity/Verastem: Consultancy, Research Funding; Kura: Consultancy; Miragen: Consultancy; Affimed: Consultancy; Millennium/Takeda: Consultancy, Research Funding; Aileron: Research Funding; Seattle Genetics: Consultancy, Research Funding; Mundipharma: Consultancy; Celgene: Consultancy, Research Funding; Kyowa Hakko Kirin: Consultancy; Seattle Genetics: Consultancy, Research Funding; Innate Pharma: Consultancy; Trillium: Research Funding; Forty-Seven: Research Funding; Aileron: Research Funding; Aileron: Research Funding; Astex: Consultancy; Forty-Seven: Research Funding; Miragen: Consultancy; Infinity/Verastem: Consultancy, Research Funding; Forty-Seven: Research Funding; Infinity/Verastem: Consultancy, Research Funding; Kyowa Hakko Kirin: Consultancy; Mundipharma: Consultancy; Corvus Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Astex: Consultancy; Trillium: Research Funding; Celgene: Consultancy, Research Funding; ADCT Therapeutics: Research Funding; Kura: Consultancy; Millennium/Takeda: Consultancy, Research Funding; Affimed: Consultancy; Portola: Consultancy; Seattle Genetics: Consultancy, Research Funding; Aileron: Research Funding; Forty-Seven: Research Funding; Innate Pharma: Consultancy; Kyowa Hakko Kirin: Consultancy; Portola: Consultancy; Affimed: Consultancy; ADCT Therapeutics: Research Funding; Corvus Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; ADCT Therapeutics: Research Funding; Mundipharma: Consultancy; Kyowa Hakko Kirin: Consultancy. Palomba:Hemedicus: Other: Immediate Family Member, Speakers Bureau ; Merck & Co Inc.: Other: Immediate Family Member, Consultancy (includes expert testimony); Seres Therapeutics: Other: Immediate Family Member, Equity Ownership and Membership on an entity's Board of Directors or advisory committees; STRAXIMM: Other: Immediate Family Member, Membership on an entity's Board of Directors or advisory committees; Kite Pharmaceuticals: Other: Immediate Family Member, Membership on an entity's Board of Directors or advisory committees; Pharmacyclics: Membership on an entity's Board of Directors or advisory committees; Noble Insights: Consultancy; Evelo: Other: Immediate family member, Equity Ownership; MSK (IP for Juno and Seres): Other: Immediate Family Member, Patents & Royalties - describe: intellectual property rights . Matasar:Juno Therapeutics: Consultancy; Merck: Consultancy, Equity Ownership; Genentech, Inc.: Consultancy, Honoraria, Other: Travel, accommodation, expenses , Research Funding; Bayer: Consultancy, Honoraria, Other; Roche: Consultancy, Honoraria, Other: Travel, accommodation, expenses , Research Funding; Bayer: Other: Travel, accommodation, expenses; Janssen: Honoraria, Research Funding; Pharmacyclics: Consultancy, Honoraria, Research Funding; Teva: Consultancy; Rocket Medical: Consultancy, Research Funding; Seattle Genetics: Consultancy, Honoraria, Other: Travel, accomodation, expenses, Research Funding; Daiichi Sankyo: Consultancy; GlaxoSmithKline: Honoraria, Research Funding. Straus:Hope Funds for Cancer Research: Membership on an entity's Board of Directors or advisory committees; Hope Funds for Cancer Research: Membership on an entity's Board of Directors or advisory committees; Elsevier (PracticeUpdate): Consultancy, Honoraria; Seattle Genetics: Consultancy, Honoraria; Hope Funds for Cancer Research: Membership on an entity's Board of Directors or advisory committees. Batlevi:Juno Therapeutics: Consultancy, Membership on an entity's Board of Directors or advisory committees. Moskowitz:Incyte: Research Funding; miRagen Therapeutics Inc: Consultancy, Research Funding; ADC Therapeutics: Consultancy; Seattle Genetics: Consultancy, Honoraria, Research Funding; Kyowa Hakko Kirin Pharma: Consultancy, Research Funding; Seattle Genetics: Consultancy, Honoraria, Research Funding; Merck: Research Funding; Erytech Pharma: Consultancy; ADC Therapeutics: Consultancy; Erytech Pharma: Consultancy; Kyowa Hakko Kirin Pharma: Consultancy, Research Funding; Merck: Research Funding; Incyte: Research Funding; Incyte: Research Funding; Erytech Pharma: Consultancy; miRagen Therapeutics Inc: Consultancy, Research Funding; Merck: Research Funding; Cell Medica: Consultancy; Erytech Pharma: Consultancy; Incyte: Research Funding; Takeda Pharmaceuticals: Consultancy; Cell Medica: Consultancy; Takeda Pharmaceuticals: Consultancy; Bristol-Myers Squibb: Consultancy, Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; Incyte: Research Funding; Cell Medica: Consultancy; Cell Medica: Consultancy; miRagen Therapeutics Inc: Consultancy, Research Funding; Cell Medica: Consultancy; Takeda Pharmaceuticals: Consultancy; Takeda Pharmaceuticals: Consultancy; Incyte: Research Funding; miRagen Therapeutics Inc: Consultancy, Research Funding; Takeda Pharmaceuticals: Consultancy; Kyowa Hakko Kirin Pharma: Consultancy, Research Funding; Takeda Pharmaceuticals: Consultancy; miRagen Therapeutics Inc: Consultancy, Research Funding; Incyte: Research Funding; Takeda Pharmaceuticals: Consultancy; Incyte: Research Funding; ADC Therapeutics: Consultancy; ADC Therapeutics: Consultancy; ADC Therapeutics: Consultancy; Seattle Genetics: Consultancy, Honoraria, Research Funding; Kyowa Hakko Kirin Pharma: Consultancy, Research Funding; Takeda Pharmaceuticals: Consultancy; Seattle Genetics: Consultancy, Honoraria, Research Funding; Cell Medica: Consultancy; Takeda Pharmaceuticals: Consultancy; Seattle Genetics: Consultancy, Honoraria, Research Funding; Seattle Genetics: Consultancy, Honoraria, Research Funding; Kyowa Hakko Kirin Pharma: Consultancy, Research Funding; Kyowa Hakko Kirin Pharma: Consultancy, Research Funding; Seattle Genetics: Consultancy, Honoraria, Research Funding; Merck: Research Funding; Seattle Genetics: Consultancy, Honoraria, Research Funding; Merck: Research Funding; Merck: Research Funding; Merck: Research Funding; Merck: Research Funding; Erytech Pharma: Consultancy; Bristol-Myers Squibb: Consultancy, Research Funding; Merck: Research Funding; miRagen Therapeutics Inc: Consultancy, Research Funding; miRagen Therapeutics Inc: Consultancy, Research Funding; Cell Medica: Consultancy; miRagen Therapeutics Inc: Consultancy, Research Funding; ADC Therapeutics: Consultancy; Bristol-Myers Squibb: Consultancy, Research Funding; Seattle Genetics: Consultancy, Honoraria, Research Funding; Seattle Genetics: Consultancy, Honoraria, Research Funding; Merck: Research Funding; Merck: Research Funding; Cell Medica: Consultancy; Cell Medica: Consultancy; Cell Medica: Consultancy; Incyte: Research Funding; Incyte: Research Funding; ADC Therapeutics: Consultancy; Incyte: Research Funding; ADC Therapeutics: Consultancy; ADC Therapeutics: Consultancy; Bristol-Myers Squibb: Consultancy, Research Funding; Erytech Pharma: Consultancy; miRagen Therapeutics Inc: Consultancy, Research Funding; Erytech Pharma: Consultancy; Cell Medica: Consultancy; Kyowa Hakko Kirin Pharma: Consultancy, Research Funding; miRagen Therapeutics Inc: Consultancy, Research Funding; Seattle Genetics: Consultancy, Honoraria, Research Funding; Takeda Pharmaceuticals: Consultancy; Erytech Pharma: Consultancy; Erytech Pharma: Consultancy; miRagen Therapeutics Inc: Consultancy, Research Funding; Erytech Pharma: Consultancy; ADC Therapeutics: Consultancy; Cell Medica: Consultancy; ADC Therapeutics: Consultancy; Erytech Pharma: Consultancy; miRagen Therapeutics Inc: Consultancy, Research Funding; miRagen Therapeutics Inc: Consultancy, Research Funding; Seattle Genetics: Consultancy, Honoraria, Research Funding; ADC Therapeutics: Consultancy; ADC Therapeutics: Consultancy; Bristol-Myers Squibb: Consultancy, Research Funding; ADC Therapeutics: Consultancy; Erytech Pharma: Consultancy; Bristol-Myers Squibb: Consultancy, Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; Erytech Pharma: Consultancy; Bristol-Myers Squibb: Consultancy, Research Funding; Incyte: Research Funding; miRagen Therapeutics Inc: Consultancy, Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; Kyowa Hakko Kirin Pharma: Consultancy, Research Funding; Merck: Research Funding; Kyowa Hakko Kirin Pharma: Consultancy, Research Funding; Takeda Pharmaceuticals: Consultancy; Merck: Research Funding; Seattle Genetics: Consultancy, Honoraria, Research Funding; Cell Medica: Consultancy; Bristol-Myers Squibb: Consultancy, Research Funding; Merck: Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; ADC Therapeutics: Consultancy; Erytech Pharma: Consultancy; Bristol-Myers Squibb: Consultancy, Research Funding; Incyte: Research Funding; miRagen Therapeutics Inc: Consultancy, Research Funding; Kyowa Hakko Kirin Pharma: Consultancy, Research Funding; Kyowa Hakko Kirin Pharma: Consultancy, Research Funding; Erytech Pharma: Consultancy; Takeda Pharmaceuticals: Consultancy; Kyowa Hakko Kirin Pharma: Consultancy, Research Funding; Incyte: Research Funding; Cell Medica: Consultancy; Takeda Pharmaceuticals: Consultancy; Takeda Pharmaceuticals: Consultancy; Kyowa Hakko Kirin Pharma: Consultancy, Research Funding; Cell Medica: Consultancy; Takeda Pharmaceuticals: Consultancy; Kyowa Hakko Kirin Pharma: Consultancy, Research Funding; Seattle Genetics: Consultancy, Honoraria, Research Funding; Kyowa Hakko Kirin Pharma: Consultancy, Research Funding; Incyte: Research Funding; Seattle Genetics: Consultancy, Honoraria, Research Funding; Merck: Research Funding. von Keudell:Bayer: Consultancy; Genentech: Consultancy; Pharmacyclics: Consultancy; Pharmacyclics: Consultancy; Genentech: Consultancy; Bayer: Consultancy. Dogan:Roche: Consultancy, Research Funding; Corvus Pharmaceuticals: Consultancy; Seattle Genetics: Consultancy; Celgene: Consultancy; Takeda: Consultancy; Novartis: Consultancy. Zelenetz:DAVA Oncology: Consultancy, Membership on an entity's Board of Directors or advisory committees; Bayer: Consultancy, Membership on an entity's Board of Directors or advisory committees; Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees; Karyopharm: Consultancy, Membership on an entity's Board of Directors or advisory committees; DAVA Oncology: Consultancy, Membership on an entity's Board of Directors or advisory committees; Karyopharm: Consultancy, Membership on an entity's Board of Directors or advisory committees; Verastem: Consultancy, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; Morphosys: Consultancy, Membership on an entity's Board of Directors or advisory committees; Pharmacyclics/AbbVie: Consultancy, Membership on an entity's Board of Directors or advisory committees; Gilead: Consultancy, Membership on an entity's Board of Directors or advisory committees; Pharmacyclics/AbbVie: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Gilead: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees; Bayer: Consultancy, Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees; DAVA Oncology: Consultancy, Membership on an entity's Board of Directors or advisory committees; Genentech/Roche: Consultancy, Membership on an entity's Board of Directors or advisory committees; Karyopharm: Consultancy, Membership on an entity's Board of Directors or advisory committees; Morphosys: Consultancy, Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Morphosys: Consultancy, Membership on an entity's Board of Directors or advisory committees; MEI Pharma: Consultancy, Membership on an entity's Board of Directors or advisory committees; Astra-Zeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees; MEI Pharma: Consultancy, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees; Pharmacyclics/AbbVie: Consultancy, Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Beigene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Astra-Zeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees; Verastem: Consultancy, Membership on an entity's Board of Directors or advisory committees; Gilead: Consultancy, Membership on an entity's Board of Directors or advisory committees; Morphosys: Consultancy, Membership on an entity's Board of Directors or advisory committees; Verastem: Consultancy, Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Karyopharm: Consultancy, Membership on an entity's Board of Directors or advisory committees; Genentech/Roche: Consultancy, Membership on an entity's Board of Directors or advisory committees; Genentech/Roche: Consultancy, Membership on an entity's Board of Directors or advisory committees; Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Verastem: Consultancy, Membership on an entity's Board of Directors or advisory committees; Morphosys: Consultancy, Membership on an entity's Board of Directors or advisory committees; Pharmacyclics/AbbVie: Consultancy, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Karyopharm: Consultancy, Membership on an entity's Board of Directors or advisory committees; Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees; Verastem: Consultancy, Membership on an entity's Board of Directors or advisory committees; Pharmacyclics/AbbVie: Consultancy, Membership on an entity's Board of Directors or advisory committees; Pharmacyclics/AbbVie: Consultancy, Membership on an entity's Board of Directors or advisory committees; DAVA Oncology: Consultancy, Membership on an entity's Board of Directors or advisory committees; Genentech/Roche: Consultancy, Membership on an entity's Board of Directors or advisory committees; Verastem: Consultancy, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; Gilead: Consultancy, Membership on an entity's Board of Directors or advisory committees; Gilead: Consultancy, Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Karyopharm: Consultancy, Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; Morphosys: Consultancy, Membership on an entity's Board of Directors or advisory committees; Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Beigene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Genentech/Roche: Consultancy, Membership on an entity's Board of Directors or advisory committees. Younes:BMS: Research Funding; AstraZeneca: Research Funding; Genentech: Research Funding; Roche: Consultancy, Honoraria, Research Funding; Xynomics: Consultancy; Syndax: Research Funding; Epizyme: Consultancy, Honoraria; HCM: Consultancy; Celgene: Consultancy, Honoraria; Takeda: Honoraria; Abbvie: Honoraria; Merck: Honoraria, Research Funding; Curis: Honoraria, Research Funding; Pharmacyclics: Research Funding; Janssen: Honoraria, Research Funding; Biopath: Consultancy.

Introduction Indolent lymphomas, such as follicular lymphoma (FL) and marginal zone lymphoma (MZL), are highly radiosensitive and often respond to very low dose radiation therapy (VLDRT). We investigated the outcomes of patients treated with 4 Gy from a large, contemporary, real world cohort, and a subset of potentially curable (PC) patients with early stage (Ann Arbor stage I-II) disease and no prior therapy to the targeted lesion(s) before VLDRT. Methods We analyzed 256 treated sites from 210 consecutive adult patients (Table 1) with FL or MZL who were treated with VLDRT of 2 Gy x 2 fractions between 2006 and 2019 at our comprehensive cancer center. Initial overall response rate (ORR) was defined as complete response (CR) or partial response (PR) using Lugano criteria at first follow-up post-RT (median: 2.1 months; Interquartile range: 1.6-2.5 months). Stable disease (SD) or progressive disease (PD) at 2 months post-RT were considered local failure (LF). Freedom from local failure (FFLF) was defined as time from VLDRT to LF. Patients were censored at the start of a subsequent line of therapy if the VLDRT-treated site had not progressed. Event-free survival (EFS) was calculated per patient from VLDRT to LF or distant PD. FFLF and EFS were estimated using Kaplan-Meier and compared using log-rank. Results Initial ORR for all sites was 88% (CR: 65%, PR: 23%); 12% (n=31) were initially nonresponding (SD: 7%, PD: 5%). Thirteen sites with initial PR/SD/PD received additional RT (median: 30 Gy) within 6 months of VLDRT and had subsequent CR (n=7), PR (n=5), and PD (n=1). With median follow-up of 21 months, 2-year FFLF was 70%. Initial response to VLDRT was prognostic with a significantly improved 2-year FFLF for sites with CR (n=166) compared to those with PR (n=58) (88% vs. 66%, p In the subset of PC patients (n=50), there were 52 lesions. The histology of these sites was split between FL (n=21, 41%), MZL (n=22, 42%) and indolent lymphoma not further classified (n=9, 17%). The majority of the lesions in the PC cohort were extranodal (n=42, 81%). Median follow-up was 1 year with a 1-year EFS of 82%. Of the 12 PC patients who progressed post VLDRT, two thirds developed a distant site of recurrence outside of the VLDRT field. In field recurrence alone was rare (n=4). Diffuse large B cell lymphoma transformation after VLDRT was rare in the PC (n=0) and overall (n=6, 3%) cohort; all cases of transformed DLBCL were diagnosed out of VLDRT field. Conclusions Overall, patients with FL and MZL treated with only 4 Gy have excellent initial ORR. Upfront CR is prognostic of improved disease control. Early evaluation following VLDRT identifies nonresponders who may benefit from additional RT and spares many patients from higher doses of RT with durable local control. Our analysis of PC patients suggests that VLDRT does not compromise the standard curative RT approach. Disclosures No relevant conflicts of interest to declare.

The purpose of this study was to evaluate electrophysiologic study (EPS) in risk stratification of relative indications for pacemaker implantation (PMI) after transcatheter aortic valve implantation (TAVI).We reviewed files of all patients who had a left bundle branch block (LBBB) and underwent EPS after TAVI between 3/2009 and 5/2015. The indications for EPS were new-onset LBBB and the presence of an old or a new-onset LBBB associated with either PR prolongation after TAVI (∆PR20 ms) or with "slow" atrial fibrillation (100/min). Pacemakers were implanted when significant infranodal disease was demonstrated. The control group comprised of 55 consecutive patients who underwent TAVI and had an indication for an EPS per our definitions. These patients were discharged without further intervention. All patients were followed during 1 year for the composite endpoint of mortality or PMI after hospital discharge.Indications for EPS were new LBBB (n = 8, 30.8%), new LBBB + ∆PR20 ms (n = 9, 34.6%), baseline LBBB + ∆PR20 ms (n = 7, 26.9%) and new LBBB + slow AF100 bpm (n = 2, 7.7%). Multilevel conduction disturbances involving the AV node (n = 19, 73.1%), the His (n = 3, 11.5%), and the infra-His system (n = 4, 15.4%) were found. Post discharge, there were 5 (9%) deaths and 3 (5.5%) PMI in the control group compared to none in the EPS group corresponding to event-free survival of 85 and 100%, respectively (p = 0.04).Patients with LBBB with or without ∆PR20 ms are at a higher risk of mortality and late PMI at 1-year follow-up. EPS can be used to safely identify patients in whom a PMI is needed.

Botezomib-based induction is highly effective for the treatment of newly diagnosed multiple myeloma (NDMM). We investigated the outcomes of NDMM patients who failed to respond to bortezomib-based induction in a 'real-life' clinical setting. In a cohort of 295 consecutive NDMM patients in 3 medical centers, 74 (25%) failed to achieve at least partial response after 4 induction cycles, and were classified as non-responsive. Compared to induction responders, they were older, more frequently anemic, had a higher incidence of del17p and ISS-3, and a worse performance status. In multivariable analysis, bortezomib-based induction failure occurred in 25% of patients and was the strongest independent factor predicting mortality with a 5-fold hazard ratio (95% CI 1.44-8.68). Three-year overall survival in responsive vs. non-responsive patients were 76% vs. 53%, respectively (p

Objective To present a framework for combining implicit knowledge acquisition from multiple experts with machine learning and to evaluate this framework in the context of anemia alerts. Materials and Methods Five internal medicine residents reviewed 18 anemia alerts, while ‘talking aloud’. They identified features that were reviewed by two or more physicians to determine appropriate alert level, etiology and treatment recommendation. Based on these features, data were extracted from 100 randomly-selected anemia cases for a training set and an additional 82 cases for a test set. Two staff internists assigned an alert level, etiology and treatment recommendation before and after reviewing the entire electronic medical record. The training set of 118 cases (100 plus 18) and the test set of 82 cases were explored using RIDOR and JRip algorithms. Results The feature set was sufficient to assess 93% of anemia cases (intraclass correlation for alert level before and after review of the records by internists 1 and 2 were 0.92 and 0.95, respectively). High-precision classifiers were constructed to identify low-level alerts (precision p=0.87, recall R=0.4), iron deficiency (p=1.0, R=0.73), and anemia associated with kidney disease (p=0.87, R=0.77). Discussion It was possible to identify low-level alerts and several conditions commonly associated with chronic anemia. This approach may reduce the number of clinically unimportant alerts. The study was limited to anemia alerts. Furthermore, clinicians were aware of the study hypotheses potentially biasing their evaluation. Conclusion Implicit knowledge acquisition, collaborative filtering and machine learning were combined automatically to induce clinically meaningful and precise decision rules.

Patients with acute decompensated heart failure (ADHF) are frequently treated with unnecessary antibiotics since they are confused with pneumonia patients.To study the efficacy of measuring C-reactive protein (CRP) levels on admission and CRP velocity in differentiating ADHF from pneumonia.A retrospective observational study of ADHF and pneumonia patients admitted to a tertiary hospital during 2 years. Patients who were already treated with antibiotics on admission were excluded. Efficacy of CRP as a diagnostic marker was evaluated by using receiver operator curves (ROC).Overall, 72 ADHF and 50 pneumonia patients were included in the study. The mean CRP levels on admission were 13.5+/-13.5 mg/L for the ADHF patients and 127+/-84 mg/L for the pneumonia patients (p0.001). CRP increases ofor =0.56 mg/L/h were diagnostic of pneumonia. CRP levels on admission together with CRP increases had a sensitivity of 0.96 and a specificity of 0.972 (p0.001) as markers to distinguish pneumonia from ADHF.This study emphasizes the dynamic nature of biomarkers. Demonstrating the efficiency of repeated CRP measurements in an acute setting will provide clinicians with a valuable tool for establishing the correct diagnosis and refraining from unnecessary use of antibiotics.

Background Nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) is a rare disease. In the absence of consensus guidelines, treatment is controversial. Here, we describe the characteristics and outcomes of consecutive NLPHL patients diagnosed at Memorial Sloan Kettering Cancer Center (MSKCC) with a focus on active surveillance (AS) as a first-line management strategy. Methods We included consecutive patients aged 16 years (y) or older who were diagnosed and followed at MSKCC between 1974 and 2016. All cases were confirmed by a MSKCC hematopathologist as NLPHL without evidence of transformation. We excluded composite lymphomas and patients with any prior hematological malignancy or concomitant active cancer. We compared outcomes between patients followed expectantly (AS) and those treated actively (AT), which included radiotherapy (RT) only, chemotherapy (+/- Rituximab) (CT), combined modality (+/- Rituximab) (CMT), and rituximab monotherapy (R). Progression-free survival (PFS) was defined as time from diagnosis to a biopsy-proven disease progression or relapse, initiation of further treatment or death. PFS2 was defined as time from diagnosis to second biopsy-proven disease progression or relapse, initiation of 3rd-line treatment or death. AS was considered a 1st-line treatment. We used univariable and multivariable survival analyses stratifying patients by disease stage. Results In total, 163 patients were included. The median follow-up was 5.7y (Min-Max: 0.3 - 42.7) with 24.5% (n=40) of patients followed for 10y or more. Patient characteristics for all, AS and AT patients are shown in Table 1. Patients were treated with RT only (n=75, 46.0%), AS (n=37, 22.7%), CT (n=26, 15.9%), CMT (n=19, 11.7%) or R alone (n=6, 3.7%). Overall, outcome of patients was excellent, with 10-year PFS, PFS2 and overall survival (OS) estimates of 71.2% [95%-CI: 59.3-80.1], 92.5% [95%-CI: 83.7-96.6] and 96.6% [95%-CI: 87.6-99.1], respectively. Seven patients died, 3 deaths were likely treatment related and only one lymphoma related death occurred after progression. Twelve transformations to aggressive lymphomas occurred after a median of 7.0y (Min-Max: 0.4 - 15.6). The transformation rate was 0.99% per patient year. Twelve secondary cancers occurred after a median of 7.8y (Min-Max: 1.1 - 24.8). Only bulky disease ≥ 5 cm (n=21, HR: 3.1 [95%-CI: 1.3-7.2], p=0.008) and extranodal disease (n=11, HR: 7.7 [95%-CI: 2.1-28.5], p=0.002] were risk factors for a shorter PFS in the final multivariate model after correcting for received treatment. In pairwise comparison, PFS with CMT (p=0.038) and RT (p=0.032) was superior to AS, but CT was not (p>0.999). PFS2 and OS were not significantly different between groups. Patients, who received AT (n=126) overall tended to have superior PFS than those in the AS group (n=37) (5-year PFS 97.2% [95%-CI: 79.2-92.2] vs. 76.5% [95%-CI: 55.7-88.5], p=0.068), though this benefit was mainly seen in early stage disease (Ann Arbor I/II) (5-year PFS 94.2% [95%-CI: 86.7-97.6] vs. 65.1% [95%-CI: 43.5-80.2], p Conclusion NLPHL has an excellent prognosis. Bulky and extranodal disease were identified as potential risk factors for progression. With the limitations of a retrospective analysis, it can be concluded that AS is a viable management strategy in NLHPL. The majority of AS patients require no treatment after multiple years of observation and those that do, can be adequately managed with established treatments. Additionally, no evidence was found for an increased rate of transformation or worse PFS2 or OS in AS patients. Treatment related deaths exceeded deaths from lymphoma. Figure 1 Figure 1. Disclosures Moskowitz: Celgene: Consultancy; Genentech BioOncology: Consultancy; Seattle Genetics: Consultancy, Other: Ad Board, Research Funding; Merck: Consultancy, Research Funding; Pharmacyclics: Research Funding. Zelenetz: Genentech/Roche, GSK, Gilead, Celgene, Janssen, Hospira, Amgen, Takeda Pharma, Novartis, Nanostring Technologies, Portola Pharmaceuticals, Adaptive Biotechnology: Consultancy; GSK, Janssen, Roche, Gilead, Bristol Myers: Research Funding; Boehringer Ingelheim: Other: DMC Membership. Kumar: Seattle Genetics: Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees. Moskowitz: Incyte: Research Funding; Bristol Myers-Squibb: Consultancy, Research Funding; Seattle Genetics: Honoraria, Research Funding; Takeda: Honoraria; ADC Therapeutics: Research Funding.

Background: Prognosis of follicular lymphoma (FL) has long been defined by the FLIPI score (Solal-Céligny et al., 2004) which is a 5 factor risk model consisting of age, stage, lactate dehydrogenase, hemoglobin and number of nodal areas. The FLIPI model has been validated at diagnosis in both the pre- and post-Rituximab eras. However, many patients are initially observed and have prolonged lead time from diagnosis to first treatment. In this study, we investigated whether FLIPI risk group at diagnosis changed by the time of initial treatment, and whether change of FLIPI risk group impacted treated outcome. Patients and Methods: All adult (≥18 yo) patients with de novo follicular lymphoma (FL) treated at our center between 1998 and 2007 were evaluated. Study excluded patients with ≤2 follow up visits, known divergent of composite histology at diagnosis, and active concurrent malignancies. FLIPI was scored at diagnosis and at initiation of first treatment. For patients with missing FLIPI data, FLIPI category was scored if the omission did not alter the FLIPI category. Stable FLIPI risk group was defined as FLIPI score being low or intermediate at diagnosis and at initiation of first treatment (Low-Low, Int-Int). Progressed FLIPI risk group was defined by the population which changed categories from low or intermediate at diagnosis to a higher category at initiation of treatment (Low-Int, Low-High, Int-High). FLIPI scores were available for 570 patients at both diagnosis and initial treatment. Overall survival (OS) and progression free survival (PFS) were evaluated by Kaplan-Meier method and compared by log-rank tests. Time of diagnosis was used as time origin for OS analyses. When OS analyses involved FLIPI score at the first treatment, time of the first treatment was used as the entry time to adjust the risk sets to account for the fact that FLIPI at first treatment is unknown before the onset of the first treatment. Chi-squared tests and Fisher's exact tests were used to compare categorical variables by FLIPI score change status. Progression free survival before and after 24 months (PFS24) of initial therapy were calculated. Results: For 898 FL patients, median follow up was 9.2 years (range 0.23 - 16.84), median OS not reached. Based on FLIPI at diagnosis, the 5 year OS is 97.2% for low risk, 93.0% for int risk, and 80.2% for high risk, 10 yr OS is 90.9% for low risk, 77.7% for int risk, and 67.6% for high risk. Of 570 patients with FLIPI at diagnosis and first treatment, median time to first treatment was 0.18 years (range 0-12.5) for patients with stable FLIPI (N=280) and 2.70 years (range 0.01-13.33) for patients with progressed FLIPI (N=83). For patients observed ≥ 6 and 12 months, the median time to first treatment was 1.21 years (N=47, range 0.51-12.5) and 2.49 years (N=29, range 1.0-12.5) for patients with stable FLIPI and 3.77 years (N=62, range 0.54-13.3) and 3.92 years (N=57, range 1.13-13.3) for patients with progressed FLIPI, respectively. Progressed FLIPI was observed in 14.6% (83/570) of patients. The incidence of progressed FLIPI was 51.4% (57/111) in patients observed ≥1 year before initiating therapy. Parameters contributing to progressed FLIPI compared to stable FLIPI were decreased hemoglobin (29% versus 6%), increased nodal areas affected (43% versus 2%) and higher LDH (37% versus 5%). Patients with stable FLIPI had longer PFS at 12 and 24 months, 88.6% versus 73.8% (P=0.006) and 79.3% versus 66.1% (P= 0.031) (Figure 1). Analysis of patients initially observed ≥ 6 or 12 months demonstrated that progressed FLIPI negatively affected OS and PFS (Figure 2, observed ≥ 12 month data not shown). Median PFS for patients observed ≥ 6 months was 8.36 years for stable FLIPI, 3.14 years for progressed FLIPI. At observation of ≥ 12 months, median PFS was 6.25 and 3.22 years for stable and progressed FLIPI, respectively. Increased FLIPI was associated with increased risk of transformation throughout the disease course (25% vs 16%, P=0.039). Conclusion: Progressed FLIPI between diagnosis and first line treatment is associated with a reduced PFS, and increased incidence of histologic transformation. In patients who are initially observed, a progressed FLIPI reduces OS and PFS. The effect on PFS may be related to treatment bias and ongoing analysis is underway. Progressed FLIPI potentially identifies a population with heightened risk of transformation. Disclosures Hamlin: Seattle Genetics: Research Funding; Gilead: Membership on an entity's Board of Directors or advisory committees; Portola: Research Funding; Novartis: Research Funding; Molecular Templates: Research Funding; Xencor: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees. Horwitz:Seattle Genetics: Consultancy, Research Funding; Celgene: Consultancy; Huya: Consultancy; Infinity: Consultancy, Research Funding; Kyowa Hakka Kirin: Consultancy, Research Funding; Takeda: Consultancy, Research Funding; ADCT Therapeutics: Research Funding; Spectrum: Consultancy, Research Funding; Bristol-Myers Squibb: Consultancy. Kumar:Celgene: Honoraria, Other: Scientific Advisory Board; Pharmacyclics: Research Funding; Seattle Genetics: Research Funding; Adaptive Biotechnologies: Research Funding; Celgene: Research Funding. Moskowitz:Bristol Myers Squibb: Honoraria; Merck: Honoraria; Seattle Genetics: Honoraria, Research Funding. Moskowitz:Merck: Membership on an entity's Board of Directors or advisory committees, Research Funding; Bristol-Myers Squibb: Membership on an entity's Board of Directors or advisory committees, Research Funding; Seattle Genetics: Membership on an entity's Board of Directors or advisory committees, Research Funding. Palomba:Pharmacyclics: Consultancy. Zelenetz:Gilead Sciences: Research Funding.

Introduction In their lifetime, patients with follicular lymphoma frequently require multiple treatments, which have improved their survival over the past few decades. The expected treatment outcome based on lines of treatment in the post-Rituximab era is currently unknown. We analyzed the progression free survival and event free survival by line of treatment to aid estimating clinical endpoints when designing future clinical trials for multiply relapsed patients. Patients and Methods Adults (≥18 years) with de novo follicular lymphoma (FL) treated at our center between 1998 and 2007 were eligible (N=1134). 236 patients with ≤2 visits, mixed histology at initial diagnosis, and active concurrent malignancy were excluded. Of the remaining 898 patients, 105 were observed and did not require treatment during the timeframe of this dataset, and 2 had incomplete data, therefore 791 patients were eligible for response, progression and event free survival (PFS and EFS) analysis (Figure 1). Response was documented by investigators based on clinical or radiographic assessment. Complete response was based on radiographic assessment. PFS was defined as start of treatment to progression of disease or death. Patients with inadequate response to treatment, change of treatment, or stable disease without subsequent documented relapse were censored in the PFS analysis. Events for EFS were defined as progression, change of treatment, and death. PFS and EFS of sequential lines of treatment were evaluated by Kaplan-Meier method and compared across lines using log-rank test with adjustment for within-patient correlation. PFS and EFS were compared by other clinical variables using regular log-rank tests. Results Median age of diagnosis was 57.3 years with 1:1 male to female ratio. Median overall survival was not reached with median follow up of 9 years (N=898, range 0.2 - 16.8 years, Figure 1A). Median time to first treatment for the entire group was 2.3 months (range 0 - 13.3 years). In first line treatment of the 791 patients, 51% (N=406) received Rituximab with chemotherapy (R-Chemo), 13% (N=101) received chemotherapy only (Chemo), 19% (N=150) received Rituximab monotherapy (R-Mono), and 17% (N=129) received other treatments including radiation and surgery. For second line treatment, 405 patients were treated with about 37% receiving R-Chemo and 34% receiving R-Mono. As line of treatment increased, the percentage of patients with radiographically assessed complete response diminished from 71% at first line treatment to 25% by fifth line treatment (Figure 1B). Median PFS for first, second and third line treatment are 4.8, 1.6, and 1 year, respectively (Figure 2A). Median EFS for first, second and third line treatment are 3.8, 1.1, 0.8 year, respectively (Figure 2B). For subsequent lines of treatment, both median PFS and EFS were Conclusion Follicular lymphoma is an indolent disease often requiring multiple lines of treatment. However, PFS and EFS for multiple lines of treatment in FL has not been described in the post-Rituximab era. The work has benchmarked the median response by line of treatment. After third line treatment, the PFS was ≤1 year. This analysis serves to aide comparison of different therapies for future drug approval in relapsed FL. Disclosures Hamlin: Xencor: Membership on an entity's Board of Directors or advisory committees; Portola: Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees; Molecular Templates: Research Funding; Novartis: Research Funding; Seattle Genetics: Research Funding; Gilead: Membership on an entity's Board of Directors or advisory committees. Horwitz:Spectrum: Consultancy, Research Funding; Bristol-Myers Squibb: Consultancy; Huya: Consultancy; Infinity: Consultancy, Research Funding; Kyowa Hakka Kirin: Consultancy, Research Funding; Takeda: Consultancy, Research Funding; Seattle Genetics: Consultancy, Research Funding; Celgene: Consultancy; ADCT Therapeutics: Research Funding. Kumar:Celgene: Honoraria, Other: Scientific Advisory Board; Celgene: Research Funding; Adaptive Biotechnologies: Research Funding; Seattle Genetics: Research Funding; Pharmacyclics: Research Funding. Moskowitz:Merck: Honoraria; Seattle Genetics: Honoraria, Research Funding; Bristol Myers Squibb: Honoraria. Moskowitz:Merck: Membership on an entity's Board of Directors or advisory committees, Research Funding; Bristol-Myers Squibb: Membership on an entity's Board of Directors or advisory committees, Research Funding; Seattle Genetics: Membership on an entity's Board of Directors or advisory committees, Research Funding. Palomba:Pharmacyclics: Consultancy. Zelenetz:Gilead Sciences: Research Funding.

Distinguishing community acquired pneumonia (CAP) from chronic obstructive pulmonary disease (COPD) exacerbation is a challenging task, since fever, productive cough, dyspnea, and leukocytosis are all common features of both conditions. Moreover, chest X-ray might not be sensitive enough. It is therefore quite common for physicians to prescribe unnecessary antibiotics for COPD exacerbation, leading to resistant bacteria and other related adverse affects.To study whether CRP levels upon admission and the delta in CRP levels following initiation of antibacterial treatment, could provide an efficient tool for distinguishing CAP from COPD exacerbation.The study group included 36 COPD exacerbation and 49 CAP patients, admitted to a single Internal Medicine department during the years 2004-2006. All patients were treated with cephalosporins and macrolides upon admission.CRP levels upon admission were significantly higher among CAP patients than among COPD exacerbation patients (111.5+/-104.4 vs. 34.9+/-28.6 mg/l, p0.0001). CRP levels on the second day of hospitalization, following antibiotic administration to all patients, made a sharp incline in 36.7% of CAP patients compared to only 5.9% of COPD exacerbation patients (p=0.005), and remained unchanged in 61.8% of COPD patients compared to 16.3% of CAP patients (p=0.0006).CRP levels upon admission and the delta in CRP levels following initiation of antibacterial treatment could provide an efficient tool for distinguishing CAP from COPD exacerbation.

INTRODUCTION Botezomib-based induction is widely used and highly effective for the treatment of patients with newly diagnosed multiple myeloma (NDMM), with an overall response rate (ORR) of 75-80%. However, the outcomes of patients who fail to respond to this treatment remain unclear. The goal of this study was to investigate the outcome of patients with NDMM who failed to respond to bortezomib-based induction as compared to induction-responsive patients. METHODS We reviewed consecutive patients with NDMM between 1-JAN-2007 and 31-JAN-2014 in three participating centers in Greece and Israel. Inclusion criteria were measurable disease and an induction regimen containing bortezomib in combination with alkylators and/or corticosteroids. Patients who failed to achieve at least partial response in accordance with IMWG criteria after 4 cycles of therapy were classified as non-responsive and their baseline characteristics, next treatment, overall survival and progression following second-line treatment (2ndPFS) were assessed and compared to responsive patients. 2ndPFS was defined as the time from 2nd line treatment to disease progression, death or censoring. In the non-responsive group we limited this analysis to patients advancing to 2nd line within six months of initiation of induction. RESULTS Two hundred and ninety five patients met inclusion criteria and 74 (25%) were non-responsive to bortezomib-containing induction. Non-responsive patients were older, more anemic and had more often ISS-3, del17p and ECOG performance status 2-4 (table 1). Notably, these patients received less often a bi-weekly bortezomib schedule, a triple-drug regimen and high dose melphalan treatment at first line. Of the non-responsive patients 57% (n=42) received salvage treatment immediately following induction non-response, with an ORR of 59% (25/42); 12/31(39%) of those treated with salvage 2nd line and 13/15(87%) of those who underwent HDM at first line, responded. Failure to respond to bortezomib induction was associated with increased mortality (HR 5.06, 95% CI 2.80 – 9.16) (Fig. a), which remained significant in multivariate analysis. One- and 3-years OS in responsive vs. non-responsive patients were 97% vs 76% and 88% vs 53%, respectively (p 2ndPFS in patients who received salvage second line therapy immediately following induction failure was similar to that measured in bortezomib-responsive patients receiving 2nd-line therapy for disease progression, approaching 14 months. However, survival from time of salvage 2nd-line treatment was significantly lower among patients non-responsive to bortezomib-based induction compared to that measured in responsive patients (25 months vs. not reached, respectively, p=0.024; Fig. b). CONCLUSIONS Failure to respond to a bortezomib-based induction was found to be an independent risk factor for mortality. Despite the non-inferior 2ndPFS reported in these patients as compared with their bortezomib-responsive counterparts, survival remained significantly inferior. Possibly this difference is because non-responsive patients are less likely to respond to further proteasome inhibitor therapy at following relapses. Randomized controlled trials are needed to test whether intensification of induction and/or of further treatment may improve the poor prognosis of patients who fail to respond to bortezomib-based induction. Table 1: All patients n = 295 Induction non-responsive n = 74 Induction - responsive n =221 P value Demographic Median Age (yrs) 62.0 66.8 61.0 0.004 Gender Male Female 148 (50%) 147 (50%) 42 (55%) 33 (45%) 107 (48%) 114 (52%) 0.347 Patient / Disease ECOG 0-1 2-4 182 (63%) 107 (37%) 33 (45%) 40 (55%) 149 (69%) 67 (31%) 2mg% 23 (14%) 69 (34%) 66 (27%) 23 (9.5%) 114 (43%) 64 (23%) 10 (26%) 13 (28%) 21 (36%) 5 (8.1%) 35 (54%) 20 (30%) 13 (10%) 56 (36%) 45 (24%) 18 (9.7%) 79 (39) 44 (21%) 0.031 0.297 0.091 0.805 0.044 0.094 Therapy Induction regimen VCD Vd VMP PAD 204 (69%) 49 (17%) 11 (4%) 19 (6%) 52 (57%) 18 (24%) 3 (4%) 4 (5%) 162 (73%) 31 (14%) 8 (4%) 15 (7%) 0.007 Any triplet 243 (82%) 55 (74%) 188 (85%) 0.051 Bortezomib schedule Bi-weekly Weekly 239 (81%) 56 (19%) 52 (70%) 22 (30%) 187 (85%) 34 (15%) 0.010 HDM at first line 143 (48%) 15 (20%) 128 (58%) Figure 1 Figure 1. Disclosures Dimopoulos: Celgene: Consultancy, Honoraria.