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The cell of origin and the tumor microenvironment’s role remain elusive for the most common peripheral T-cell lymphomas (PTCLs). As macrophages promote the growth and survival of malignant T cells and are abundant constituents of the tumor microenvironment, their functional polarization was examined in T-cell lymphoproliferative disorders. Cytokines that are abundant within the tumor microenvironment, particularly interleukin (IL)-10, were observed to promote alternative macrophage polarization. Macrophage polarization was signal transducer and activator of transcription 3 dependent and was impaired by the Janus kinase inhibitor ruxolitinib. In conventional T cells, the production of T helper (Th)2-associated cytokines and IL-10, both of which promote alternative macrophage polarization, is regulated by the T-cell transcription factor GATA-binding protein 3 (GATA-3). Therefore, its role in the T-cell lymphomas was examined. GATA-3 expression was observed in 45% of PTCLs, not otherwise specified (PTCL, NOS) and was associated with distinct molecular features, including the production of Th2-associated cytokines. In addition, GATA-3 expression identified a subset of PTCL, NOS with distinct clinical features, including inferior progression-free and overall survival. Collectively, these data suggest that further understanding the cell of origin and lymphocyte ontogeny among the T-cell lymphomas may improve our understanding of the tumor microenvironment’s pathogenic role in these aggressive lymphomas.

Mantle cell lymphoma (MCL) is an aggressive B-cell non-Hodgkin lymphoma characterized by overexpression of cyclin D1 resulting from the t(11;14) chromosomal translocation. MCL is biologically and clinically heterogeneous and frequently disseminates to extranodal areas. MCL remains a clinically challenging lymphoma subtype, as there is no proven curative therapy and no standard of care has been established for initial or subsequent lines of therapy. However, there have been considerable advances in the last several years in the treatment of MCL, leading to improved survival. Recent investigations into the biology of MCL, clinically relevant biomarkers, novel therapeutic targets and new treatment strategies were discussed at a recent workshop of the Lymphoma Research Foundation's Mantle Cell Lymphoma Consortium. The presentations are summarized in this manuscript, which is intended to highlight areas of active investigation and identify topics for future research.

Immunoglobulin light chain (AL) Amyloidosis is a condition whereby misfolded proteins generated by plasma cells deposit in tissues causing organ dysfunction. Chemotherapy and autologous stem cell transplant when eligible are standard treatment options. Several studies report long-term outcomes of patients post-transplant. However, there is a paucity of literature describing outcomes of relapsed patients post-transplant. We performed a retrospective study to assess outcomes and therapies employed upon relapse after transplant. Between 1996 and 2009, 410 patients received transplant at the Mayo Clinic as first-line therapy. Of those patients, 42 (10%) died within 3 months of transplant, 64 (16%) died without documented relapse, 158 (38%) were alive without documented progression, and 146 (36%) had documented progression. Those 146 patients are the subject of our study, and their median time to hematologic relapse/progression was 23.6 months (95%CI 18.3, 26.3 months). Their median overall survival and 5-yrs overall survival from post-transplant relapse/progression was 51.7 months (95%CI 34.1-62.3) and 39%, respectively. The most common first regimen for treatment after relapse was lenalidomide or thalidomide. In conclusion, our study indicates that patients with AL amyloidosis fare well post-transplant relapse/progression. Additionally, it provides a yardstick to design clinical trials to determine best treatment options.

Everolimus is an oral raptor mTOR inhibitor and has shown activity in patients with Waldenstrom's macroglobulinemia (WM). This study examines a large cohort of patients with relapsed/refractory WM with long-term follow up for survival. Patients were eligible if they had measurable disease, a platelet count >75,000 x 10(6)/L, an absolute neutrophil count >1,000 x 10(6)/L. Patients received everolimus 10 mg PO daily and were evaluated monthly. A success was defined as a complete or partial response (PR); minor responses (MR) were recorded and considered to be of clinical benefit. Sixty patients were enrolled and treated. The overall response rate (ORR) was 50% (all PR); the clinical benefit rate including MR or better was 73% (95% CI: 60-84%) with 23% MR. The median time to response for patients who achieved PR was 2 months (range, 1-26). The median duration of response has not been reached and median progression-free survival (PFS) was 21 months. Grade 3 or higher toxicities (at least possibly related to everolimus) were observed in 67% of patients. The most common grade 3 or 4 toxicities were anemia (27%), leukopenia (22%), and thrombocytopenia (20%). Other nonhematological toxicities were diarrhea (5%), fatigue (8%), stomatitis (8%) and pulmonary toxicity (5%). Everolimus has a high single-agent activity of 73% including MR, with a progression free survival of 21 months, indicating that this agent is active in relapsed/refractory WM.

The detection of serum free light (FLC) is useful in the diagnosis of several hematological diseases. The role and biological relevance of monoclonal or polyclonal FLC elevations in predicting long-term outcome in diffuse large B-cell lymphoma (DLBCL) is unknown. We determined the relationship of the type of FLC elevations to outcome, tumor genotype, and pattern of serum cytokine elevations in 276 patients with untreated DLBCL. Elevated FLC was an adverse prognostic factor through 6 years of follow-up (monoclonal, Event free survival (EFS) HR = 3.56, 95% CI: 1.88–6.76, P

Epstein-Barr virus (EBV) is a ubiquitous virus that commonly affects children and adolescents. In addition to causing a viral illness, it is also associated with various malignancies in particular B cell lymphomas and lymphoproliferative disorders. Differentiating between the two processes can be a diagnostic challenge. Here, we present a case of an atypical EBV infection in an elderly patient with severe systemic symptoms, multiorgan involvement, lymphadenopathy, and negative EBV serology. Excisional lymph node biopsy demonstrated features of a lymphoproliferative process involving EBV. Despite supportive care, she experienced continued clinical deterioration and was successfully treated with rituximab. This case illustrates the diagnostic challenges of these cases particularly in the elderly who may have age related immunosenescence, the utility of EBV PCR testing, and the clinical efficacy of rituximab in clearing the infected cells.

Summary Histological transformation (HT) of follicular lymphoma (FL) to an aggressive lymphoma after chemotherapy remains a key issue. The incidence of HT after radioimmunotherapy (RIT) is unknown. This single institution study analysed the risk of HT in FL after treatment with yttrium-90 ibritumomab tiuxetan in 115 consecutive patients treated during 1987–2012. RIT was administered for progressive FL in 111 (97%) patients and as first-line therapy in the remaining 4. 28% (n = 32) had HT, occurring at a median of 60 months from diagnosis and 20 months after RIT. 48% (12/25) of patients who received fludarabine developed HT. The estimated 10-year risk of HT in the fludarabine and non-fludarabine groups was 67% and 26% respectively (P = 0·015). Only prior fludarabine was significantly associated with predicting the risk of HT after RIT. 8% (9/115) of patients developed therapy-related myelodysplastic syndrome/acute myeloid leukaemia (tMDS/AML) at a median of 41·4 months (range, 5–89). The estimated 10-year risk of tMDS/AML in non-fludarabine treated patients (n = 90) versus fludarabine treated (n = 25) was 13% and 29%, respectively. The estimated overall risk of FL undergoing HT at 10 years without fludarabine exposure appears similar to patients reported in the literature that have not received RIT. Patients with prior purine-analogue therapy are at significantly higher risk of HT.

Patients with indolent non-Hodgkin lymphoma (NHL) have multiple treatment options yet there is no consensus as to the best initial therapy. Lenalidomide, an immunomodulatory agent, has single agent activity in relapsed lymphoma. This trial was conducted to assess feasibility, efficacy, and safety of adding lenalidomide to rituximab, cyclophosphamide, and dexamethasone (LR-CD) in untreated indolent NHL patients requiring therapy. This was a single institution phase II trial. Treatment consisted of IV rituximab 375 mg/m2 day 1; oral lenalidomide 20 mg days 1–21; cyclophosphamide 250 mg/m2 days 1, 8, and 15; and dexamethasone 40 mg days 1, 8, 15, and 22 of a 28-day cycle. Treatment continued 2 cycles beyond best response for a maximum of 12 cycles without rituximab maintenance. Thirty-three patients were treated. Median age was 68 (43–83 years). 39% had stage IV disease. Histologic subtypes included 8 follicular lymphoma (FL), 7 marginal zone lymphoma (MZL) (1 splenic, 2 extranodal, and 4 nodal), 15 Waldenstrom's macroglobulinemia (WM), 1 lymphoplasmacytic lymphoma, 1 small lymphocytic lymphoma, and 1 low-grade B-cell lymphoma with plasmacytic differentiation (unable to be classified better as MZL or LPL). Hematologic toxicity was the most common adverse event. Median time of follow-up was 23.4 months (range 1.8–50.9). The overall response rate was 87.9%, with 30.3% complete response. The median duration of response was 38.7 months. The median progression free survival was 39.7 months, while median overall survival (OS) has not yet been reached. Lenalidomide can be safely added to a simple regimen of rituximab, oral cyclophosphamide, and dexamethasone and is an effective combination as initial therapy for low-grade B-cell NHL.

Background: FDG PET/CT and bone marrow biopsy (BMB) are considered standard procedures for the staging of patients with new, untreated FL. A key issue in FL is the early identification of patients who will fail early. We recently reported (Am J Hematology 2019) that the presence of ≥2 EN sites, spleen, bone or soft tissue involvement as detected by PET all predicted failure to achieve EFS24. In Hodgkin lymphoma and diffuse large B-cell NHL, PET has replaced the routine need for a staging BMB. However, there is no such evidence in FL. The goal of this study was to determine the value of FDG PET/CT in determining bone involvement in FL using BMB as the gold standard. Methods: Patients were identified using the Mayo Clinic Lymphoma Database. 548 patients with newly diagnosed FL grades 1-3A between years 2003-2016, available BMB results, and PET/CT imaging at diagnosis, were included in the analysis. The presence of bone and spleen involvement on PET/CT, SUVmax and SUVmean of the axial skeleton at L3, and BMB results were recorded and compared. Results: In all, 36% (197/548) of patients had a positive BMB, and 34% (189/548) had bone involvement detected on PET/CT. Compared to BMB, the sensitivity and specificity of PET/CT in detecting bone involvement as determined by BMB were 60% and 80%, respectively. We noted that 59 patients had focal bone involvement on PET/CT rather than a diffuse component, and found that 47% (28/59) of these patients had a negative BMB obtained in the posterior iliac crest. Excluding these patients, the sensitivity and specificity of PET/CT in detecting bone involvement were 53% and 88%, respectively (Table 1). With respect to the spleen, 29% (157/548) of patients had evidence of splenic FL involvement on PET/CT, and of these, 69% (109/157) also had a positive BMB. The sensitivity and specificity of spleen involvement on PET/CT in predicting bone involvement on BMB were 55% and 86%, respectively (Table 2). We recorded SUV data at L3 in the 439 patients who had either a diffuse pattern of bone involvement on PET/CT, or a PET/CT read as negative. We analyzed the positive and negative predictive values (PPV and NPV) of SUVmax and SUVmean at several cut-off points to determine whether axial bone SUV is reliable at determining patients with a positive or negative BMB. The NPV for an SUVmax of less than 2.0 was 96% (n=25 patients classified as negative). For SUVmean, the best cut-off point was at less than 1.4, where NPV was 100% (n=15 patients classified as negative). There was no logical cut-off point for a significant PPV > 95%. Conclusion: In newly diagnosed FL, the sensitivity and specificity of bone involvement on PET/CT are insufficient for PET/CT to routinely replace BMB. However, in patients where the need for BMB at staging is being debated, certain factors on PET/CT can help facilitate this decision. The detection of focal bone lesions, especially those that may be missed on posterior iliac crest BMB, can make BMB unnecessary. If both the spleen and bone appear involved on PET/CT, this confers a relatively high chance that BMB will be positive. If SUVmax at L3 is less than 2.0, or if SUVmean is less than 1.4, the BMB will likely be negative, with a NPV > 95%. This decision-making algorithm is outlined in Figure 1 and may serve as a useful guideline for clinical trials and routine practice. Disclosures No relevant conflicts of interest to declare.

Introduction: Chronic myelomonocytic leukemia (CMML), an aggressive myeloid malignancy, can be categorized into two subtypes, proliferative CMML (pCMML) and dysplastic (dCMML), based on a white blood cell (WBC) count of ≥ 13 x 109/L for the former (Arber et al. Blood 2016). While this WBC cut off is somewhat arbitrary, patients with pCMML have unique phenotypic features and a shorter survival. We carried out this study to assess the genomic, transcriptomic and epigenetic landscapes of these two CMML subtypes. Methods: Peripheral blood (PB) and bone marrow (BM) mononuclear cells (MNC) were obtained from WHO-defined CMML patients. Next generation sequencing (NGS) using a 36-gene panel was performed on 350 patients with Illumina HiSeq4000 platform with median read depth of 400X. RNA sequencing (RNA-seq) was performed on 25 patients by bulk whole transcriptome sequencing using Illumina TruSeq. DNA immunoprecipitation sequencing (DIP-seq) was performed on 18 patients using 5-methylcystocine (5mC), 5-hydroxymethylcytosine (5hmC) and bridging monoclonal antibodies with subsequent paired-end sequencing using HiSeq4000. Chromatin immunoprecipitation sequencing (ChIP-seq) was performed on 30 patients with Illumina HiSeq2500 to a depth of 25 million for histone 3 lysine 4 monomethylation (H3K4me1) and histone 3 lysine 4 trimethylation (H3K4me3) and 50 million reads for histone 3 lysine 27 trimethylation (H3K27me3) and Input per sample. Results: Five hundred and seventy-three patients with WHO defined CMML were included; median age 71 years (range 18-95 years), 67% males. 282 patients had pCMML (49%), while 291 (51%) had dCMML. As pre-defined, patients with pCMML were more likely to have higher absolute monocyte counts (p Conclusions: Despite the somewhat arbitrary WBC distinction between pCMML and dCMML, clear phenotypic, genetic, transcriptomic, epigenetic and survival differences exist between the two subtypes, providing strong biological rationale for this distinction. pCMML patients have a higher frequency of oncogenic RAS pathway mutations, a unique transcriptomic profile enriched in mitotic check point kinases and a unique chromatin configuration with global and sequence specific enrichment in H3K4me1, with no significant global differences in 5mC, 5hmC, or H3K4me3 and H3K27me3 occupancy. Figure 1 Disclosures Geissler: AOP: Honoraria; Pfizer: Honoraria; AstraZeneca: Honoraria; Novartis: Honoraria; Celgene: Honoraria; Roche: Honoraria; Abbvie: Honoraria; Ratiopharm: Honoraria; Amgen: Honoraria. Al-Kali:Astex Pharmaceuticals, Inc.: Research Funding. Patnaik:Stem Line Pharmaceuticals.: Membership on an entity's Board of Directors or advisory committees.

Background: Standard first-line treatment for patients diagnosed with diffuse large B-cell lymphoma (DLBCL) is the R-CHOP regimen. Despite numerous efforts to improve on this regimen, in all comers and specifically in those with activated B-cell (ABC)-type DLBCL, results from large randomized studies have failed to show a significant clinical advantage above this standard. Recently, 2 large clinical trials in previously untreated DLBCL evaluated the combination of lenalidomide/R-CHOP (R2-CHOP) vs standard R-CHOP and demonstrated discordant results. We analyzed data from these trials to identify differences that may have impacted the disparate trial outcomes while identifying patient characteristics associated with benefit from the addition of lenalidomide across the trials. Methods: The 2 trials included in this evaluation are ROBUST, an international, randomized, double-blinded, placebo-controlled, phase III study of R2-CHOP vs placebo/R-CHOP, and the Intergroup ECOG-ACRIN 1412 (E1412) trial, a US-only, randomized, open-label, phase II study of R2-CHOP vs R-CHOP. Additional key study design differences included dosing, and subtype timing and inclusion (both studies used gene expression profiling [GEP] by NanoString). R-CHOP dosing differed only for prednisone, which was a flat 100 mg dose, d1-5 in ROBUST and 100 mg/m2, d1-5 in E1412. The lenalidomide dose and schedule varied between studies: 15 mg/d, d1-14/21 for ROBUST (210 mg/cycle) and 25 mg/d, d1-10/21 (250 mg/cycle) for E1412. ROBUST enrolled only patients prospectively identified with the ABC subtype, whereas E1412 enrolled all otherwise eligible patients and retrospectively evaluated for ABC-type with prespecified ABC-type accrual and power parameters. Both studies enrolled patients with IPI status ≥ 2, ECOG PS 0-2, and Ann Arbor stage II-IV (E1412 stage II with mass > 10 cm). The primary endpoint in both was progression-free survival (PFS; central review for ROBUST and investigator-assessed for E1412). Secondary endpoints included event-free survival (EFS; key for ROBUST), overall and complete response rates, overall survival (OS), and safety. Results: ROBUST enrolled 570 ABC patients and E1412 enrolled 280 GCB, ABC, and unclassified DLBCL patients. Patient profiles in both studies (ROBUST [ABC]/E1412 [all COO]) were similar in terms of median ages (65 y/66 y), male sex (58%/61%), and ECOG PS 1-2 (55%/63%). Patients in E1412 were more high risk: IPI 2 (42% ROBUST/34% E1412), IPI ≥ 3 (58%/66%), and Ann Arbor stage III/IV disease (87%/97%). Importantly, there was a notable difference in the time from patient diagnosis to treatment: median 31 days for ROBUST and 21 days (22% > 31 d) for E1412. Only 6% of patients in ROBUST were treated within 2 weeks of diagnosis vs 30% in E1412. At a median follow-up of ~2.5 y for both studies, E1412 met its primary endpoint of improvement in PFS with 34% reduction in the risk of PD/death (2-y PFS: 76% vs 70%) for all patients, but did not reach statistical significance in ABC-DLBCL patients for 2-y PFS (71% vs 61%) or 2-y OS (88% vs 76%). ROBUST showed no significant improvement in the primary PFS endpoint (2-y PFS: 67% vs 64%) or 2-y OS (79% vs 80%) in ABC patients. Subgroup analyses of PFS comparing R2-CHOP vs R-CHOP control within each study suggested that certain baseline factors favor the R2-CHOP arm, including: female sex, high IPI score (≥ 3), non-bulky disease (< 7 cm), and high Ann Arbor stage IV disease. Conclusion: While the ROBUST study design integrated state-of-the-art, real-time GEP to prospectively identify ABC-DLBCL patients with rapid lab turnaround time, cases of logistical delays in tissue submission for central analysis and staging procedures may have resulted in accrual of patients with lower-risk DLBCL and prolonged time from diagnosis to treatment. In contrast, E1412 retrospectively stratified patients by COO through GEP and was able to accrue higher-risk patients irrespective of COO within a shorter time from diagnosis to treatment, which among other differences (eg, smaller population size, study phase), could contribute to the improvement over R-CHOP control. Our comparative findings have significant implications for the design of future biomarker-driven trials and provide momentum for studies of novel combinations with R-CHOP in DLBCL. Further investigation into other factors, including dose intensity and their correlation with outcomes, will be presented. Disclosures Nowakowski: Celgene: Consultancy, Research Funding; NanoString: Research Funding; MorphoSys: Consultancy, Research Funding; Genentech, Inc.: Research Funding; F. Hoffmann-La Roche Ltd: Research Funding; Selvita: Membership on an entity's Board of Directors or advisory committees; Curis: Research Funding; Bayer: Consultancy, Research Funding. Chiappella:Servier: Other: advisory board, Speakers Bureau; Roche: Speakers Bureau; Teva: Speakers Bureau; Celgene: Other: advisory board, Speakers Bureau; Janssen: Other: advisory board, Speakers Bureau. Hong:Dana Farber Cancer Institute: Employment; Merck: Consultancy. Scott:Roche/Genentech: Research Funding; Celgene: Consultancy; Janssen: Consultancy, Research Funding; NanoString: Patents & Royalties: Named inventor on a patent licensed to NanoSting [Institution], Research Funding. Amengual:Appia Pharmaceuticals: Research Funding; Epizyme: Speakers Bureau. Leonard:BeiGene: Consultancy; Miltenyi: Consultancy; Sandoz: Consultancy; Gilead: Consultancy; Celgene: Consultancy; ADC Therapeutics: Consultancy; MorphoSys: Consultancy; ADC Therapeutics: Consultancy; Epizyme, Inc: Consultancy; Miltenyi: Consultancy; Genentech, Inc./F. Hoffmann-La Roche Ltd: Consultancy; Karyopharm Therapeutics: Consultancy; Akcea Therapeutics: Consultancy; Merck: Consultancy; Nordic Nanovector: Consultancy; Akcea Therapeutics: Consultancy; Bayer Corporation: Consultancy; Sandoz: Consultancy; MorphoSys: Consultancy; Gilead: Consultancy; BeiGene: Consultancy; AstraZeneca: Consultancy; Nordic Nanovector: Consultancy; Sutro Biopharma: Consultancy; Merck: Consultancy. Friedberg:Bayer: Honoraria, Other: Data & Safety Monitoring Committee; Acerta: Other: Data & Safety Monitoring Committee. Kostakoglu:F. Hoffman-La Roche: Consultancy; Genentech: Consultancy. Jurczak:Morphosys: Research Funding; Bayer: Research Funding; Roche: Research Funding; Incyte: Research Funding; Gilead: Research Funding; Celgene Corporation: Research Funding; Sandoz: Membership on an entity's Board of Directors or advisory committees, Research Funding; AstraZeneca: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novo Nordisk: Research Funding; Servier: Research Funding; Takeda: Research Funding; TG Therapeutics: Research Funding; Celtrion: Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Loxo: Membership on an entity's Board of Directors or advisory committees, Research Funding. Yamamoto:Bristol-Myers Squibb: Consultancy, Honoraria; Bayer: Research Funding; Celgene Corporation: Consultancy, Honoraria, Research Funding; Mundipharma: Consultancy, Honoraria, Research Funding; Astra-Zeneca: Consultancy, Research Funding; Eisai: Consultancy, Honoraria, Research Funding; Meiji Seika Pharma: Consultancy, Honoraria; ARIAD: Research Funding; MSD: Consultancy, Honoraria; Gilead Sciences: Research Funding; Ono: Consultancy, Honoraria, Research Funding; SymBio: Research Funding; HUYA/IQVIA Services Japan: Consultancy, Honoraria; AbbVie: Consultancy, Research Funding; Chugai: Consultancy, Honoraria, Research Funding; Pfizer: Honoraria; Sumitomo Dainippon: Honoraria; Incyte: Research Funding; Janssen: Honoraria; Kyowa Kirin: Honoraria; Novartis: Honoraria, Research Funding; Otsuka: Honoraria; Sanofi: Honoraria; Solasia Pharma: Research Funding; Takeda: Consultancy, Honoraria, Research Funding. Czuczman:Celgene Corporation: Employment, Equity Ownership. Russo:Celgene Corporation: Employment, Equity Ownership. Hudak:Celgene Corporation: Employment, Equity Ownership; Novartis: Employment, Equity Ownership. Zhang:Celgene Corporation: Employment, Equity Ownership. Wade:Celgene: Employment, Equity Ownership. Kahl:ADC Therapeutics: Consultancy, Research Funding; BeiGene: Consultancy; TG Therapeutics: Consultancy; Seattle Genetics: Consultancy. Vitolo:Abbvie: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; F. Hoffmann-La Roche: Speakers Bureau; Juno Therapeutics: Membership on an entity's Board of Directors or advisory committees; Novartis: 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; Gilead: 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; Celgene: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. OffLabel Disclosure: Yes, these trials discuss off-label clinical trial investigation of lenalidomide plus R-CHOP in patients with newly diagnosed diffuse large B-cell lymphoma.

Initial therapy for MCL is effective, but most patients eventually relapse. Validated intermediate biomarkers for MCL are important to provide early assessment of treatment efficacy, prognostic information and potentially guide consolidation. The US-Canadian Intergroup trial E1411 randomly assigned patients (pts) to receive induction with BR ± bortezomib (V), followed by consolidation with R ± L. As a planned correlative, MRD was assessed after cycle 3 (I3), end of induction (EOI) and after 4 cycles of consolidation (C4) by two methods: a research version of clonoSEQ® a next generation sequencing (NGS) MRD assay, (Adaptive Biotechnologies, Seattle, WA) that leverages multiplex PCR followed by NGS to identify and track rearrangements of IgH, V-J, D-J and IgK/L loci as well as translocations in Bcl1/2-IgH, and flow cytometry (FC) (I3 and EOI only) at a central laboratory (Mayo Clinic). While outcomes by treatment arm remain blinded, we report here the results of the MRD assessments by each method and the associated progression free survival (PFS). In E1411, 373 pts, accrued between May 2012 - Sept. 2016, were randomly assigned (stratified by MIPI and age ( BR-based initial MCL therapy achieved early MRD negativity (< 10-4) in a high proportion of patients. Analyzing PB at mid-induction (I3): by NGS 89% MRD-, 9% MRD+ and 2% indeterminate, whereas by FC 87% MRD-, 12% MRD+ and 1% indeterminate. Concordance was high with 127 MRD- by both methods, 13 MRD+ by both, and 6 NGS-/FC+ (Kappa Statistic = 0.79, p-value = 0.031). By NGS, of 12 pts MRD+ at I3, 7 became MRD- at EOI, and 4 remained MRD+ (1 indeterminate). Analyzing at EOI: MRD- rates were 91% by NGS analysis of PB (147/161) and 90% in BM (96/107), vs 95% (174/183) by FC in PB. As some were indeterminate, only 7% were MRD+ by NGS in BM, 3% by NGS in PB and 5% by FC. In 88 informative samples with EOI NGS in both BM and PB, concordance was high, with 81 negative in both, 1 positive in both and 6 BM+/PB- (Kappa Statistic = 0.23, p-value = 0.031). Of 101 pts with data at all 3 timepoints, I3, EOI, and C4: 7 were MRD+ at I3, 5 of these were MRD- at EOI, but 2 of these 5 were again MRD+ at C4. Of 2 MRD+ EOI, 1 became MRD- at C4. By FC, of 17 patients MRD+ at I3, 11 (65%) became MRD- at EOI. MRD status correlated with progression-free survival (PFS). Due to the low MRD+ rate at EOI and C4, we focus here on MRD status at I3 (10-4 cutoff for both NGS and FC), using a landmark analysis of 4 months on study. Median PFS (Figure) for pts MRD- at I3 mid-induction was 58.9 months by either NGS or FC, while for those MRD+ by NGS it was 26.9 months, vs 29.9 months MRD+ by FC. Conclusions: Both NGS and FC were feasible to assess MRD status in this multi-center trial. Results of NGS and FC are concordant at the 10-4 cutoff. NGS can be more sensitive when adequate material is available, and analysis of this subgroup is ongoing. The high MRD- rate (≥ 90%) at EOI in this BR-based trial and MRD correlation with PFS supports its use as a platform for MCL trials, although consolidation may confound PFS. Early interim MRD testing at cycle 3 identifies a high-risk population who may benefit from alternative treatment strategies. Analysis by treatment arm with longer follow-up, as well as comparison with centrally reviewed PET/CTs included in this study, will help define the most informative method(s), cutoff values, and timing for assessing degree of response in MCL. Figure. Disclosures Smith: Astra-Zeneca: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; EUSA: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Parekh:Foundation Medicine Inc.: Consultancy; Celgene Corporation: Research Funding; Karyopharm Inc.: Research Funding. Martin:Sandoz: Consultancy; Karyopharm: Consultancy; Teneobio: Consultancy; Celgene: Consultancy; Janssen: Consultancy; I-MAB: Consultancy. Till:Mustang Bio: Patents & Royalties, Research Funding. Leonard:Gilead: Consultancy; Akcea Therapeutics: Consultancy; Bayer Corporation: Consultancy; Genentech, Inc./F. Hoffmann-La Roche Ltd: Consultancy; BeiGene: Consultancy; Celgene: Consultancy; Akcea Therapeutics: Consultancy; Nordic Nanovector: Consultancy; ADC Therapeutics: Consultancy; Sandoz: Consultancy; MorphoSys: Consultancy; Sutro Biopharma: Consultancy; Karyopharm Therapeutics: Consultancy; Karyopharm Therapeutics: Consultancy; Merck: Consultancy; Genentech, Inc./F. Hoffmann-La Roche Ltd: Consultancy; Epizyme, Inc: Consultancy; Gilead: Consultancy; AstraZeneca: Consultancy; Epizyme, Inc: Consultancy; Bayer Corporation: Consultancy; Miltenyi: Consultancy; Celgene: Consultancy; ADC Therapeutics: Consultancy; MorphoSys: Consultancy; Sandoz: Consultancy; Miltenyi: Consultancy; AstraZeneca: Consultancy; Nordic Nanovector: Consultancy; Merck: Consultancy; BeiGene: Consultancy; Sutro Biopharma: Consultancy. Friedberg:Bayer: Honoraria, Other: Data & Safety Monitoring Committee; Acerta: Other: Data & Safety Monitoring Committee. Kahl:TG Therapeutics: Consultancy; ADC Therapeutics: Consultancy, Research Funding; Seattle Genetics: Consultancy; BeiGene: Consultancy.

Background: Central nervous system (CNS) involvement by peripheral T cell lymphoma (PTCL) is a rare condition. Among primary CNS lymphomas, only 2% are secondary to PTCL, while the risk of CNS relapse in all cases of PTCL is estimated at 2% to 6%. Little is known about the presentation and outcomes of PTCL patients with CNS involvement given the rarity of this entity. In this study, we describe patient characteristics, histology, and clinical course of patients with CNS involvement by PTCL. Methods: The Mayo Clinic Lymphoma Database was used to identify PTCL patients with primary or secondary CNS involvement seen at our institution between 2000 and 2018. A total of 12 patients were identified and their medical records were reviewed for patient and disease characteristics, CNS-directed treatment modality, and outcomes. The Kaplan-Meier method was used for time-to-event analysis. Results: The median age at CNS diagnosis was 63 years (range 41 to 76) and 11 (93%) patients were male. The histological diagnoses were PTCL, NOS in 9 (75%) patients, enteropathy-associated T-cell lymphoma in 2 (17%) patients, and angioimmunoblastic T-cell lymphoma in 1 (8%) patient. Five patients presented with primary T-cell CNS lymphoma (all with a PTCL, NOS histology), while the remaining 7 (58%) patients also had systemic involvement. All patients presented with neurologic symptoms at the time of CNS involvement diagnosis including: focal motor deficits in 6 patients (unilateral upper extremity weakness, gait impairments, and hemiparesis), cognitive decline in 5 patients (memory impairments, reduced attention, and confusion), headache in 4 patients, and seizure in 3 patients. The CNS disease location included the brain parenchyma in 9 (75%) patients, leptomeninges in 1 (8%) patient, and lumbar plexus in 1 (8%) patient. One patient (8%) had positive CSF finding only without radiologic evidence of involvement. CSF analysis was performed in 11 patients. Elevated protein levels were noted in 3 (27%) patients, malignant cells in 2 (18%), and no clear abnormalities in the remaining 6 (55%) patients. Concomitant bone marrow involvement was seen in only 1 patient. Elevated LDH was seen in 2 patients. The a median LDH was 195 U/L (range 139 to 4,360) The most common CNS-directed therapies were: high-dose methotrexate (MTX)-based regimens in 8 (67%) patients, including high-dose MTX in combination with temozolomide (n=2), or cytarabine and thiotepa (n=2). Intrathecal MTX, temozolomide and dexamethasone, lenalidomide, high-dose steroids, and surgical resection were the treatment modality used for one patient each. At a median follow up of 18 months, eight (75%) out of 12 patients were not alive at the time of last follow up. The median overall survival (OS) from diagnosis was 16 months (95% CI: 2.8-173). The median progression free survival (PFS) from initiation of CNS-directed therapy was 9 months (95% CI: 1.6-33) (figure). Four patients had a PFS longer than 12 months. These 4 patients were treated with: temozolomide/dexamethasone, high-dose MTX, lenalidomide, and high-dose MTX followed by cytarabine/thiothepa. Conclusion: CNS involvement by T-cell lymphoma is a rare complication that carries a poor prognosis. Early onset of neurologic symptoms should trigger prompt investigation of CNS involvement. Despite the short OS and PFS, some patients may achieve a relatively longer disease free interval. Disclosures Bennani: Adicet Bio: Other: Advisory board; Seattle Genetics: Other: Advisory board; Purdue Pharma: Other: Advisory board; Seattle Genetics: Other: Advisory board; Seattle Genetics: Other: Advisory board; Bristol-Myers Squibb: Research Funding; Bristol-Myers Squibb: Research Funding; Kite Pharma: Other: Advisory board; Kite Pharma: Other: Advisory board; Bristol-Myers Squibb: Research Funding; Adicet Bio: Other: Advisory board; Purdue Pharma: Other: Advisory board; Purdue Pharma: Other: Advisory board; Adicet Bio: Other: Advisory board; Kite Pharma: Other: Advisory board. Cerhan:Celgene: Research Funding; NanoString: Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees. Nowakowski:Celgene: Consultancy, Research Funding; Bayer: Consultancy, Research Funding; Curis: Research Funding; F. Hoffmann-La Roche Ltd: Research Funding; Genentech, Inc.: Research Funding; MorphoSys: Consultancy, Research Funding; NanoString: Research Funding; Selvita: Membership on an entity's Board of Directors or advisory committees. Ansell:Mayo Clinic Rochester: Employment; Affimed: Research Funding; Bristol-Myers Squibb: Research Funding; Bristol-Myers Squibb: Research Funding; Regeneron: Research Funding; Trillium: Research Funding; Seattle Genetics: Research Funding; Regeneron: Research Funding; LAM Therapeutics: Research Funding; Trillium: Research Funding; Mayo Clinic Rochester: Employment; Affimed: Research Funding; LAM Therapeutics: Research Funding; Seattle Genetics: Research Funding. Paludo:Celgene: Research Funding; Verily Life Sciences: Research Funding; Verily Life Sciences: Research Funding; Celgene: Research Funding.

Introduction: Additional Sex Combs-Like 1 (ASXL1) is a chromatin modifier frequently affected by truncating mutations in myeloid malignancies. These mutations are associated with poor survival outcomes and increased rates of acute leukemic transformation. In chronic myelomonocytic leukemia (CMML), ASXL1 mutations are thought to affect transcriptional activity mainly by modifying histone marks, however additional epigenomic mechanisms have not been fully explored. We interrogated the epigenome of patients with ASXL1-mutant (MT) and -wildtype (WT) CMML using a multiomics approach to define cis-regulatory elements (CREs) such as distal enhancers (DEs). Methods: Bone marrow mononuclear cells from patients with CMML were subjected to targeted NGS of DNA, whole transcriptome shotgun sequencing (RNA-seq), immunoprecipitation (IP) of DNA (hydroxy-)methyl residues (DIP-seq), IP of the histone modifications H3K4me1, H3K4me3, and H3K27me3 (ChIP-seq), and DNA transposase accessibility studies (ATAC-seq). After quality control all samples were sequenced on an Illumina HiSeq 4000 before further processing and data analysis. Global assessments of DNA (hydroxy-)methylation, DNA accessibility, and histone modifications between ASXL1 MT and WT CMML were performed. The samples in the two groups were treated as biological replicates and subjected to a consensus peak calling strategy requiring an overlap of at least 30% between samples and an adjusted p-value < 5x10-5 for a signal peak to be considered statistically significant. Differential gene expression was estimated to define the up-regulated genes in ASXL1 MT CMML. Potential CREs were defined as sites with statistically significant signal peaks overlapping in at least two of the three epigenomic marks: H3K4me1, 5hmC, and ATAC. Potential DEs were defined as CREs in non-coding regions outside promoter regions (defined as transcription start site ±3kb) that were annotated in GeneHancer. Annotated DEs only present in ASXL1 MT but not WT CMML (specific DEs) were intersected with the list of up-regulated genes and the ReMap atlas. Results: Sixteen WHO-defined CMML patients were included, median age 69 years (48 - 77), 63% male; of which 8 patients (50%, all truncating frame shift mutations) were ASXL1 MT and 8 (50%) WT. The burden and spectrum of co-mutations was similar between ASXL1 WT and MT CMML (21 versus 23 per group; p = 0.684; heatmap). There was a predominant up-regulation of gene expression in ASXL1 MT CMML: 707 genes up- and 124 down-regulated (volcano plot, FDR < 0.050 for all genes). There were 64336 potential CREs, the vast majority (97%) being present in both ASXL1 MT and WT CMML (left Venn diagram). These CREs were most commonly located in introns, promoter regions, and distal non-coding regions (bar graph and pie chart). There were 1303 CREs unique to ASXL1 MT CMML (specific DEs), 1161 (90%) of which were annotated in GeneHancer (left Euler diagram). Of these 1161 annotated specific DEs 859 (74%) were located outside promoter regions and 34 (4%) of them were known to be associated with genes up-regulated in ASXL1 MT CMML (Euler diagrams). These specific DEs were characterized by an increase in H3K4me1 occupancy and DNA accessibility (average signal tracks, purple bars indicating annotated DEs, thin bars below peaks indicating statistical significance). We previously observed epigenomic modification of promoter regions in 519 of the 707 up-regulated genes (73%) facilitating transcriptional activity in ASXL1 MT CMML. For 13 of the up-regulated genes (right Venn diagram, blue genes in volcano plot) the specific DEs were the sole identified mechanism, while for the other 21 genes there were additional mechanisms noted in the promoter region. The top five transcription factor candidates binding the 34 specific DEs included JMJD1C, MYC, KDM5B, RCOR1, and HDAC2 (-log10(E) > 40 for all candidates). Conclusions: Using a multiomics approach based on H3K4me1, 5hmC, and ATAC data we identified potential CREs in ASXL1 MT CMML and characterized potential DEs using publicly available annotation data. Specific DEs were associated with up-regulated genes serving as a possible explanation for the observed transcriptional activity, shedding further light on the adverse prognostic impact associated with ASXL1 mutations. Figure 1 Disclosures Patnaik: Stem Line Pharmaceuticals.: Membership on an entity's Board of Directors or advisory committees.

Introduction: New Diffuse Large B-cell (DLBCL) treatments remain a clinical need despite the success of rituximab combined with CHOP chemotherapy (RCHOP), which results in durable responses in 60-70% of patients. Those refractory to, or who relapse following, first-line therapy have a very poor outcome, with only 20% surviving beyond 5 years. Rationally-targeted frontline strategies are needed, especially for those with high-risk disease. Significant advances have been made in the genomic classification of DLBCL, but none have impacted the design of phase III trials for untreated DLBCL patients. Building on new genetic profiling studies to personalize clinical treatment, an NCI initiative, could allow clinicians to add targeted therapies to the RCHOP backbone based on individual tumor signatures. The phase II ECOG-ACRIN1412 trial, which compared RCHOP combined with lenalidomide (R2CHOP) versus RCHOP showed significantly superior event free survival (EFS) and overall survival benefits for those treated with R2CHOP. Herein, we report the profile of a high-risk ABC/non-GCB subset of DLBCL driven by genomic alterations in inflammatory genes that are susceptible to front-line R2CHOP, but continue to experience poor outcome with RCHOP alone. Methods: We studied a total of 196 DLBCL patients. 47 were treated with R2CHOP from an investigator-initiated, open-label, single-arm phase II study (NCT00670358). 149 were newly diagnosed DLBCL cases treated with RCHOP, or R-immunochemotherapy (herein called RCHOP), and followed prospectively through the Molecular Epidemiology Resource (MER) of the University of Iowa/Mayo Clinic SPORE that served as a contemporary cohort. Patients from each treatment group were divided based on their event free survival at 24 months (EFS24). DNA alterations within these populations were identified through whole exome sequencing (WES). Variants were analyzed for their presence in EFS24 achievement or failure groups in both RCHOP and R2CHOP. Both tumor and germline sequencing was performed for 47/47 R2CHOP cases and 49/149 RCHOP cases. Gene expression data from the PanCan panel of 730 B-cell-related genes was analyzed to determine gene expression profiles characteristic of the high-risk/R2CHOP-profile on 59 available non-GCB DLBCL cases (45 RCHOP; 14 R2CHOP). A two-sided comparative marker analysis T statistic test was applied to assess what genes displayed differential expression based on achieving EFS24 in both R2CHOP and RCHOP populations. Positive values represented associations with achieving EFS24 and negative values were associated with cases of EFS24 failure. Results: Three genes were enriched in the RCHOP cases that failed EFS24 but achieved EFS24 with R2CHOP among non-GCB patients: PIM1, SPEN, and MYD88 (L265P), herein referred to as Responder Alterations. In R2CHOP cases, patients with a Responder Alteration had a better overall EFS (P = 0.051) compared to wild type patients. In contrast, RCHOP treated patients with a Responder Alteration in their tumor had a significantly worse overall EFS (P = 0.0004) compared to patients without a mutation. Together, PIM1, SPEN, or MYD88 (L265P) mutations were present in 38.0% (30/79) of all non-GCB cases. Collective R2CHOP and RCHOP EFS24 differential gene expression T values were significantly different for 18 previously-defined signatures. The R2CHOP cases that achieved EFS24 were enriched for genes involved in cell cycle, JAK-STAT, cytokine signaling, and NF-κB pathways based on these signatures and ontology analyses. Lastly, cases with WES and PanCan data were analyzed together to observe differential gene expression patterns between cases with and without signature mutations. These data suggest that R2CHOP disrupts tumors reliant on IRF4, NF-κB, and STAT transcription factors, leading to a loss of proliferative feedback systems. Conclusions: Our combined analysis of DNA and RNA across R2CHOP and RCHOP treatment cohorts identifies a high-risk non-GCB phenotype that encompasses approximately 38% of non-GCB patients, is capable of sustaining JAK-STAT and NF-κB signaling, and is sensitive to R2CHOP. Our study lays the groundwork for a precision therapy approach in DLBCL in which DNA or RNA profiles can be used to identify patients early in treatment who may not benefit from the current standard of care, RCHOP, and who would benefit from the addition of lenalidomide or other targeted agents. Disclosures Gandhi: Celgene Corporation: Employment, Equity Ownership, Patents & Royalties. Ansell:LAM Therapeutics: Research Funding; Seattle Genetics: Research Funding; LAM Therapeutics: Research Funding; Seattle Genetics: Research Funding; Regeneron: Research Funding; Bristol-Myers Squibb: Research Funding; Affimed: Research Funding; Trillium: Research Funding; Trillium: Research Funding; Regeneron: Research Funding; Bristol-Myers Squibb: Research Funding; LAM Therapeutics: Research Funding; Trillium: Research Funding; Affimed: Research Funding; LAM Therapeutics: Research Funding; Bristol-Myers Squibb: Research Funding; Trillium: Research Funding; Affimed: Research Funding; Bristol-Myers Squibb: Research Funding; Trillium: Research Funding; LAM Therapeutics: Research Funding; Bristol-Myers Squibb: Research Funding; Regeneron: Research Funding; Affimed: Research Funding; Seattle Genetics: Research Funding; Mayo Clinic Rochester: Employment; Regeneron: Research Funding; Seattle Genetics: Research Funding; Mayo Clinic Rochester: Employment; Seattle Genetics: Research Funding; LAM Therapeutics: Research Funding; LAM Therapeutics: Research Funding; LAM Therapeutics: Research Funding; Regeneron: Research Funding; Regeneron: Research Funding; Seattle Genetics: Research Funding; Seattle Genetics: Research Funding; Trillium: Research Funding; Trillium: Research Funding; Affimed: Research Funding; Affimed: Research Funding; Mayo Clinic Rochester: Employment; Mayo Clinic Rochester: Employment; Mayo Clinic Rochester: Employment; Seattle Genetics: Research Funding; Mayo Clinic Rochester: Employment; Bristol-Myers Squibb: Research Funding; Bristol-Myers Squibb: Research Funding; Affimed: Research Funding; Regeneron: Research Funding; Regeneron: Research Funding; Bristol-Myers Squibb: Research Funding; Regeneron: Research Funding; Seattle Genetics: Research Funding; Trillium: Research Funding; Mayo Clinic Rochester: Employment; Mayo Clinic Rochester: Employment; Trillium: Research Funding; Affimed: Research Funding; Mayo Clinic Rochester: Employment; Bristol-Myers Squibb: Research Funding; Affimed: Research Funding; LAM Therapeutics: Research Funding. Cerhan:Celgene: Research Funding; NanoString: Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees. Nowakowski:Curis: Research Funding; Bayer: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; F. Hoffmann-La Roche Ltd: Research Funding; Genentech, Inc.: Research Funding; MorphoSys: Consultancy, Research Funding; NanoString: Research Funding; Selvita: Membership on an entity's Board of Directors or advisory committees. Novak:Celgene Coorperation: Research Funding.

Background: While there is evidence in the literature of increased prevalence of hypogammaglobulinemia in chronic lymphocytic leukemia (CLL), there are no studies evaluating the prevalence of hypogammaglobulinemia in newly diagnosed diffuse large B cell lymphoma (DLBCL) or the relationship between hypogammaglobulinemia and presentation or outcomes. The objective of this study was to examine the prevalence of hypogammaglobulinemia in newly diagnosed DLBCL patients and to test the hypothesis that DLBCL patients with baseline hypogammaglobulinemia have a distinct clinical profile and outcome. Methods: We obtained banked frozen sera from 200 newly diagnosed, treatment-naïve, DLBCL patients from the Lymphoma SPORE Molecular Epidemiology Resource (MER), a prospective cohort study conducted at the Mayo Clinic and the University of Iowa. IgG/A/M levels were measured using immunoturbidimetric assay whereas IgE level was measured using electrochemiluminescence immunoassay; deficiency was defined using standard reference ranges. IgE levels were considered deficient if Results: The mean age (SD) of the cohort was 65.6 (13.4) years, 54% were males and 98% of the patients were white. Over a median follow-up of five years, there were 59 (29.5%) deaths. The prevalence of hypogammaglobulinemia, defined as any deficiency, in newly diagnosed, treatment-naïve DLBCL was 22.1% (44/199) in our cohort, and the most common Ig deficiency was for IgG ( Conclusions: To the best of our knowledge, this is the first study to report the prevalence of hypogammaglobulinemia in treatment naïve DLBCL. We found that any Ig deficiency was not uncommon in our cohort and it was associated with an inferior EFS and OS in DLBCL patients. The prevalence of hypogammaglobulinemia in DLBCL patients seems to be lower than has been described in CLL patients. While the underlying relationship between these two immunologic disorders deserves further study, our findings highlight the interaction between global immune dysfunction and emergence of a clonal B cell process. Disclosures Nowakowski: Genentech, Inc.: Research Funding; F. Hoffmann-La Roche Ltd: Research Funding; Curis: Research Funding; Bayer: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Selvita: Membership on an entity's Board of Directors or advisory committees; NanoString: Research Funding; MorphoSys: Consultancy, Research Funding. Farooq:Celgene: Honoraria; Kite Pharma: Research Funding. Cerhan:NanoString: Research Funding; Celgene: Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees.

INTRODUCTION Complete staging via bone marrow assessment is standard of practice for most newly diagnosed non-Hodgkin lymphoma (NHL) patients, though the methods and patterns of bone marrow assessment vary in clinical practice. The 2014 Lugano Classification recommends that in diffuse large B cell lymphoma (DLBCL), positron emission tomography-computed tomography (PET/CT) alone can designated advanced-stage disease in many, but not all cases. For most other NHL subtypes, obtaining bone marrow biopsy (BMB) remains recommended. We aimed to assess clinical practice patterns of marrow assessment and the performance of PET/CT in the clinical setting. METHODS The Lymphoma Epidemiology of Outcomes (LEO) cohort is a prospective cohort from 8 academic medical centers. All patients were enrolled in the cohort within 6 months of diagnosis, and prospectively followed. Patients with lymphoma enrolled in the cohort between July 2015 and June 2017 were included for study. Baseline clinical characteristics at diagnosis, whether BMB and/or PET/CT were performed, and the result of these assessments were extracted from the database. Bone marrow involvement on PET/CT was abstracted via review of radiology reports. No central review of images was utilized. RESULTS In total, 3,251 patients were included, consisting of the following subtypes: DLBCL (n=1,098), follicular lymphoma (FL n=730), mantle cell lymphoma (MCL n=302), T-cell lymphoma (TCL n=278), marginal zone lymphoma (MZL n=269), other NHL (n=505) and composite lymphoma (n=69). Other clinical characteristics are shown in table 1. Staging BMB was obtained in 78% of patients, PET/CT was obtained in 56%, both BMB and PET/CT were obtained in 46% while neither were obtained in 9% (table 1). There were significant differences in lymphoma subtype between patients having any bone marrow assessment vs no bone marrow assessment (p Among patients with DLBCL who had positive bone marrow by either PET/CT or BMB (N=107), 41% (44/107) were positive by BMB only, 19% (20/107) were positive by PET/CT only, and 40% (43/107) were positive by both. Figure 1 shows results of similar analyses for FL, MCL, MZL, and TCL. Using BMB as a gold standard for marrow involvement, the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of PET/CT for marrow assessment in DLBCL is 49%, 90%, 68% and 91%, respectively. Data for other subtypes are shown in table 2. Patients undergoing both PET/CT and BMB had lower median LDH (231 U/L vs 254 U/L, p=0.0032) than those undergoing one or neither assessments. CONCLUSION Overall, 91% of all patients with newly diagnosed NHL had bone marrow assessments via either PET/CT, BMB or both. The significant variation in the frequency of BMB and PET/CT use among the 8 centers reflects a lack of clear consensus on staging practices regarding bone marrow assessment. The sensitivity of PET/CT for detection of marrow involvement was less than 50% across all subtypes. It is possible the sensitivity of PET/CT could be improved via a centralized review process of the images, as is performed in some clinical trials, however practical approaches for implementing such reviews in clinical practice have not been developed. Between 92-100% of all positive bone marrows were detected by BMB, except in cases with DLBCL in which 19% of positive bone marrows were missed by BMB but detected by PET/CT. Thus, in our analysis, BMB more reliably captured marrow involvement that PET/CT in all subtypes in which both assessments were performed. However, neither PET/CT nor BMB alone were able to identify all cases of bone marrow involvement and use of both modalities may be necessary in cases where marrow involvement would have clinically important implications. Disclosures Rutherford: Juno Therapeutics Inc: Consultancy, Honoraria; Janssen Scientific Affairs: Consultancy, Honoraria; Seattle Genetics: Consultancy, Honoraria; Verastem: Consultancy, Honoraria; Karyopharm: Honoraria, Membership on an entity's Board of Directors or advisory committees; AstraZeneca: Consultancy, Honoraria; Celgene: Consultancy, Honoraria; Heron: Consultancy, Honoraria. Kahl:ADC Therapeutics: Consultancy, Research Funding; Seattle Genetics: Consultancy; TG Therapeutics: Consultancy; BeiGene: Consultancy. Lossos:Janssen Scientific: Membership on an entity's Board of Directors or advisory committees; NIH: Research Funding; Seattle Genetics: Membership on an entity's Board of Directors or advisory committees. Friedberg:Acerta: Other: Data & Safety Monitoring Committee; Bayer: Honoraria, Other: Data & Safety Monitoring Committee. Casulo:Celgene: Research Funding; Roche: Other: Travel, accommodation, expenses; Gilead: Honoraria, Other: Travel, accommodation, expenses. Cohen:Astra Zeneca: Research Funding; Takeda Pharmaceuticals North America, Inc.: Research Funding; Hutchison: Research Funding; Gilead/Kite: Consultancy; Bristol-Meyers Squibb Company: Research Funding; LAM Therapeutics: Research Funding; UNUM: Research Funding; Lymphoma Research Foundation: Research Funding; ASH: Research Funding; Seattle Genetics, Inc.: Consultancy, Research Funding; Janssen Pharmaceuticals: Consultancy; Genentech, Inc.: Consultancy, Research Funding. Nastoupil:TG Therapeutics: Honoraria, Research Funding; Novartis: Honoraria; Spectrum: Honoraria; Celgene: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Genentech, Inc.: Honoraria, Research Funding; Gilead: Honoraria; Bayer: Honoraria. Flowers:Denovo Biopharma: Consultancy; Spectrum: Consultancy; National Cancer Institute: Research Funding; Optimum Rx: Consultancy; Burroughs Wellcome Fund: Research Funding; Acerta: Research Funding; Bayer: Consultancy; BeiGene: Consultancy, Research Funding; Eastern Cooperative Oncology Group: Research Funding; TG Therapeutics: Research Funding; Genentech, Inc./F. Hoffmann-La Roche Ltd: Consultancy, Research Funding; Gilead: Consultancy, Research Funding; Karyopharm: Consultancy; AstraZeneca: Consultancy; Pharmacyclics/Janssen: Consultancy, Research Funding; AbbVie: Consultancy, Research Funding; V Foundation: Research Funding; Millenium/Takeda: Research Funding; Celgene: Consultancy, Research Funding. Cerhan:Janssen: Membership on an entity's Board of Directors or advisory committees; Celgene: Research Funding; NanoString: Research Funding. Martin:Sandoz: Consultancy; Karyopharm: Consultancy; Celgene: Consultancy; Teneobio: Consultancy; I-MAB: Consultancy; Janssen: Consultancy.

Background Follicular lymphoma (FL) is the second most common lymphoma accounting for approximately 15% of all non-Hodgkin's lymphoma (NHL). Yttrium-90 ibritumomab tiuxetan [(90)Y-IT; Zevalin] is a radio-immunoconjugate (RIC) which targets CD20. It is approved in relapsed/refractory low-grade NHL and as consolidation after upfront induction chemoimmunotherapy for FL. This study analyzed patients with previously untreated (UFL) or relapsed/refractory low-grade FL (RFL) treated at our institution with (90)Y-IT. It represents the largest reported cohort for therapeutic use of (90)Y-IT in low-grade FL. Methods Medical records of patients with low-grade FL (WHO grade 1-2) who received treatment with (90)Y-IT at Mayo Clinic Cancer Center between January 2003 and December 2018 were analyzed. Overall response rate (ORR) and complete response rate (CR) were calculated. Progression-free survival (PFS), time to next therapy (TTNT), and overall survival (OS) were analyzed using the Kaplan-Meier method. Results Our cohort consists of 137 patients - 29% (40/137) with UFL and 71% (97/137) with RFL. The median age at diagnosis was 60 years (range, 18-86) with 54% (74/137) males. The median number of previous treatments in RFL patients was 1 (range, 1-5). ECOG performance status at the time of treatment was 0 in 90% and 1 in 10% of patients. 87% (119/137) had stage III/IV disease at the time of (90)Y-IT therapy. The median follow up from the time of (90)Y-IT therapy was 10.2 years (95% CI; 8.8, 11.6); 69% (95/137) of patients are alive. The ORR was 100% in UFL with 93% (37/40) CR while ORR in UFL was 93% (90/97) with 73% (71/97) CR. 45% (48/108) of the CR patients remain in continuous CR (CCR) with a median follow-up of 7 years (95% CI; 5.2, 9.9). CCR was observed in 55% (22/40) of UFL patients compared to 27% (26/97) of RFL patients. 63% (86/137) of patients had relapsed. More relapses occurred in the RFL group (69/97; 71%) compared to the UFL group (17/40; 43%), (p=0.002). In the entire cohort, the median PFS was 2.5 years (95% CI; 2.1, 3.5) and TTNT was 3.6 years (95% CI; 2.5, 4.7). Median PFS was significantly higher in UFL group compared to RFL group- 4.1 years (95% CI; 2.3, NR) vs 2.2 years (95% CI; 1.6, 3.1), respectively (Figure 1-A). Median TTNT was higher in UFL group compared to RFL group- NR (95% CI; 4.1 years, NR) vs 2.4 years (95% CI; 2, 3.6), respectively (Figure 1-B). Median OS (entire cohort) was 18 years (95% CI; 15.8, NR) with no statistically significant difference between UFL group and RFL group; NR (95% CI; NR, NR) vs 18 years (95% CI; 12.3, 20.5), respectively (Figure 1-C). Transformation to high grade lymphoma was seen in 19% (18/97) in RFL group compared to 2.5% (1/40) in UFL group, (p=0.005). Median time to transformation was 4.3 years (range, 1-11). More patients developed therapy-related myelodysplastic syndrome/acute myeloid leukemia (MDS/AML) in the RFL group 14% (14/97) compared to 2.5% (1/40) in the UFL group (p= 0.02). Median time to develop MDS/AML was 3.3 years (range, 0-9.7). Grade ³3 neutropenia was observed in 46% of patients with median time to recovery of 21 days (range, 2-706). Grade ³3 thrombocytopenia was observed in 47% of patients with median time to recovery of 23 days (range, 7-548). Eighteen patients required growth factors support and 14 required transfusions. Non-hematologic AEs included mild to severe fatigue in 35 patients. Conclusion Radio-immunoconjugate therapy with (90)Y-IT is an effective single-agent regimen for low-grade FL. The response and survival data in this large real-world cohort is superior to the pivotal trials of this agent conducted nearly 20 years ago. The data in untreated FL is also of interest and provides the rationale for our current randomized phase 2 trial in untreated FL (https://clinicaltrials.gov/show/NCT02320292). Long-term complete remission (>7 years) was seen in 35% of the study population. Based on these promising results, clinical trials combining RIC with novel agents that could potentiate its effects are warranted. Figure 1 (A) Progression-free survival; comparing time to progression or death after (90)Y-IT treatment between previously untreated patients (UFL) and patients with relapsed/refractory FL (RFL), (B) Time to next therapy; comparing time to starting next line of treatment after (90)Y-IT treatment between UFL and RFL, (C) Overall survival; comparing time to death from all causes after (90)Y-IT treatment between UFL and RFL. Figure 1 Disclosures Tun: DTRM Biopharma: Research Funding; TG Therapeutics: Research Funding; BMS: Research Funding; Curis: Research Funding; Celgene: Research Funding; Mundi-pharma: Research Funding. OffLabel Disclosure: Yttrium-90 ibritumomab tiuxetan [(90)Y-IT; Zevalin] is a radio-immunoconjugate (RIC) which targets CD20. It is approved in relapsed/refractory low-grade NHL and as consolidation after upfront induction chemoimmunotherapy for FL. We are discussing its use as a frontline therapy in low grade FL.

Introduction: The phase 3 international, randomized, double-blind ROBUST clinical trial (NCT02285062) compared progression-free survival between patients with previously untreated ABC-type DLBCL treated with placebo plus rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (placebo-R-CHOP) versus lenalidomide + R-CHOP (R2-CHOP) for 6 21-day cycles. HRQoL, as measured by the Functional Assessment of Cancer Therapy-Lymphoma (FACT-Lym) and the EuroQoL 5-dimension 3-level (EQ-5D-3L) patient-reported questionnaires, was evaluated as a secondary endpoint for the 2 treatment arms. Methods: For each treatment group, FACT-Lym and EQ-5D-3L scores were measured at baseline (BL), mid-, end-of-treatment (EOT), and post-treatment, in 12-week intervals from Week 34 onward. Patients were evaluated if they had completed BL and ≥ 1 post-BL calculable FACT-Lym subscale measurements. Non-inferiority (NI) of R2-CHOP versus placebo-R-CHOP was measured for 4 key FACT-Lym subscales: Physical Well-Being (PWB), Additional Concerns (AC), Functional Well-Being (FWB), and Trial Outcome Index (TOI). NI was assessed at EOT (typically 3-4 weeks after completing Cycle 6) and at post-treatment follow-up at Week 34 by analysis of covariance (ANCOVA). The NI margins were prespecified as 1 less than the higher published minimal important difference (MID) for each subscale. Since a range of MIDs have been published, a more conservative value was also used as a sensitivity analysis. Time to improvement (TTI), using published responder definitions, was also assessed for the FACT-Lym subscales. EQ-5D-3L scores were summarized descriptively. Results: Demographic and baseline disease characteristics were balanced across the 2 treatment arms (N = 285 per arm). The percentage of patients who completed the FACT-Lym out of the expected population remained > 85% at all time points with > 50 patients still on the study in each treatment arm up to Week 142. Completion rates and reasons for missing assessments were balanced across the 2 treatment arms. FACT-Lym subscale scores were generally higher after EOT, similar for both treatment groups, and mean changes from BL were close to or above MID (where defined), except for the Social/Family Well-Being subscale. Mean differences in FACT-Lym TOI between treatment arms are shown in Table 1. As positive treatment differences favor R2-CHOP and -10 was the predefined NI margin, NI was demonstrated for the FACT-Lym TOI subscale at both EOT and Week 34 assessments. Superiority of R2-CHOP was demonstrated at EOT as the confidence interval (CI) lies completely above 0 (P < 0.04); however, this difference was not clinically meaningful. Furthermore, NI was also demonstrated when using the sensitivity analysis margin of -4.5. ANCOVA models were also fitted for the other key subscales of PWB, AC and FWB (Table 2). NI was demonstrated for all NI margins at both time points for the PWB and AC subscales. The FACT-Lym FWB subscale demonstrated NI for both margins at EOT and Week 34 for the primary NI margin of -2 based on the MID minus 1, but did not demonstrate NI when an NI margin of -1, based on an alternative published MID, was used. The TTI curves and associated summary statistics were similar for the 2 treatment arms, with a median TTI for the FACT-Lym TOI of 21 weeks (95% CI 15-22) for patients treated with R2-CHOP and 18 weeks (95% CI 15-22) for patients treated with placebo-R-CHOP. Mean EQ-5D-3L visual analogue scale (VAS) and Utility Index (UK weights) change from baseline scores were higher in both treatment arms and the mean changes were above, or close to, the published MID (7 for VAS, 0.1 for Utility Index) at EOT assessments. Prespecified sensitivity and subgroup analyses supported the conclusions from the primary HRQoL analyses. Conclusions: The predefined NI levels were met for the 4 key FACT-Lym subscales. Similar results were observed across the other HRQoL assessments, sensitivity, and subgroup analyses. Adding lenalidomide to the R-CHOP regimen did not adversely affect the HRQoL of patients with DLBCL as measured by FACT-Lym and EQ-5D-3L. These data serve as a benchmark for future clinical trials combining next-generation immunomodulatory drugs with standard R-CHOP to improve clinical efficacy while maintaining HRQoL in patients with DLBCL. HRQoL analyses should become an integral part of future clinical trials of novel combination regimens in DLBCL. Disclosures Chiappella: Roche: Speakers Bureau; Teva: Speakers Bureau; Servier: Other: advisory board, Speakers Bureau; Janssen: Other: advisory board, Speakers Bureau; Celgene: Other: advisory board, Speakers Bureau. Cocks:Adelphi Values: Employment; Amgen: Consultancy; BMS: Consultancy; Celgene Corporation: Consultancy; Endomag Ltd.: Consultancy. Greenwood:Adelphi Values: Employment. Williams:Adelphi Values: Employment. Scott:Celgene: Consultancy; Roche/Genentech: Research Funding; NanoString: Patents & Royalties: Named inventor on a patent licensed to NanoSting [Institution], Research Funding; Janssen: Consultancy, Research Funding. Yamamoto:SymBio: Research Funding; Ono: Consultancy, Honoraria, Research Funding; Otsuka: Honoraria; Sanofi: Honoraria; Astra-Zeneca: Consultancy, Research Funding; Sumitomo Dainippon: Honoraria; Chugai: Consultancy, Honoraria, Research Funding; Eisai: Consultancy, Honoraria, Research Funding; Janssen: Honoraria; Gilead Sciences: Research Funding; Solasia Pharma: Research Funding; Bayer: Research Funding; Celgene Corporation: Consultancy, Honoraria, Research Funding; ARIAD: Research Funding; Pfizer: Honoraria; Bristol-Myers Squibb: Consultancy, Honoraria; Kyowa Kirin: Honoraria; MSD: Consultancy, Honoraria; Mundipharma: Consultancy, Honoraria, Research Funding; AbbVie: Consultancy, Research Funding; Meiji Seika Pharma: Consultancy, Honoraria; HUYA/IQVIA Services Japan: Consultancy, Honoraria; Novartis: Honoraria, Research Funding; Incyte: Research Funding; Takeda: Consultancy, Honoraria, Research Funding. Jurczak:Bayer: Research Funding; Takeda: Research Funding; Gilead: Research Funding; Sandoz: Membership on an entity's Board of Directors or advisory committees, Research Funding; Morphosys: Research Funding; Incyte: Research Funding; Celgene Corporation: Research Funding; Loxo: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Roche: Research Funding; AstraZeneca: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celtrion: Research Funding; Novo Nordisk: Research Funding; Servier: Research Funding; TG Therapeutics: Research Funding. Özcan:Sanofi: Other: Travel support; Abdi Ibrahim: Other: Travel support; BMS: Other: Travel support; Takeda: Honoraria, Other: Travel support, Research Funding; Archigen: Research Funding; Roche: Other: Travel support, Research Funding; Bayer: Research Funding; Janssen: Other: Travel support, Research Funding; Celgene Corporation: Research Funding, Travel support; AbbVie: Other: Travel support, Research Funding; MSD: Research Funding; Novartis: Research Funding; Jazz: Other: Travel support; Amgen: Honoraria, Other: Travel support. Belada:Roche: Consultancy; Gilead Sciences: Consultancy; Takeda: Consultancy. Margunato-Debay:Celgene Corporation: Employment, Equity Ownership. Czuczman:Celgene Corporation: Employment, Equity Ownership. Zhai:Celgene Corporation: Employment, Equity Ownership. Braverman:Celgene Corporation: Employment. Vitolo:Juno Therapeutics: Membership on an entity's Board of Directors or advisory committees; Abbvie: 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; Celgene: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: 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; F. Hoffmann-La Roche: Speakers Bureau; Gilead: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Nowakowski:Selvita: Membership on an entity's Board of Directors or advisory committees; NanoString: Research Funding; MorphoSys: Consultancy, Research Funding; Curis: Research Funding; Bayer: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Genentech, Inc.: Research Funding; F. Hoffmann-La Roche Ltd: Research Funding.

Background: The 2018 iwCLL guidelines recommend close observation of early stage CLL pts who do not meet indications for therapy ("watch and wait" strategy). Prior attempts at early therapeutic intervention in unselected early-stage CLL pts using alkylating agents such as chlorambucil and chemoimmunotherapy failed to show a significant benefit; and these therapies were associated with substantial toxicities. The introduction of Bruton tyrosine kinase (BTK) inhibitors has revolutionized the treatment landscape of CLL. The German CLL Study group recently presented results of the CLL12 study which demonstrated a significant improvement in event-free survival (EFS) among untreated early stage high risk CLL pts who received ibrutinib compared to placebo (median EFS not reached vs. 47.8 months, respectively; Langerbeins, EHA, 2019). Acalabrutinib is a more selective second-generation BTK inhibitor that has fewer adverse events in pts with CLL, and has shown equally impressive clinical activity for CLL pts. We are conducting an investigator initiated randomized phase 2 study to compare acalabrutinib with or without obinutuzumab (a glycoengineered anti-CD20 monoclonal antibody approved in the treatment of CLL) among high risk early stage CLL pts. Study Design: All pts with newly diagnosed (65 years (1 point), Rai stage I-IV (1 point), del17p and/or TP53 mutation (4 points), unmutated immunoglobulin heavy chain (IGHV) genes (2 points), and serum β2-microglobulin >3.5 g/dL (2 points). Pts with high (4-6) and very high (7-10) risk CLL-IPI are randomly (1:1) assigned to acalabrutinib 100 mg orally twice daily (Arm A) or acalabrutinib with obinutuzumab at a standard approved schedule (Arm B). Treatment with acalabrutinib is continued for a minimum of 2 years unless the patient has unacceptable side effects or withdraws consent. Pts with low (0-1) and intermediate (2-3) risk CLL-IPI score are assigned to an observation arm with follow-up once every 6 months for 2 years, and then according to routine clinical practice (Arm C). Endpoints: The primary endpoint of the intervention arms (Arms A and B) is the achievement of minimal residual disease (MRD)-negative complete remission in the bone marrow after 2 years of therapy. MRD is assessed using an 8-color flow cytometry with a detection limit of 0.01%. The primary endpoint of the observation arm (Arm C) is time to first therapy. Secondary endpoints for all arms are: progression-free survival, overall survival, and safety. Statistical design: A randomized trial comparing the experimental arm (acalabrutinib plus obinutuzumab) against the control arm (acalabrutinib alone) will be conducted as described by Rubinstein. A sample size of 36 pts per arm provides 80% power to detect an improvement in MRD-negative complete response rate from 10% to 30%, using a one-sided test at a significance level of 0.10 (EAST 6.4). We anticipate accruing an additional 8 high/very high risk pts (4 in each arm) to account for ineligibility, cancellation, or major treatment violation. The total enrollment for Arms A and B will be 80 pts. We will enroll 40 pts to Arm C; for a total enrollment of 120 pts. Key correlatives: Comprehensive profiling to assess the innate and adaptive immune system in paired peripheral blood and bone marrow will be conducted in all pts registered to Arms A and B at baseline, 12 and 24 months after enrollment. In addition, bone marrow hematopoietic function will be assessed in all pts at these time points. We will employ a CLL focused custom 61-gene panel to estimate tumor mutational burden as well as mutational profiles for each patient at baseline, 12, and 24 month time points, as well at the time of disease progression. Preliminary results: The trial is registered at clinicaltrials.gov NCT03516617. The trial opened to accrual at all three Mayo Clinic sites (Rochester, MN; Jacksonville, FL; and Scottsdale, AZ) in September 2018. Twenty-eight pts have been registered; the baseline characteristics are shown in Table 1. The trial is expected to complete enrollment in September 2020; and the primary analysis will be available in September 2022. Disclosures Parikh: Janssen: Research Funding; AstraZeneca: Honoraria, Research Funding; Pharmacyclics: Honoraria, Research Funding; MorphoSys: Research Funding; AbbVie: Honoraria, Research Funding; Acerta Pharma: Research Funding; Ascentage Pharma: Research Funding; Genentech: Honoraria. Ding:DTRM Biopharma: Research Funding; Merck: Research Funding. Ailawadhi:Pharmacyclics: Research Funding; Cellectar: Research Funding; Takeda: Consultancy; Amgen: Consultancy, Research Funding; Janssen: Consultancy, Research Funding; Celgene: Consultancy. Kenderian:Novartis: Patents & Royalties, Research Funding; Tolero: Research Funding; Humanigen: Other: Scientific advisory board , Patents & Royalties, Research Funding; Lentigen: Research Funding; Morphosys: Research Funding; Kite/Gilead: Research Funding. Chanan-Khan:Mayo Clinic: Employment; Ascentage: Research Funding; Millennium: Research Funding; Jansen: Research Funding; AbbVie: Research Funding; Xencor: Research Funding; Pharmacyclics: Research Funding; Merck: Research Funding. Kay:Infinity Pharmaceuticals: Other: DSMB; Celgene: Other: Data Safety Monitoring Board; Agios: Other: DSMB; MorphoSys: Other: Data Safety Monitoring Board. OffLabel Disclosure: Drug: Acalabrutinib Purpose: treatment of CLL

Background: Follicular lymphoma (FL) is the most frequent indolent lymphoma. While immunochemotherapy (IC) treated FL patients who achieve event-free status at 24 months after diagnosis (EFS24) have the subsequent life expectancy of the general population, those who fail to achieve EFS24 have aggressive disease with poor outcomes. Similarly, in FL patients initially observed or treated with rituximab monotherapy, EFS at 12 months (EFS12) is a strong predictor of subsequent outcome. Thus, an unmet patient need is to predict at diagnosis those at greatest risk of early failure in order to identify better treatments. The lymphoma microenvironment may be a key determinant of early failure. Therefore, we aimed to improve risk stratification of newly diagnosed FL patients by using a discovery and validation study design to identify microenvironment determinants of early failure and then integrate them into the Follicular Lymphoma International Prognostic Index (FLIPI). Patients and Methods: We evaluated 496 patients with FL grade 1-3A who were prospectively enrolled into the Molecular Epidemiology Resource (MER) cohort from 2002-2012. In the discovery set of patients (N=166), we stained tissue microarrays for CD4, CD8, FOXP3, CD32b, CD14, CD68, CD70, SIRPa, TIM3, PD-1 and PDL1. Immunohistochemical staining was determined both within and between malignant follicles. Stains were scored to the nearest decile as the percentages of cells positive. Scores for each stain were dichotomized as 0% vs >0% except for CD32b ( Results: In the discovery set, CD4, CD8, FOXP3, PD-1, and SIRPα were associated with risk of early failure at P≤0.15 and were subsequently evaluated in the validation set. Only CD4 expression inside the follicle validated. Specifically, lack of CD4 expression inside the follicle was associated with higher risk of early failure in the discovery (OR=1.77, P=0.15) and validation (OR=2.59, P=0.001) sets, with a pooled OR=2.29 (95% CI 1.47-3.58; P Conclusion: Integration of CD4 expression inside the follicle at diagnosis with FLIPI improves identification of FL patients at risk for early failure. Disclosures Novak: Celgene Coorperation: Research Funding. Nowakowski:Curis: Research Funding; Bayer: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; F. Hoffmann-La Roche Ltd: Research Funding; Selvita: Membership on an entity's Board of Directors or advisory committees; NanoString: Research Funding; Genentech, Inc.: Research Funding; MorphoSys: Consultancy, Research Funding. Cerhan:NanoString: Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees; Celgene: Research Funding. Ansell:LAM Therapeutics: Research Funding; Mayo Clinic Rochester: Employment; Affimed: Research Funding; Affimed: Research Funding; Trillium: Research Funding; Bristol-Myers Squibb: Research Funding; Mayo Clinic Rochester: Employment; Affimed: Research Funding; Trillium: Research Funding; Seattle Genetics: Research Funding; Regeneron: Research Funding; Bristol-Myers Squibb: Research Funding; Trillium: Research Funding; Trillium: Research Funding; LAM Therapeutics: Research Funding; Regeneron: Research Funding; LAM Therapeutics: Research Funding; LAM Therapeutics: Research Funding; Seattle Genetics: Research Funding; LAM Therapeutics: Research Funding; Bristol-Myers Squibb: Research Funding; LAM Therapeutics: Research Funding; Regeneron: Research Funding; Bristol-Myers Squibb: Research Funding; LAM Therapeutics: Research Funding; Seattle Genetics: Research Funding; Seattle Genetics: Research Funding; Mayo Clinic Rochester: Employment; Affimed: Research Funding; Bristol-Myers Squibb: Research Funding; Bristol-Myers Squibb: Research Funding; Seattle Genetics: Research Funding; Seattle Genetics: Research Funding; LAM Therapeutics: Research Funding; Trillium: Research Funding; LAM Therapeutics: Research Funding; Affimed: Research Funding; Regeneron: Research Funding; Trillium: Research Funding; Mayo Clinic Rochester: Employment; Regeneron: Research Funding; Seattle Genetics: Research Funding; Regeneron: Research Funding; Bristol-Myers Squibb: Research Funding; Trillium: Research Funding; Regeneron: Research Funding; Mayo Clinic Rochester: Employment; Affimed: Research Funding; Mayo Clinic Rochester: Employment; Seattle Genetics: Research Funding; Affimed: Research Funding; Bristol-Myers Squibb: Research Funding; Bristol-Myers Squibb: Research Funding; Affimed: Research Funding; Trillium: Research Funding; Regeneron: Research Funding; Affimed: Research Funding; Trillium: Research Funding; Mayo Clinic Rochester: Employment; Regeneron: Research Funding; Seattle Genetics: Research Funding; Mayo Clinic Rochester: Employment; Mayo Clinic Rochester: Employment.

Introduction: The use of PET-CR as a surrogate endpoint would expedite the development of novel therapies and enable better estimates of sample size based on early outcomes of a trial. Previous studies have reported an association between end-of-therapy (EOT) PET results and long-term progression-free (PFS) and overall survival (OS) in diffuse large B-cell lymphoma (DLBCL) patients receiving standard first-line chemoimmunotherapy. We have also previously shown that the overall predictability of PET-CR for PFS and OS in these trials is similar to that in 18 literature-based studies. (15-ICML 2019, P195). To assess the potential for PET-CR as a surrogate endpoint in registration trials, we conducted a prospectively designed individual patient-level-data meta-analysis of available clinical trials. Methods: We synthesized patient-level data from three prospective phase II and III trials (GOYA [NCT01287741], GATHER [NCT01414855], MAYO [NCT00670358]) conducted in previously untreated DLBCL patients, using a Bayesian hierarchical model. We considered the two treatment arms in GOYA (GOYA-R-CHOP [rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone] and GOYA-G-CHOP [obinutuzumab, cyclophosphamide, doxorubicin, vincristine, and prednisone]) separate; hence a total of four arms, excluding patients without baseline PET scans. We investigated the relationship between PET-CR and long-term survival outcomes overall and within patient subgroups. We used Kaplan-Meier plots to compare survival endpoints by PET-CR status. We considered hypothetical RCTs that have PET-CR and PFS as endpoints to show how our model of the relationship between PET-CR and PFS can be used to predict the trial outcome. Results: We included 1496 patients (GOYA-R, GOYA-G, GATHER, MAYO, respectively: 665, 669, 100, 62). EOT PET-CR status was determined by the Lugano criteria in GOYA and by IHP in the other two studies. The overall rate of PET-CR was 72%; respectively 72%, 73%, 62% and 74% per arm. Panel A of the Figure shows Kaplan-Meier plots of PFS by PET-CR status. The Bayesian modeled hazard ratio (HR) comparing PET-CR versus nonCR was 0.13 (95% CI: 0.10, 0.15). The model can be used in planning a clinical trial as follows. Suppose a new therapy improves the PET-CR rate from 70% to 85%. Based on our model the expected HR for PFS treatment effect would be 0.71 (95% CI: 0.58, 0.84). The trial sample size required to demonstrate such an improvement with 90% power is about 650 patients, assuming an accrual rate of 50 patients per month and a minimum follow-up time of 12 months. Panel B of the Figure shows the model-based PFS HR and its CI (shaded) as it depends on the PET-CR rate of the new therapy. This plot also shows the estimated total trial sample size (in red), again assuming the relationship between PET-CR and PFS in our model. However, our model may not apply for the new therapy; and the trial could have an adaptive design with final sample size tailored to the accruing information about PET-CR and PFS and their relationship for the therapies in the trial. Conclusions: Achieving an EOT PET-CR in newly diagnosed DLBCL is highly predictive of favorable outcome in the populations we considered. The estimated HR is 0.13 for PFS, PET-CR versus nonCR, and it is 0.10 for OS. Based on our model, a treatment that improves PET-CR rate could be reasonably expected to have a benefit on PFS and OS, for the populations we considered. Whether a new therapy, with a different mechanism of action, that improves PET-CR rate will extend PFS in a clinical trial is less clear. An adaptive trial could be initiated based on our model as a hypothesis. This hypothesis can be verified or updated using accruing information in the trial itself. Our model can also help in planning clinical trials for re-estimating sample size during the trial and considering early stopping for futility. Further work should investigate the applicability of PET-CR in predicting PFS and/or OS for treatments that have different mechanisms of action and for other populations of patients. Acknowledgements: This work was funded by Genentech/Roche. Disclosures Berry: Berry Consultants, LLC: Consultancy, Employment, Equity Ownership, Other: Berry Consultants, LLC is a company that provides statistical design and analysis services to pharmaceutical companies (including Genentech/Roche), medical device companies, U.S. NIH cooperative groups, patient advocacy groups, and international consortia. Broglio:Berry Consultants LLC: Employment. Ward:Hoffmann La Roche: Employment, Equity Ownership. Mattiello:F. Hoffmann-La Roche Ltd: Employment. Sahin:F. Hoffmann-La Roche Ltd: Employment, Equity Ownership. Nielsen:F. Hoffmann-La Roche Ltd: Employment, Equity Ownership. McGlothlin:Berry Consultants, LLC: Consultancy, Employment. Elliott:Berry Consultants, LLC: Employment. Sehn:Lundbeck: Consultancy, Honoraria; TG Therapeutics: Consultancy, Honoraria; Kite Pharma: Consultancy, Honoraria; Morphosys: Consultancy, Honoraria; Apobiologix: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Abbvie: Consultancy, Honoraria; Acerta: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Abbvie: Consultancy, Honoraria; TEVA Pharmaceuticals Industries: Consultancy, Honoraria; Janssen-Ortho: Consultancy, Honoraria; Merck: Consultancy, Honoraria; Merck: Consultancy, Honoraria; TG Therapeutics: Consultancy, Honoraria; Astra Zeneca: Consultancy, Honoraria; TEVA Pharmaceuticals Industries: Consultancy, Honoraria; Seattle Genetics: Consultancy, Honoraria; F. Hoffmann-La Roche/Genentech: Consultancy, Honoraria, Research Funding; Astra Zeneca: Consultancy, Honoraria; Kite Pharma: Consultancy, Honoraria; F. Hoffmann-La Roche/Genentech: Consultancy, Honoraria, Research Funding; Verastem: Consultancy, Honoraria; Morphosys: Consultancy, Honoraria; Celgene: Consultancy, Honoraria; Gilead: Consultancy, Honoraria; Lundbeck: Consultancy, Honoraria; Acerta: Consultancy, Honoraria; Karyopharm: Consultancy, Honoraria; Janssen-Ortho: Honoraria; Takeda: Consultancy, Honoraria; Seattle Genetics: Consultancy, Honoraria. Trněný:Abbvie: Consultancy, Honoraria; Gilead Sciences: Consultancy, Honoraria; Incyte: Consultancy, Honoraria; Celgene: Consultancy; Janssen: Consultancy, Honoraria; Bristol-Myers Squibb: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; F. Hoffmann-La Roche: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; MorphoSys: Consultancy, Honoraria. Vitolo:Novartis: 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; Abbvie: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Juno Therapeutics: Membership on an entity's Board of Directors or advisory committees; Gilead: 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; Celgene: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; F. Hoffmann-La Roche: Speakers Bureau. Martelli:Servier: Honoraria; F. Hoffman-La Roche, Celgene, Janssen, Sandoz, Novartis, Gilead: Honoraria, Membership on an entity's Board of Directors or advisory committees; Servier: Honoraria; F. Hoffman-La Roche, Celgene, Janssen, Sandoz, Novartis, Gilead: Honoraria, Membership on an entity's Board of Directors or advisory committees. Kostakoglu:F. Hoffman-La Roche: Consultancy; Genentech: Consultancy. Nowakowski:F. Hoffmann-La Roche Ltd: Research Funding; Curis: Research Funding; Bayer: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Genentech, Inc.: Research Funding; MorphoSys: Consultancy, Research Funding; Selvita: Membership on an entity's Board of Directors or advisory committees; NanoString: Research Funding.

Background Burkitt NHL (BL) is a rare hematologic malignancy that occurs in younger adults and is highly curable with aggressive chemoimmunotherapy induction regimens. Unfortunately, patients that are refractory or relapse after these regimens fare poorly and treatment guidelines are not well established. The typical approach is with standard platinum-based salvage regimens; those who obtain a complete remission (CR) become eligible for autologous or allogeneic stem cell transplantation (SCT). Chimeric antigen receptor T (CAR-T) cell therapy and bispecific antibodies offer potential novel approaches for these patients, especially those who are unable to achieve remission in order to proceed with SCT; however, CAR-T therapy is not approved nor even tested in BL other than promising single case reports (Avigdor A, Bone Marrow Transplant. 2018 May 24). The goal of this study was to learn the clinical features and outcome of R/R BL in order to design a prospective strategy for novel therapy use in relapsed/refractory (R/R) BL patients. Methods We reviewed the Mayo Clinic Lymphoma database to find cases of BL diagnosed and treated between 1/1/2000 - 9/30/2018. Forty-two cases were identified and 32 (76%) entered CR and never relapsed; 10 (24%) did not respond or relapsed and are the focus of this report. Demographic, clinical response to treatment regimens, and long-term outcomes were extracted from the Mayo Clinic electronic medical record. Results The 10 patients with R/R BL had a median age of 41 years (range, 28-59); all had received aggressive chemoimmunotherapy induction regimens; 7 were primary refractory and 3 relapsed within 3 months (2-4) of achieving first CR. All 3 patients that relapsed did so in the central nervous system (CNS) despite receiving CNS prophylaxis with their induction therapy regimen. The response to salvage therapy was 30% (3/10) with 10% CR and 30% (3/10) proceeded to autologous SCT (no patients made it to allogenic SCT). The median progression free survival (PFS) and overall survival (OS) from diagnosis of all 10 patients was 4 months (1-9) and 70% (7/10) died within 6±4 months from date of relapse. The 3 patients with relapsed BL survived 7, 10, and17 months from date of relapse. The 3 patients who did survive to receive a SCT lived 2, 4, and 13 months from date of SCT. None of the 10 patients survived past 26 months from date of diagnosis. Conclusions Patients with R/R BL represent an uncommon and unique subset of aggressive NHL that require a new therapeutic approach such as CAR-T. Our study demonstrates the very poor outcome with traditional salvage therapies and the very short OS of these young, otherwise healthy patients. We recommend that these patients be considered as emergencies and referred promptly for novel therapies such as CAR-T trials at the very first sign of treatment failure. Waiting with the intent of attaining response to traditional therapies is futile. Insurance approval initiation and harvesting of T-cells should be rapidly performed, preferably prior to initiating salvage therapy, given the rapid clinical deterioration and demise of these patients. Disclosures Kenderian: Lentigen: Research Funding; Novartis: Patents & Royalties, Research Funding; Tolero: Research Funding; Humanigen: Other: Scientific advisory board , Patents & Royalties, Research Funding; Morphosys: Research Funding; Kite/Gilead: Research Funding. Bennani:Kite Pharma: Other: Advisory board; Bristol-Myers Squibb: Research Funding; Adicet Bio: Other: Advisory board; Adicet Bio: Other: Advisory board; Seattle Genetics: Other: Advisory board; Purdue Pharma: Other: Advisory board; Seattle Genetics: Other: Advisory board; Purdue Pharma: Other: Advisory board; Purdue Pharma: Other: Advisory board; Bristol-Myers Squibb: Research Funding; Adicet Bio: Other: Advisory board; Kite Pharma: Other: Advisory board; Kite Pharma: Other: Advisory board; Seattle Genetics: Other: Advisory board; Bristol-Myers Squibb: Research Funding. Nowakowski:Selvita: Membership on an entity's Board of Directors or advisory committees; NanoString: Research Funding; MorphoSys: Consultancy, Research Funding; Genentech, Inc.: Research Funding; F. Hoffmann-La Roche Ltd: Research Funding; Curis: Research Funding; Bayer: Consultancy, Research Funding; Celgene: Consultancy, Research Funding.

Background Tipifarnib is a potent and selective inhibitor of the enzyme farnesyltransferase (FT). FT catalyzes post-translational attachment of farnesyl groups required for localization of signaling molecules to the inner cell membrane. CXCL12 is a ligand for CXCR4 that is essential for T cell homing to lymphoid organs and the bone marrow, and for the maintenance of immune cell progenitors. We have previously shown that FT inhibition by tipifarnib downregulates CXCL12 secretion. Herein we report preliminary efficacy, safety and biomarker data from a Phase 2 study of tipifarnib in angioimmunoblastic T-cell lymphoma (AITL) and CXCL12+ peripheral T-cell lymphoma (PTCL) patients (pts). Methods This Phase 2 study (NCT02464228) is a multi-institutional, single-arm, open-label trial initially designed as a two-stage (11+7 pts) design to determine the efficacy, safety and biomarkers of tipifarnib in pts with relapsed/refractory (R/R) PTCL age >/=18 years and a performance status of 0-2. Based on initial findings, the study was amended to include a cohort of AITL (n=12) and PTCL (n=12) pts with the CXCL12 rs2839695 A/A genotype (wt CXCL12 3'UTR cohort). Pts received tipifarnib 300 mg administered orally twice daily on days 1-21 of 28-day treatment cycles until progression of disease (PD) or unacceptable toxicity. The primary endpoint of the study is overall response rate (ORR). Tumor Whole Exon Sequencing (WES) was generated by NGS and gene expression data generated by RNA Seq. Ancillary studies also investigated the prognostic value of CXCL12 expression in pts who received standard of care treatment. Results As of 24 May 2019, 50 PTCL pts (23 AITL, 25 PTCL-NOS, 1 ALK- ALCL, 1 gamma-delta TCL) have been treated with tipifarnib, 19 pts in stages 1 and 2, and 31 pts in the ongoing AITL histology and wt CXCL12 3'UTR cohorts. Median number of prior treatment regimens was 3; 19 pts had a prior stem cell transplant. All pts (n=48 with available safety data) had at least one treatment-emergent adverse event (TEAE); 42 (88%) had at least 1 study drug-related TEAE and 13 (27%) at least 1 drug related SAE. The most frequently observed drug-related TEAEs of Grade >3 occurring in 10% or more of pts were blood and lymphatic system disorders, including neutropenia (40%), thrombocytopenia (33%), leukopenia (25%), anemia and febrile neutropenia (19% each). There have been 14 deaths on study; one related to study drug (lung infection). Of 18 evaluable pts enrolled in Stages 1 and 2 of the trial, 3 partial responses (PR), 2 of them in pts with AITL histology, and 5 best responses of stable disease (SD) were observed. In the AITL cohort (11 evaluable of 16 pts enrolled), a 45% ORR and 73% clinical benefit rate (CBR; 3 CR, 2 PR and 3 SD) was observed. In the wt CXCL12 3'UTR cohort (n=12 evaluable pts), a 42% ORR was observed (3 CR, 2 PR), with 2 of the 3 CRs observed in patients of AITL histology (n=4). A total of 23 AITL subjects were enrolled in the overall study of whom 16 had WES data. A strong association with the activity of tipifarnib was observed in 8 of the 16 (50%) carrying KIR3DL2 gene variants C336R/Q386E: 50% CR rate, 75% ORR, 100% clinical benefit rate. These tumors expressed also very low levels of CXCL5, a ligand for CXCR2, that may mediate resistance to tipifarnib. High Allele Frequency of KIR3DL2 variants predicted CR to tipifarnib treatment (ROC AUC=0.94, p Conclusion The AITL and wt CXCL12 3'UTR cohorts met pre-specified statistical hypotheses supporting proof-of-concept for tipifarnib in PTCL. AITL histology, KIR3DL2 and CXCL12 genotype provided robust tools for the selection/stratification of PTCL subjects treated with tipifarnib. Extended enrollment of AITL patients continues and an update on enrollment and outcomes will be provided at the time of the presentation. Disclosures Sokol: EUSA: Consultancy. Foss:Mallinckrodt: Consultancy; Eisai: Consultancy; Spectrum: Other: fees for non-CME/CE services ; Acrotech: Consultancy; Seattle Genetics: Consultancy, Other: fees for non-CME/CE services ; miRagen: Consultancy. Kim:Donga: Research Funding; Celltrion: Research Funding; J&J: Research Funding; Roche: Research Funding; Kyowa-Kirin: Research Funding; Novartis: Research Funding; Mundipharma: Research Funding. Jacobsen:Kura Oncology: Research Funding. Advani:Kyowa Kirin Pharmaceutical Developments, Inc.: Consultancy; Kura: Research Funding; Roche/Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Research Funding; Pharmacyclics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; AstraZeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees; Autolus: Consultancy, Membership on an entity's Board of Directors or advisory committees; Seattle Genetics: Consultancy, Research Funding; Agensys: Research Funding; Stanford University: Employment, Equity Ownership; Bayer: Consultancy, Membership on an entity's Board of Directors or advisory committees; Merck: Research Funding; Regeneron: Research Funding; Bristol-Myers Squibb: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Research Funding; Celmed: Consultancy, Membership on an entity's Board of Directors or advisory committees; Forty-Seven: Research Funding; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees; Cell Medica, Ltd: Consultancy; Gilead Sciences, Inc./Kite Pharma, Inc.: Consultancy, Membership on an entity's Board of Directors or advisory committees; Infinity Pharma: Research Funding; Millennium: Research Funding. Roncero:Kura Oncology: Research Funding. Terol:Janssen: Consultancy, Research Funding; Roche: Consultancy; Gilead: Research Funding; Astra Zeneca: Consultancy; Abbvie: Consultancy. Domingo-Domenech:Bristol-Myers Squibb: Other: Travel expenses; Roche: Other: Travel expenses; Seattle Genetics: Research Funding; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Travel expenses. Piris:Millenium/Takeda: Membership on an entity's Board of Directors or advisory committees, Other: Lecture Fees, Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees, Research Funding; Jansen: Membership on an entity's Board of Directors or advisory committees, Other: Lecture Fees; Nanostring: Membership on an entity's Board of Directors or advisory committees; Kyowa Kirin: Membership on an entity's Board of Directors or advisory committees; Kura: Research Funding. Rodriguez:Kura Oncology: Research Funding. Bolognese:Kura Oncology: Consultancy. Kessler:Kura Oncology: Employment. Mishra:Kura Oncology: Employment. Curry:Kura Oncology: Employment. Kurman:Kura Oncology: Employment. Scholz:Kura Oncology: Employment, Equity Ownership, Patents & Royalties. Gualberto:Kura Oncology: Employment, Equity Ownership, Patents & Royalties.

Introduction: Peripheral T-cell lymphomas (PTCL) are a heterogeneous group of mature aggressive T-cell non-Hodgkin lymphomas. They carry a worse prognosis for most subtypes compared with their B-cell counterparts. Despite the recent approval of newer therapies, the response rate and duration of clinical benefit is short and the outlook for patients with relapsed/refractory (RR) PTCL remains poor. There is therefore a need for novel effective therapies in PTCL. Targeting the profoundly immunosuppressive tumor microenvironment (TME) in PTCL is one such approach. Preclinical data show that malignant cells in PTCL overexpress programmed death ligand 1 (PD-L1), which signals via programmed death-1 (PD-1) receptor, and provides an inhibitory signal further suppressing antitumor immunity. PD-1/PD-L1/2 interactions in PTCL are particularly complicated as both the receptor and ligands can be expressed on the malignant T-cell. While the use of anti-PD-1 blocking antibodies has shown remarkable efficacy particularly in relapsed Hodgkin lymphoma, only a small number of patients with PTCL have been treated with checkpoint blockade. We conducted an investigator-initiated phase 2 prospective study of single-agent nivolumab for RR PTCL. We report here the results of the prespecified interim analysis. Study design and patient selection: Nivolumab was given at a flat dose of 240 mg intravenously (IV) every 2 weeks for 8 cycles then 480 mg IV every 4 weeks starting cycle 9. The primary objective was to assess the overall response rate (ORR) defined as proportion of subjects achieving either a partial response (PR) or complete response (CR) within 12 cycles of treatment. Secondary objectives were to assess safety and tolerability of nivolumab in PTCL and to assess progression-free survival (PFS), duration of response (DOR) and overall survival (OS). Pre-planned sample size was 39, assuming that an ORR of 10% or less would be considered negative and an ORR of 30% or greater would warrant further study. We used a one-stage design with an interim analysis (upon enrolling 12 subjects) based on a Simon optimal design to assess efficacy. This design had a 90% power with a 1-sided 10% level test. The Duffy and Santner method was utilized to determine confidence intervals for the ORR. Kaplan-Meier methods were used to assess PFS, OS, and DOR. This study was sponsored by Bristol-Myers Squibb (NCT03075553). Results: Twelve patients who received at least one cycle of nivolumab were included in this interim analysis. Patient characteristics are illustrated in table 1. Half (6/12) of the patients had angioimmunoblastic T-cell lymphoma (AITL), 3/12 had PTCL, not otherwise specified (NOS), one had ALK negative anaplastic large cell lymphoma (ALK- ALCL). Most (11/12) were advanced stage (stage 4), had extranodal disease and half of the patients had received a prior autologous transplant. The ORR was 33% (4/12) (95% CI: 12.3 - 63.7%): 1 CR seen in ALK-ALCL; 2 PR, 1 in PTCL, NOS and 1 in enteropathy associated T-cell lymphoma; 1 CR in AITL. The median DOR was 3.6 months (95% CI: 1.9-6.9). The median PFS for all 12 patients was short at 1.9 months (95% CI: 1.5-8.7); median OS was 7.9 months (95% CI: 3.4-10.8) (Panel A). Hyperprogressive disease (defined as dramatic progression within 1 cycle of treatment) occurred in 4 patients. Observed grade 3 and higher adverse events (AEs) were as follows: non-hematologic AEs in 5/12 (41.7%), while hematologic AEs were seen in 3/12 (25%) patients. Conclusions: Nivolumab had modest clinical activity in patients with R/R PTCL and the study met the criteria at interim analysis to continue accrual. However, due to the high number of patients with hyperprogressive disease, the moderate activity of the drug, and short DOR, a decision was made to halt the study. These findings likely reflect the distinct biology of PTCL and should be considered when designing future studies using checkpoint inhibitors in these diseases. Further studies are indicated using nivolumab in combination (rather than a single-agent) and use of biomarkers to better predict the responders. Disclosures Bennani: Purdue Pharma: Other: Advisory board; Adicet Bio: Other: Advisory board; Seattle Genetics: Other: Advisory board; Adicet Bio: Other: Advisory board; Purdue Pharma: Other: Advisory board; Adicet Bio: Other: Advisory board; Seattle Genetics: Other: Advisory board; Bristol-Myers Squibb: Research Funding; Kite Pharma: Other: Advisory board; Bristol-Myers Squibb: Research Funding; Kite Pharma: Other: Advisory board; Purdue Pharma: Other: Advisory board; Bristol-Myers Squibb: Research Funding; Kite Pharma: Other: Advisory board; Seattle Genetics: Other: Advisory board. Nowakowski:Selvita: Membership on an entity's Board of Directors or advisory committees; NanoString: Research Funding; Celgene: Consultancy, Research Funding; Bayer: Consultancy, Research Funding; Curis: Research Funding; F. Hoffmann-La Roche Ltd: Research Funding; Genentech, Inc.: Research Funding; MorphoSys: Consultancy, Research Funding. Ansell:Merck: Other: research funding for clinical trials; Seattle Genetics: Other: research funding for clinical trials; Takeda: Other: research funding for clinical trials; Bristol Myers Squibb: Other: research funding for clinical trials; Regeneron: Other: research funding for clinical trials; Affimed: Other: research funding for clinical trials; Pfizer: Other: research funding for clinical trials; AI Therapeutics: Other: research funding for clinical trials.

Background MZL is a low-grade non-Hodgkin's lymphoma (NHL) which involves lymph nodes, extranodal sites, or spleen. It is sensitive to radiation therapy, which is used in localized disease with curative intent. Yttrium-90 ibritumomab tiuxetan [(90)Y-IT; Zevalin] is a radio-immunoconjugate (RIC) that targets CD20. It is approved for relapsed/refractory low grade and follicular NHL. The data on its use in MZL is limited. We present long-term outcome of the largest reported cohort of MZL patients who received (90)Y-IT. Methods Medical records of patients who received treatment with (90)Y-IT at Mayo Clinic Cancer Center between January 2004 and December 2018 were analyzed. We selected patients with MZL and reviewed clinical data including age, gender, MZL type, clinical stage (Ann Arbor Staging System), treatment response, (90)Y-IT related adverse effects (AEs), as well as lymphoma and treatment related events. All patients received (90)Y-IT according to the standard treatment guidelines. Overall response rate (ORR) and complete response rate (CR) were calculated. Progression-free survival (PFS), time to next therapy (TTNT), and overall survival (OS) were analyzed using the Kaplan-Meier method. Results Twenty-one patients were identified (Table 1). The median age at diagnosis was 60 years (range, 11-81) and 71% (15/21) were female. 52% (11/21) were previously-untreated (UMZL) while 48% (10/21) were relapsed (RMZL). The median number of pretreatments in RMZL patients was 2 (range, 1-3). ECOG performance status at the time of treatment was 0 in 90% (19/21) and 1 in 10% (2/21). 62% (13/21) were stage III/IV disease at the time of (90)Y-IT therapy. The median follow-up was 8.5 years (95% CI; 4.5, 12.4); 17 (81%) patients remain alive. The ORR was 91% (19/21) with the two non-responders being in the RMZL group. The CR rate was 81% (17/21) and 65% (11/17) remain in CR at a median follow-up of 5.7 years (95% CI; 1.4, 11). Nine (43%) patients had a relapse during the study period. More relapses occurred in the RMZL group (7/10; 70%) compared to (2/11; 18%) in the UMZL group. Median PFS (whole cohort) was 10 years (95% CI; 2.1, NR) and TTNT (whole cohort) was not reached (NR) (95% CI; 2.1 years, NR). Median PFS was significantly higher in UMZL group compared to RMZL group NR (95% CI; 2.5 years, NR) vs 2.1 years (95% CI; 0.17, 9.9), respectively (Figure 1-A).Median OS (whole cohort) was 19.3 years (95% CI; 8.9, 19.3) without statistical difference in between UMZL group and RMZL group NR (95% CI; NR, NR) vs 16.6 years (95% CI; 9, 19.4), respectively (Figure 1-B). None of the 11 UMZL patients died at median follow up of 4.7 years (95% CI; 1.6, 9.2). All 4 deaths were in the RMZL group with 3 dying of transformation to high-grade lymphoma at 8, 22, and 25 months post-(90)Y-IT treatment. One patient died of myelodysplastic syndrome 7.3 years post-(90)Y-IT treatment while in CR. Toxicities were primarily hematologic. Grade ³3 neutropenia was observed in 6/21 (29%) patients with median time to nadir of 48.5 days (range, 19-70) and median time to recovery to normal absolute neutrophil count of 39.5 days (range, 7-476). Grade ³3 thrombocytopenia was observed in 3 (14%) patients with median time to nadir of 35 days (range, 19-357) and median time to recovery of 21 days (range, 2-538). Grade ³3 anemia was observed in only one patient. Only two patients required transfusions and growth factor support. Non-hematologic AEs included mild to severe fatigue in 4 patients. Conclusion RIC with (90)Y-IT is efficacious and well-tolerated in patients with previously untreated as well as relapsed MZL. As expected it appears to be more efficacious in previously untreated patients. Long-term complete remission (>5 years) was observed in 52% of the study population (43% of UMZL and 9% of RMZL). Combination of efficacy, tolerability, and treatment schedule most convenient for patients makes (90)Y-IT a reasonable alternative to systemic therapy with immunotherapy, chemotherapy, or chemo-immunotherapy in management of MZL. Figure 1: (A) Progression-free survival; comparing time to progression or death after (90)Y-IT treatment between previously untreated patients (UMZL) and patients with relapsed MZL (RMZL), (B) Overall survival; comparing time to death from all causes after (90)Y-IT treatment between UMZL patients and RMZL patients. Disclosures Tun: Curis: Research Funding; TG Therapeutics: Research Funding; BMS: Research Funding; DTRM Biopharma: Research Funding; Celgene: Research Funding; Mundi-pharma: Research Funding. OffLabel Disclosure: The use of Yttrium-90 ibritumomab tiuxetan as a first line treatment for marginal zone lymphoma

Background: CXCL12 is a negative prognostic factor for head & neck (HNSCC) and pancreatic (PDCA) cancers, among others. Its receptor, CXCR4, is a negative prognostic factor in lymphoma/leukemia. CXCR4 signals in part through RAS species, and the expression of CXCL12 and CXCR4 appears to be itself regulated by farnesylated proteins. We provide evidence that targeting the CXCL12/CXCR4 pathway with the farnesyltransferase inhibitor tipifarnib translates to long term clinical benefit. Methods: Next generation sequencing and analyses of gene expression were conducted in tumor samples from squamous cell carcinoma, lymphoma, and acute myeloid leukemia (AML) patients treated in tipifarnib trials (studies KO-TIP-001, KO-TIP-002, CTEP20), and complemented with analyses of related tumor gene expression databases in TCGA and GEO. Results: Activating HRAS mutations in HNSCC and KRAS mutations in PDCA were mutually exclusive with CXCL12 expression, consistent with a role for RAS downstream from CXCR4. Contrary to KRAS and NRAS, HRAS is exclusively farnesylated, and treatment with tipifarnib in patients (pts) with advanced HNSCC tumors with a HRAS mutation variant allele frequency (VAF) >20% resulted in 8 partial responses (PR) in 14 pts. Two complete responses (CR), 3 PRs and 4 disease stabilizations (90% clinical benefit) were observed in 10 pts with relapsed/refractory peripheral T cell lymphoma overexpressing CXCL12. Decreases in plasma CXCL12 levels during treatment were observed. Seven CRs were observed in 11 elderly/unfit AML pts overexpressing CXCL12 in bone marrow (NRAS wt or unknown). Ex vivo treatment of bone marrow stromal cell cultures with tipifarnib decreased secretion of CXCL12. Finally, based on the reported relationship between CXCL12 expression and the suppression of pain in PDCA, we conducted a retrospective analysis of a phase 3 study of gemcitabine plus tipifarnib (GT) in advanced PDCA. Notably, absence of abdominal pain at study entry was associated with higher median survival in the GT arm (no pain, pain): 10.2 vs 5.9 months, HR=0.52, p Conclusions: The mechanism of action of tipifarnib appears to involve targeting the CXCL12/CXCR4 pathway and demonstrates a crucial association with the tumor microenvironment and objective clinical responses. Citation Format: Antonio Gualberto, Catherine Scholz, Vishnu Mishra, Matthew R. Janes, Linda Kessler, Eric Van Cutsem, Alan L. Ho, Thomas Witzig. Mechanism of action of the farnesyltransferase inhibitor, tipifarnib, and its clinical applications [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr CT191.

7554 Background: Predicting early clinical failure in patients with untreated FL is important but difficult. Lymphoma involvement of EN sites is better detected by FDG-PET/CT than CT alone, but PET parameters are not part of the usual predictive indices. We aimed to determine the incidence and patterns of spleen and EN disease using PET/CT, and learn if they are useful in predicting early clinical failure. Methods: PET/CT images from 613 cases of newly diagnosed FL between 2003 – 2016 were retrospectively reviewed. The location, pattern, and number of EN sites, as well as splenic involvement, were recorded. Associations with outcomes were assessed using event-free survival (EFS) and overall survival (OS). Results: 49% (301/613) of patients had PET/CT-detected EN involvement, and 28% (171/613) had spleen involvement. Presence of ≥2 EN sites, spleen, bone, or soft tissue involvement, as well as a multifocal on diffuse pattern of bone involvement by imaging, were univariate predictors of EFS; presence of ≥2 EN sites and bone involvement pattern were also predictive of OS. In a multivariate analysis with FLIPI-2 factors, spleen involvement, pattern of bone involvement, and soft tissue involvement independently predicted a lower EFS (Table). When the multivariate analysis was performed using PRIMA-PI factors, the presence of ≥2 EN sites was an adverse independent prognostic factor for OS (HR 2.28; 95% CI 1.01-5.18; p=0.05). Conclusions: Baseline PET/CT identifies EN and spleen sites of disease that can predict early clinical failure of FL. These results may be useful to better identify high-risk patients and guide appropriate therapy. [Table: see text]

7559 Background: Waldenström macroglobulinemia (WM) is a rare indolent lymphoma commonly treated with rituximab (R)-based therapy. The use of rituximab maintenance (mR) in WM is controversial. We present a case-control study of patients (pts) with WM treated with mR. Methods: Pts evaluated at Mayo Clinic, Rochester with active WM that received mR between 1/2000 & 6/2018 were included. Cases comprised pts who received mR following R-based induction as primary therapy. Cases were matched based on the time of diagnosis in 1:2 ratio with a control group treated with R-based primary induction therapy without mR. Time to event analyses were performed from initiation of R-based induction. Results: Of 776 pts with active WM, 42 (5%) cases received mR and 84 pts were selected as controls. The median follow-up and the proportion of high risk pts were comparable between the two cohorts (Table). Pts in the mR cohort show a trend toward longer time to next therapy (TTNT) and a significantly longer overall survival (OS) compared to the control group (Table). The R-based induction therapies were comparable in the two cohorts (p = 0.6). Median duration of mR was 1.9 yrs (95% CI 1.6-2) and mR was used most frequently every (q) 2 (range 1-6) months. Of the 42 mR pts, 25 (60%) received an R-based combination for induction and 17 (40%) received R monotherapy as induction. Five (12%) pts discontinued mR due to toxicity, infections were reported in 13 pts (31%) during mR therapy and 3 pts (7%) received IVIg infusions for recurrent infections. Conclusions: R-based induction followed by mR demonstrates a longer OS in WM compared to R-treated control population not receiving mR, albeit at a high rate of infections. Despite limitations of a retrospective study, with a heterogeneously treated cohort, these data add to the body of literature supporting Rituximab maintenance. Results from an ongoing randomized controlled trial are awaited. [Table: see text]

7519 Background: Acalabrutinib, a highly selective, potent, covalent Bruton tyrosine kinase (BTK) inhibitor, has a 24% overall response rate (ORR) as a single agent in R/R DLBCL. Pem targets PD-1, an immune checkpoint that limits anticancer responses. Pem showed responses in patients (pts) with Richter transformation who failed ibrutinib and can augment acalabrutinib activity in vitro. This study assessed acalabrutinib + Pem in R/R DLBCL. Methods: Pts with DLBCL, ≥1 prior chemoimmunotherapy and no prior allogeneic transplant received acalabrutinib 100 mg PO BID until progressive disease (PD) + Pem 200 mg/kg IV Q3W up to 2 y. Germinal center B-cell (GCB) vs non-GCB subtype was assessed by immunohistochemistry. Primary endpoint was safety. Results: Sixty-one pts (30 GCB; 31 non-GCB) were accrued, with a median age (range) of 67 y (30-85) and a median of 3 (1-8) prior therapies; 1 pt had prior autologous transplant. The most common Gr 3/4 adverse events (AEs) were neutropenia (15%) and anemia (11%). Gr 5 AEs were respiratory failure (n=3), sepsis, septic shock and abdominal abscess (n=1 each). All Gr atrial fibrillation was 5% (n=3), and major hemorrhage (≥ Gr 3) was 11% (4 gastrointestinal, 1 pulmonary, 1 epistaxis, 1 hematuria). Gr 3/4 immune-mediated events were elevated alanine aminotransferase (n=4), pneumonitis (n=2) and colitis (n=1). The ORR was 26% (Table) and was similar in GCB (27%) and non-GCB (26%) tumors. The median time on study was 5.2 mo (0.4-30.4+). Acalabrutinib/Pem discontinuations were due to PD (62%/56%) and AEs (15%/26%). As of June 2018, 10 pts remain on study; 6 on active therapy and 7 without PD. Conclusions: Acalabrutinib + Pem was well tolerated, with meaningful activity and some exceptional responders (>24 mo) in these R/R DLBCL pts. Randomized trials of the combination vs single agent are needed. Clinical trial information: NCT02362035. [Table: see text]

e19039 Background: In patients with lymphoma, lactate dehydrogenase (LDH) is an important prognostic marker. Serum lactate can also be elevated due to hypermetabolism from aggressive lymphoma. We have observed critically ill lymphoma patients with elevated serum lactate who had a delay in the diagnosis and treatment of their underlying lymphoma because the cause of the elevated lactate was presumed to be infection. This clinical observation led us to perform a study to evaluate the relationship between serum lactate and LDH levels in lymphoma patients. Methods: We used the Mayo Clinic Lymphoma Database to search for patients with lymphoma and elevated lactate during a recent two year time period, January 2014 through December 2015. Fifty patients met these initial criteria and underwent medical chart review. The patients were divided into two groups – those with documented infection (SepsisLA group) and those without infection (all cultures negative) where the elevated lactate was due to lymphoma hypermetabolism (LymLA group). The Wilcoxon/Kruskal-Wallis test was used to compare the SepsisLA and LymLA groups. Kaplan-Meier analysis was used to estimate survival. Results: The mean age of the 66 patients was 65 ± 14.8 years and 60% were male. At the time of presentation, the mean lactate and LDH values were 4.5 ± 2.81mmol/L (UNL < 2 mmol/L) and 835.1 ± 1741.4 U/L (UNL < 222 U/L), respectively. 64% (32/50) of patients had elevated LDH values. After review, 32 (64%) patients were in the SepsisLA group; 18 (36%) were in the LymLA group. DLBCL was the most common disease type in both the SepsisLA (50%; 16/32) and LymLA (88%; 16/18). The sepsisLA and LymLA groups were not significantly different in terms of age, sex, lactate levels, or maxSUV on PET scan (N = 13). However, patients in the LymLA group did have higher LDH values (p = 0.02) compared to those with SepsisLA. Patients with LymLA had a reduced overall survival (OS) (1.45 median months) compared to those with SepsisLA (7.83 median months) p = 0.02. Conclusions: This study demonstrates that the level of lactate elevation is not helpful indiscriminating SepsisLA vs LymLA; however an elevated LDH with elevated lactate is more likely LymLA. Lymphoma pts with LymLA had an inferior survival compared to SepsisLA. We are unable to define the true incidence and prognostic value of elevated serum lactate in lymphoma; this will require a prospective study with fresh samples. In summary, lymphoma activity can masquerade as infection with elevated lactate. Once sepsis is ruled out, treatment for the lymphoma should not be delayed as this presentation portends poor prognosis.

6511 Background: Conventional adverse event (AE) analysis (ToxC) focuses on incidence of grade (gr) 3+ toxicities, and fails to capture AE time profile. Novel metrics that reflect chronic low gr and overall AE burden are needed. We applied the Toxicity over Time (ToxT) approach to ECOG-ACRIN 2408 to depict time-dependent toxicity of lenalidomide (L) with rituximab maintenance (MR) in follicular lymphoma (FL), and we developed a novel summary metric of symptomatic AE burden, the maximum gr over time (MGOT). Methods: In E2408, high risk FL patients (pts) were randomized (1:2:2) to: A) bendamustine-rituxumab (BR) x 6 then MR x 2 years (yrs) vs B) BR-bortezomib x 6 then MR x 2 yrs vs C) BR x 6 then MR x 2 yrs + L x 1 yr (MRL). Analysis included 3 laboratory and 5 symptomatic AEs of highest incidence during maintenance on arms A and C. Treatment-related AEs of any gr were analyzed by ToxC and ToxT. Repeated measures, time-to-event (TTE) and area under the curve (AUC) analyses capture trends over time in ToxT. MGOT combines the 5 symptomatic AEs. Results: 104 randomized pts (30 MR, 74 MRL) were included. For the laboratory AEs, by ToxC, neutropenia incidence was significantly higher in MRL (84%) than MR (47%, p < .001). ToxT additionally shows neutropenia does not worsen over time (10/14/20% gr 1/2/3+ at c1, 6/21/12% gr 1/2/3+ at c12). For the symptomatic AEs, ToxC indicates 2% gr 3+ GI AEs. However, gr 1-2 GI AEs are more common on MRL (59%) than MR (26%, p < .001). ToxT AUC captures a higher burden of GI AEs over time on MRL(2.8) vs MR(1.4, p = .002). TTE depicts sooner GI AE onset in MRL (10% vs 0% gr 2+ GI by day 50, p = 0.03). Bar charts of incidence and grade by cycle illustrate this improves over time (34/7/4% gr 1/2/3+ at c1, 13/0/0% gr 1/2/3+ at c12). ToxT MGOT analyses demonstrate earlier time to gr 2+ symptomatic AE on MRL vs MR (63% vs 31% by day 50, p < .001) and suggest that overall AE burden over time is higher for patients on MRL(AUC 18.2) than MR(11.8, p < .001). Conclusions: ToxT depicts AE time profile and can guide AE interventions. Summary metrics suggest that symptomatic AEs occur earlier and their burden over time is higher on MRL. We are implementing ToxT in patient-reported AE data to better characterize pt tolerability.

e19063 Background: Constitutive activation of the JAK-STAT pathway has been reported in lymphomas, suggesting that targeting this pathway could show clinical benefit. Ruxolitinib phosphate, an oral JAK inhibitor represents a potential therapeutic agent for high grade lymphomas. This study is designed to investigate benefits of ruxolitinib in patients with relapsed or refractory PTCL and DLBCL Methods: Patients with relapsed/refractory DLBCL and aggressive T cell lymphomas who were ineligible for, or relapsed after, stem cell transplantation were eligible. Patients received ruxolitinib, at a dose of 10mg or 5mg BID, with gradual escalation to 25mg BID. Weekly hematological assessments were done during the first cycle, CT scans were done after every two cycles. Descriptive statistics for response to therapy were collected. Progression free survival (PFS), Overall survival (OS) curves were plotted using Kaplan-Meier method, comparisons between groups were made using the log rank test. Primary outcome of the study was to assess the overall response rate (ORR). Secondary objectives were to determine PFS, OS, duration of response and safety. Relationship between responses to oral ruxolitnib and gene expression profiling was explored. Results: Of the 60 patients enrolled, 25 patients had PTCL, 32 DLBCL, 3 pending path review. Median age was 62 yrs., 56.6% had stage IV disease. Median number of cycles received was 2 (min 1, max 60). At the time of evaluation, 76% patients had progressed on therapy. The median follow-up of patients was 3.7 months (min 0.9; max 61.4). Data for 41 patients was available for evaluation of response. Complete response (CR) was noted in 1 patient with PTCL. Partial response (PR) was noted in 1, stable disease (SD) in 4 patients. Among the responders, a PTCL patient with SD had a sustained response for 60 months, a patient with PR had a response duration of 31 months. The median OS and PFS were 5.9 and 1.8 months. PFS was 2.2 months in patients with PTCL and 1.8 months in DLBCL. Median OS was 5 months in patients with DLBCL, 6.9 months in PTCL. The estimated 6 month PFS and OS were 17% (95%CI: 9%, 28%) , 49% (95%CI: 35%, 62%). There was no difference in PFS or OS between PTCL and DLBCL (p = 0.42, p = 0.94). Grade 3 or higher adverse events were seen in 62%. Anemia was seen in 20%, thrombocytopenia in 8%, infections in 6%. Conclusions: Ruxolitinib can produce responses in some patients with relapsed/refractory NHL, particularly in patients with PTCL. It may play a role in combination therapies in future. Clinical trial information: NCT01431209.

7509 Background: Waldenstrom macroglobulinemia (WM) is a rare lymphoma for which scant comparative data exist to guide frontline therapy. Herein, we compare 3 commonly used regimens in WM: R-Benda, DRC, and BDR in frontline setting. Methods: Patients (Pts) with active WM seen at Mayo Clinic between 2000 & 2018 who received R-Benda, DRC or BDR as primary therapy were included in this retrospective study. Response rates were assessed by Consensus Criteria. All time to event analyses were performed from the frontline therapy, using Kaplan-Meier method. Results: The study included 172 pts with active WM (R-Benda, n=67, DRC, n=75, BDR, n=30).The median follow-up for the entire cohort was 3.7 years (y) (95% CI 3.7-3.0). Baseline characteristics, including IPSS, and time to frontline therapy from WM diagnosis were similar across the 3 cohorts. Clinically relevant endpoints are shown in the Table. Hematologic and non-hematologic toxicities were similar across the 3 groups. Grade 3 neuropathy requiring treatment discontinuation was encountered in 13% pts treated with BDR. 56 pts received subsequent salvage therapy [(10% in R-Benda arm, 44% in DRC arm, & 53% in BDR arm]; 29% pts in the R-Benda arm and 30% pts in DRC arm received a PI-based regimen while 69% pts in the BDR arm received alkylator-rituximab based therapy. Conclusions: Outcomes (MRR, TTNT and EFS) with frontline R-Benda are superior in comparison to frontline DRC or BDR in patients with WM. Clinically relevant endpoints are not significantly different with DRC vs. BDR. The toxicity profile across the 3 groups was comparable. [Table: see text]

7556 Background: The frontline treatment for advanced follicular lymphoma has evolved with the introduction of maintenance therapy, bendamustine (Benda), obinutuzumab (G), and lenalidomide (Len). We conducted a network meta-analysis of phase 3 randomized controlled trials (RCTs) to identify the regimens with superior efficacy. Methods: Data were extracted from 7 RCTs (FOLL05, StiL NHL1, BRIGHT, PRIMA, GALLIUM, StiL NHL7, and RELEVANCE). Progression-free survival (PFS) was compared between 11 regimens with different immunochemotherapy and maintenance strategies. To incorporate direct and indirect comparisons, random-effects Bayesian network meta-analyses were conducted after adjusting for study-wise variation. The posterior inference was derived based on Markov chain Monte Carlo methods and implemented using JAGS v4.3.0. Pairwise comparison of hazard ratios (HRs) and 95% credible intervals (CIs) were calculated. Results: PFS HRs of other regimens compared to the reference regimen are summarized in the Table. Compared to Rituximab(R)-Benda, R-CHOP had inferior PFS, R-CHOP-R, G-CHOP-G, and R-Len-R had similar PFS, while R-Benda-R, R-Benda-R4 and G-Benda-G had better PFS. Compared to R-CHOP-R, G-CHOP-G and R-Len-R had similar PFS, while R-Benda-R, R-Benda-R4 and G-Benda-G had better PFS. In addition, the PFS for G-Benda-G was similar to R-Benda-R4 (HR 0.94, 95% CI 0.78-1.09) but better than R-Benda-R (HR 0.82, 95% CI 0.75-0.97). Conclusions: Compared with the commonly used R-Benda and R-CHOP-R regimens, G-CHOP-G, R-Benda-R and R-Benda-R4 had better PFS, while the chemotherapy-free regimen R-Len-R had similar PFS. [Table: see text]

Purpose To study the impact of achieving stringent complete response (sCR), an increasingly attainable goal, after autologous stem-cell transplantation (ASCT) in patients with multiple myeloma (MM). Patients and Methods Maximal response rates were determined in 445 consecutive patients who underwent ASCT within 12 months of diagnosis of MM. The patients achieving varying degrees of complete response (CR) are the focus of our study. Results One hundred and nine patients (25%) achieved sCR after ASCT. The median overall survival (OS) rate from the time of transplantation for patients attaining sCR was not reached (NR), in contrast to those patients achieving conventional complete response (CR; n = 37; OS, 81 months) or near CR (nCR; n = 91; OS, 60 months; P < .001). Five-year OS rates were 80%, 53%, and 47% for sCR, CR, and nCR, respectively. The median time to progression (TTP) from ASCT of patients achieving sCR was significantly longer (50 months) than TTP of patients achieving CR or nCR (20 months and 19 months, respectively). On multivariable analysis, post-ASCT response of sCR was an independent prognostic factor for survival (hazard ratio, 0.44; 95% CI, 0.25 to 0.80; versus CR; P = .008), in addition to proliferation rate, pre-ASCT cytogenetics, and performance status. OS rates of patients attaining sCR continued to remain superior at 2-year landmark (median, NR v 70 months for conventional CR group; P = .007). Conclusion Improved long-term outcome is seen after ASCT with achievement of sCR when compared with lesser degrees of responses. Myeloma trials reporting the response rates should identify patients achieving sCR and CR separately, owing to markedly disparate outcomes of the two categories.

Purpose This study sought to characterize transformation incidence and outcome for patients with follicular lymphoma (FL) in a prospective observational series begun after diffusion of rituximab use. Patients and Methods Patients with newly diagnosed FL were prospectively enrolled onto the University of Iowa/Mayo Clinic Specialized Program of Research Excellence Molecular Epidemiology Resource from 2002 to 2009. Patients were actively followed for re-treatment, clinical or pathologic transformation, and death. Risk of transformation was analyzed via time to transformation by using death as a competing risk. Results In all, there were 631 patients with newly diagnosed grade 1 to 3a FL who had a median age at enrollment of 60 years. At a median follow-up of 60 months (range, 11 to 110 months), 79 patients had died, and 60 patients developed transformed lymphoma, of which 51 were biopsy proven. The overall transformation rate at 5 years was 10.7%, with an estimated rate of 2% per year. Increased lactate dehydrogenase was associated with increased risk of transformation. Transformation rate at 5 years was highest in patients who were initially observed and lowest in patients who initially received rituximab monotherapy (14.4% v 3.2%; P = .021). Median overall survival following transformation was 50 months and was superior in patients with transformation greater than 18 months after FL diagnosis compared with patients with earlier transformation (5-year overall survival, 66% v 22%; P < .001). Conclusion Follicular transformation rates in the immunochemotherapy era are similar to risk of death without transformation and may be lower than reported in older series. Post-transformation prognosis is substantially better than described in older series. Initial management strategies may influence the risk of transformation.

Protein tyrosine phosphatases such as PTPN6 can be downregulated in various neoplasms. PTPN6 expression by immunohistochemistry in 40 diffuse large B-cell lymphoma (DLBCL) tumors was lost or suppressed in 53% (21/40). To elucidate the molecular mechanisms of PTPN6 suppression, we performed a comprehensive epigenetic analysis of PTPN6 promoter 2 (P2). None of the DLBCL primary tumors (0/37) had PTPN6 hypermethylation on the CpG1 island using methylation-specific PCR, pyrosequencing, and high-resolution melting assays. However, hypermethylation in 57% (21/37) of cases was found in a novel CpG island (CpG2) in P2. PTPN6 gene suppression was reversed by 5-aza-deoxycytidine (5-Aza), a DNA methyltransferase inhibitor, and the histone deacetylase inhibitor (HDACi) LBH589. LBH589 and 5-Aza in combination inhibited DLBCL survival and PTPN6 hypermethylation at CpG2. The role of histone modifications was investigated with a chromatin-immunoprecipitation assay demonstrating that PTPN6 P2 is associated with silencing histone marks H3K27me3 and H3K9me3 in DLBCL cells but not normal B cells. 3-Deazaneplanocin A, a histone methyltransferase inhibitor, decreased the H3K27me3 mark, whereas HDACi LBH589 increased the H3K9Ac mark within P2 resulting in re-expression of PTPN6. These studies have uncovered novel epigenetic mechanisms of PTPN6 suppression and suggest that PTPN6 may be a potential target of epigenetic therapy in DLBCL.

WOS: 000323657500004, PubMed ID: 23812490, CXCR5 [chemokine (C-X-C motif) receptor 5; also known as Burkitt lymphoma receptor 1 (BCR1)] is expressed on mature B-cells, subsets of CD4(+) and CD8(+) T-cells, and skin-derived migratory dendritic cells. Together with its ligand, CXCL13, CXCR5 is involved in guiding B-cells into the B-cell zones of secondary lymphoid organs as well as T-cell migration. This study evaluated the role of common germline genetic variation in CXCR5 in the risk and prognosis of non-Hodgkin lymphoma (NHL) using a clinic-based study of 1,521 controls and 2,694 NHL cases including 710 chronic lymphocytic leukemia/small lymphocytic lymphoma, 586 diffuse large B-cell lymphoma (DLBCL), 588 follicular lymphoma (FL), 137 mantle cell lymphoma (MCL), 230 marginal zone lymphoma (MZL), and 158 peripheral T-cell lymphoma (PTCL). Of the ten CXCR5 tag SNPs in our study, five were associated with risk of NHL, with rs1790192 having the strongest association (OR 1.19, 95 % CI 1.08-1.30; p = 0.0003). This SNP was most strongly associated with the risk of FL (OR 1.44, 95 % CI 1.25-1.66; p = 3.1 x 10(-7)), with a lower degree of association with DLBCL (OR 1.16, 95 % CI 1.01-1.33; p = 0.04) and PTCL (OR 1.29, 95 % CI 1.02-1.64; p = 0.04) but no association with the risk of MCL or MZL. For FL patients that were observed as initial disease management, the number of minor alleles of rs1790192 was associated with better event-free survival (HR 0.64; 95 % CI 0.47-0.87; p = 0.004). These results provide additional evidence for a role of host genetic variation in CXCR5 in lymphomagenesis, particularly for FL., National Institutes of Health (NIH)United States Department of Health & Human ServicesNational Institutes of Health (NIH) - USA [R01 CA92153, R01 CA129539, P50 CA97274]; [R25 CA92049], This study was supported by National Institutes of Health (NIH) Grants R01 CA92153, R01 CA129539, and P50 CA97274; Dr. Charbonneau was supported by R25 CA92049.

Summary B cell receptor (BCR) signaling pathway components represent promising treatment targets in diffuse large B cell lymphoma (DLBCL) and additional B cell tumors. BCR signaling activates spleen tyrosine kinase (SYK) and downstream pathways including PI3K/AKT and NF-κB. In previous studies, chemical SYK blockade selectively decreased BCR signaling and induced apoptosis of BCR-dependent DLBCLs. Herein, we characterize distinct SYK/PI3K-dependent survival pathways in DLBCLs with high or low baseline NF-κB activity including selective repression of the pro-apoptotic HRK protein in NF-κB-low tumors. We also define SYK/PI3K-dependent cholesterol biosynthesis as a feed-forward mechanism of maintaining the integrity of BCRs in lipid rafts in DLBCLs with low or high NF-κB. In addition, SYK amplification and PTEN deletion are identified as selective genetic alterations in primary "BCR"-type DLBCLs.

Interim Positron-Emission Tomography (int-PET) and the peripheral blood absolute lymphocyte/monocyte ratio at di- agnosis (ALC/AMC-DX) have been shown to be predictors for progression-free survival (PFS) and time to progression (TTP) in classical Hodgkin lymphoma (cHL). Therefore, we studied if the combination of ALC/AMC-DX and the (int-PET) can further stratified PFS and TTP in cHL patients. Patients were required to be diagnosed, treated, and followed with int-PET at Mayo Clinic, Rochester, Minnesota. From 2000 until 2008, 111 cHL patients qualified for the study. The median follow-up was 2.8 years (range: 0.3 - 10.4 years). Patients with a negative int-PET (N = 98) pre- sented with a higher ALC/AMC-DX (median of 2.32, range: 0.26 - 37.5) compared with patients with a positive int-PET (N = 13) (median of 0.9, range: 0.29 - 3.10), p 1.1. Group 1 experienced superior PFS and TTP in comparison with the other groups. In conclusion, the combination of ALC/AMC-DX and the int-PET provides a simple model to assess clinical outcomes in cHL.

Background Abnormal immune function is a key factor in predisposition to non-Hodgkin lymphoma (NHL). We evaluated the association of 30 cytokines individually and as a profile with diffuse large B-cell (DLBCL) and follicular (FL) lymphomas. Methods We used a multiplexed assay to measure 30 cytokine concentrations in pre-treatment serum in a case-control study of 234 FL, 188 DLBCL, and 400 control participants. Unconditional logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) adjusted for age and sex, and polytomous regression was used to evaluate heterogeneity between FL and DLBCL. Principal components analysis (PCA) was used to assess cytokine profiles associated with FL and DLBCL. Results In single cytokine modeling, we found that 12 of the 30 circulating serum cytokines were significantly (P

Disease bulk is an important prognostic factor in early stage Hodgkin lymphoma, but its definition is unclear in the computed tomography era. This retrospective analysis investigated the prognostic significance of bulky disease measured in transverse and coronal planes on computed tomography imaging. Early stage Hodgkin lymphoma patients (n=185) treated with chemotherapy with or without radiotherapy from 2000–2010 were included. The longest diameter of the largest lymph node mass was measured in transverse and coronal axes on pre-treatment imaging. The optimal cut off for disease bulk was maximal diameter greater than 7 cm measured in either the transverse or coronal plane. Thirty patients with maximal transverse diameter of 7 cm or under were found to have bulk in coronal axis. The 4-year overall survival was 96.5% (CI: 93.3%, 100%) and 4-year relapse-free survival was 86.8% (CI: 81.9%, 92.1%) for all patients. Relapse-free survival at four years for bulky patients was 80.5% (CI: 73%, 88.9%) compared to 94.4% (CI: 89.1%, 100%) for non-bulky; Cox HR 4.21 (CI: 1.43, 12.38) (P=0.004). In bulky patients, relapse-free survival was not impacted in patients treated with chemoradiotherapy; however, it was significantly lower in patients treated with chemotherapy alone. In an independent validation cohort of 38 patients treated with chemotherapy alone, patients with bulky disease had an inferior relapse-free survival [at 4 years, 71.1% (CI: 52.1%, 97%) vs. 94.1% (CI: 83.6%, 100%), Cox HR 5.27 (CI: 0.62, 45.16); P=0.09]. Presence of bulky disease on multidimensional computed tomography imaging is a significant prognostic factor in early stage Hodgkin lymphoma. Coronal reformations may be included for routine Hodgkin lymphoma staging evaluation. In future, our definition of disease bulk may be useful in identifying patients who are most appropriate for chemotherapy alone.

Genome-wide association studies (GWASs) of follicular lymphoma (FL) have previously identified human leukocyte antigen (HLA) gene variants. To identify additional FL susceptibility loci, we conducted a large-scale two-stage GWAS in 4,523 case subjects and 13,344 control subjects of European ancestry. Five non-HLA loci were associated with FL risk: 11q23.3 (rs4938573, p = 5.79 × 10 -20) near CXCR5; 11q24.3 (rs4937362, p = 6.76 × 10 -11) near ETS1; 3q28 (rs6444305, p = 1.10 × 10 -10) in LPP; 18q21.33 (rs17749561, p = 8.28 × 10 -10) near BCL2; and 8q24.21 (rs13254990, p = 1.06 × 10 -8) near PVT1. In an analysis of the HLA region, we identified four linked HLA-DRß1 multiallelic amino acids at positions 11, 13, 28, and 30 that were associated with FL risk (pomnibus = 4.20 × 10 -67 to 2.67 × 10 -70). Additional independent signals included rs17203612 in HLA class II (odds ratio [ORper-allele] = 1.44; p = 4.59 × 10 -16) and rs3130437 in HLA class I (ORper-allele = 1.23; p = 8.23 × 10 -9). Our findings further expand the number of loci associated with FL and provide evidence that multiple common variants outside the HLA region make a significant contribution to FL risk. © 2014 by The American Society of Human Genetics. All rights reserved.

International audience; Evidence from a small number of studies suggests that longer telomere length measured in peripheral leukocytes is associated with an increased risk of non-Hodgkin lymphoma (NHL). However, these studies may be biased by reverse causation, confounded by unmeasured environmental exposures and might miss time points for which prospective telomere measurement would best reveal a relationship between telomere length and NHL risk. We performed an analysis of genetically inferred telomere length and NHL risk in a study of 10 102 NHL cases of the four most common B-cell histologic types and 9562 controls using a genetic risk score (GRS) comprising nine telomere length-associated single-nucleotide polymorphisms. This approach uses existing genotype data and estimates telomere length by weighing the number of telomere length-associated variant alleles an individual carries with the published change in kb of telomere length. The analysis of the telomere length GRS resulted in an association between longer telomere length and increased NHL risk [four B-cell histologic types combined; odds ratio (OR) = 1.49, 95% CI 1.22-1.82,P-value = 8.5 x 10(-5)]. Subtype-specific analyses indicated that chronic lymphocytic leukemia or small lymphocytic lymphoma (CLL/SLL) was the principal NHL subtype contributing to this association (OR = 2.60, 95% CI 1.93-3.51,P-value = 4.0 x 10(-10)). Significant interactions were observed across strata of sex for CLL/SLL and marginal zone lymphoma subtypes as well as age for the follicular lymphoma subtype. Our results indicate that a genetic background that favors longer telomere length may increase NHL risk, particularly risk of CLL/SLL, and are consistent with earlier studies relating longer telomere length with increased NHL risk

We report the long-term follow-up results of a phase II trial of IL-1 receptor antagonist and low-dose dexamethasone for early stage multiple myeloma (MM). Patients were eligible if they had smoldering multiple myeloma (SMM) or indolent multiple myeloma (IMM) without the need for immediate therapy. Forty seven patients were enrolled and subsequently treated with IL-1Ra; in 25/47 low-dose dexamethasone (20 mg weekly) was added. The primary endpoint was progression-free survival (PFS). In the clinical trial, three patients achieved a minor response (MR) to IL-1Ra alone; five patients a partial response (PR) and four patients an MR after addition of dexamethasone. Seven patients showed a decrease in the plasma cell labeling index (PCLI) which paralleled a decrease in the high sensitivity C-reactive protein (hs-CRP). The median PFS for the 47 patients was 1116 days (37.2 months). The median PFS for patients without (n = 22) and with (n = 25) a decrease in their baseline hs-CRP was 326 days (11 months) vs. 3139 days (104 months) respectively (P0.0001). The median overall survival (OS) for the 47 patients was 3482 days (9.5 years). The median OS for patients without and with a decrease in their baseline hs-CRP was 2885 days (7.9 years) vs. median not reached, respectively (P = 0.001). In SMM/IMM patients at risk for progression to active myeloma, reduction in the hs-CRP indicates successful targeting of the IL-1/IL-6 axis resulting in improved PFS and OS. (Clinical Trials.gov Identifier: NCT00635154) Am. J. Hematol. 91:571-574, 2016. © 2016 Wiley Periodicals, Inc.

Summary Background The PI3K–mTORC pathway is upregulated in diffuse large B-cell lymphoma (DLBCL) and can be targeted with the mTOR complex 1 (mTORC1) inhibitor everolimus. Everolimus has activity in relapsed DLBCL. These data provide the rationale to combine everolimus with standard treatment for DLBCL of rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone delivered in a 21-day cycle (R-CHOP-21) for six cycles. Methods We did a phase 1 and feasibility study (NCCTG 1085) of oral everolimus 10 mg/day plus R-CHOP-21 in patients aged at least 18 years with new, untreated, CD20-positive DLBCL (stages II–IV) in the NCCTG (Alliance) National Cancer Institute Cooperative Group (USA). Patients received standard R-CHOP-21 (intravenous rituximab 375 mg/m 2 , intravenous cyclophosphamide 750 mg/m 2 , intravenous doxorubicin 50 mg/m 2 , and intravenous vincristine 1·4 mg/m 2 [maximum 2·0 mg] all on day 1 of the 21-day cycle; and oral prednisone 100 mg/m 2 each day on days 1–5 of the cycle) for six cycles with scheduled subcutaneous pegfilgrastim 6 mg on day 2 of each cycle. We tested two schedules: everolimus given in the fasting state either on days 1–10 or days 1–14 of the R-CHOP cycle. The primary endpoint of the phase 1 portion of this study was to establish the maximum tolerated dose of everolimus that could be combined with R-CHOP-21. The primary endpoint of the feasibility portion of the study was to determine the feasibility of the regimen, which was assessed by determining the rate of significant toxicity. Secondary endpoints were the proportion of patients who achieved an overall response, a complete response, event-free survival at 12 months and 24 months from enrolment, progression-free survival, and overall survival; relapse of DLBCL; and duration of response. We deemed patients as assessable for the primary endpoint in the phase 1 portion if they completed the first cycle as planned. In the feasibility portion, all patients who received at least one dose of everolimus were included. This trial is registered with ClinicalTrials.gov, number NCT01334502. Findings Between March 21, 2012, and Sept 15, 2014, we enrolled 26 patients into the study. Two were ineligible, therefore results are presented for 24 eligible patients. Nine patients were enrolled into the phase 1 portion of the trial (three given everolimus on days 1–10, and six given everolimus on days 1–14) without any dose-limiting toxicities; therefore, everolimus 10 mg/day given on days 1–14 with R-CHOP-21 was tested in 15 additional patients for a total of 24. One (5%, 95% CI 0–24%) of 21 patients had a toxicity during the feasibility phase—a treatment delay of 12 days due to grade 3 hypokalaemia possibly related to everolimus. The median follow-up was 21·5 months (IQR 17–29). 23 (96%, 95% CI 79–100%) of 24 patients achieved an overall response, and all 23 (96%, 79–100%) also attained a complete metabolic response by PET. The remaining patient withdrew consent after in cycle 1 and attained a complete response with R-CHOP alone. All 24 (100%) patients met 12-month event-free survival, and nine had sufficient follow-up data to be event-free at 24 months. None of the 24 patients had died by the last follow-up (March 30, 2016), and none had had a relapse with DLBCL. Because no events occurred during the study or follow-up, we were unable to assess the duration of response or progression-free survival. The most common grade 3–4 adverse events were haematological; the most common of these was grade 4 neutropenia in 18 (75%) of 24 patients. Five (21%) of 24 had grade 3 febrile neutropenia. Interpretation The mTORC1 inhibitor everolimus given for 14 days in combination with R-CHOP-21 for patients with DLBCL is safe. These findings suggest that drugs that target the PI3K–mTORC pathway add benefit when combined with standard R-CHOP. The everolimus with R-CHOP regimen should be tested against standard R-CHOP alone in a randomised trial, to support the benefits of this novel combination noted in this study. Funding National Cancer Institute of the US National Institutes of Health.

WOS: 000313111300022, PubMed ID: 23018644, STAT3 regulates cell growth by upregulating downstream targets, such as Myc. The frequency of phosphorylated STAT3 (pSTAT3) and Myc expression and their prognostic relevance is unknown within diffuse large B-cell lymphoma (DLBCL) germinal center B-cell (GCB) and non-GCB subtypes. pSTAT3 and Myc were studied by immunohistochemistry (IHC) on tumors from 40 DLBCL patients uniformly treated on a clinical trial of epratuzumab/rituximab-CHOP. A total of 35% of cases were pSTAT3-positive, and pSTAT3 positivity was more frequent in the non-GCB (P = .06) type but did not correlate with event-free survival (EFS). Myc expression was observed in 50% of cases and was more frequent in non-GCB type (P = .07). Myc-positive cases had inferior EFS in all patients, including the GCB and pSTAT3-positive cases, were more likely to express Myc (P = .06). Myc translocations involving the major breakpoint regions were found in 10% (3 of 29) of cases, and all 3 cases were GCB and had an inferior EFS (P = .09). pSTAT3, but not Myc expression, was correlated with elevated pretreatment serum cytokines, such as IL-10 (P = .05), G-CSF (P = .03), and TNF-alpha (P = .04). pSTAT3 IHC in DLBCL tumors has the potential to identify patients for STAT3 pathway-directed therapy; Myc IHC is a potential marker for inferior EFS in GCB patients. (Blood. 2012;120(22):4400-4406), University of Iowa/Mayo Clinic Lymphoma Specialized Program of Research Excellence [P50 CA097274]; Goodwin Foundation; North Central Cancer Treatment Group [CA25224, CA114740]; Predolin Foundation; [R01-CA127433], This work was supported in part by the University of Iowa/Mayo Clinic Lymphoma Specialized Program of Research Excellence (Career Development Award P50 CA097274; M.G.), Goodwin Foundation Pilot award (M.G.), the North Central Cancer Treatment Group (CA25224; and Biospecimen Resource Grant CA114740), and the Predolin Foundation Award. This work is supported in part by R01-CA127433 to T.E.W.

Genetic aberrations, including trisomies 3 and 18, and well-defined IGH translocations, have been described in marginal zone lymphomas (MZLs); however, these known genetic events are present in only a subset of cases. Here, we report the cloning of an IGH translocation partner on chromosome X, t(X;14)(p11.4;q32) that deregulates expression of an poorly characterized orphan G-protein–coupled receptor, GPR34. Elevated GPR34 gene expression was detected independent of the translocation in multiple subtypes of non-Hodgkin lymphoma and distinguished a unique molecular subtype of MZL. Increased expression of GPR34 was also detected in tissue from brain tumors and surface expression of GPR34 was detected on human MZL tumor cells and normal immune cells. Overexpression of GPR34 in lymphoma and HeLa cells resulted in phosphorylation of ERK, PKC, and CREB; induced CRE, AP1, and NF-κB–mediated gene transcription; and increased cell proliferation. In summary, these results are the first to identify a role for a GPR34 in lymphoma cell growth, provide insight into GPR34-mediated signaling, identify a genetically unique subset of MZLs that express high levels of GPR34, and suggest that MEK inhibitors may be useful for treatment of GPR34-expressing tumors.