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Purpose: The aim of this research was to further investigate the contribution of CD20 antigen expression to rituximab activity and define the mechanisms responsible for CD20 downregulation in rituximab-resistant cell lines (RRCL).Experimental Design: Rituximab-sensitive cell lines, RRCL, and primary neoplastic B cells were evaluated by chromium-51 release assays, ImageStream image analysis, immunohistochemical staining, flow cytometric analysis, CD20 knockdown, promoter activity, chromatin immunoprecipitation (ChIP) analysis of CD20 promoter, and CD20 plasmid transfection experiments to identify mechanisms associated with CD20 regulation in RRCL.Results: RRCL exhibited a gradual loss of CD20 surface expression with repeated exposure to rituximab. We identified a CD20 antigen surface threshold level required for effective rituximab-associated complement-mediated cytotoxicity (CMC). However, a direct correlation between CD20 surface expression and rituximab-CMC was observed only in rituximab-sensitive cell lines. CD20 promoter activity was decreased in RRCL. Detailed analysis of various CD20 promoter fragments suggested a lack of positive regulatory factors in RRCL. ChIP analysis showed reduced binding of several key positive regulatory proteins on CD20 promoter in RRCL. Interleukin-4 (IL-4) induced higher CD20 promoter activity and CD20 expression but modestly improved rituximab activity in RRCL and in primary B-cell lymphoma cells. Forced CD20 expression restored cytoplasmic but not surface CD20, suggesting the existence of a defect in CD20 protein transport in RRCL.Conclusions: We identified several mechanisms that alter CD20 expression in RRCL and showed that, whereas CD20 expression is important for rituximab activity, additional factors likely contribute to rituximab sensitivity in B-cell lymphoma. Clin Cancer Res; 18(4); 1039–50. ©2012 AACR.

DLC-001 Study Design (CONSORT diagram)

Grade 3/4 Treatment-Emergent Adverse Events Reported in {greater than or equal to}5% of Patients (Safety Population)

List of Primer Sequences

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Purpose: Targeting malignant B cells using rituximab (anti-CD20) has improved the efficacy of chemotherapy regimens used to treat patients with non-Hodgkin's lymphoma. Despite the promising clinical results obtained using rituximab, many patients relapse with therapy-resistant disease following rituximab-based treatments. We have created a cell line model of rituximab resistance using three B-cell non-Hodgkin's lymphoma–derived cell lines (Raji, RL, and SUDHL-4). In an attempt to define strategies to overcome rituximab resistance, we sought to determine the chemotherapy sensitivity of our rituximab-resistant cell lines (RRCL).Experimental Design: Parental, rituximab-sensitive cell lines (RSCL) Raji, RL, and SUDHL-4, along with RRCLs derived from them, were exposed to several chemotherapeutic agents with different mechanisms of action and the ability of these agents to induce apoptotic cell death was measured. Expression of multidomain Bcl-2 family proteins was studied as potential mediators of chemotherapy/rituximab resistance.Results: We found that RRCLs are resistant to multiple chemotherapeutic agents and have significantly decreased expression of the Bcl-2 family proteins Bax, Bak, and Bcl-2. RRCLs do not undergo rituximab- or chemotherapy-induced apoptosis but die in a caspase-dependent manner when either wild-type Bax or Bak is exogenously expressed. Furthermore, forced expression of Bak sensitized RRCL to chemotherapy-induced apoptosis.Conclusions: Whereas a single or limited exposure of lymphoma cells to rituximab may lead to a favorable ratio of proapoptotic to antiapoptotic Bcl-2 family proteins, repeated exposure to rituximab is associated with a therapy-resistant phenotype via modulation of Bax and Bak expression.

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Investigator's Choice (IC) Dosing Regimens

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Purpose: Randomized, multicenter, open-label, phase 2/3 trial investigating lenalidomide versus investigator's choice (IC) in relapsed/refractory diffuse large B-cell lymphoma (DLBCL).Experimental Design: Patients with DLBCL who received ≥2 prior therapies were stratified by DLBCL subtype [germinal center B-cell (GCB) vs. non-GCB; determined by immunohistochemistry (IHC)] and then randomized 1:1 to lenalidomide (25 mg/day, 21 days of 28-day cycle) or IC (gemcitabine, rituximab, etoposide, or oxaliplatin). Crossover to lenalidomide was permitted for IC-treated patients with radiologically confirmed progressive disease. The primary endpoint was overall response rate (ORR). Progression-free survival (PFS), overall survival, and subtype analysis [GCB vs. activated B-cell (ABC)] using gene expression profiling (GEP) were exploratory endpoints.Results: Stage 1: 102 DLBCL patients (by IHC: non-GCB, n = 54; GCB, n = 48) received ≥1 dose of lenalidomide or IC. Hematologic treatment-emergent adverse events with lenalidomide versus IC included neutropenia (42.6%; 36.4%), anemia (33.3%; 47.3%), thrombocytopenia (24.1%; 43.6%), and leukopenia (5.6%; 12.7%), respectively. Overall, lenalidomide-treated patients had an ORR of 27.5% versus 11.8% in IC (ORRs were similar regardless of IHC-defined DLBCL subtype). Median PFS was increased in patients receiving lenalidomide (13.6 weeks) versus IC (7.9 weeks; P = 0.041), with greater improvements in non-GCB patients (15.1 vs. 7.1 weeks, respectively; P = 0.021) compared with GCB (10.1 vs. 9.0 weeks, respectively; P = 0.550).Conclusions: The clinical benefit of lenalidomide monotherapy in DLBCL patients was more evident in the non-GCB subtype. Exploratory analyses suggest that this preferential benefit was more pronounced in the GEP-defined ABC population, demonstrating a need for additional studies of lenalidomide in DLBCL using GEP subtyping. Clin Cancer Res; 23(15); 4127–37. ©2017 AACR.

Supplementary Figures S1-S4 from Acquired Resistance to Rituximab Is Associated with Chemotherapy Resistance Resulting from Decreased Bax and Bak Expression

BACKGROUND: Ofatumumab is a humanized type 1 anti-CD20 monoclonal antibody. Preclinical studies show improved complement-mediated cytotoxicity (CMC) compared to rituximab in mantle cell lymphoma (MCL). We evaluated the safety and efficacy of combining ofatumumab with HyperCVAD/MA (O-HyperCVAD) in newly diagnosed MCL. STUDY DESIGN: In this single-arm phase II study, 37 patients were treated with the combination of O-HyperCVAD for 4 or 6 cycles, followed by high dose chemotherapy and autologous stem cell transplant (HDC-ASCT). Primary objectives were overall response rate (ORR) and complete response (CR) rate at the end of therapy. Secondary objectives included minimal residual disease (MRD) negativity, progression free survival (PFS) and overall survival (OS). RESULTS: Median age was 60 years; ORR was 86% and 73% achieved a CR by modified Cheson criteria. The MRD negativity rate was 78% after 2 cycles of therapy, increasing to 96% at the end of induction; median PFS and OS were 45.5 months and 56 months respectively. Achieving a post-induction CR by both imaging and flow cytometry was associated with improved PFS and OS. Early MRD negativity (post-2 cycles) was also associated with an improved PFS but not OS. There were 3 deaths while on therapy, and grade 3 and 4 adverse events (AEs) were observed in 22% and 68% of the patients. CONCLUSION: The addition of ofatumumab to HyperCVAD/HD-MA led to high rates of MRD negativity by flow cytometry in patients with newly diagnosed MCL. Achieving a CR post-induction by both imaging and flow cytometry is associated with improved overall survival.

Patients with chronic lymphocytic leukemia (CLL) are known to be at a higher risk of developing other primary cancers (OPC). Identifying latency and risk factors associated with OPCs in CLL is of interest as select patients may potentially benefit from early treatment of CLL with targeted therapies to improve immune surveillance. In this single-center retrospective study, 16.9% of 969 patients with CLL were diagnosed with an OPC. Interestingly, 44% of OPCs were diagnosed prior to the CLL diagnosis, including 30% that were diagnosed1 year prior. This included a majority of genitourinary cancers and melanoma skin cancers. Patients with CLL and an OPC were older than pts with no OPCs but no other risk factors for developing OPCs were identified. Our data suggest that not only are patients with CLL at higher risk of developing OPCs and warrant appropriate cancer surveillance, but the risk also precedes CLL diagnosis by several years.

In the last decade, a better understanding of the molecular pathogenesis of B-cell non-Hodgkin lymphomas has resulted in the development of novel targeted therapies, such as small molecule inhibitors of select kinases in the B-cell receptor pathway, antibody–drug conjugates, and small molecules that target a variety of proteins (eg, CD-19, EZH2, and XPO-1–mediated nuclear export). Anti-CD19 CAR T-cell therapy, first approved for relapsed/refractory (R/R) diffuse large B-cell lymphoma, has also emerged as a novel treatment option for R/R follicular lymphoma and mantle cell lymphoma. These NCCN Guideline Insights highlight the new targeted therapy options included in the NCCN Guidelines for B-Cell Lymphomas for the treatment of R/R disease.

The CORAL study highlighted the need to develop novel salvage regimens in relapsed/refractory (R/R) diffuse large B-cell lymphoma (DLBCL) previously treated with rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone. Carfilzomib (CFZ) can overcome rituximab chemotherapy resistance in lymphoma preclinical models by targeting the ubiquitin-proteasome system. We conducted an investigator initiated, single-center, open-label, prospective phase 1 study evaluating the safety and efficacy of CFZ in combination with rituximab, ifosfamide, carboplatin, and etoposide (C-R-ICE) in high-dose chemotherapy with autologous stem cell transplant (HDC-ASCT) eligible patients with R/R DLBCL (NCT01959698). In the dose-escalation phase, 18 patients were enrolled at 6 dose levels with no dose-limiting toxicities noted. CFZ 45 mg/m2 was selected as the recommended dose for expansion. Eleven additional patients were enrolled in the dose-expansion phase. Overall response rate (ORR) was 66% (48% CR; 17% PR); 52% patients underwent HDC-ASCT. An ORR of 85% was observed in patients with nongerminal center B-cell–like (non-GCB) DLBCL compared with only 13% in those with GCB DLBCL. Median progression-free survival (PFS) was 15.2 months (5.1 months, not reached [NR]), and median overall survival (OS) was 22.6 months (6.8 months, NR). Patients with non-GCB subtype had a significantly longer PFS (NR vs 6.6 months; P = .0001) and OS (NR vs 6.6 months; P = .001) than those with GCB subtype. C-R-ICE is well tolerated in patients with R/R DLBCL with toxicities comparable to rituximab, ifosfamide, carboplatin, and etoposide therapy. Our data show that patients with non-GCB DLBCL benefit significantly from incorporating CFZ into second-line therapy and HDC-ASCT.

Following a similar report on multiple myeloma, Ghione and colleagues report the expected observation that patients with non-Hodgkin lymphoma (NHL) receiving anti-B cell therapies have markedly reduced antibody responses to COVID-19 immunization. Although there is no information regarding T-cell immunity, this suggests that while vaccination is certainly still recommended for this population, patients should be strongly encouraged to maintain social distancing precautions and should be revaccinated after an appropriate interval from the end of their antilymphoma therapy.

Langerhans cell histiocytosis (LCH) is a rare disease, afflicting approximately 4.6 and 1-2 per 1 million children and adults, respectively. While LCH can involve numerous organ systems such as the lung or bone, it is uncommon for the disease to be limited to the skin. Radiotherapy has an established role for osseous lesions. However, the efficacy and dose for nonosseous manifestations of the disease are not well described. In the current case report, we detail a 49-year-old adult male with skin-limited LCH requiring palliative radiotherapy (RT) to numerous sites for pain control. The patient was initially diagnosed and treated with single agent cytarabine for approximately 6 months. Despite treatment, he had little symptomatic response of his cutaneous lesions. We delivered a single dose of 8 Gray (Gy) to 3 separate skin lesions, including the bilateral groin, right popliteal region, and right axillary lesion, which resulted in pain reduction and partial response at four-month follow-up. Subsequently, we decided to treat the left axillary untreated lesion to a higher dose of 24 Gy in 12 fractions. At four-month follow-up, the left axilla RT resulted in complete clinical response and improved pain control compared to the right axilla. Following RT treatments, the patient was found to have a BRAF mutation, and vemurafenib was initiated. Further follow-up with positron emissions tomography demonstrated complete metabolic response in numerous disease areas, including both axillae. Based on this case report’s findings, a higher radiotherapy dose may be more effective for treating cutaneous LCH.

Intercellular adhesion molecule-1 (ICAM-1) is a cell-surface receptor contributing to lymphocyte homing, adhesion and activation. The prognostic significance of the protein is unknown in diffuse large B-cell lymphoma (DLBCL) in post-rituximab era. We detected expression of ICAM-1 immunohistochemically in 102 DLBCL tissue samples. Overexpression of ICAM-1 was found in 28 (27.5%) cases. In patients with low ICAM-1 expression levels, the addition of rituximab to CHOP (cyclophosphamide, doxorubicin, vincristine and prednisone) chemotherapy resulted in an improved overall response rate, progression-free survival (PFS) and overall survival (OS) (P=0.019, 0.01, 0.02). In pre-clinical models, we found that chronic exposure of cell lines to rituximab led to downregulation of ICAM-1 and acquirement of a rituximab resistant phenotype. In vitro exposure of rituximab resulted in rapid aggregation of B-cells regardless of the ICAM-1 expression levels. MTT assay showed knockdown of ICAM-1 could cause rituximab resistance. Neutralization of ICAM-1 did not affect rituximab activity in vitro and in vivo. Our data illustrated that in post-rituximab era, R-CHOP significantly improved the ORR, PFS and OS in ICAM-1 negative subset patients. Downregulation of ICAM-1 may contribute to rituximab resistance, and that rituximab, by promoting cell-cell aggregation, may sensitize cells to the cytotoxic effects of chemotherapy agents.

The NCCN Clinical Practice Guidelines in Oncology for Hodgkin Lymphoma (HL) provide recommendations for the management of adult patients with HL. The NCCN panel meets at least annually to review comments from reviewers within their institutions, examine relevant data, and reevaluate and update their recommendations. Current management of classic HL involves initial treatment with chemotherapy alone or combined modality therapy followed by restaging with PET/CT to assess treatment response. Overall, the introduction of less toxic and more effective regimens has significantly advanced HL cure rates. This portion of the NCCN Guidelines focuses on the management of classic HL.

We studied the biological activity of pevonedistat, a first-in-class NEDD8-activating enzyme (NAE) inhibitor, in combination with various cytotoxic chemotherapy agents and small molecule inhibitors in lymphoma pre-clinical models. Pevonedistat induced cell death in activated B-cell (ABC) diffuse large B-cell lymphoma (DLBCL) cell lines and to a lesser degree in germinal center B-cell (GCB) DLBCL cell lines. In pevonedistat sensitive cells, we observed inhibition of NFκB activity by p65 co-localization studies, decreased expression of BCL-2/BCL-XL and upregulation of BAK levels. Pevonedistat enhanced the activity of cytarabine, cisplatin, doxorubicin and etoposide in ABC-, but not in the GCB-DLBCL cell lines. It also exhibited synergy with ibrutinib, selinexor, venetoclax and A-1331852 (a novel BCL-XL inhibitor). In vivo, the combination of pevonedistat and ibrutinib or pevonedistat and cytarabine prolonged survival in SCID mice xenograft models when compared with monotherapy controls. Our data suggest that targeting the neddylation pathway in DLBCL is a viable therapeutic strategy and support further clinical studies of pevonedistat as a single agent or in combination with chemotherapy or novel targeted agents.

Preclinical data demonstrated that combining an anti–programmed cell death 1 (PD-1) inhibitor with a cyclin-dependent kinase 9 (CDK9) inhibitor provided enhanced antitumor activity with no significant toxicities, suggesting this combination may be a potential therapeutic option. The multicohort, phase 1 KEYNOTE-155 study evaluated the safety and antitumor activity of the PD-1 inhibitor pembrolizumab plus the CDK9 inhibitor dinaciclib in patients with relapsed or refractory (rr) chronic lymphocytic leukemia (CLL), diffuse large B-cell lymphoma (DLBCL) and multiple myeloma (MM). Patients enrolled were ≥18 years of age with a confirmed diagnosis of CLL, DLBCL, or MM. The study included 2 phases: a dose-evaluation phase to determine dose-limiting toxicities and a signal-detection phase. Patients received pembrolizumab 200 mg every 3 weeks plus dinaciclib 7 mg/m2 on day 1 and 10 mg/m2 on day 8 of cycle 1 and 14 mg/m2 on days 1 and 8 of cycles 2 and later. Primary endpoint was safety, and a key secondary endpoint was objective response rate (ORR). Seventy-two patients were enrolled and received ≥1 dose of study treatment (CLL, n = 17; DLBCL, n = 38; MM, n = 17). Pembrolizumab plus dinaciclib was generally well tolerated and produced no unexpected toxicities. The ORRs were 29.4% (5/17, rrCLL), 21.1% (8/38, rrDLBCL), and 0% (0/17, rrMM), respectively. At data cutoff, all 72 patients had discontinued treatment, 38 (52.8%) because of progressive disease. These findings demonstrate activity with combination pembrolizumab plus dinaciclib and suggest that a careful and comprehensive approach to explore anti–PD-1 and CDK9 inhibitor combinations is warranted. This trial was registered at www.clinicaltrials.gov as NCT02684617.

This is the first longitudinal study of immune profiles and autologous hematopoietic cell transplant (AHCT) survival in B-cell non-Hodgkin lymphoma (B-NHL) patients and the effect of plerixafor mobilization on immune reconstitution in this population. A comprehensive immunophenotyping panel was performed in 104 consecutive adult B-NHL patients (58% diffuse large B cell and 42% mantle cell) who received AHCT (1/2008–11/2014), at a median of 28 days pre-AHCT (N = 104) and Day +100 (N = 83) post-AHCT. Median follow-up post-AHCT was 61 months (range: 8–120 months). Compared to patients mobilized with filgrastim and plerixafor, patients mobilized with filgrastim alone had a higher proportion of CD4+ naive (p = 0.006) and CD8+ central memory T-cells (p = 0.006) pre-AHCT. For patients transplanted in complete remission (CR), a higher proportion of CD8+ effector memory T-cells pre-AHCT was associated with worse progression-free survival (PFS; p

Diffuse large B-cell lymphomas (DLBCLs) and follicular lymphoma (FL) are the most common subtypes of B-cell non-Hodgkin’s lymphomas in adults. Histologic transformation of FL to DLBCL (TFL) occurs in approximately 15% of patients and is generally associated with a poor clinical outcome. Phosphatidylinositol 3-kinase (PI3K) inhibitors have shown promising results in the treatment of relapsed/refractory FL. CAR T-cell therapy (axicabtagene ciloleucel and tisagenlecleucel) has emerged as a novel treatment option for relapsed/refractory DLBCL and TFL. These NCCN Guidelines Insights highlight important updates to the NCCN Guidelines for B-Cell Lymphomas regarding the treatment of TFL and relapsed/refractory FL and DLBCL.

PURPOSE Mantle cell lymphoma (MCL) is a B-cell lymphoma characterized by cyclin D1 expression. Autologous hematopoietic cell transplantation (AHCT) consolidation after induction chemotherapy is often used for eligible patients; however, the benefit remains uncertain in the rituximab era. Herein we retrospectively assessed the impact of AHCT consolidation on survival in a large cohort of transplantation-eligible patients age 65 years or younger. PATIENTS AND METHODS We retrospectively studied transplantation-eligible adults age 65 years or younger with newly diagnosed MCL treated between 2000 and 2015. The primary objective was to assess for improved progression-free survival (PFS) with AHCT consolidation and secondarily to assess for improved overall survival (OS). Cox multivariable regression analysis and propensity score–weighted (PSW) analysis were performed. RESULTS Data were collected from 25 medical centers for 1,254 patients; 1,029 met inclusion criteria. Median follow-up for the cohort was 76 months. Median PFS and OS were 62 and 139 months, respectively. On unadjusted analysis, AHCT was associated with improved PFS (75 v 44 months with v without AHCT, respectively; P < .01) and OS (147 v 115 months with v without AHCT, respectively; P < .05). On multivariable regression analysis, AHCT was associated with improved PFS (hazard ratio [HR], 0.54; 95% CI, 0.44 to 0.66; P < .01) and a trend toward improved OS (HR, 0.77; 95% CI, 0.59 to 1.01; P = .06). After PSW analysis, AHCT remained associated with improved PFS (HR, 0.70; 95% CI, 0.59 to 0.84; P < .05) but not improved OS (HR, 0.87; 95% CI, 0.69 to 1.1; P = .2). CONCLUSION In this large cohort of younger, transplantation-eligible patients with MCL, AHCT consolidation after induction was associated with significantly improved PFS but not OS after PSW analysis. Within the limitations of a retrospective analysis, our findings suggest that in younger, fit patients, AHCT consolidation may improve PFS.

Introduction: Ibrutinib is a first-in-class small molecule inhibitor that binds irreversibly to Bruton's Tyrosine Kinase (BTK) and has shown remarkable efficacy in the treatment of CLL. Current guidelines recommend life-long therapy with administration at a fixed daily dose of 420 mg. However, lower doses of ibrutinib have been demonstrated to adequately abrogate kinase function. Limited clinical data suggests that dose reductions are not associated with inferior outcomes. Hypothetically, judicious dose reductions to manage toxicities could result in improved tolerance and decreased discontinuation rates. Our objective was to study the impact of dose reductions on outcomes in CLL patients treated with ibrutinib in a real-world setting. Methods: We conducted a retrospective chart review of all CLL patients treated with ibrutinib at Roswell Park Comprehensive Cancer Center between January 2014 and June 2017. Patients who underwent ibrutinib dose reduction were identified. Baseline characteristics and outcomes were compared between patients who underwent dose reductions vs those who did not. Reason and timing of dose reduction was also elucidated. Mann-Whitney U and Fisher's Chi Square test were used to compare groups, Kaplan Meier methods were used for time to event analysis, and Cox regression was used to obtain hazard ratios (HR). Overall survival (OS) was calculated as time from start of ibrutinib until death or last follow-up, freedom from progression (PFS) was taken as time from start of ibrutinib until progression or last follow-up. All analyses were performed in SAS v9.4 (Cary, NC). Results: A total of 70 CLL patients treated with ibrutinib were followed for a median period of 21.9 months. Most patients had RR disease (n = 63) and 7 received ibrutinib as frontline therapy. All patients received a fixed dose regimen with the standard dose of 420 mg once daily. Twenty-three (31.3%) patients required dose reductions and received ibrutinib at a median dose of 140 mg . Eleven (47.8%) of these had dose reductions within 3 months of treatment initiation. There was no statistically significant difference in baseline characteristics including age, number of prior lines of treatment, WBC count, hemoglobin or LDH level in the dose reduced group (DRG) and standard dose group (SDG). Patients in the DRG had a lower median platelet count at initiation of ibrutinib than patients in the SDG (86 x 103/mm3 vs 145 x 103/mm3, p Disclosures No relevant conflicts of interest to declare.

Introduction: T-cell lymphoma (TCL) accounts for 15% of all non-Hodgkin’s lymphoma cases with most patients developing relapsed/refractory (R/R) disease. The management of R/R TCL is challenging and responses to second and beyond-line therapy are generally poor. Pre-clinical and clinical studies have identified the relevance of PI3K/AKT/mTOR signaling pathway in TCL biology. The combination of PI3K inhibitor (PI3Ki) Duvelisib and the HDACi Romidepsin improved the overall response rate (ORR) of R/R TCL to 50-55% in a phase I/II study (Horwitz et. al. ASH 2018, Lugano 2021). Evaluation of PI3Ki and HDACi combinations in TCL pre-clinical models is needed to guide the design of future clinical trials. Methods: A panel of TCL cells lines were chosen representing T-cell acute lymphoblastic leukemia, T-lymphoblastic lymphoma, cutaneous T-cell lymphoma. A panel of PI3Ki (Omipalisib, Umbralisib and Duvelisib) and HDACi (Entinostat and Romidepsin) were selected to determine which combination would be most synergistic. Entinostat, an oral HDACi, was chosen for its remarkable preclinical and clinical activity in other lymphoma subtypes. Umbralisib is a new PI3Kδ inhibitor which was recently approved for treatment of follicular lymphoma and marginal zone lymphoma. Cells were exposed to Omipalisib (3.125-100nM), Umbralisib (1-320uM), or Duvelisib (1-100uM) alone or in combination with Entinostat (0.08-10uM) or Romidepsin (0.25-6) for 24, 48 and 72 hrs. Cell viability was measured using the CellTiter-Glo viability assay. Half-maximal inhibitory concentration (IC50) at 72hrs was determined for each drug and coefficient of synergy was calculated using Calcusyn Software. Changes in cellular metabolism and cell cycle distribution after exposure to PI3Ki were determined using DiOC6 staining and Propidium Iodide staining respectively. Epigenetic changes following exposure to Entinostat or Romidepsin were investigated for possible mechanisms. Results: In vitro exposure of TCL cell lines to PI3Ki or HDACi resulted in dose-dependent cell death. The IC50 at 72 hrs was 30-500nM for Omipalisib, 9-35uM for Umbralisib, 1-35uM for Duvelisib, 0.2-2uM for Entinostat and for 1-4nM Romidepsin. All HDACi and Pi3Ki combinations demonstrated additive and/or synergistic activity. Duvelisib combined with Entinostat or Romidepsin exhibited the most synergy. Methylation profiling demonstrated genomic wide hypomethylation, specifically DNMT3A, in Romidepsin treated samples compared to Entinostat. Conclusions: PI3Ki and HDACi combinations show significant synergy in TCL preclinical models. DNMT3A hypomethylation following Romidepsin exposure is being explored as the basis of PI3Ki and HDACi synergy. If confirmed in clinical trials, these results may refine the tolerability of the regimen for patients treated with this very promising PI3Ki/HDACi combination. Citation Format: Gabrielle Hartman, Cory Mavis, Juan J. Gu, Amber White, Taylor Mandeville, Pallawi Torka, Paola Ghione, Francisco J. Hernandez-Ilizaliturri. Novel pharmacological approaches of inhibiting the PI3K/AKT/mTOR signaling pathway in T-cell lymphoma (TCL) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2661.

LBA7564 Background: Patients with r/r B-NHL have a dismal prognosis. DIAL (Dual Immunomodulation in Aggressive Lymphoma) was a multi-center randomized phase II study testing the efficacy of nivolumab (PD-1 inhibitor) plus varlilumab (CD27 agonist) in this population. Methods: Patients were randomized (1:1) to nivolumab (240 mg IV every 2 weeks for 4 months, 480 mg IV monthly thereafter; group 1) alone or combined with varlilumab (3 mg/kg IV monthly; group 2). Cross-over (group 1 to 2) was allowed for progression. Primary endpoint was overall response (ORR) per LYRIC criteria. A sample size of 48 patients per arm would provide 80% power to detect increase in ORR from 25% to 45% using a one-sided test (p = 0.15). Pre-specified interim analysis occurred after half of the patients completed first radiologic assessment. Secondary endpoints included overall survival (OS), progression-free survival (PFS), and adverse events (AEs). Exploratory endpoints included tumor genomic assessment and immune profiling of blood and tumor. Results: 53 patients were enrolled (27 in group 1; 26 in group 2). Interim analysis included 24 patients from each arm. Mean age was 65.2 years, 34 (70.8%) were male, and 36 (75%) received prior CAR-T cell therapy. Baseline characteristics were balanced between arms. Grade ≥ 3 AEs were observed in 8 (33.3%) and 7 (30.4%) of patients in groups 1 and 2, respectively. Common AEs (> 5%) of any grade included fatigue, lymphopenia, diarrhea, rash. There were no treatment-associated deaths. Toxicity profile was similar between arms. Table summarizes efficacy outcomes. ORR was achieved in 6 patients (12.5%), not statistically different between arms; 4 responses were complete. Seven patients crossed over (1 responded after crossing). Median OS (8.6 vs 7.3 months; p = 0.39) and PFS (2.7 vs 1.4 months; p = 0.06) were similar between arms. Subgroup analysis of patients with prior CAR-T cell therapy showed similar ORR (5/36; 14%), not statistically different between arms. Correlative analysis results will be presented at conference. The trial met futility criterion on interim analysis and enrollment ceased based on pre-specified stopping rule. Conclusions: Dual immunomodulatory therapy did not enhance anti-tumor activity in patients with aggressive B-NHL compared to nivolumab alone. Response rates were low and consistent with previous data using PD-1 inhibitors in this population. Prior therapy with CAR-T cell does not seem to sensitize patients to PD-1 blockade. Toxicity profile was acceptable and dual therapy did not increase the rate of AEs. Clinical trial information: NCT03038672. [Table: see text]

Clinical observations suggest the existence of shared resistance pathways between rituximab and chemotherapy agents. To explore the mechanisms of rituximab resistance, our group created rituximab-resistant cell lines (RRCLs), which display altered expression of several inhibitor of apoptosis (IAP) family proteins. Here, we provide evidence to support pharmacologically targeting IAPs in lymphoma with LCL-161, a small molecule mimetic of the second mitochondria-derived activator of caspases (SMAC). The antitumor effect of LCL-161 was determined using luminescent adenosine triphosphate assays, flow cytometry, SCID mouse xenografts, and ex vivo patient biopsy sample studies. In vitro exposure to LCL-161 also resulted in a dose-dependent decrease in IAP levels, along with synergistic enhancement of the antitumor effect of cytotoxic chemotherapy, in rituximab-sensitive cell lines and RRCLs. In addition, LCL-161 increased the cytotoxic effect of the proteasome inhibitor carfilzomib in ex vivo lymphoma patient samples. The combination of LCL-161 with the chemotherapy regimen rituximab, gemcitabine, and vinorelbine (RGV) improved in vivo survival compared with RGV alone in severe combined immunodeficient mice implanted with RRCLs but not in animals implanted with rituximab-sensitive cell lines. In summary, LCL-161 exhibits synergistic antitumor activity in both in vitro and in vivo models of resistant lymphoma. Our data support further preclinical investigation of LCL-161 as a novel antilymphoma agent.

The role of 18F-Fluoro-2-deoxy-D-glucose positron emission tomography combined with computerized tomography (PET-CT) in evaluation of bone marrow involvement (BMI) in patients with T-cell lymphoma (TCL) is poorly understood. We investigated whether PET-CT could replace bone marrow aspiration and biopsy (BMAB) in TCL. Sixty patients with newly diagnosed TCL who underwent both diagnostic PET-CT and BMAB were identified. BMI was tissue-confirmed in 15 (25%) cases, however only 8 of these 15 showed BMI on PET-CT (sensitivity of 53.3%, specificity of 100%). BMI by BMAB was associated with lower progression-free survival (PFS) (P=0.038) and overall survival (OS) (P=0.003) while PET-CT BMI was associated only with OS (P=0.02). BMI detected by BMAB in the setting of a negative PET-CT had similar inferior prognosis as BMI identified on PET-CT. Thus, PET-CT in TCL misses BMI in almost half of the cases detected by BMAB and hence cannot substitute BMAB in evaluation of TCL.

Immunochemotherapy followed by autologous transplant (ASCT) in CALGB/Alliance 59909 achieved a median progression-free survival (PFS) in mantle cell lymphoma (MCL) of 5 years, but late recurrences occurred. We evaluated tolerability and efficacy of adding post-transplant bortezomib consolidation (BC) or maintenance (BM) to this regimen in CALGB/Alliance 50403, a randomized phase II trial. Following augmented-dose R-CHOP/ methotrexate, high-dose cytarabine-based stem cell mobilization, cyclophosphamide/carmustine/etoposide (CBV) autotransplant, and rituximab, patients were randomized to BC (1.3 mg/m2 IV days 1, 4, 8, 11 of a 3-week cycle for four cycles) or BM (1.6 mg/m2 IV once weekly × 4 every 8 weeks for 18 months) beginning day 90. The primary endpoint was PFS, measured from randomization for each arm. Proliferation signature, Ki67, and postinduction minimal residual disease (MRD) in bone marrow were assessed. Of 151 patients enrolled; 118 (80%) underwent ASCT, and 102 (68%) were randomized. Both arms met the primary endpoint, with median PFS significantly greater than 4 years (P < .001). The 8-year PFS estimates in the BC and BM arms were 54.1% (95% CI 40.9%-71.5%) and 64.4% (95% 51.8%-79.0%), respectively. Progression-free survival was significantly longer for transplanted patients on 50403 compared with those on 59909. Both the PFS and OS were significantly better for those who were MRD-negative post-induction. The high risk proliferation signature was associated with adverse outcome. Both BM and BC were efficacious and tolerable, although toxicity was significant. The comparison between studies 50403 and 59909 with long-term follow up suggests a PFS benefit from the addition of BC or BM post- transplant.

There is a paucity of data regarding outcomes and response to standard therapy in patients with limited-stage (LS) agressive B-cell lymphoma (LS-ABCL) who harbor MYC rearrangement (MYC-R) with or without BCL2 and/or BCL6 rearrangements. We conducted a multicenter retrospective study of MYC-R LS-ABCL patients who received either rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP), or more intensive immunochemotherapy (IIC) plus or minus consolidative involved-field radiation therapy (IFRT). One hundred four patients from 15 academic centers were included. Forty four patients (42%) received R-CHOP, of whom 52% had IFRT. Sixty patients (58%) received IIC, of whom 40% had IFRT. Overall response rate was 91% (84% complete response [CR]; 7% partial response). Patients with double-hit lymphoma (DHL; n = 40) had a lower CR rate compared with patients with MYC-R only (75% vs 98%; P = .003). CR rate was higher in the IFRT vs no-IFRT group (98% vs 72%; P < .001). Median follow-up was 3.2 years; 2-year progression-free survival (PFS) and overal survival (OS) were 78% and 86% for the entire cohort, and 74% and 81% for the DHL patients, respectively. PFS and OS were similar across treatment groups (IFRT vs no IFRT, R-CHOP vs IIC) in the entire cohort and in DHL patients. Our data provide a historical benchmark for MYC-R LS-ABCL and LS-DHL patients and show that outcomes for this population may be better than previously recognized. There was no benefit of using IIC over R-CHOP in patients with MYC-R LS-ABCL and LS-DHL.

The NCCN Clinical Practice Guidelines in Oncology for Hodgkin Lymphoma (HL) provide recommendations for the management of adult patients with HL. The NCCN Guidelines Panel meets at least annually to review comments from reviewers within the NCCN Member Institutions, examine relevant data, and reevaluate and update the recommendations. These NCCN Guidelines Insights summarize recent updates centered on treatment considerations for relapsed/refractory classic HL.

Background To explore the role of augmenting neutrophil function in B-cell lymphoma, we conducted a phase II study evaluating the safety and clinical efficacy of pegfilgrastim and rituximab in low-grade CD20+ B-cell non-Hodgkin lymphoma (B-NHL). Patients and Methods Twenty patients with indolent B-NHL were treated with rituximab (375 mg/m2) every other week for 4 doses, followed by every 2 months for 4 additional doses. Pegfilgrastim was administered subcutaneously 3 days before each dose of rituximab. Clinical activity and tolerability were assessed using standard criteria. Biologic monitoring included phenotype characteristics of the host neutrophils, changes in oxidative burst, and functional assays. Results The patient demographics included median age of 64 years, 70% were male, 70% had follicular lymphoma, and 90% had stage III-IV disease. The median number of previous therapies was 2 (range, 0-5); 90% had received previous anti-CD20 monoclonal antibody therapy. The addition of pegfilgrastim to rituximab did not increase rituximab-related toxicities. The overall response rate was 60% (12 of 20), with a complete response (CR) rate of 35% (7 of 20). The median progression-free survival (PFS) duration was 17.9 months (95% confidence interval, 9.9-27.6 months); the median overall survival was not reached. A shorter time-to-peak oxidative burst after the first dose of pegfilgrastim was associated with greater CR rates (P = .04) and longer PFS (P = .03). Conclusion The pegfilgrastim-rituximab combination was well tolerated, with favorable outcomes compared with historical controls. A shorter time-to-peak oxidative burst was associated with higher CR rates and longer PFS. Our results support further evaluation of strategies that enhance the innate immune system to improve rituximab activity in B-NHL.

Background: Early reports suggested that cancer patients have a 1.7-fold increased risk of contracting SARS-CoV-2 and higher rates of severe events and mortality compared with general population. Patients with hematologic malignancies may have worse COVID-19 outcomes, due to an impaired humoral immune response from their underlying malignancy and concurrent anticancer therapy. In this multi-center, retrospective, observational study, we evaluate the associations of COVID-19 outcomes with patient and lymphoma disease characteristics. Methods: EMRs at 10 study centers across the USA identified 519 patients with a diagnosis of lymphoma, CLL, or other lymphoid malignancies, who had a documented positive result of SARS-CoV-2 PCR or nucleocapsid antibody testing. Descriptive statistics were used to summarize the demographic and clinical characteristics. Logistic regression was used to evaluate the associations of individual characteristics with COVID-19 outcomes, adjusted for center (NYU vs. other). The interactions between each of the variables was also included in these models; since the interactions were generally small and non-significant, only the main effect of center was included. Two-sided p-values ≤0.05 were considered significant; there were no adjustments for multiple variables or endpoints. Each analysis was based on complete data for that analysis. Results: Tables 1 and 2 provide demographic and clinical characteristics, respectively, of the 519 patients. The mean age was 61.9 years, with 296 (57%) male and 374 (72%) white patients. NYU had the largest cohort (318 patients), with the remaining centers contributing a range of 3 to 69 patients (median 14). Logistic regression models for the association of each COVID-19 outcome with individual clinical and patient characteristics included adjustments for the center (NYU/other). While center effects were statistically significant, center by covariate interaction effects were not and are not included in the final models. The odds ratio (OR) estimates and p-values for each patient and CLL/lymphoma clinical variable are shown in Tables 3 and 4, respectively. The risks of experiencing a severe event, death, and hospital admission increased with age; for each 10 years of age increase, the ORs were 1.58 for experiencing severe events, 1.78 for death, and 1.65 for hospital admission. The risks of poor outcome were higher in males than in females (OR 1.93 for severe events, 1.85 for death, and 1.47 for hospital admission). Patients with Charlson Comorbidity Index (CCI) >5 had a higher risk of severe events (OR 2.46), mortality (3.30) and hospital admission (2.73) compared to patients with CCI ≤5. Compared to patients with HL, patients with aggressive NHL had a higher risk of severe events (OR 4.05), mortality (4.68) and hospital admission (4.65). Patients with CLL similarly had a higher risk of severe events (OR 4.64), mortality (4.65) and hospital admission (5.93) compared to HL patients. Patients with indolent NHL had a higher risk of hospital admission (OR 3.95) but not a higher risk of mortality compared to HL. Patients in remission at the time of COVID-19 diagnosis had a lower risk of severe events (OR 0.42), mortality (0.36) and hospital admission (0.40) relative to those who were not in remission. Patients who received cytotoxic chemotherapy within 28 days of their COVID-19 diagnosis had a higher risk of severe events (OR 2.54), mortality (2.79), and hospital admission (2.31). Patients who received an anti-CD20 monoclonal antibody within 6 months of COVID-19 diagnosis had a higher risk of severe events (OR 2.60), mortality (2.17) and hospital admission (3.28). Conclusions: In addition to demographic and comorbidity risk factors identified in previous studies, our study shows that patients with aggressive NHL and CLL, or patients who have received recent cytotoxic chemotherapy or anti-CD20 mAB, may be at risk for poor COVID-19 outcome. The difference in risk between NHL and HL patients is likely associated with young age of HL patients but may also be related to differences in underlying innate and adaptive immune defects. Patients at high risk for poor outcome should be a priority for studies of monoclonal antibody prophylaxis. If defects in humoral immunity are at the root of poor outcome, this may be compounded by poor response to vaccination. Multivariate analysis of this data will be completed in advance of the meeting. Figure 1 Figure 1. Disclosures Olszewski: Celldex Therapeutics: Research Funding; PrecisionBio: Research Funding; TG Therapeutics: Research Funding; Acrotech Pharma: Research Funding; Genentech, Inc.: Research Funding; Genmab: Research Funding. Barta: Daiichi Sankyo: Honoraria; Seagen: Honoraria; Acrotech: Honoraria; Kyowa Kirin: Honoraria. Hernandez-Ilizaliturri: AbbVie: Other: Advisory Boards; Incyte: Other: Advisory Boards; Celgene: Other: Advisory Boards; BMS: Other: Advisory Boards; Pharmacyclics: Other: Advisory Boards; Amgen: Other: Advisory Boards; Kite: Other: Advisory Boards; Gilead: Other: Advisory Boards; Epyzime: Other: Advisory Boards. Leslie: Janssen: Consultancy, Speakers Bureau; Merck: Consultancy; Abbvie: Consultancy, Honoraria; Epizyme: Consultancy, Honoraria, Speakers Bureau; PCYC/Janssen: Consultancy, Honoraria, Speakers Bureau; Seagen: Consultancy, Honoraria, Speakers Bureau; TG Therapeutics: Consultancy, Honoraria, Speakers Bureau; Celgene/BMS: Consultancy, Honoraria, Speakers Bureau; Kite, a Gilead Company: Consultancy, Honoraria, Speakers Bureau; ADC Therapeutics: Consultancy; BeiGene: Consultancy, Honoraria, Speakers Bureau; Karyopharm Therapeutics: Honoraria, Speakers Bureau; AstraZeneca: Consultancy, Honoraria, Speakers Bureau; Pharmacyclics: Consultancy, Honoraria, Speakers Bureau. Diefenbach: Bristol-Myers Squibb: Consultancy, Honoraria, Research Funding; Merck Sharp & Dohme: Consultancy, Honoraria, Research Funding; Morphosys: Consultancy, Honoraria, Research Funding; Genentech, Inc./ F. Hoffmann-La Roche Ltd: Consultancy, Honoraria, Research Funding; Perlmutter Cancer Center at NYU Langone Health: Current Employment; Incyte: Research Funding; AbbVie: Research Funding; Trillium: Research Funding; IGM Biosciences: Research Funding; IMab: Research Funding; Janssen: Consultancy, Honoraria, Research Funding; Gilead: Current equity holder in publicly-traded company; MEI: Consultancy, Research Funding; Celgene: Research Funding; Seattle Genetics: Consultancy, Honoraria, Research Funding.

In order to identify cellular pathways associated with therapy-resistant aggressive lymphoma, we generated rituximab-resistant cell lines (RRCL) and found that the acquirement of rituximab resistance was associated with a deregulation in glucose metabolism and an increase in the apoptotic threshold leading to chemotherapy resistance. Hexokinase II (HKII), the predominant isoform overexpressed in cancer cells, has dual functions of promoting glycolysis as well as inhibiting mitochondrial-mediated apoptosis. We found that RRCL demonstrated higher HKII levels. Targeting HKII resulted in decreased mitochondrial membrane potential, ATP production, cell viability; and re-sensitization to chemotherapy agents. Analyzed gene expression profiling data from diffuse large B-cell lymphoma patients, high-HKII levels were associated with a shorter progression free survival (PFS) and/or overall survival (OS). Our data suggest that over-expression of HKII is associated with resistance to rituximab and chemotherapy agents in aggressive lymphoma and identifies this enzyme isoform as a potential therapeutic target.

Gray zone lymphoma (GZL) is described as sharing features with classical Hodgkin lymphoma (cHL) and diffuse large B-cell lymphoma (DLBCL). However, there remains complexity in establishing diagnosis, delineating prognosis, and determining optimum therapy. Sixty-eight cases diagnosed as GZL across 15 North American academic centers were evaluated by central pathology review to achieve consensus. Of these, only 26 (38%) were confirmed as GZL. Morphology was critical to GZL consensus diagnosis (eg, tumor cell richness); immunohistochemistry showed universal B-cell derivation, frequent CD30 expression, and rare Epstein-Barr virus (EBV) positivity (CD20+, 83%; PAX5+, 100%; BCL6+, 20%; MUM1+, 100%; CD30+, 92%; EBV+, 4%). Forty-two cases were reclassified: nodular sclerosis (NS) cHL, n = 27 (including n = 10 NS grade 2); lymphocyte predominant HL, n = 4; DLBCL, n = 4; EBV+ DLBCL, n = 3; primary mediastinal large BCL n = 2; lymphocyte-rich cHL and BCL-not otherwise specified, n = 1 each. GZL consensus-confirmed vs reclassified cases, respectively, more often had mediastinal disease (69% vs 41%; P = .038) and less likely more than 1 extranodal site (0% vs 25%; P = .019). With a 44-month median follow-up, 3-year progression-free survival (PFS) and overall survival for patients with confirmed GZL were 39% and 95%, respectively, vs 58% and 85%, respectively, for reclassified cases (P = .19 and P = .15, respectively). Interestingly, NS grade 2 reclassified patients had similar PFS as GZL consensus-confirmed cases. For prognostication of GZL cases, hypoalbuminemia was a negative factor (3-year PFS, 12% vs 64%; P = .01), whereas frontline cyclophosphamide, doxorubicin, vincristine, and prednisone ± rituximab (CHOP±R) was associated with improved 3-year PFS (70% vs 20%; P = .03); both factors remained significant on multivariate analysis. Altogether, accurate diagnosis of GZL remains challenging, and improved therapeutic strategies are needed.

Background. Despite advances in therapy, treatment of R/R NHL remains a challenge. PEVO (TAK924) is a first-in-class, selective, small molecule, NAE inhibitor with preclinical activity in NHL, including mantle cell lymphoma (MCL), chronic lymphocytic leukemia (CLL) and diffuse large B cell lymphoma (DLBCL). We and others have demonstrated synergy between PEVO and the Bruton tyrosine kinase inhibitor ibrutinib, in in vitro and in vivo models of CLL and MCL. We report the results of a phase 1 study of PEVO in combination with ibrutinib in patients with R/R NHL. Methods. This was a multicenter, open-label, Phase I, investigator-sponsored study (NCT03479268). Patients with NHL or CLL ≥18 years of age whose disease had relapsed or was refractory to ≥1 prior lines of therapy were enrolled. The Phase I portion of the study followed mTPI design with five planned dose levels of PEVO (15, 20, 25, 37.5 and 50 mg/m 2). PEVO was given IV on days 1, 3 and 5 of a 21-day cycle for a total of 8 cycles. Ibrutinib was administered once a day starting on Cycle 1 day 2 at a fixed dose of 420 mg (560 mg in MCL) orally for a total of 18 cycles. Primary study objectives were safety and tolerability; secondary objectives included preliminary measures of efficacy. Response was assessed by Lugano (NHL) and IWCLL criteria. Exploratory objectives included pharmacokinetic (PK) and pharmacodynamic endpoints. Dose limiting toxicities (DLT) were defined as grade 4 hematologic or grade 3 non-hematologic toxicities. Results. Of the eighteen patients enrolled, 8 had MCL, 4 had DLBCL, 4 had CLL and one patient each had marginal zone and follicular lymphoma; 72% (13/18) were men. Median age was 71 (51-90) years, 94% had an ECOG performance status ≤1. Patients had received a median of 1 prior line of therapy (range, 1-3), 3 patients had undergone prior autologous stem cell transplant. Three patients each were treated on dose level cohorts 1-4. One DLT, mediastinal hemorrhage, was observed at dose level 5. Therefore, the recommended phase 2 dose (RP2D) of PEVO was 50 mg/m 2. The most common treatment-related adverse events (AEs, any grade) were bruising and diarrhea (44% each; Table 1). There was one case each (5.6%) of the following grade 3-4 AEs: arthralgia, bone pain, diarrhea and mediastinal hemorrhage. Three patients (16.6%) developed grade 1-2 atrial fibrillation on study but all continued therapy. Treatment discontinuation due to AE occurred in one patient (5.6%, mediastinal hemorrhage). The overall response rate (ORR) was 66% for all patients. Among eight patients with MCL, ORR was 100% (50% complete response). The median PEVO elimination T 1/2 was 6.7 h (range, 4.9-12.1 h) on day 1 and 6.4 h (3.2-11.0 h) on day 3 (Wilcoxon p=0.12). PEVO exhibited linear PK with dose-dependent increases in C max and AUC (0-inf) (Figure 1), which were unaffected by concurrent ibrutinib (Wilcoxon p=0.09 and 0.94, respectively). Discussion. The combination of pevonedistat and ibrutinib is safe and well-tolerated in patients with R/R NHL. It is associated with high response rates in patients with R/R MCL. The study is currently enrolling patients in the expansion cohort to further characterize the efficacy of this promising regimen. Figure 1 Figure 1. Disclosures Torka: TG Therapeutics: Membership on an entity's Board of Directors or advisory committees. Herrera: Bristol Myers Squibb: Consultancy, Research Funding; Genentech: Consultancy, Research Funding; Karyopharm: Consultancy; Takeda: Consultancy; ADC Therapeutics: Consultancy, Research Funding; Tubulis: Consultancy; Seagen: Consultancy, Research Funding; Kite, a Gilead Company: Research Funding; Merck: Consultancy, Research Funding; AstraZeneca: Consultancy, Research Funding; Gilead Sciences: Research Funding. Hernandez-Ilizaliturri: AbbVie: Other: Advisory Boards; Incyte: Other: Advisory Boards; Celgene: Other: Advisory Boards; BMS: Other: Advisory Boards; Pharmacyclics: Other: Advisory Boards; Amgen: Other: Advisory Boards; Kite: Other: Advisory Boards; Gilead: Other: Advisory Boards; Epyzime: Other: Advisory Boards. Danilov: SecuraBio: Research Funding; Genentech: Consultancy, Honoraria, Research Funding; Bayer Oncology: Consultancy, Honoraria, Research Funding; Takeda Oncology: Research Funding; Rigel Pharm: Honoraria; TG Therapeutics: Consultancy, Research Funding; Gilead Sciences: Research Funding; Bristol-Meyers-Squibb: Honoraria, Research Funding; Abbvie: Consultancy, Honoraria; Beigene: Consultancy, Honoraria; Pharmacyclics: Consultancy, Honoraria; Astra Zeneca: Consultancy, Honoraria, Research Funding. OffLabel Disclosure: pevonedistat - clinical trial

INTRODUCTION Diffuse large B-cell lymphoma (DLBCL) represents several distinct clinical pathologic entities recently identified by molecular profiling. Treatment with anti-CD19 chimeric antigen receptor (CAR) T-cell therapies is now standard for many patients with relapsed/refractory (R/R) disease. Although antigen loss of CD19 represents a known cause of late relapses, the majority of CAR-T cell treatment failure occurs very soon after treatment at which time the impact of molecular subtype and other somatic mutations of DLBCL is undefined. We sought to determine impact of molecular features of DLBCL tumors on clinical outcomes in a cohort of patients with R/R disease who were treated with axicabtagene ciloleucel (axi-cel) or tisagenlecleucel (tisa-cel) in order to provide insight into the mechanism of response or resistance to CAR-T cell therapy. METHODS We collected clinical data and formalin-fixed, paraffin embedded (FFPE) biopsy specimens from 121 DLBCL patients at the time of R/R disease after prior treatment with standard chemoimmunotherapy across 12 US academic medical centers who subsequently received commercial CAR-T cell treatment. Whole exome and transcriptome sequencing was performed on all cases to measure gene expression and gene copy number alterations. Genetic analysis was done on 96 patients with pre-treatment biopsies that passed sequencing quality filters, and expression analysis on 93 patients. Progression-free and overall survival (PFS, OS) measured from the day of CAR-T cell infusion were estimated using the Kaplan-Meier method and compared with the log-rank test. RESULTS Baseline demographics and treatment details of the patient population are shown in the Table (Panel A). Best overall response was CR in 43% of patients and PR in 10% patients. PFS and OS were significantly different based on best response to treatment (P CONCLUSIONS DLBCL patients whose tumors have molecular features that are predictive of inferior response to standard frontline treatment including the high-risk subgroups (C2/A53) and (C5/MCD) have favorable treatment outcomes with CAR-T cell therapy. In contrast, individual driver mutations including MYC and BCL2, CDKN2A, and KLHL6 are associated with inferior PFS with CAR-T cell therapy, while mutations in BTG2, MYD88, and CD79B are associated with a favorable PFS. In addition, gene expression analysis implicates a potential role for the microenvironment in modulating responses to CAR-T therapy. These findings suggest that predictive biomarkers for response to traditional chemoimmunotherapy and cellular immunotherapy are distinct. Our results provide insight into potentially targetable pathways for the development of rational treatment strategies that may augment response CAR-T cell therapy. Figure 1 Figure 1. Disclosures Hill: Celgene (BMS): Consultancy, Honoraria, Research Funding; Pfizer: Consultancy, Honoraria; Gentenech: Consultancy, Honoraria, Research Funding; Kite, a Gilead Company: Consultancy, Honoraria, Other: Travel Support, Research Funding; Beigene: Consultancy, Honoraria, Research Funding; AstraZenica: Consultancy, Honoraria; Epizyme: Consultancy, Honoraria; Incyte/Morphysis: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Honoraria, Research Funding; Karyopharm: Consultancy, Honoraria, Research Funding; AbbVie: Consultancy, Honoraria, Research Funding. McKinney: Novartis: Research Funding; Nordic Nanovector: Research Funding; Molecular Templates: Consultancy, Research Funding; Kite/Gilead: Honoraria, Speakers Bureau; Incyte: Research Funding; Genetech: Consultancy, Honoraria, Research Funding; Epizyme: Consultancy; Celgene: Consultancy, Research Funding; BTG: Consultancy; Beigene: Research Funding; ADC Therapeutics: Consultancy, Speakers Bureau; Pharmacyclics: Consultancy; Verastem: Consultancy. Neff: Spring Discovery: Consultancy, Ended employment in the past 24 months; EUSA Pharma: Speakers Bureau; Enzyvant: Consultancy. Reshef: BMS, Regeneron, TScan, Synthekine, Atara, Jasper, Bayer: Consultancy; ilead, BMS, Precision, Immatics, Atara, Takeda, Shire, Pharmacyclics, Incyte: Research Funding; Bayer: Consultancy; Gilead and Novartis: Honoraria. Oluwole: Janssen: Consultancy; Pfizer: Consultancy; Curio Science: Consultancy; Kite, a Gilead Company: Consultancy, Research Funding. Ghosh: Incyte: Consultancy, Honoraria; Pharmacyclics LLC, an AbbVie Company: Consultancy, Honoraria, Research Funding, Speakers Bureau; Janssen: Consultancy, Honoraria, Speakers Bureau; Seattle Genetics: Consultancy, Honoraria, Speakers Bureau; TG Therapeutics: Consultancy, Honoraria, Research Funding; Gilead: Consultancy, Honoraria, Research Funding, Speakers Bureau; Genmab: Consultancy, Honoraria; Epizyme: Honoraria, Speakers Bureau; Bristol Myers Squibb: Consultancy, Honoraria, Research Funding, Speakers Bureau; AstraZeneca: Consultancy, Honoraria, Speakers Bureau; ADC Therapeutics: Consultancy, Honoraria; Adaptive Biotech: Consultancy, Honoraria; AbbVie: Honoraria, Speakers Bureau; Karyopharma: Consultancy, Honoraria; Genentech: Research Funding. Chen: Actinium Pharmaceuticals: Other: Principal Investigator, SIERRA Trial, Actinium. Hernandez-Ilizaliturri: AbbVie: Other: Advisory Boards; Incyte: Other: Advisory Boards; Celgene: Other: Advisory Boards; BMS: Other: Advisory Boards; Pharmacyclics: Other: Advisory Boards; Amgen: Other: Advisory Boards; Kite: Other: Advisory Boards; Gilead: Other: Advisory Boards; Epyzime: Other: Advisory Boards. Shah: Lily: Consultancy, Honoraria, Research Funding; Miltenyi Biotec: Consultancy, Honoraria, Research Funding; Kite: Consultancy; Epizyme: Consultancy; Legend: Consultancy; Incyte: Consultancy; Umoja: Consultancy. Stephens: Epizyme: Membership on an entity's Board of Directors or advisory committees; Karyopharm: Membership on an entity's Board of Directors or advisory committees, Research Funding; Innate Pharma: Membership on an entity's Board of Directors or advisory committees; Beigene: Membership on an entity's Board of Directors or advisory committees; TG Therapeutics: Membership on an entity's Board of Directors or advisory committees; Adaptive: Membership on an entity's Board of Directors or advisory committees; JUNO: Research Funding; Novartis: Research Funding; Abbvie: Consultancy; AstraZeneca: Consultancy; CSL Behring: Consultancy; Celgene: Consultancy; Mingsight: Research Funding; Arqule: Research Funding. Patel: Janssen: Consultancy; Kite Pharma: Consultancy, Speakers Bureau; TG Therapeutics: Consultancy, Speakers Bureau; MEI Pharma: Consultancy; Abbvie: Consultancy; Genentech: Consultancy; Bristol Myers Squibb: Consultancy, Speakers Bureau; BeiGene: Consultancy; Morphosys: Consultancy; Pharmacyclics: Consultancy; AstraZeneca: Consultancy, Research Funding, Speakers Bureau; ADC Therapeutics: Consultancy; Lilly: Consultancy. Pagel: Gilead: Consultancy; Actinium Pharmaceuticals: Consultancy; Kite, a Gilead Company: Consultancy; Incyte/MorphoSys: Consultancy; AstraZeneca: Consultancy; Pharmacyclics/AbbVie: Consultancy; Epizyme: Consultancy; BeiGene: Consultancy; MEI Pharma: Consultancy. Hsi: AbbVie Inc, Eli Lilly: Research Funding. Goy: Genentech/Hoffman la Roche: Research Funding; AbbVie/Pharmacyclics: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Acerta: Consultancy, Research Funding; AstraZeneca: Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Kite, a Gilead Company: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Gilead: Membership on an entity's Board of Directors or advisory committees; Medscape: Consultancy; AstraZeneca: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Physicians' Education Resource: Consultancy, Other: Meeting/travel support; Xcenda: Consultancy, Honoraria; Genomic Testing Cooperative: Current holder of stock options in a privately-held company, Membership on an entity's Board of Directors or advisory committees, Other: Leadership role; LLC(Targeted Oncology): Consultancy; Hoffman la Roche: Consultancy; Vincerx: Honoraria, Membership on an entity's Board of Directors or advisory committees; Rosewell Park: Consultancy; Infinity/Verastem: Research Funding; MorphoSys: Honoraria, Other; Elsevier PracticeUpdate: Oncology: Consultancy, Honoraria; Xcenda: Consultancy; Bristol Meyers Squibb: Membership on an entity's Board of Directors or advisory committees; Vincerx pharma: Membership on an entity's Board of Directors or advisory committees; OncLive Peer Exchange: Honoraria; COTA (Cancer Outcome Tracking Analysis): Current holder of stock options in a privately-held company, Membership on an entity's Board of Directors or advisory committees, Other: Leadership role; Kite Pharma: Membership on an entity's Board of Directors or advisory committees; Elsevier's Practice Update Oncology, Intellisphere, LLC(Targeted Oncology): Consultancy; Incyte: Honoraria; AbbVie/Pharmacyclics: Membership on an entity's Board of Directors or advisory committees; Michael J Hennessey Associates INC: Consultancy; Novartis: Consultancy, Honoraria; Janssen: Membership on an entity's Board of Directors or advisory committees; Janssen: Research Funding; Karyopharm: Research Funding; Bristol Meyers Squibb: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Phamacyclics: Research Funding; Constellation: Research Funding; Hackensack Meridian Health, Regional Cancer Care Associates/OMI: Current Employment. Ohgami: Stemline Therapeutics: Research Funding. Andreadis: CRISPR Therapeutics: Research Funding; GenMAB: Research Funding; Novartis: Research Funding; Roche: Current equity holder in publicly-traded company, Ended employment in the past 24 months; Epizyme: Honoraria; Incyte: Honoraria; TG Therapeutics: Honoraria; Kite: Honoraria; Karyopharm: Honoraria; Atara: Consultancy, Honoraria; BMS: Research Funding; Merck: Research Funding. Thacker: Data Driven Bioscience: Current Employment. Rozzi: Data Driven Bioscience: Current Employment. Parker: Data Driven Bioscience: Current Employment. Happ: Data Driven Bioscience: Current Employment. Dave: Data Driven Bioscience: Current equity holder in publicly-traded company.