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Patients with non–Hodgkin lymphoma and chronic lymphocytic leukemia (NHL/CLL) elicit inadequate antibody responses after initial SARS-CoV-2 vaccination and remain at high risk of severe COVID-19 disease. We investigated IgG, IgA, and IgM responses after booster vaccination against recent SARS-CoV-2 variants including Omicron BA.5 in 67 patients. Patients had lower fold increase and total anti-spike binding titers after booster than healthy individuals. Antibody responses negatively correlated with recent anti-CD20 therapy and low B-cell numbers. Antibodies generated after booster demonstrated similar binding properties against SARS-CoV-2 variants compared with those generated by healthy controls with lower binding against Omicron variants. Importantly, 43% of patients showed anti-Omicron BA.1 neutralizing antibodies after booster and all these patients also had anti-Omicron BA.5 neutralizing antibodies. Patients with NHL/CLL demonstrated inferior antibody responses after booster vaccination, particularly against Omicron variants. Prioritization of prophylactic and treatment agents and vaccination of patients and close contacts with updated vaccine formulations are essential. Significance: Limited data exist on antibody responses against current SARS-CoV-2 variants after booster vaccination in patients with NHL/CLL. We showed inferior antibody responses against Omicron variants after booster vaccination in these patients but some generated anti-Omicron titers. This stresses the importance of vaccinating patients with updated formulations.

Induction chemotherapy followed by autologous stem cell transplantation (ASCT) is a standard first-line treatment for fit patients with mantle cell lymphoma (MCL). We conducted a single-center phase I trial investigating post-transplant maintenance with ixazomib, an oral proteasome inhibitor.Patients enrolled between days +70 and +180 post ASCT. Patients received ixazomib per dose cohort on days 1, 8, and 15 of each 28-day cycle for up to 10 cycles. During recruitment, published phase III data reported a survival benefit with rituximab maintenance, so all subsequent patients received ixazomib 4 mg at the same schedule along with rituximab 375 mg/mSeven patients received ixazomib monotherapy; 1 dose limiting toxicity (grade 3 neutropenia) occurred at dose level 2 (4 mg). Five patients received combination Ixazomib plus rituximab, with 2 experiencing DLTs (both Grade 4 neutropenia). Grade 3-4 neutropenia, lymphopenia, and thrombocytopenia occurred in 57%, 8%, and 8% of patients, respectively. Non-hematologic adverse events (AE) included nausea (42%), peripheral neuropathy (42%), and abdominal discomfort (33%), all of which were grade 1 or 2 in severity. There were no infectious AEs. With a median follow up of 46 months, all patients are alive and in complete remission.The trial was closed to further accrual due to high rates of treatment-related myelosuppression. The current dose and schedule of ixazomib, especially when combined with rituximab, results in unacceptable hematologic toxicity when administered as post-transplant maintenance in MCL. Ixazomib maintenance micro abstract: The authors conducted a phase I study investigating the use of ixazomib, an oral proteasome inhibitor, with or without rituximab in patients with mantle cell lymphoma in first remission following chemoimmunotherapy and autologous stem cell transplantation. All patients treated on study remain in complete remission with a median follow-up of 46 months, but the study was closed early due to a high rate of hematologic adverse events.

Patients with non–Hodgkin lymphoma and chronic lymphocytic leukemia (NHL/CLL) elicit inadequate antibody responses after initial SARS-CoV-2 vaccination and remain at high risk of severe COVID-19 disease. We investigated IgG, IgA, and IgM responses after booster vaccination against recent SARS-CoV-2 variants including Omicron BA.5 in 67 patients. Patients had lower fold increase and total anti-spike binding titers after booster than healthy individuals. Antibody responses negatively correlated with recent anti-CD20 therapy and low B-cell numbers. Antibodies generated after booster demonstrated similar binding properties against SARS-CoV-2 variants compared with those generated by healthy controls with lower binding against Omicron variants. Importantly, 43% of patients showed anti-Omicron BA.1 neutralizing antibodies after booster and all these patients also had anti-Omicron BA.5 neutralizing antibodies. Patients with NHL/CLL demonstrated inferior antibody responses after booster vaccination, particularly against Omicron variants. Prioritization of prophylactic and treatment agents and vaccination of patients and close contacts with updated vaccine formulations are essential.Significance:Limited data exist on antibody responses against current SARS-CoV-2 variants after booster vaccination in patients with NHL/CLL. We showed inferior antibody responses against Omicron variants after booster vaccination in these patients but some generated anti-Omicron titers. This stresses the importance of vaccinating patients with updated formulations.

Supplementary Table 3. Univariate analyses of clinical variables associated with booster response

Supplemental Figure 2. Positive correlations in antibody binding titers between anti-Spike IgG and anti-RBD, anti-NTD IgG, and anti-spike IgA and IgM

Risk factors for progression to advanced-stage mycosis fungoides (MF) are poorly defined.The authors performed a single-center, retrospective cohort study among patients with MF at an academic medical center from 1990 to 2020 to identify clinical variables associated with progression to advanced-stage MF (stage IIB-IVB), and 388 patients who had a clinicopathologic diagnosis of early stage (IA-IIA) MF were identified from their cutaneous lymphoma database. Baseline clinical characteristics, laboratory values, imaging, and blood flow cytometry or T-cell receptor gene rearrangement (TCR) data were collected. Logistic regression was used to assess risk factors associated with progression.Overall, 93 of 388 patients (24.0%) progressed to advanced stage. Patients who progressed had an increased risk of death (hazard ratio, 4.50; 95% CI, 2.89-7.00; p .001). Progression was associated with a higher overall stage at diagnosis, tumor stage, lymph node stage, low-level blood involvement, as measured with TCR data and/or flow cytometry, and elevated lactate dehydrogenase (LDH). Limitations included missing data for LDH, imaging, peripheral blood TCR data, or flow cytometry assessed at diagnosis.Staging and baseline laboratory assessments with imaging, peripheral blood flow cytometry, TCR data, and LDH in patients who have newly diagnosed MF may identify those who are at risk for progression to advanced stage.

ImportanceTo our knowledge, this is the first clinical trial designed to investigate concurrent treatment with a checkpoint inhibitor and conventional chemotherapy in relapsed or refractory classic Hodgkin lymphoma in patients destined for an autologous stem cell transplant.ObjectiveTo evaluate the complete response rate as assessed by 18F-fluorodeoxyglucose–positron emission tomography with computed tomography (FDG-PET/CT) after salvage therapy for patients with relapsed or refractory classic Hodgkin lymphoma.Design, Setting, and ParticipantsA single-group, phase 2, multi-institutional nonrandomized clinical trial to evaluate the addition of pembrolizumab to ifosfamide, carboplatin, and etoposide (ICE) chemotherapy was conducted from April 20, 2017, to October 29, 2020, at 5 US sites. The 42 patients were aged 18 years or older, with an Eastern Cooperative Oncology Group Performance Status Scale score of 0 or 1 and biopsy-proven relapsed or refractory classic Hodgkin lymphoma after 1 or 2 prior lines of chemotherapy. Patients were required to be appropriate candidates for transplant, with measurable lesions detected by FDG-PET/CT.InterventionsTwo cycles of pembrolizumab (200 mg intravenously on day 1) with ICE chemotherapy every 21 days, followed by stem cell mobilization and collection, and then 1 cycle of pembrolizumab monotherapy followed by FDG-PET/CT response assessment.Main Outcomes and MeasuresThe primary end point was complete response rate detected by FDG-PET/CT, defined as a Deauville score of 3 or lower. Patients with a complete response proceeded to an autologous stem cell transplant. Secondary end points included progression-free survival, overall survival, stem cell mobilization, and neutrophil and platelet engraftment. Adverse events were monitored to assess safety.ResultsForty-two patients were enrolled, with 37 evaluable for the primary end point. The median age was 34 years (range, 19-70 years), 25 patients were female (68%), 6 were African American (16%), and 26 were White (70%). The complete response rate for the 37 patients assessed by FDG-PET/CT imaging was 86.5% (95% CI, 71.2%-95.5%); the overall response rate was 97.3% (36 patients), with 10.8% partial responses (4 patients). New areas of FDG-PET positivity in 2 patients were biopsied, showing noncaseating granuloma in 1 case and a reactive lymph node in a second. Progression-free survival and overall survival 2-year estimates were 87.2% (32 patients; 95% CI, 77.3%-98.3%) and 95.1% (95% CI, 88.8%-100%), respectively. The addition of pembrolizumab to ICE chemotherapy did not negatively affect stem cell mobilization or collection or engraftment, similar to prior experience in this patient population and setting.Conclusions and RelevanceResults suggest that the addition of pembrolizumab to ICE chemotherapy was well tolerated and highly effective in comparison with prior reports of chemotherapy-only regimens, supporting further investigation in patients with relapsed or refractory classic Hodgkin lymphoma eligible for an autologous stem cell transplant.Trial RegistrationClinicalTrials.gov Identifier: NCT03077828

Adolescents and young adults (AYAs) with cancer constitute approximately 70,000 patients diagnosed each year. Survival rates for AYAs with cancer have increased steadily in recent decades due to improvements in therapeutic regimens and early detection. Given the large and growing number of AYA cancer survivors, additional research is needed on the immediate and long-term psychosocial support required for this population including family planning and fertility. Fertility and fertility preservation in female AYAs, in particular, is historically understudied and has psychologically relevant ramifications distinct from male AYAs. Decision science can contribute to this area of oncological care and has implications for clinical encounters and research concerning female AYA patients with cancer. Patient-centered care and shared decision-making that integrates recent research regarding fertility preservation in the context of cancer.

Patients with CTCL are at increased risk for bacteremia which is a leading cause of morbidity and mortality. We assessed risk factors for and the impact of bacteremia on survival in a retrospective cohort of 188 CTCL patients at a single US academic institution treated between 1990 and 2018. With a median follow up of 6.2 years, 20% of patients (n = 36) developed 79 bacteremia events. Risk factors for bacteremia included advanced stage, female gender, African American (AA) race, invasive lines, and chemotherapy. Bacteremia was associated with an increased risk of death on univariate and multivariable models. Bacteremia is associated with an increased risk of death in patients with CTCL. The greatest avoidable risk factors included chemotherapy treatment and presence of an invasive line.

Sézary syndrome (SS) is an aggressive cutaneous T-cell lymphoma with poor survival. We performed a retrospective review of SS patients at Emory University from 1990 to 2020. We collected data on race, clinical characteristics, therapy, and social determinants of health. Clinical endpoints were overall survival (OS) and time to next treatment (TTNT). Univariate association and multivariable analyses were assessed by Cox proportional hazards models. Among 62 patients, 45.2% were AA. The median OS and TTNT were 3.1 years and 6.3 months, respectively, with no difference by race. AA patients had a higher median baseline LDH (360ivs./i232,ip/i = 0.002) and a longer delay in initiation of systemic therapy compared to CC patients (3.17ivs./i2.14 months,ip/i = 0.039), but a shorter commute (lt;10 miles) and no difference in insurance coverage (ip/i = 0.260). AA patients at an academic center had unique clinical features and treatment patterns, but similar survival to CC SS patients.

ImportanceMycosis fungoides and Sézary syndrome (MF/SS) has an increased incidence in Black patients, but clinical characteristics, treatments, and outcomes have been poorly characterized.ObjectiveTo assess racial differences in presentation and outcome and identify drivers for racial disparities in MF/SS.Design, Setting, and ParticipantsA retrospective cohort analysis was conducted of 566 patients with MF/SS diagnosed from 1990 to 2020 and seen at the Winship Cancer Institute of Emory University and Grady Memorial Hospital, both in Atlanta, Georgia. Self-reported race and ethnicity were obtained from patient medical records and analyzed as 2 groups: non-Hispanic Black (Black) and all other races and ethnicities, including Asian, Hispanic, White, and unknown/undeclared (non-Black).Main Outcomes and MeasuresUnivariate and multivariable models and Kaplan-Meier assessments were analyzed for overall survival and time to next treatment. The primary outcome was to assess differences in overall survival by racial and ethnic group. The hypotheses were formulated prior to data collection.ResultsOf the 566 patients with MF/SS identified (mean [SD] age 55 [16.4] years; 270 (47.7%) female), 257 were Black and 309 were non-Black. Black race was associated with increased rates of progression to a higher TNMB stage (39.8% in Black patients vs 29.1% in non-Black patients; P P = .04), but not in patients older than 60 years (HR, 1.20; 95% CI, 0.80-1.81; P = .37). On multivariate analysis, among the cohort without HMF who were younger than 60 years, Black race remained statistically significant when controlling for cancer stage and large-cell transformation (HR, 1.27; 95% CI, 1.08-2.87; P = .43).Conclusions and RelevanceIn this cohort study, Black patients with MF/SS showed distinct clinical presentations and patterns of progression with heterogeneous outcomes depending on age at presentation and presence of HMF.

Introduction Influenza infection causes significant morbidity and mortality in patients with cancer, and annual influenza vaccination for individuals with cancer is recommended. We sought to examine the documentation rate of influenza vaccine administration, refusal, or counseling in the first year after diagnosis of diffuse large B cell lymphoma (DLBCL) for patients across 3 hospitals in 2 health care systems. Patients and Methods Documentation of vaccine administration, refusal, or counseling by physicians, advanced practice providers, or nursing staff during the first period of influenza vaccine availability after diagnosis (August to April) was assessed in medical records of patients diagnosed with DLBCL between February 2015 and October 2017 who presented to Emory St. Joseph Hospital (community hospital), Winship Cancer Institute of Emory University (academic medical center), or Grady Memorial Hospital (county hospital). Results Of the 57% (61/107) of newly diagnosed patients with DLBCL who had vaccine-related documentation, 43% refused vaccination. Counseling was not documented for any patient. Inpatient nursing performed 75% of all documentation. Primary oncologists documented vaccination in 4% of all cases. Conclusion Despite the limited immunization documentation and high refusal rates observed in this study, the influenza vaccine refusal rate was lower than the average for the United States, the state of Georgia, and the previous studies of patients with cancer. Although routine outpatient vaccination occurs, improvements in screening, strategies for sharing patient vaccine-related information, and counseling of patients who refuse the vaccine are needed. Further work is also needed to determine the effectiveness of influenza vaccination in patients receiving anti-cancer therapy.

Pembrolizumab, a humanized IgG4 monoclonal antibody targeting programmed death-1 protein, has demonstrated efficacy in relapsed/refractory classical Hodgkin lymphoma (cHL). To assess the complete metabolic response (CMR) rate and safety of pembrolizumab monotherapy in newly diagnosed cHL, we conducted a multicenter, single-arm, phase 2 investigator-initiated trial of sequential pembrolizumab and doxorubicin, vinblastine, and dacarbazine (AVD) chemotherapy. Patients ≥18 years of age with untreated, early, unfavorable, or advanced-stage disease were eligible for treatment. Thirty patients (early unfavorable stage, n = 12; advanced stage, n = 18) were treated with 3 cycles of pembrolizumab monotherapy followed by AVD for 4 to 6 cycles, depending on stage and bulk. Twelve had either large mediastinal masses or bulky disease (>10 cm). After pembrolizumab monotherapy, 11 patients (37%) demonstrated CMRs, and an additional 7 of 28 (25%) patients with quantifiable positron emission tomography computed tomography scans had >90% reduction in metabolic tumor volume. All patients achieved CMR after 2 cycles of AVD and maintained their responses at the end of treatment. With a median follow-up of 22.5 months (range, 14.2-30.6) there were no changes in therapy, progressions, or deaths. No patients received consolidation radiotherapy, including those with bulky disease. Therapy was well tolerated. The most common immune-related adverse events were grade 1 rash (n = 6) and grade 2 infusion reactions (n = 4). One patient had reversible grade 4 transaminitis and a second had reversible Bell’s palsy. Brief pembrolizumab monotherapy followed by AVD was both highly effective and safe in patients with newly diagnosed cHL, including those with bulky disease. This trial was registered at www.clinicaltrials.gov as #NCT03226249.

Older patients with diffuse large B-cell lymphoma (DLBCL) may face challenges in treatment due to comorbidities and tolerance of chemotherapy. Older patients are at increased risk for treatment-related toxicity if they are unfit or frail by comprehensive geriatric assessment (CGA); however, treatment with non-anthracycline chemotherapy is associated with inferior outcomes in fit and unfit patients. Many older patients remain curable with standard R-CHOP chemotherapy. Careful assessment of frailty, function, and comorbidities using CGA may aid clinicians in initial therapy choices.

Peripheral T cell lymphomas (PTCLs) are a heterogeneous group of non-Hodgkin lymphomas with inferior prognosis compared with their B cell counterparts characterized by frequent relapses, resulting in a median 5-year survival of approximately 30%. Their diverse clinicopathologic features challenge existing treatment paradigms that treat all patients uniformly. Here we review recent advances in the treatment of these diseases. While current treatment still relies largely on combination chemotherapy, the introduction of more effective novel and targeted therapies has improved outcomes in certain subtypes. Increasing understanding of the underlying biology of PTCL has prompted further subclassification by genetic and molecular subgroups. Overall, the most significant advances in PTCL management have resulted from improved understanding and classification of the biology of PTCL. Ongoing development of subtype-specific targeted therapies will be essential to improve long-term outcomes of patients with these diseases.

Classical Hodgkin lymphoma (cHL) in older adults is associated with inferior outcomes and increased toxicity compared to younger patients. Novel therapies like brentuximab vedotin (BV) have yielded promising results, yet their optimal use in older cHL remains unclear. We performed a systematic review to assess outcomes and toxicity associated with frontline regimens in older cHL. We screened 196 references involving chemotherapy without BV and 662 references containing BV and included 9 studies (12 arms) without BV and 6 studies (7 arms) with BV. Progression-free survival (PFS) ranged from 47 to 84% at 2 years in BV-containing arms and 42-79% at 5 years in non-BV containing trials. Pulmonary toxicity was more common in arms receiving2 cycles of bleomycin, whereas peripheral neuropathy was associated with cumulative BV dose. This review summarizes available treatment outcomes in newly diagnosed older cHL patients and may aid clinicians in decision-making regarding available frontline approaches.Key PointsThis systematic review suggests that2 cycles of bleomycin is associated with excess pulmonary toxicity in cHL patients older than 60 years of age.Peripheral neuropathy was more frequent in patients receiving BV-containing regimens and was associated with cumulative BV dose.BV-containing regimens are associated with high response rates in advanced-stage patients, but follow-up is limited.

Hepatosplenic T-cell lymphoma (HSTCL) is a rare T-cell neoplasm that most commonly arises from a small subset of γ/δ T-cell receptor–expressing lymphocytes. HSTCL is more common in adolescent and young adults and has a rapidly progressive clinical course and poor outcome due to its refractoriness to conventional chemotherapy regimens. Approximately 20% of the cases arise in the background of chronic immunosuppression or immune dysregulation. Patients commonly present with constitutional symptoms, hepatic and liver enlargement, and cytopenias; hematophagocytic syndrome can also occur. The most frequent chromosomal aberrations associated with HSTCL are isochromosome 7q and trisomy 8, and most cases harbor mutations in genes involved in chromatin modification or the JAK/STAT pathway. The rarity of this disease, along with lack of nodal involvement and presenting symptoms that mimic different entities including infectious etiologies, makes this lymphoma a significant diagnostic challenge. In this review, we highlight the clinical and pathologic features of HSTCL. Moreover, we summarize the results of recent molecular studies suggesting potential targets for novel therapeutics strategies.

Peripheral T-cell lymphomas (PTCLs) are an aggressive and diverse group of lymphomas with a T-cell origin. Most patients progress following initial treatment and require salvage therapy. The burden of symptoms is high due to its extra-nodal presentation, high rate of advanced disease, and associated cytopenias combined with its predilection for an elderly population. The disease is generally incurable at relapse in the absence of transplantation and treatment is aimed at prolonging life and reducing disease-related symptoms. Belinostat is a histone deacetylate inhibitor that was granted accelerated approval by the US Food and Drug Administration on July 3, 2014, for the treatment of relapsed PTCL. Here, a systemic review was conducted to assess the safety and efficacy of belinostat. A safety analysis involved 512 patients with relapsed malignancies, and an efficacy analysis focused on patients with relapsed PTCL and included a total of 144 patients. Common adverse events were noted including fatigue (35%), nausea (42.8%), and vomiting (28.5%), but comparatively low rates of grade 3/4 hematologic toxicity overall (6.4%). Efficacy analysis demonstrated an overall response rate of 25.7% and complete responses of 10.4% with the majority of discontinuations occurring for lack of efficacy. Ultimately, these results demonstrate that belinostat has comparable efficacy to other agents used in this setting and is well tolerated in regard to hematologic events, but there is limited data on patient-reported outcomes, reduction in disease-related symptoms, or quality of life., Video abstract

Patients with PDGFRA-rearranged hematopoietic neoplasms typically present with chronic eosinophilic leukemia and rarely with acute myeloid leukemia or T-lymphoblastic lymphoma. However, mature T-cell lymphoma has not been previously associated with PDGFRA aberrations. We report a patient who presented with simultaneous T-lymphoblastic lymphoma, focal myeloid proliferation, and cutaneous cytotoxic T-cell lymphoma refractory to chemotherapy. The presence of myeloid and lymphoid lineages prompted genetic and molecular studies. A PDGFRA rearrangement was identified in all compartments: cutaneous, lymph node, and bone marrow. Treatment with imatinib resulted in an excellent response in cutaneous and systemic disease. We report the first case of a mature cutaneous T-cell lymphoma with PDGFRA rearrangement, expanding the spectrum of neoplasms associated with this genetic abnormality. Our case underscores the great importance of recognizing PDGFRA rearrangement in unusual cases of cutaneous T-cell lymphoma, systemic lymphoid, and myeloid neoplasms. These patients may respond well to tyrosine kinase inhibitors, despite resistance to conventional chemotherapy.

Since 2012, the FDA has approved 88 new oncologic therapies or indications, including 28 drugs for hematologic malignancies (centerwatch.com/drug-information/fda-approved). Correspondingly, the Sur...

Introduction Large cell transformation (LCT) in mycosis fungoides is defined as 25% large cells and is traditionally associated with a poor prognosis and a median survival of 3-5 years. There is no consensus on the appropriate management for these patients. We aimed to characterize clinical and pathologic features of patients with transformed mycosis fungoides (tMF) at our institution and to describe treatment patterns and patient outcomes. Methods We performed a retrospective review of 63 patients with a histopathologic diagnosis of tMF seen at the Winship Cancer Institute of Emory University from 1990-2021. Clinical data collected from the electronic medical record included demographics, baseline laboratory values, disease characteristics, pathologic characteristics, and therapy. Kaplan-Meier curves for OS and PFS were generated for the whole cohort. Descriptive analysis was performed for covariates. The association of baseline variables with OS was modeled by Cox proportional hazards model. Results Among 63 patients with tMF, there was even distribution among male (54%) and female (46%) patients (Figure 1A). The median age at the time of large cell transformation (LCT) was 63 years (range, 20-87). This population included 46% African American (AA), 50.8% White, 1.6% other races (n=1). At the time of diagnosis, the stage was 1A-1B in 23 (36.5%), 2A in 11 (17.5%), 2B in 20 (31.7%), 3A-3B in 3 (4.8%), 4A in 5 (7.9%) and 4B in 1. The ECOG performance status (PS) was 0-1 in 49 (77.8%), 2 in 7 patients (11.1%), 3 in 3 patients, and 4 in one patient. Most patients had patches and plaques at diagnosis, 23 (36.5%) had tumors, and 9 (14.3%) had ulceration. Only 2 patients had hypopigmented MF. The most common therapies prior to LCT were topical steroids (n=34), phototherapy (n=25), topical nitrogen mustard (n=20), oral retinoids (n=14), and oral methotrexate (n=8). Radiation (RT) was received in 22 patients prior to transformation with 16 having localized RT and 9 total skin electron beam therapy (TSEB). The median time from diagnosis to LCT was 2.1 years (range, 0-32 years). Most patients had advanced stage at the time of LCT (n=45, 86%), with stage 2B the most frequent 23 (36.5%). Other stages at LCT were 1A in 1 patient, 2A in 6, 3A-B in 6, 4A in 14 and 4B in 11. Overall, 47 (74.6%) patients experienced progression in their TNMB stage following LCT. LCT occurred in the skin in 51 patients (81%), lymph nodes in 21 (33.3%), and viscera in 5 (7.9%). The percentage of large cells was >50% in 24 patients (38.1%), and < 50% in 13 (20.6%). CD30 percentage was missing in the majority of patients (n=37, 58.7%). T-cell rearrangement in blood, skin, and lymph nodes was not consistently characterized with data missing in nearly half the patients (n=30, 47.6%). In those with TCR checked in at least one location, it was non-clonal in 19, had clonal persistence in 6 (9.5%), clonality in at least one sample but either not rechecked, or not persistent in 6 (9.5%), and oligoclonal in 2 (n=3.2). The most common treated for LCT was total skin electron beam therapy (TSEB, n=16) and chemotherapy (n=14), followed by brentuximab vedotin and localized RT in 9 patients each. Other treatments included topical corticosteroids (N=2), histone deacetylase inhibitors (n=4), and mogamulizumab (n=4). The median overall survival was 2.3 years from LCT (95% CI 1.1-3.5 years), and the median PFS was 2.6 years (95% CI, 1.1-4.1 years) (Figure 1B) . The median time to treatment following LCT was 30 days (range, -1 day to 2.3 years). By cox regression, neither baseline demographic factors, tumor characteristics, treatment, nor time to LCT were associated with progression-free or overall survival. Only response to treatment for LCT (complete response, partial response, or stable disease) was associated with survival (p=0.041, Figure 1C). Conclusions We characterized the clinical features and outcomes of a cohort of patients with tMF seen at Emory University over a 30 year period. We found poor outcomes despite many patients receiving novel and targeted therapies in the modern era. Key pathologic and clinical variables such as CD30 percentage and t-cell gene rearrangement studies were not reported for many patients, suggesting standardized practices are needed in the diagnosis and pathologic evaluation of patients with tMF. Additional pathologic correlatives will be updated at the time of the presentation. Figure 1 Figure 1. Disclosures Allen: ADC Therapeutics: Consultancy; Kyowa Kirin: Consultancy; Secure Bio: Consultancy.

Background: Genomic copy number alterations (CNAs) of chromosome 9p24.1 characterize classic Hodgkin lymphoma (cHL) leading to increased expression of programmed cell death ligands -1 and -2 (PD-L1 and PD-L2). Amplifications and high level copy number gains (CNG) have been associated with advanced stage cHL and inferior treatment outcomes with standard chemotherapy. Few studies have assessed 9p24.1 genomic alterations in the frontline setting in the context of PD-1 blockade monotherapy. We conducted a phase 2 clinical trial of sequential pembrolizumab (PEM) x 3 followed by doxorubicin, vinblastine, and dacarbazine (AVD) chemotherapy (4-6 cycles) in newly diagnosed cHL. Interim response to single agent PEM was assessed by PET-CT and by decline in metabolic tumor volume (MTV). Herein, we report updates after extended follow-up of patients (median 33.1 months), and results of correlative studies analyzing 9p24.1 CNAs and PD-1 pathway expression. Methods: Pre-treatment diagnostic biopsy specimens were double stained for PD-L1 (E1L3N, XP Cell Signaling) and PAX5, single stained for PD-L2 and pSTAT3, and scored by two expert hematopathologists (QC, LBS) for percentage positive cells and intensity of staining. A modified H score was calculated as the product of staining intensity (0-3) and percentage of positive tumor cells (0-100%), ranging from 0 - 300 was calculated for PD-L1, PD-L2, and pSTAT3. Fluorescence in situ hybridization (FISH) to assess chromosome 9p24.1 CNAs was performed by co-hybridizing PD-L1/PD-L2 probes (target) with the centromeric 9 probe (control). In each case, the percentage and magnitude of 9p24.1 CNAs were evaluated. Four FISH categories were defined based on the target:control ratio and total copy numbers (CNs) of the target per Hodgkin Reed-Sternberg (HRS) cell to include: amplification (ratio≥3), copy number gain (CNGs) (1≤ratio The relationships between PD-1 pathway markers, genomic alterations, and response to single agent PEM by MTV were assessed statistically using Fisher's Exact test, Kruskal-Wallis test, or Spearman's rank correlation as appropriate. PD-L1 H Scores were grouped into terciles of approximately equal size for categorical analysis. Response was defined as a complete metabolic response (CMR), ≥ 90% reduction in MTV (near CMR), or partial response with < 90% reduction by MTV (PR). Kaplan-Meier curves were used to analyze progression-free survival (PFS) and overall survival (OS). Results: Thirty patients were enrolled from September 2017 through August 1, 2019; 28 had tissue available for FISH analysis and 29 for immunohistochemistry. Patient responses to single agent PEM were PMR in 11 (36.7%), near-CMR in 8 (26.7%), and CMR in 11 (36.7%). CMR rate following AVD x 2 was 100%. With the extended follow-up (median 33.1 months, range 26.0-43.0), PFS and OS both remained at 100% (Figures 1a, 1b). Among 28 cases with available FISH analysis, all patients demonstrated genomic alterations in 9p24.1. The highest level alteration was amplification in 14 patients (50%) and copy number gain in 14 (50.0%) Six of 22 examined cases were EBER-positive. Forty-one percent (n=7) of patients with a CMR or near CMR had amplifications in 9p24.1, compared to 64% (n=7) with a PMR following PEM monotherapy (p=0.2). The median PD-L1 H score was 215 (range 20-300). Of 29 patients assessed, 28% had PD-L1 H scores in the first tercile (H-score 1-190), 34% in the second tercile (190-240), and 38% in the third tercile (240-300). There was no association between response to single agent PEM and 9p24.1 alteration, PD-L1, PD-L2 or STAT3 H-scores, % residual disomy, or EBER status (see Figure 1c for PD-L1 results). Conclusions: We found that after extended follow-up, sequential pembrolizumab and AVD chemotherapy remains a highly effective strategy with 100% of patients remaining alive without relapse. The high response rates observed at all PD-L1/PD-L2 levels in this clinical study suggest that even low levels of PD ligand expression may be sufficient for response to PD-1 blockade in previously untreated cHL. We gratefully acknowledge support from Merck & Co. Figure 1 Figure 1. Disclosures Allen: Kyowa Kirin: Consultancy; Secure Bio: Consultancy; ADC Therapeutics: Consultancy; MorphoSys: Consultancy; Epizyme: Consultancy. Advani: Astellas/Agensys: Research Funding; AstraZeneca: Membership on an entity's Board of Directors or advisory committees; Bayer: Membership on an entity's Board of Directors or advisory committees; Bristol Myer Squibb: Membership on an entity's Board of Directors or advisory committees; Cell Medica: Membership on an entity's Board of Directors or advisory committees; Forty Seven: Membership on an entity's Board of Directors or advisory committees, Research Funding; Genetech Inc.: Membership on an entity's Board of Directors or advisory committees, Research Funding; Gilead: Membership on an entity's Board of Directors or advisory committees; Janssen Pharmaceutical: Research Funding; Juno: Membership on an entity's Board of Directors or advisory committees; Kite Pharma: Membership on an entity's Board of Directors or advisory committees; Kura: Research Funding; Kyowa: Membership on an entity's Board of Directors or advisory committees; Merck: Research Funding; Millenium: Research Funding; Pharmacyclics: Consultancy, Research Funding; Portola Pharmaceuticals: Consultancy; Regeneron: Research Funding; Roche: Membership on an entity's Board of Directors or advisory committees; Sanofi: Membership on an entity's Board of Directors or advisory committees; Seattle Genetics: Research Funding; Takeda: Membership on an entity's Board of Directors or advisory committees. Gordon: Zylem Biosciences: Patents & Royalties: Patents, No royalties; Bristol Myers Squibb: Honoraria, Research Funding. Winter: Actinium Pharma: Consultancy; BMS: Other: Husband: Data and Safety Monitoring Board; Novartis: Other: Husband: Consultancy, Data and Safety Monitoring Board; Ariad/Takeda: Other: Husband: Data and Safety Monitoring Board; Epizyme: Other: Husband: Data and Safety Monitoring Board; Agios: Other: Husband: Consultancy; Gilead: Other: Husband: Consultancy; Janssen: Other: Husband: Consultancy; Karyopharm (Curio Science): Honoraria; Merck: Consultancy, Honoraria, Research Funding.

Introduction: Diffuse large B-cell lymphomas (DLBCL) transformed from indolent B-cell non-Hodgkin lymphomas (B-NHL) or Richter transformation (RT) from chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL) are associated with a poor prognosis, particularly in patients (pts) with relapsed/refractory (RR) disease. PD-1/PD-L1 blockade has produced anti-tumor responses in pts with lymphoma; however, the response rate in pts with DLBCL is low. Preclinical data suggest that some "immunogenic" chemotherapies alter the tumor microenvironment and act synergistically with checkpoint blockade to improve anti-tumor responses. We evaluated the addition of the PD-L1 inhibitor, atezolizumab, to immunogenic chemoimmunotherapy, rituximab with gemcitabine and oxaliplatin (R-GEMOX) in pts with RR transformed DLBCL. Methods: Pts with DLBCL transformed from indolent B-NHL or RT from CLL that had received ≥ 1 prior regimen with ECOG performance status ≤ 2, and adequate organ and hematologic function were eligible for this phase 1 study. Two cohorts were enrolled, one for pts with DLBCL transformed from follicular lymphoma (FL) and another for pts with non-FL transformed DLBCL, including RT. R-GEMOX was administered without atezolizumab on C1D1, R-GEMOX+Atezo was given subsequently (Days 1+15 of 28 day cycles) for a maximum of 6 doses. Pts in CR could proceed to R+atezo q3w maintenance for up to 2 years. Pts could proceed to hematopoietic cell transplantation (HCT) without subsequent maintenance at the discretion of the treating MD. A safety lead-in (6 pts, any cohort) with dose-limiting toxicity (DLT) evaluation (28-day period, after 1 st dose of atezo) at dose level (DL) 1 (rituximab 375mg/m2, gemcitabine 1000mg/m2, oxaliplatin 100mg/m2, atezolizumab 840mg, with de-escalation dose level available) was enrolled to confirm the recommended phase 2 dose (RP2D). After confirmation of the RP2D, expansion will continue until enrollment of n=14 transformed FL and n=10 non-FL transformed DLBCL. Responses were assessed by investigators by PET-CT (after C2, C4, and then q12weeks) according to the 2014 Lugano Classification. The primary endpoint was safety and determination of the RP2D. Results: 23 pts were enrolled, 22 were evaluable for response and adverse events (AEs), 1 is too early. Baseline characteristics are summarized in Table 1. 1/6 pts had a DLT related to atezolizumab during safety lead-in: grade (G) 4 Stevens-Johnson syndrome leading to death. DL1 was the RP2D. 2 pts were replaced during safety lead-in due to progressive disease (PD) prior to completing DLT evaluation. The most common AEs with R-GEMOX+Atezo (n=22) were fatigue (50%), elevated transaminases (45%), thrombocytopenia (45%), nausea/vomiting (41%), diarrhea (32%), fever (32%), hypertension (HTN) (27%), and neutropenia (27%). Common G3-4 AEs included lymphopenia (n=4), neutropenia (n=4), HTN (n=3), leukopenia (n=3), thrombocytopenia (n=3). Among 7 pts who proceeded to maintenance R-atezo, the most common AEs were fatigue (n=4) and HTN (n=3). There were 2 deaths related to study therapy, the pt with SJS and 1 pt with infusion reaction leading to respiratory failure who also had PD with both factors likely contributing to death. In addition, 1 pt had both sepsis and PD and died during maintenance, considered possibly related to treatment. 7 deaths were unrelated to treatment, including 1 from complications after autologous HCT, and 6 after PD. 5 pts remain on treatment; 17 pts are off treatment. Reasons for study discontinuation include: insufficient response/PD (n=12), HCT (n=2), death due to toxicity (n=2), and G3 neuropathy during maintenance (n=1). Among the 22 pts, the ORR was 50% and CR rate was 29%. The 9 pts with transformed FL had an ORR of 67% and CR rate of 33%. The 13 pts with non-FL transformed DLBCL/RT had an ORR of 38% and CR rate of 23%. Of 9 pts with RT there was 1 CR and 1 PR while all 3 pts with transformed marginal zone lymphoma responded (2 CR, 1 PR). Among responders (n=11), the median duration of response was not reached (Figure 1). Of the 6 pts with CR, 2 proceeded to HCT, and 4 had ongoing CR lasting 30.7+ months (mo), 13.9+ mo, 6.8+ mo, 5.0+ mo. Of the 5 patients with PR, 1 pt died of SJS without PD, PR lasted 3 and 4 mo in 2 patients (PD), and 2 pts have ongoing response (0.5+ and 2.0+ mo). Conclusions: R-GemOx+Atezo was tolerable and produced objective responses in patients with transformed DLBCL/RT, with all pts in CR having ongoing response. Figure 1 Figure 1. Disclosures Herrera: Gilead Sciences: Research Funding; ADC Therapeutics: Consultancy, Research Funding; Genentech: Consultancy, Research Funding; Tubulis: Consultancy; Takeda: Consultancy; Merck: Consultancy, Research Funding; Bristol Myers Squibb: Consultancy, Research Funding; Kite, a Gilead Company: Research Funding; AstraZeneca: Consultancy, Research Funding; Karyopharm: Consultancy; Seagen: Consultancy, Research Funding. Allen: Epizyme: Consultancy; Kyowa Kirin: Consultancy; Secure Bio: Consultancy; ADC Therapeutics: Consultancy; MorphoSys: Consultancy. Popplewell: Hoffman La Roche: Other: Food; Novartis: Other: Travel; Pfizer: Other: Travel. Shouse: Beigene: Honoraria; Kite Pharma: Speakers Bureau. Siddiqi: AstraZeneca: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Pharmacyclics LLC, an AbbVie Company: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Oncternal: Research Funding; BeiGene: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Juno Therapeutics: Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Kite Pharma: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees; Janssen: Speakers Bureau; TG Therapeutics: Research Funding. Danilov: Gilead Sciences: Research Funding; Pharmacyclics: Consultancy, Honoraria; Beigene: Consultancy, Honoraria; Abbvie: Consultancy, Honoraria; TG Therapeutics: Consultancy, Research Funding; Takeda Oncology: Research Funding; Genentech: Consultancy, Honoraria, Research Funding; SecuraBio: Research Funding; Bayer Oncology: Consultancy, Honoraria, Research Funding; Astra Zeneca: Consultancy, Honoraria, Research Funding; Bristol-Meyers-Squibb: Honoraria, Research Funding; Rigel Pharm: Honoraria. Tuscano: Seattle Genetics: Research Funding; Bristol Myers Squibb: Research Funding; Takeda: Research Funding; Acrotech: Research Funding; Genentech: Research Funding; Pharmacyclics: Research Funding; Abbvie: Research Funding. OffLabel Disclosure: Atezolizumab is not approved for the treatment of aggressive B-cell non-Hodgkin lymphoma

Introduction: Approximately 30-35% of patients with classic Hodgkin Lymphoma will prove refractory to frontline therapy or relapse subsequently. Traditional second-line chemotherapy regimens including ifosfamide, carboplatin, and etoposide (ICE) result in complete response rates of ~50%. Achievement of complete metabolic response (CMR) assessed by PET/CT imaging prior to autologous hematopoietic stem cell transplant (AHSCT) predicts favorable progression free survival (PFS) and overall survival (OS). PD-1 blockade is a well-established therapeutic strategy for the treatment of cHL. Pembrolizumab (PEM) is a checkpoint inhibitor targeting PD-1 currently FDA approved as monotherapy in relapsed cHL. We hypothesized that PEM in combination with ICE (PEM-ICE) chemotherapy would be a safe and effective regimen that would yield high CMR rates prior to AHSCT. Methods: This single arm, phase II, multi-institutional clinical trial evaluated the addition of PEM to ICE chemotherapy in AHSCT eligible patients with relapsed and refractory cHL (NCT03077828). The regimen consisted of 21 day cycles of PEM 200 mg IV on day 1 with standard ICE including ifosfamide 5 g/m2 with MESNA as a 24hr continuous infusion on day 2, carboplatin AUC 5 IV (max 800 mg) on day 2, and etoposide 100 mg/m2/day IV on days 1 to 3. Two cycles of PEM-ICE were followed by stem cell mobilization/collection. One cycle of PEM 200 mg IV monotherapy was then administered. Our primary endpoint was the rate of CMR on PET/CT (PET2) imaging defined as a Deauville score of ≤ 3. Images were reviewed centrally. An optional third cycle of PEM-ICE was permitted for patients achieving CMR to allow for appropriate timing of AHSCT. Secondary objectives included clinical outcomes (PFS and OS), safety and tolerability, and transplantation related metrics including ability to collect stem cells and time to engraftment. Results: A total of 42 patients were enrolled with 37 patients evaluable for the primary endpoint. Median age was 34 (19-70) with female predominance (n=27, 64%). 16 patients had primary refractory disease. The CMR rate assessed by PET/CT imaging following 2 cycles of PEM-ICE was 86.5% (95% CI, 71.2-95%), meeting our primary endpoint of improvement over historical outcomes to 70%. The PET2 ORR was 97.3% with 11% PR and 2.7% PD. PET2 scores were Deauville 1 in 45% (n=17), Deauville 2 in 27.0% (n=10), Deauville 3 in 8.1% (n=3), Deauville 4 in 13.5% (n=5), and Deauville 5 in 5.4% (n=2). New areas of PET-positivity in two cases were biopsied showing noncaseating granuloma in one case and EBV but no cHL in another. Five patients received the optional third cycle of PEM-ICE chemotherapy with 35 of the 37 evaluable patients proceeding to AHSCT. Seven patients had radiation as part of the conditioning regimen with an additional 4 patients receiving consolidative radiation following transplant. After a median follow up of 27 months, the median PFS was 26.9 months with survival probability at 24 months of 88.2% (Figure 1). Median OS was not reached with too few events but remained 95.1% at 27 months. The addition of PEM to ICE did not impair stem cell mobilization and all patients successfully collected, with 35 (87%) within 2 apheresis sessions (range 1-7). No patients had engraftment delays or failure. Of the 42 patients, all received at least one dose of PEM and were therefore eligible for toxicity analyses. 34 patients (81%) experienced adverse events (AEs) attributed to PEM and 22 patients (52.3%) had grade 3-4 AEs comprised of cytopenias, elevated AST/ALT, hyponatremia, hypophosphatemia, and fatigue. Five patients had severe AEs attributed to PEM which included anemia, back pain, decreased EF, fever, and thrombocytopenia. There were no significant PEM-related autoimmune events that delayed a patient's treatment on protocol. There were two grade 5 toxicities on the protocol including a patient with cardiac arrest during stem cell collection and a patient with acute respiratory distress syndrome attributed to engraftment syndrome. Both were judged "possibly" related to PEM. Conclusions: Pembrolizumab with ICE chemotherapy is a tolerable and efficacious regimen with high CMR rate as assessed by PET/CT. Despite short follow up, patients had excellent PFS and OS in the post-transplant setting. The results support further investigation of PEM-ICE as second-line treatment for AHSCT eligible patients with relapsed and refractory classical Hodgkin lymphoma. Figure 1 Figure 1. Disclosures Casulo: BMS: Research Funding; Verastem: Research Funding; Genentech: Research Funding; Gilead: Research Funding. Allen: Kyowa Kirin: Consultancy, Honoraria, Research Funding; Daichii Sankyo: Consultancy, Honoraria; Secure Bio: Consultancy, Honoraria. Karmali: Epizyme: Consultancy; AstraZeneca: Speakers Bureau; Roche: Consultancy; Genentech: Consultancy; EUSA: Consultancy; Janssen/Pharmacyclics: Consultancy; Karyopharm: Consultancy; Morphosys: Consultancy, Speakers Bureau; BeiGene: Consultancy, Speakers Bureau; Kite, a Gilead Company: Consultancy, Research Funding, Speakers Bureau; BMS/Celgene/Juno: Consultancy, Research Funding; Takeda: Research Funding. Gordon: Zylem Biosciences: Patents & Royalties: Patents, No royalties; Bristol Myers Squibb: Honoraria, Research Funding. Winter: Actinium Pharma: Consultancy; BMS: Other: Husband: Data and Safety Monitoring Board; Karyopharm (Curio Science): Honoraria; Novartis: Other: Husband: Consultancy, Data and Safety Monitoring Board; Merck: Consultancy, Honoraria, Research Funding; Ariad/Takeda: Other: Husband: Data and Safety Monitoring Board; Epizyme: Other: Husband: Data and Safety Monitoring Board; Agios: Other: Husband: Consultancy; Gilead: Other: Husband: Consultancy; Janssen: Other: Husband: Consultancy. OffLabel Disclosure: new combination of study agent with standard of care chemotherapy regimen

Introduction Central nervous system (CNS) relapse (CNSr) in patients with aggressive non-Hodgkin lymphoma (NHL) occurs uncommonly (estimated incidence 5%) but carries a high morbidity and mortality. Studies have identified risk factors for CNSr such as high tumor burden and extranodal (EN) disease. However, most focus on B-cell NHL with minimal data in T-cell lymphomas (TCL), which are significantly less common and more heterogenous. The few small series of CNSr in TCL report a median overall survival (OS) less than 3 months (mo) with incidence ranging from 2.6-9%. To better define CNSr in TCL, we performed a multi-institutional retrospective analysis of TCL patients with CNSr and herein describe clinicopathologic characteristics and treatment of CNSr. Methods We performed a retrospective observational study using data from 9 US academic centers with IRB approval at individual sites. We included adult patients diagnosed with a mature T-cell neoplasm as per the 2016 WHO classification between 1/1/2009-1/1/2019, who were found to have CNSr at any time after initial diagnosis, and collected patient, disease, and treatment characteristics at time of initial diagnosis as well as at CNSr. Patients with a diagnosis of a precursor T-cell malignancy or with CNS disease identified at initial TCL diagnosis (TCLd) and/or prior to first-line systemic treatment were excluded. Results In this analysis, we report the outcomes of 75 patients (male n=45, female n=30). At TCLd, the median age was 59 years (range 20-81), and 61% of patients (n=46) had an IPI score of at least 3, 92% (n=69) had EN involvement with 37% (n=28) involving at least 2 EN sites, and 59% (n=44) had BM involvement. The most common pathologic diagnoses were peripheral T-cell lymphoma, not otherwise specified (PTCL, NOS; 24%, n=18), angioimmunoblastic T-cell lymphoma (AITL; 17%, n=13), adult T-cell leukemia/lymphoma (ATLL; 17%, n=13), and mycosis fungoides (MF; 12%, n=9) (Figure 1A). First-line systemic therapy for TCL included anthracyclines for 72% (n=54). Autologous and allogenic transplants were performed prior to CNSr in 12% (n=9) and 8% (n=6) of patients, respectively. Prior to CNSr, 48% (n=36) had non-CNS relapse. Some form of CNS prophylaxis was used during initial systemic lymphoma therapy in 24% of patients (n=18), predominantly intrathecal methotrexate (IT MTX; n=16). Median time from TCLd to CNSr was 8.5mo, though this was significantly longer in MF (46.8mo [range 17.5-187.7]) versus PTCL, NOS (7.6mo [range 1.1-58.4], P=0.0002), AITL (21.2mo [range 2.0-61.6, P=0.008), and ATLL (7.3mo [range 0.7-46.4], P=0.0005) (Figure 1B). CNSr developed within 6mo of TCLd in 31% of patients (n=23) and within 12mo in 57% (n=43). Symptoms related to CNSr occurred in 71% of patients (n=53). CNSr patterns were 61% leptomeningeal (n=46), 21% parenchymal (n=16), and 17% both (n=13) with no significant survival difference between leptomeningeal or parenchymal disease alone (HR 1.45, 95% CI 0.78-2.70, P=0.28). Concomitant systemic relapse was observed in 59% of patients (n=44). The most common CNS-directed therapy for CNSr was IT MTX (56%; n=42), though multiple different IT and/or systemic regimens were used. Patients received a median of 1 line of CNS-directed treatment (range 0-5). The overall response rate to initial CNS directed treatment was 32% (16% CR, 16% PR). Median follow up after CNSr was 40.7mo. At last follow up, 83% had died (n=62). Median OS after CNSr was 4.6mo (range 0.1-68.7) (Figure 1C). Those with ATLL had the shortest median OS after CNSr (2.7mo) versus 6.3mo in MF (HR 3.69, 95% CI 1.44-9.42, P=0.005), 6.5mo in AITL (HR 2.16, 95% CI 0.92-5.06, P=0.054), and 4.8mo in PTCL, NOS (HR 1.49, 95% CI 0.70-3.19, P=0.27) (Figure 1D). The most common cause of death was progressive lymphoma (77%; n=48). Conclusions This is to our knowledge the largest series of CNSr in TCL to date. Most CNSr occurred within 12mo, though CNSr occurred later in patients with MF. Although the prognosis after CNSr was generally poor, we found that median OS in CNSr was longer than previously reported, perhaps reflecting more effective treatments for CNS and systemic relapse, inclusion of MF, or lead time bias. Further analysis of the impact of different treatment strategies and outcomes in CNSr was limited by the small sample size and heterogeneity within our cohort, and future analyses in a larger cohort should focus on factors associated with outcomes. Figure 1 Figure 1. Disclosures Horwitz: ADC Therapeutics, Affimed, Aileron, Celgene, Daiichi Sankyo, Forty Seven, Inc., Kyowa Hakko Kirin, Millennium /Takeda, Seattle Genetics, Trillium Therapeutics, and Verastem/SecuraBio.: Consultancy, Research Funding; Affimed: Research Funding; Aileron: Research Funding; Acrotech Biopharma, Affimed, ADC Therapeutics, Astex, Merck, Portola Pharma, C4 Therapeutics, Celgene, Janssen, Kura Oncology, Kyowa Hakko Kirin, Myeloid Therapeutics, ONO Pharmaceuticals, Seattle Genetics, Shoreline Biosciences, Inc, Takeda, Trillium Th: Consultancy; Celgene: Research Funding; C4 Therapeutics: Consultancy; Crispr Therapeutics: Research Funding; Daiichi Sankyo: Research Funding; Forty Seven, Inc.: Research Funding; Kura Oncology: Consultancy; Kyowa Hakko Kirin: Consultancy, Research Funding; Millennium/Takeda: Research Funding; Myeloid Therapeutics: Consultancy; ONO Pharmaceuticals: Consultancy; Seattle Genetics: Consultancy, Research Funding; Secura Bio: Consultancy; Shoreline Biosciences, Inc.: Consultancy; Takeda: Consultancy; Trillium Therapeutics: Consultancy, Research Funding; Tubulis: Consultancy; Verastem/Securabio: Research Funding. Bennani: Purdue Pharma: Other: Advisory Board; Daichii Sankyo Inc: Other: Advisory Board; Kyowa Kirin: Other: Advisory Board; Vividion: Other: Advisory Board; Kymera: Other: Advisory Board; Verastem: Other: Advisory Board. Chavez: AstraZeneca: Research Funding; ADC Therapeutics: Consultancy, Research Funding; Merk: Research Funding; MorphoSys, AstraZeneca, BeiGene, Genentech, Kite, a Gilead Company, and Epizyme: Speakers Bureau; MorphoSys, Bayer, Karyopharm, Kite, a Gilead Company, Novartis, Janssen, AbbVie, TeneoBio, and Pfizer: Consultancy; BMS: Speakers Bureau. Sokol: Dren Bio: Membership on an entity's Board of Directors or advisory committees; Kyowa-Kirin: Membership on an entity's Board of Directors or advisory committees. Saeed: Nektar Therapeutics: Consultancy, Other: research investigator; MEI Pharma Inc: Consultancy, Other: investigator; Celgene Corporation: Consultancy, Other: investigator; MorphoSys AG: Consultancy, Membership on an entity's Board of Directors or advisory committees; Bristol-Myers Squibb Company: Consultancy; sano-aventis U.S.: Consultancy, Membership on an entity's Board of Directors or advisory committees; Janssen Pharmaceutica Products, LP: Consultancy, Other: investigator; Kite Pharma: Consultancy, Other: investigator; Other-TG therapeutics: Consultancy, Other: investigator; Other-Epizyme, Inc.: Consultancy; Other-Secura Bio, Inc.: Consultancy; Seattle Genetics, Inc.: Consultancy, Membership on an entity's Board of Directors or advisory committees. Mehta-Shah: Kiowa Hakko Kirin: Consultancy; C4 Therapeutics: Consultancy; Verastem: Research Funding; Karyopharm: Consultancy; Ono Pharmaceuticals: Consultancy; Secura Bio: Consultancy, Research Funding; Daiichi Sankyo: Consultancy, Research Funding; AstraZeneca: Research Funding; Bristol Myers Squibb: Research Funding; Celgene: Research Funding; Innate Pharmaceuticals: Research Funding; Roche/Genentech: Research Funding; Corvus Pharmaceuticals: Research Funding. Olszewski: TG Therapeutics: Research Funding; PrecisionBio: Research Funding; Celldex Therapeutics: Research Funding; Acrotech Pharma: Research Funding; Genentech, Inc.: Research Funding; Genmab: Research Funding. Allen: Epizyme: Consultancy; MorphoSys: Consultancy; ADC Therapeutics: Consultancy; Secure Bio: Consultancy; Kyowa Kirin: Consultancy. Gerson: Abbvie: Consultancy; Kite: Consultancy; TG Therapeutics: Consultancy; Pharmacyclics: Consultancy. Landsburg: Triphase: Research Funding; Takeda: Research Funding; Curis: Research Funding; ADCT: Membership on an entity's Board of Directors or advisory committees; Karyopharm: Membership on an entity's Board of Directors or advisory committees, Other: DSMB member; Incyte: Membership on an entity's Board of Directors or advisory committees; Morphosys: Membership on an entity's Board of Directors or advisory committees. Schuster: Adaptive Biotechnologies: Research Funding; Pharmacyclics: Research Funding; Merck: Research Funding; Genentech/Roche: Consultancy, Research Funding; Tessa Theraputics: Consultancy; Juno Theraputics: Consultancy, Research Funding; Loxo Oncology: Consultancy; BeiGene: Consultancy; Alimera Sciences: Consultancy; Acerta Pharma/AstraZeneca: Consultancy; Abbvie: Consultancy, Research Funding; Nordic Nanovector: Consultancy; Novartis: Consultancy, Honoraria, Patents & Royalties, Research Funding; Incyte: Research Funding; TG Theraputics: Research Funding; Celgene: Consultancy, Honoraria, Research Funding. Svoboda: Atara: Consultancy; Adaptive: Consultancy, Research Funding; Astra Zeneca: Consultancy, Research Funding; Imbrium: Consultancy; Pharmacyclics: Consultancy, Research Funding; Genmab: Consultancy; Merck: Research Funding; Incyte: Research Funding; BMS: Consultancy, Research Funding; TG: Research Funding; Seattle Genetics: Consultancy, Research Funding. Barta: Kyowa Kirin: Honoraria; Acrotech: Honoraria; Daiichi Sankyo: Honoraria; Seagen: Honoraria.

Introduction: Advanced stage mycosis fungoides (MF) has a median survival of 3-5 years, while early stage MF is a chronic disease typically associated with an excellent prognosis and a median survival of 20 years or more. Prior studies suggest approximately 20% of early stage MF may progress to advanced stage, but risk factors for progression remain poorly studied, particularly among African American (AA) patients. We aimed to identify clinic features associated with progression to advanced stage MF in a large urban medical center. Methods We performed a retrospective review of 388 patients with early stage (1A-2A) MF at the Winship Cancer Institute of Emory University diagnosed between 1970 and 2021. Clinical data collected from the electronic medical record included demographics, laboratory values, disease characteristics, and therapy. Our primary endpoint was to identify variables associated with progression to advanced stage MF. Progression to advanced stage was defined as a highest overall TNMB stage of 2B-4B. Overall survival (OS) was measured from time of diagnosis to date of death or last follow-up. Kaplan-Meier curves for OS were generated for the whole cohort and by progression group. Descriptive analysis was performed for each variable, and a comparison between patients who did or did not progress to advanced stage was performed using ANOVA for numerical covariates and chi-square test for categorical covariates. The association of baseline variables with OS was modeled by Cox proportional hazards model and multivariable analyses were performed on significant variables. Results Among 388 patients, the median follow up was 5 years (range 0-51). There was even distribution among male (49.0%) and female (51.0%) patients. The median age at diagnosis was 53 years (range 8-95). This population included 41.4% AA, 55.0% White, 2.3% Asian, and 1.3% other races. Stage distribution was as follows: 34.2% (n=133) stage 1A, 51.5% stage 1B (n=200), and 14.2% stage 2A (n=55). Forty-nine patients had hypopigmented MF (45 AA), and 9.4% (n=34) patients developing large cell transformation (LCT) during their disease course. Treatment at diagnosis was topical in 52.3% (n=203), systemic in 1.8% (n=7), radiation in 3.4% (n=13), and multimodality in 29.4% (n=114). Overall, 93 patients (24.1%) progressed to advanced stage. Progression to a higher stage was statistically associated with higher overall TNMB stage at diagnosis (p Progression to advanced stage was associated with an increased risk of death (4.75 (0.05-7.38), p < 0.001, figure 2). The median survival for patients who did and did not progress were 11 years (95% CI 7, 15) and 31 years (95% CI 25, not reached), p 60 (p 60 (3.32 (2.00-5.51), p Conclusions We demonstrate that progression to advanced stage is associated with several baseline laboratory and disease characteristics, which bear immediate clinical relevance to the work up and staging of early stage MF. These data suggest that consistent staging and laboratory analyses with imaging for lymph node assessment, peripheral blood flow cytometry, and TCR in all newly diagnosed MF patients may aid in identifying patients at risk for progression to advanced stage disease. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

Importance The prognostic significance of clonal T-cell receptor (TCR) rearrangement or low-level blood involvement as assessed by flow cytometry for patients with early-stage cutaneous T-cell lymphoma (CTCL) is not clear. Objective To assess the association of low-level blood involvement by TCR clonality and flow cytometry with outcomes for patients with early-stage CTCL. Design, setting, and participants A retrospective cohort analysis was conducted from September 1, 2019, to February 29, 2020, of 322 patients with early-stage (I-IIA) CTCL seen at the Winship Cancer Institute of Emory University and Grady Memorial Hospital. T-cell receptor gene rearrangement and flow cytometry records from the peripheral blood were documented at initial assessment. Exposures T-cell receptor clonality and peripheral blood flow cytometry. Main outcomes and measures Univariate and multivariable models and Kaplan-Meier assessments were analyzed for overall survival (OS) and time to next treatment. The primary outcome was OS from diagnosis and time to next treatment, and the hypotheses were formulated prior to data collection. Results A total of 322 patients (166 female patients [51.6%]; median age at diagnosis, 53.8 years [range, 8.6-87.4 years]) with early-stage CTCL diagnosed from 1990 to 2018 were identified; of these, 258 had data available for both flow cytometry and TCR. Positive results for both TCR clonality and flow cytometry were associated with inferior OS in early-stage CTCL compared with both having negative results (hazard ratio [HR], 2.86; 95% CI, 1.02-8.06; P = .046). Positive results for only TCR clonality or only flow cytometry were not associated with OS (TCR clonality: HR, 1.31; 95% CI, 0.70-2.47; P = .40; flow cytometry: HR, 1.21; 95% CI, 0.58-2.52; P = .61) or time to next treatment (TCR clonality: HR, 1.05; 95% CI, 0.77-1.43; P = .76; flow cytometry: HR, 0.74; 95% CI, 0.47-1.16; P = .12). However, positive flow cytometry results were associated with reduced OS in the stage IIA subgroup (n = 94; HR, 1.17; 95% CI, 1.18-8.74; P = .02). Covariates associated with reduced survival included advanced age at diagnosis, male sex, and higher disease stage. Conclusions and relevance This cohort study of patients with early-stage CTCL suggests that low-level blood involvement as indicated by positive results for both TCR gene rearrangement and flow cytometry was associated with inferior OS, whereas positive results for either flow cytometry or TCR clonality was not. More precise measurements of blood involvement in CTCL and larger multi-institutional cohorts are needed to validate the prognostic significance of low-level blood involvement in early-stage CTCL.

Background: Allogeneic hematopoietic transplantation (HCT) is frequently considered for patients (pts) with relapsed T-cell lymphoma (TCL) and less often as consolidation of initial therapy. Outcomes from prior registry data show that only 31% of pts remain disease free 3 years after HCT (Smith et al. JCO 2013). However, several single institution studies have superior outcomes. We previously presented an analysis of allogeneic transplant in T-cell lymphoma but have expanded this effort to 12 academic centers with longer follow up (Mehta-Shah ASH 2017). Methods: We analyzed the patient characteristics at time of diagnosis and transplant, treatment history, overall (OS) and progression-free survival (PFS) in consecutive TCL pts who had an HCT from 1/1/2000-12/31/2019 at 12 academic institutions. Results: Patient characteristics are shown in Table 1. 508 pts were identified with median age 51 years (16 - 72). 452 (86.5%) had known remission status at the time of HCT: 245 (54.4%) complete remission (CR), 168 (37.2%) partial remission (PR), 23 (5.0%) stable disease (SD), 16 (3.2%) progressive disease (PD). Seventy-eight (15.5%) had a prior autologous HCT. Thirty-six (7%) pts underwent HCT in CR1, 352 (69%) for relapsed/refractory TCL, and was not specified in 120 pts (24%). The median HCT comorbidity index (HCT-CI) score was 1 (0-11). Conditioning regimens were myeloablative (n=180), reduced intensity/non-myeloablative (n=323), unknown (n=3). Donor type was known for 471 pts: 192 matched related (MRD), 183 matched unrelated (MUD), 53 mismatched (MMD), 18 haploidentical donors, 25 umbilical cord blood. In this series, the 2 year OS and PFS rate following HCT were 59.1% (95%CI: 54.6-63.3%) and 45.8% (95%CI: 41.3-50.2%) respectively. 5 year OS and PFS rate were 50.8% (95%CI: 46.1-55.3%) and 39.4% (95%CI: 34.9-43.9%) (Fig 1) For disease specific 2-year and 5-year PFS, see Table 1. At a median follow-up of 29.7 mo (0.1-263 mo), 163 pts had relapsed and 261 pts had died. The median time from relapse post HCT to death was 10.2 mo (0-158.4 mo). Of 261 deaths: 81 were due to transplant related mortality (TRM), 69 were confirmed to be from TCL, and 111 were from non-relapse mortality/unknown. There was not a significant difference in PFS for pts with AITL, PTCL-NOS, ALK positive ALCL or ALK negative ALCL, with median PFS of 23.2 mo (95%CI:15.3-64.2). However, when AITL was compared specifically to PTCL-NOS or ALCL, those with AITL had a trend towards improved median PFS (51.4 mo vs. 18.4 mo, p=0.14) and improved median OS (not reached vs. 73.1 mo, p=0.26). At 5 years, PFS was worse for CTCL (18.6%, 95% CI: 9.7%-30.0%) compared to PTCL subtypes (43.8%; 95% CI: 37.3%-50.0%)(p Disease status at the time of HCT was associated with PFS (p Conclusions: We present the largest series of HCT in TCL. In this dataset, HCT provided durable disease control for a significant portion of pts with relapsed or refractory or otherwise high risk TCL. Depth of response to therapy immediate prior to HCT was associated with PFS. Patients with AITL appeared to have a trend towards improved outcome with HCT compared to other common PTCL histologies. Patients with CTCL had a higher rate of relapse compared to PTCL subtypes, but OS was similar. MRD HCTs were associated with lower TRM. This data supports the curative potential of HCT in a patient group with otherwise poor survival and limited treatment options. Disclosures Mehta-Shah: Corvus: Research Funding; Genetech/Roche: Research Funding; Verastem: Research Funding; Karyopharm Therapeutics: Consultancy; Bristol Myers-Squibb: Research Funding; Celgene: Research Funding; C4 Therapeutics: Consultancy; Kyowa Hakko Kirin: Consultancy; Innate Pharmaceuticals: Research Funding. Dahi:Kite: Consultancy. Sauter:Sanofi-Genzyme: Consultancy, Research Funding; Kite - a Gilead Company: Consultancy; Spectrum Pharamaceuticals: Consultancy; Gamida Cell: Consultancy; GSK: Consultancy; Bristol-Myers Squibb: Research Funding; Celgene: Consultancy, Research Funding; Novartis: Consultancy; Genmab: Consultancy; Precision Biosciences: Consultancy, Research Funding; Juno Therapeutics: Consultancy, Research Funding. Moskowitz:Merck: Research Funding; Imbrium Therapeutics, L.P.: Consultancy; Bristol-Myers Squibb: Research Funding; Miragen Therapeutics: Consultancy; Merck: Consultancy; Seattle Genetics: Consultancy; Incyte: Research Funding; Seattle Genetics: Research Funding. Jacobsen:Novartis: Research Funding; Takeda: Honoraria; Pharmacyclics: Research Funding; F. Hoffmann-LaRoche: Research Funding; Astra-Zeneca: Consultancy; Acerta: Consultancy; Merck: Consultancy. William:Celgene: Consultancy, Honoraria; Guidepoint Global: Consultancy; Seattle Genetics: Research Funding; Dova: Research Funding; Incyte: Research Funding; Merck: Research Funding; Kyowa Kirin: Consultancy, Honoraria. Barta:Monsanto: Consultancy; Pfizer: Honoraria; Janssen: Honoraria; Seattle Genetics: Honoraria, Research Funding; Atara: Honoraria. Allen:Clinical Care Options: Speakers Bureau; Curio Sciences: Honoraria; Research to Practice: Speakers Bureau; Imbrium: Consultancy, Other; Bayer: Consultancy, Other. Song:Sanofi: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen, Celgene,Takeda: Consultancy, Honoraria; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Gilead: Honoraria, Membership on an entity's Board of Directors or advisory committees; GlaxoSmithKline: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene/BMS: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Research Funding; Otsuka: Honoraria. Ruan:Celgene: Consultancy, Research Funding; Seattle Genetics: Research Funding; Kite Pharma: Consultancy; Juno: Consultancy; BMS: Consultancy, Research Funding; Pharmacyclics: Research Funding; AstraZeneca: Consultancy, Research Funding. McKinney:Kite/Gilead: Honoraria, Speakers Bureau; Kite/Gilead, Seattle Genetics, Molecular Templates, BTG, Pharmacyclics, Verastem, Genentech, Inc., Celgene: Consultancy; UNUM, Molecular Templates, Incyte, Beigene, Denovo Biopharma, Pharmacyclics, Nordic Nanovector, BMS, Genentech, Inc., Celgene: Research Funding. Beaven:Tessa Therapeutics: Research Funding; Roche: Research Funding; Seattle Genetics: Research Funding; MorphoSysAb: Research Funding; LoxoOncology: Research Funding; Celgene: Research Funding. Haverkos:Viracta THerapeutics: Consultancy. Alpdogan:Seattle Genetics: Consultancy; Kiowa Kirin: Consultancy. Porcu:Kiowa Kirin: Research Funding; Kura Oncology: Research Funding; Innate Pharma: Membership on an entity's Board of Directors or advisory committees, Research Funding; Galderma: Research Funding; Daiichi: Consultancy, Honoraria; Celgene: Research Funding; Cell Medica: Research Funding; Miragen: Research Funding; Verastem: Consultancy; Viracta Therapeutics: Membership on an entity's Board of Directors or advisory committees. Horwitz:Daiichi Sankyo: Research Funding; GlaxoSmithKline: Consultancy; Janssen: Consultancy; Kura Oncology: Consultancy; Myeloid Therapeutics: Consultancy; Miragen: Consultancy; ADCT Therapeutics: Consultancy, Research Funding; Aileron: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Forty Seven: Consultancy, Research Funding; Infinity/Verastem: Research Funding; Kyowa Hakka Kirin: Consultancy, Research Funding; Millenium/Takeda: Consultancy, Research Funding; Seattle Genetics: Consultancy, Research Funding; Trillium: Consultancy, Research Funding; Corvus: Consultancy; Innate Pharma: Consultancy; Mundipharma: Consultancy; Portola: Consultancy, Research Funding; Beigene: Consultancy; C4 Therapeutics: Consultancy; Verastem: Consultancy, Research Funding; Vividion Therapeutics: Consultancy; Affirmed: Consultancy; ASTEX: Consultancy.

Introduction Sézary syndrome (SS) is an aggressive, leukemic subtype of cutaneous T-cell lymphoma (CTCL) with a median survival of 3-5 years. Approved therapies include skin-directed therapy, radiation, and systemic therapies such as chemotherapy, histone deacetylase (HDAC) inhibitors, interferon, extracorporeal photopheresis (ECP), and oral retinoids. There is no consensus first-line therapy for SS and there is limited data regarding prognostic biomarkers. We assessed treatment patterns, outcomes, and racial differences at our institution. Methods We performed a retrospective review of 62 patients at Winship Cancer Institute of Emory University from 1990-2020 with a confirmed diagnosis of SS. Clinical data collected from the electronic medical record included demographics, baseline laboratory values, disease characteristics, and therapy. Clinical outcomes were measured by overall survival (OS) and time to next treatment (TTNT). OS was measured from time of diagnosis to date of death or last follow-up. TTNT was defined as the number of months from the start of the first line of therapy until the initiation of the subsequent therapeutic regimen. Descriptive analysis was performed for each variable and a comparison between African American (AA) and white patients was performed using ANOVA for numerical covariates and chi-square test or Fisher's exact test for categorical covariates. Kaplan-Meier curves for OS and TTNT were generated for the whole cohort. A Kaplan-Meier curve was also generated to compare time from diagnosis to initiation of first systemic therapy stratified by race along with the log-rank p-value. The univariate association of baseline variables with OS and TTNT was assessed by Cox proportional hazards models and the multivariable analyses (MVA) were performed on variables that had p-value less than 0.05 on univariate analyses. Results Males made up (58.1%) of our patients and the median age at diagnosis was 65.9 years. Nearly one-half (45.2%) of patients were AA. The median Sézary count at diagnosis was 1320 cells/uL. The median time from diagnosis to first systemic therapy was 2.4 months and the median number of systemic therapies was 3.0. Information regarding systemic treatments received after diagnosis is presented inTable 1. The most common first-line systemic therapies were oral retinoids (43.5%), ECP (32.3%), and interferon (30.6%). HDAC inhibitors and total skin electron beam (TSEB) radiation were common treatments beyond first line (46.8% received HDAC inhibitors, 38.7% received TSEB), but were rarely used in the first-line setting. The median OS and TTNT were 3.1 years and 6.3 months, respectively(Figure 1). In MVA, elevated WBC and LDH were significantly associated with shorter OS (WBC HR: 1.05, 95% CI: 1.01-1.08, p=0.01; LDH HR: 1.003, 95% CI: 1.001-1.005, p=0.011) and shorter TTNT (WBC HR: 1.04, 95% CI: 1.002-1.08, p=0.041; LDH HR: 1.002, 95% CI: 1.001-1.004, p=0.048). In analysis by race, AA patients had a higher proportion of females compared to non-hispanic white patients (53.6% vs 28.1%, p=0.045). AA patients also had lower median hemoglobin at diagnosis (12.6 vs 14.3, p=0.036), higher median LDH at diagnosis (360 vs 232, p=0.002), and longer median time from diagnosis to first systemic therapy compared to non-hispanic white patients (3.17 months vs 2.14 months, p=0.039,Figure 2). Conclusions SS is an aggressive subtype of CTCL with no consensus first-line therapy and limited data on prognostic biomarkers. In our cohort, oral retinoids, ECP, and interferon were the most commonly utilized treatments in the first-line setting. Elevated WBC and LDH were significantly associated with both OS and TTNT which suggests that these may have value as prognostic biomarkers in SS. AA patients may have delayed time from diagnosis to starting systemic therapy and higher LDH at diagnosis. This data is hypothesis-generating and should be validated in larger, prospective studies. Disclosures Allen: Bayer:Consultancy, Other;Imbrium:Consultancy, Other;Research to Practice:Speakers Bureau;Clinical Care Options:Speakers Bureau;Curio Sciences:Honoraria.

Background: In patients with chemo-sensitive relapsed diffuse large B-cell lymphoma (DLBCL), autologous hematopoietic cell transplant (ASCT) has long been the standard of care. Several recent studies have identified patient groups with poor post-transplant outcomes and in recent years chimeric antigen receptor (CAR)-T therapy has been utilized in patients who do not have adequate disease control to proceed with ASCT or who progress after ASCT. We hypothesized that the availability of CART to treat patients with aggressive lymphoma who were not ideal candidates for ASCT would lead to improved survival among lymphoma patients proceeding to transplant. We evaluated whether the demographics, baseline characteristics and post-ASCT outcomes for patients with relapsed non-Hodgkin lymphoma (NHL) have changed in the CAR-T era. Methods: We included patients initially diagnosed with DLBCL since 2012 who subsequently relapsed and received ASCT. Patients who completed ASCT without a documented relapse or who received CART therapy prior to an ASCT were excluded as were patients without adequate follow-up data. Patients who completed ASCT prior to January 1, 2018, were part of the pre-CART group while those completing ASCT on January 1, 2018 and later were part of the post-CART group. We compared demographics as well as disease and treatment-related variables of interest between the pre- and post-CART groups using Fisher's Exact or chi Square tests as appropriate for categorical and ANOVA for numeric variables. In addition, we determined progression-free (PFS) and overall survival (OS) from the date of ASCT using the Kaplan-Meier method and determined predictors of post-ASCT PFS and OS using the Cox Proportional Hazards model with backward elimination. Results: Of 84 included patients, 55 were in the pre-CART group and 29 were in the post-CART group. Median age at diagnosis for all patients was 55 years (range 22-73). 50 were male, and 60 had stage 3 or 4 disease. While there were no differences in demographics based on treatment group, the ECOG performance status for patients in the post-CART group was improved compared to those pre-CART (Table 1, p=0.040). There was also no difference in time from diagnosis to transplant between the two groups (Table 1, p=0.292). With a median follow-up post ASCT of 2.22 years for the pre-CART group and 1.24 years for the post-CART group, the median OS was 4.7 years (95% CI: 3.4 - Not Reached) for the entire cohort, 4.7 years (95% CI: 2.8 - Not Reached) for the pre-CART group and not reached (95% CI: NR-NR) for the post-CART group. The median PFS was not reached in either cohort (p=0.932). Neither univariate nor multivariable analysis showed any of covariates as being significant predictors of post-ASCT PFS. In the multivariable model for OS, receiving R-CHOP chemotherapy compared to other induction regimens (HR 0.28 [0.10-0.74], p=0.01) predicted improved OS while increased age (HR 1.06 [1.01-1.11], p=0.03) predicted inferior OS. The receipt of ASCT after CART cell era, conditioning regimen, or first salvage regimen all did not impact PFS or OS. Conclusion: In comparison with those patients receiving autologous transplantation prior to the adoption of CAR T cell, patients receiving ASCT more recently had no change PFS or OS despite having better performance status prior to ASCT. Our findings suggest that selection of appropriate candidates for ASCT in the current era is critical and that patients who are at higher risk for early post-ASCT relapse should be considered for novel approaches including immune effector cell therapy. Additional follow-up will be needed to determine if newer currently approved therapies for post-ASCT relapse can improve OS in relapsed/refractory DLBCL who relapse after ASCT. Disclosures Waller: Verastem Oncology, Inc: Consultancy, Research Funding. Allen:Curio Sciences: Honoraria; Bayer: Consultancy, Other; Clinical Care Options: Speakers Bureau; Research to Practice: Speakers Bureau; Imbrium: Consultancy, Other. Lonial:JUNO Therapeutics: Consultancy; Amgen: Consultancy, Honoraria, Other: Personal fees; Abbvie: Consultancy; Sanofi: Consultancy; Karyopharm: Consultancy; Genentech: Consultancy; Onyx: Honoraria; Janssen: Consultancy, Honoraria, Other: Personal fees, Research Funding; Takeda: Consultancy, Other: Personal fees, Research Funding; Novartis: Consultancy, Honoraria, Other: Personal fees; BMS: Consultancy, Honoraria, Other: Personal fees, Research Funding; GSK: Consultancy, Honoraria, Other: Personal fees; Merck: Consultancy, Honoraria, Other: Personal fees; Millennium: Consultancy, Honoraria; TG Therapeutics: Membership on an entity's Board of Directors or advisory committees. Kaufman:Tecnopharma: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Karyopharm: Membership on an entity's Board of Directors or advisory committees; Pharmacyclics: Membership on an entity's Board of Directors or advisory committees; Incyte: Consultancy, Membership on an entity's Board of Directors or advisory committees; Takeda: Consultancy, Honoraria; Celgene: Consultancy, Honoraria; Bristol-Myers Squibb: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; AbbVie: Consultancy; TG Therapeutics: Consultancy, Membership on an entity's Board of Directors or advisory committees; Sanofi/Genyzme: Consultancy, Honoraria. Hofmeister:Janssen: Honoraria, Research Funding; Oncolytics Biotech: Research Funding; Imbrium: Honoraria; Oncopeptides: Honoraria; Bristol Myers Squibb: Honoraria, Research Funding; Nektar: Honoraria, Research Funding; Sanofi: Honoraria, Research Funding; Karyopharm: Honoraria, Research Funding. Dhodapkar:Janssen: Membership on an entity's Board of Directors or advisory committees, Other; Kite: Membership on an entity's Board of Directors or advisory committees, Other; Lava Therapeutics: Membership on an entity's Board of Directors or advisory committees, Other; Celgene/BMS: Membership on an entity's Board of Directors or advisory committees, Other; Amgen: Membership on an entity's Board of Directors or advisory committees, Other; Roche/Genentech: Membership on an entity's Board of Directors or advisory committees, Other. Nooka:Oncopeptides: Consultancy, Honoraria; Spectrum Pharmaceuticals: Consultancy; Celgene: Consultancy, Honoraria, Research Funding; Sanofi: Consultancy, Honoraria; Adaptive Technologies: Consultancy, Honoraria; Karyopharm Therapeutics, Adaptive technologies: Consultancy, Honoraria, Research Funding; GlaxoSmithKline: Consultancy, Honoraria, Other: Personal Fees: Travel/accomodations/expenses, Research Funding; Takeda: Consultancy, Honoraria, Research Funding; Amgen: Consultancy, Honoraria, Research Funding; Bristol-Myers Squibb: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria, Research Funding. Klisovic:Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees. Langston:Bristol Myers Squib: Research Funding; Incyte: Research Funding; Jazz Pharmaceuticals: Research Funding; Astellas Pharmaceuticals: Research Funding; Kadmon Corporation: Research Funding; Takeda: Research Funding; Chimerix: Research Funding. Cohen:Janssen, Adicet, Astra Zeneca, Genentech, Aptitude Health, Cellectar, Kite/Gilead, Loxo: Consultancy; Genentech, BMS, Novartis, LAM, BioInvent, LRF, ASH, Astra Zeneca, Seattle Genetics: Research Funding.

Background: Chromosome 9p24.1/PD-L1/PD-L2 genomic copy number alterations (CNAs) including amplifications and copy number gains (CNGs) are predominant features of classic Hodgkin lymphoma (cHL) and lead to overexpression of the programmed death-1 (PD-1) ligands 1 and 2 (PD-L1 and PD-L2). Amplifications and high level CNGs have been associated with advanced stage cHL and inferior treatment outcomes with standard chemotherapy. There are few studies that correlate 9p24.1/PD-L1/PD-L2 amplifications or CNGs with response to PD-1 blockade monotherapy in the frontline setting. We conducted a phase 2 clinical trial of sequential pembrolizumab (PEM) x 3 followed by doxorubicin, vinblastine, dacarbazine (AVD) chemotherapy (4-6 cycles) for newly diagnosed cHL. Interim response to single agent PEM was assessed by PET-CT and by decline in metabolic tumor volume (MTV). Herein, we report the results of correlative studies analyzing 9p24.1 CNAs, PD-1 pathway expression and response to PD-1 blockade. Methods: Pre-treatment diagnostic biopsy specimens were double stained for PD-L1 (E1L3N, XP Cell Signaling) and PAX5, single stained for PD-L2 and pSTAT3, and scored by two expert hematopathologists (QC, LBS) for percentage positive cells and intensity of staining. A modified H score was calculated as the product of staining intensity (0-3) and percentage of positive tumor cells (0-100%), ranging from 0 - 300. Fluorescence in situ hybridization to assess (FISH) chromosome 9p24.1 CNAs was performed by co-hybridizing PD-L1/PD-L2 probes (target) with the centromeric 9 probe (control). In each case, the percentage and magnitude of 9p24.1 CNAs were evaluated. Four FISH categories were defined based on the target: control ratio and the total copy numbers (CNs) of the target per Hodgkin Reed-Sternberg (HRS) cell to include: amplification (ratio≥3, CNs≥ 6), copy number gain (CNGs) (1≤ratio Results: Thirty patients were enrolled from September 2017, through August 1, 2019; 28 had tissue available for FISH analysis and 29 for immunohistochemistry. Response to single agent PEM was PR in 11 (36.7%), near-CMR in 8 (26.7%), and CMR in 11 (36.7%). CMR rate following AVD x 2 was 100%. All patients in this analysis had genomic alterations, although 5 patients did not reach the cut off of 10%. The highest level alteration was amplification in 11 patients (36.7%), copy gain in 7 (23.3%), polysomy in 5 (16.7%) and disomy in 5 (16.7%) (Table 1). The average 9p24.1 copy number per HRS cell was 3.1 (range 2-8.1). Six of 22 examined cases were EBER-positive. There was no evidence of a statistical relationship between response to single agent PEM and 9p24.1 alteration, PD-L1, PD-L2 or STAT3 H-scores, or EBER status. We found PD-L1 H Score tercile differed statistically by FISH category (P=.024, Fisher's Exact Test). Notably, there were no patients with amplification in the lowest tercile. More compelling, we found a positive association between PD-L1 H Score and average 9p24.1 locus copy number (Spearman's ρ=.36, P=.063, Fig 1a) and a negative association between PD-L1 H Score and percent disomic cells (Spearman's ρ= -0.21, P=0.29, Fig 1b) although the statistical significance of these results was limited by the small sample size. Conclusions: Our data is consistent with prior reports indicating a positive association between 9p24.1 genetic alterations and PD-L1 expression. The high response rates observed at all PD ligand levels seen in this clinical study suggests that even low levels of PD ligand expression may be sufficient for response to PD-1 blockade in previously untreated cHL. Disclosures Allen: Bayer:Consultancy, Other;Imbrium:Consultancy, Other;Research to Practice:Speakers Bureau;Clinical Care Options:Speakers Bureau;Curio Sciences:Honoraria.Evens:Merck:Consultancy, Honoraria, Research Funding;Pharmacyclics:Consultancy, Honoraria;Novartis:Consultancy, Honoraria;MorphoSys:Consultancy, Honoraria;Research To Practice:Honoraria, Speakers Bureau;Abbvie:Consultancy, Honoraria;Mylteni:Consultancy, Honoraria;Seattle Genetics:Consultancy, Honoraria, Research Funding;Epizyme:Consultancy, Honoraria, Research Funding.Advani:Celgene, Forty Seven, Inc., Genentech/Roche, Janssen Pharmaceutical, Kura, Merck, Millenium, Pharmacyclics, Regeneron, Seattle Genetics:Research Funding;Astra Zeneca, Bayer Healthcare Pharmaceuticals, Cell Medica, Celgene, Genentech/Roche, Gilead, KitePharma, Kyowa, Portola Pharmaceuticals, Sanofi, Seattle Genetics, Takeda:Consultancy.Pro:Verastem Oncology:Research Funding.Karmali:Takeda:Research Funding;BeiGene:Speakers Bureau;BMS/Celgene/Juno:Honoraria, Other, Research Funding, Speakers Bureau;Karyopharm:Honoraria;AstraZeneca:Speakers Bureau;Gilead/Kite:Honoraria, Other, Research Funding, Speakers Bureau.Gordon:Zylem Biosciences:Patents & Royalties: Patents, No Royalties.Winter:Amgen:Consultancy;Epizyme:Other: DSMB;Norvartis:Consultancy, Other: DSMB;CVS/Caremark:Consultancy;Ariad/Takeda:Consultancy;Delta Fly Pharma:Consultancy;Merck:Membership on an entity's Board of Directors or advisory committees, Other: advisory board;Karyopharm:Membership on an entity's Board of Directors or advisory committees, Other: advisory board.

Bendamustine-rituximab (BR) is a standard of care for patients with mantle cell lymphoma (MCL) with median progression free survival (PFS) of approximately 3 years. Venetoclax has proven activity both as a single agent and in combination with other targeted therapies in relapsed MCL. We developed a phase 2 study of bendamustine, obinutuzumab, and venetoclax (BOV) for untreated patients with MCL to determine the efficacy and toxicity of this combination (NCT03872180). Patients ≥ 18 years old with untreated MCL received up to six 28-day cycles of BOV, consisting of bendamustine (90mg/m2 on D1-2) and obinutuzumab (1000mg, C1: D 1,8,15 and C2-6: D1) with a venetoclax ramp up from 20mg to 200mg during the first cycle and then 400mg on days 1-10 of cycles 2-6. Post-induction therapy is determined by the treating physician and is not dictated by the study. The primary endpoint was CR rate at the end of induction, per Lugano criteria. We assumed a historical CR rate of 60% with BR, with a goal CR rate of 85% with the BOV regimen and plan to accrue 23 total patients to assess for this difference. This was a two-stage design that included 9 patients in stage 1 with a requirement of 7 CR's in the first 9 patients to justify continued accrual. Secondary and correlative endpoints include PFS/overall survival, toxicity (including frequency and severity of tumor lysis syndrome), and MRD negativity using both commercial IgHTS assays as well as CAPP-Seq. Supportive care included G-CSF, antimicrobial prophylaxis, and prescribed monitoring for and management of tumor lysis syndrome. 11 patients have initiated therapy. Median age is 70 years (45-80), with 7 males and 4 females. All 11 patients had marrow involvement. Five patients had Ki67 index ≥30%, and TP53/17p abnormalities were found in 2 patients. Eight patients have completed 6 cycles, one patient discontinued study therapy after 5 cycles due to thrombocytopenia and 2 patients remain on therapy after 5 cycles of treatment. Of 9 patients who have completed end of treatment restaging, the ORR was 100%, including 8 CR's (89%) and 1 PR. The two patients currently completing study therapy have completed their interim PET/CT's and both have achieved CR. Three patients experienced grade 3+ obinutuzumab infusion reactions on cycle 1 day 1, with both patients requiring admission but subsequently fully recovering. One of these patients chose to forgo additional obinutuzumab while a second patient safely completed 6 cycles of treatment. The third patient initiated treatment in the hospital and experienced atrial fibrillation requiring ICU transfer, as well as grade 2 hyperkalemia while receiving day 1 treatment. Cardiology did not feel AFib was a result of TLS. She was ultimately able to safely complete 6 cycles of obinutuzumab. Although this event was not clear clinical TLS, the protocol was subsequently amended to incorporate venetoclax administration beginning on day 8 of cycle 1 to prevent overlapping infusional and TLS toxicities from venetoclax and obinutuzumab on day 1. No other patients have had TLS to date. Grade 3/4 hematologic toxicities include neutropenia (n=4), anemia (n=1), thrombocytopenia (n=4) leukopenia (n=3), and lymphopenia (n=10). Grade 3/4 non-hematologic toxicities included rash (n=2), hypophosphatemia (n=2). One patient has experienced prolonged leukopenia 2 months after finishing 6 cycles of therapy and was unable to collect stem cells after cycle 4 for a planned post-induction autologous transplant. To date, 2 patients have relapsed at 7 and 8 months after completing therapy, and one patient died suddenly while in remission of unknown causes at 6 months post-treatment. Of the two relapses, one patient chose not to receive any obinutuzumab during treatment due to a grade 3 reaction during cycle 1, and both patients initially presented with aggressive leukemic phase disease with Ki67 > 30%. Here we report the pre-planned stage 1 of this phase 2 study, the BOV regimen has resulted in CRs in 8 of the first 9 patients, and accrual continues to stage 2. Expected hematologic and infusional toxicities have been manageable. One patient has discontinued therapy due to toxicity, and the prescribed venetoclax ramp-up has successfully avoided clinically significant tumor lysis syndrome. Accrual continues, and additional follow-up of currently treated patients will provide insights into response duration, OS, and rate of MRD negativity with this regimen. Disclosures Greenwell: Acrotech Biopharma LLC, Kyowa Kirin: Consultancy; Lymphoma Research Foundation: Research Funding. Maddocks:Karyopharm: Consultancy; ADC Therapeutics, AstraZeneca: Consultancy; BMS: Consultancy, Research Funding; Morphosys: Consultancy, Honoraria; Celgene: Consultancy, Honoraria; Pharmacyclics: Consultancy, Honoraria; Seattle Genetics: Consultancy, Honoraria. Kahl:Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees; BeiGene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Roche Laboratories Inc: Consultancy; Pharmacyclics LLC: Consultancy; Genentech: Consultancy; Celgene Corporation: Consultancy; AstraZeneca Pharmaceuticals LP: Consultancy, Membership on an entity's Board of Directors or advisory committees; AbbVie: Consultancy; ADC Therapeutics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Acerta: Consultancy, Research Funding. Alizadeh:Janssen: Consultancy; Genentech: Consultancy; Pharmacyclics: Consultancy; Chugai: Consultancy; Celgene: Consultancy; Gilead: Consultancy; Roche: Consultancy; Pfizer: Research Funding. Allen:Curio Sciences: Honoraria; Bayer: Consultancy, Other; Clinical Care Options: Speakers Bureau; Research to Practice: Speakers Bureau; Imbrium: Consultancy, Other. Cohen:Genentech, BMS, Novartis, LAM, BioInvent, LRF, ASH, Astra Zeneca, Seattle Genetics: Research Funding; Janssen, Adicet, Astra Zeneca, Genentech, Aptitude Health, Cellectar, Kite/Gilead, Loxo: Consultancy.

A 26-year-old woman was initially diagnosed with stage III classical Hodgkin lymphoma (HL) treated with doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD) for 6 cycles and relapsed 9 months after completing therapy. She was treated with salvage chemotherapy followed by an autologous transplantation and 1 year of brentuximab vedotin (BV) maintenance therapy. She now presents 1 year later with relapsed disease above and below the diaphragm. What treatment would you recommend for this patient?

Background Cutaneous T-cell lymphoma (CTCL) is a rare form of non-Hodgkin lymphoma arising in the skin. Geographic clustering of CTCL has recently been reported, but its association with environmental factors is unknown. Benzene and trichloroethylene (TCE) are environmental toxins with carcinogenic properties. The authors investigated associations between geographic clustering of CTCL incidence in the state of Georgia with benzene and TCE exposure. Methods The statewide county-level incidence of CTCL within Georgia was obtained from the Georgia Cancer Registry for the years 1999 to 2015. Standardized incidence ratios (SIRs) were calculated by dividing observed cases by expected cases using national incidence rates by age, sex, and race. Clustering of CTCL was analyzed using spatial analyses. County-level concentrations of benzene and TCE between 1996 and 2014 were collected from the Environmental Protection Agency's National Air Toxics Assessment database. Linear regression analyses on CTCL incidence were performed comparing SIRs with levels of benzene and TCE by county. Results There was significant geographic clustering of CTCL in Georgia, particularly around Atlanta, which was correlated with an increased concentration of benzene and TCE exposure. Among the 4 most populous counties in Georgia, CTCL incidence was between 1.2 and 1.9 times higher than the state average, and benzene and TCE levels were between 2.9 and 8.8 times higher. Conclusions The current results demonstrate nonrandom geographic clustering of CTCL incidence in Georgia. To the authors' knowledge, this is the first analysis to identify a correlation between geographic clustering of CTCL and environmental toxic exposures.

Availability of highly effective novel agents has altered the approach to initial therapy in patients with classical Hodgkin lymphoma (cHL). We will review controversies in the following areas: (1) the role of radiation in early unfavorable disease and the optimal treatment strategies for (2) advanced-stage disease and (3) elderly patients. Strategies incorporating brentuximab vedotin into frontline treatment of cHL yielded favorable results in non-randomized elderly studies and were compared to ABVD in advanced disease among adults. Meanwhile, four cycles of escalated BEACOPP yielded unprecedented favorable results for the treatment of advanced disease in the German Hodgkin Study Group 18 study. The addition of novel agents to conventional treatment strategies has the potential to improve outcomes in high-risk groups of patients while reducing toxicity. The role of radiation therapy remains in question but may see diminished use with the incorporation of more effective agents in the frontline setting.

Background: Maintenance rituximab administered post autologous stem cell transplant (ASCT) in mantle cell lymphoma (MCL) is associated with improved overall survival (OS). Maintenance approaches with the proteasome inhibitor, bortezomib, are associated with improved progression-free survival (PFS), although its use is limited by peripheral neuropathy (Kaplan et al, 2020). We conducted a phase 1 study to evaluate the safety of maintenance therapy with ixazomib, an oral proteasome inhibitor, alone and in combination with rituximab for patients with MCL completing ASCT in first remission. Methods: Adult patients with MCL completing an ASCT in first partial or complete remission and who remained progression-free were enrolled between days 70-180 post-ASCT. Initially, patients received ixazomib monotherapy in cohorts of three using a standard 3+3 design. Patients self-administered ixazomib on days 1, 8, and 15 of each 28-day cycle at one of 3 dose levels: 2.3mg, 3mg, or 4mg. Patients continued therapy until disease progression, intolerance, or completion of 10 cycles. While we were enrolling to the 4mg dose level, the LYMA trial reported an OS benefit associated with maintenance rituximab (Le Gouill et al, 2017), so the protocol was amended to explore the combination of ixazomib and rituximab. Combination therapy consisted of ixazomib 4mg (given at the same schedule) and rituximab 375 mg/m2 given on day 1 of cycles 1, 3, 5, 7, and 9. The primary objective of the study was to evaluate the safety of this treatment and determine the maximum tolerated dose (MTD) while secondary objectives included efficacy. Results Twelve patients enrolled in the trial and received at least one dose of study therapy. Seven patients received ixazomib monotherapy (3mg = 3 patients, 4mg= 4 patients), and 5 patients received combination with rituximab and 4mg ixazomib. In all patients, the median age was 58 years (range 42-73 years) and 75% of the patients were male. Five patients had a high risk MIPI score. All patients entered the study in complete remission. Pre-transplant induction was R-HyperCVAD (n=6), VR-CAP/R-DHAP (n=2), NORDIC regimen (n=2), R-CHOP/R-DHAP (n=1), and R-DHAX (n=1). Transplant conditioning regimens were BEAM (n=7) or Bu/Cy/VP-16 (n=5). In the monotherapy group, 6 patients completed all 10 cycles of therapy. One patient experienced a dose limiting toxicity (DLT) which consisted of grade 3 neutropenia following cycle 1. In addition to the patient who experienced a DLT, one patient discontinued therapy early due to persistent abdominal pain that was ultimately determined to be unrelated to study therapy after an extensive evaluation. Two patients required dose reductions due to grade 3 hematologic toxicities. Two patients in the combination therapy group completed 10 cycles of therapy. Two patients experienced DLTs which consisted of grade 4 neutropenia, and 1 patient opted to discontinue therapy early due to persistent grade 2 peripheral neuropathy. In all patients, common adverse events (AEs) regardless of attribution were abdominal pain (n=6), leukopenia (n=5), nausea (n=4), thrombocytopenia (n=4), and peripheral neuropathy (n=3). Grade 3/4 AEs were thrombocytopenia (n=1) and neutropenia (n=4). No grade 3/4 peripheral neuropathy was observed. With a median follow up of 29.6 months, no patients experienced disease progression and all are alive. Due to the myelosuppression-related DLT's encountered in the combination arm, the study was closed to further accrual. Conclusions Our findings suggest adding rituximab to ixazomib at the evaluated dose and schedule as post-ASCT maintenance is associated with myelosuppression, and we would suggest future studies evaluate an alternative dose/schedule to mitigate this risk. The lack of early progressions is encouraging, confirming the findings from CALGB50403 that proteasome inhibition may provide therapeutic benefit in this setting. Further evaluation of rituximab-containing post-induction combination therapies may identify a safer dosing strategy while improving long-term remission rates. Disclosures Allen: Bayer: Consultancy, Other; Curio Sciences: Honoraria; Clinical Care Options: Speakers Bureau; Research to Practice: Speakers Bureau; Imbrium: Consultancy, Other. Waller:Verastem Oncology, Inc: Consultancy, Research Funding. Flowers:Bayer: Consultancy; Denovo Biopharma: Consultancy; Genentech, Inc./F. Hoffmann-La Roche Ltd: Consultancy, Research Funding; AbbVie: Consultancy, Research Funding; BeiGene: Consultancy; Celgene: Consultancy, Research Funding; Gilead: Consultancy, Research Funding; Karyopharm: Consultancy; OptumRx: Consultancy; Pharmacyclics/Janssen: Consultancy; Spectrum: Consultancy; Acerta: Research Funding; Millennium/Takeda: Consultancy, Research Funding; TG Therapeutics: Research Funding; Burroughs Wellcome Fund: Research Funding; Eastern Cooperative Oncology Group: Research Funding; National Cancer Institute: Research Funding; V Foundation: Research Funding; Cancer Prevention and Research Institute of Texas: Research Funding; Kite: Research Funding; Leukemia and Lymphoma Society: Membership on an entity's Board of Directors or advisory committees. Cohen:Genentech, BMS, Novartis, LAM, BioInvent, LRF, ASH, Astra Zeneca, Seattle Genetics: Research Funding; Janssen, Adicet, Astra Zeneca, Genentech, Aptitude Health, Cellectar, Kite/Gilead, Loxo: Consultancy.

Maintenance therapy after total skin electron beam (TSEB) therapy has been proposed as a promising approach for patients with cutaneous T-cell lymphoma (CTCL). Previous studies reported mixed results regarding an effect of maintenance on progression-free survival (PFS), with minimal evidence for an effect on overall survival (OS). We conducted a single-center retrospective analysis of 101 patients with CTCL undergoing TSEB therapy. Pooled maintenance therapy improved PFS, and ultraviolet therapy, specifically, improved both PFS and OS, supporting the use of maintenance therapy for CTCL. BACKGROUND: Treatment of cutaneous T-cell lymphoma (CTCL) with total skin electron beam (TSEB) therapy has been associated with deep responses but short progression-free intervals. Maintenance therapy might prolong the response duration; however, limited data assessing the outcomes with maintenance therapy after TSEB are available. We evaluated the effect of maintenance therapy on the outcomes for patients with CTCL receiving TSEB therapy. MATERIALS AND METHODS: We conducted a single-center retrospective analysis of 101 patients with CTCL who had received TSEB therapy from 1998 to 2018 at the Winship Cancer Institute of Emory University and compared the overall survival (OS) and progression-free survival (PFS) for patients had received maintenance therapy, including retinoids, interferon, ultraviolet therapy, nitrogen mustard, and extracorporeal photopheresis compared with those who had not. RESULTS: We found that pooled maintenance therapies improved PFS (hazard ratio [HR], 0.60; P = .026) but not OS (median HR, 0.73; P = .264). The median PFS and OS was 7.2 months versus 9.6 months and 2.4 years versus 4.2 years for the no maintenance and maintenance groups, respectively. On exploratory analysis of the individual regimens, ultraviolet therapy was associated with improved OS (HR, 0.21; P = .034) and PFS (HR, 0.26; P = .002) compared with no maintenance. CONCLUSION: Among the patients with CTCL who had received TSEB therapy, maintenance therapy improved PFS for all patients, and ultraviolet-based maintenance improved both PFS and OS in a subset of patients.

e20087 Background: Cutaneous T-Cell Lymphoma (CTCL) is a monoclonal lymphoproliferative disease. Studies hypothesize T-cell receptor gene (TCR) rearrangement and flow cytometry as means of predicting those at risk of aggressive disease. We aimed to assess outcomes in early-stage disease by TCR clonality and flow cytometry in peripheral blood. Methods: We performed a retrospective analysis of 328 pts with early-stage (1-2A) CTCL using our internal CTCL database with protocol approved by our institutional review board (IRB00045798). Early-stage CTCL pts included were those with TCR clonality and/or flow cytometry in the peripheral blood obtained within 6 months of diagnosis and/or at initial check. Overall survival (OS) and time to next treatment (TTNT) were examined. Missing data or OS/ TTNT values larger than 25 years were excluded. Univariate/multivariate models and Kaplan-Meier analyses were run for both OS and TTNT. Results: In the cohort (n = 328) the median age was 53.2 years (8.6-87.5), with equal sex predominance, and distribution among stages. 261 pts had TCR clonality assessed. 78.5% (n = 205) were non-clonal and 21.5% (n = 56) were clonal. 284 pts had flow assessed (n = 44/328 with missing data). 89.8% (255/284) were flow (-), initially. Of those without clonality, 95.29% (n = 182 p < 0.001) were flow (-). 76% (38/56 p < 0.001) with TCR clonality were flow (-). TCR clonality in the blood was not associated with a survival nor TTNT by univariate or multivariate analyses. Age at diagnosis was significant contributing to OS and TTNT in multivariate analyses (HR 1.04,CI 1.01-1.06,p < 0.01;HR 1.01, CI 1.00-1.02,p = 0.033, respectively). Flow cytometry status was not associated with TTNT. Flow cytometry in the blood was associated with survival but was limited to stage 2A pts (n = 98, p = 0.0171). Median survival of those with flow negative results was 20.8 yrs (CI 11.8,NA, p = 0.0171) with a 5-year survival of 95.8%(CI 87.4%-98.6%) compared to those with positive results of 12 yrs (CI 1.3, NA), p = 0.0171) with a 5-yr survival of 80.8%(CI 42.3%-94.9%). Conclusions: We found no difference in OS or TTNT by TCR status in blood for stage 1-2A disease. Flow cytometry status and OS differed in stage 2A pts. Significance of TCR clonality or flow cytometry in early-stage disease remains unclear. Findings raise questions of needing to risk-stratify in early-stage disease by TCR gene rearrangement or flow cytometry. Those with stage 2A disease, flow cytometry status may confer some benefit. Larger cohorts needed to further investigate these findings.