Nowakowski, Grzegorz S.

PURPOSE: Patients' concerns regarding clinical trial (CT) participation include apprehension about side effects, quality of life (QoL), financial burden, and quality of care. METHODS: We prospectively evaluated the experience of patients with multiple myeloma or lymphoma who were treated on CTs (CT group, n = 35) versus patients treated with standard approaches (non-CT group, n = 88) focusing on QoL, financial burden of care, and patients' perception of quality of care over a 1-year period. RESULTS: There were no significant differences in any of the patient-reported outcomes in CT versus non-CT groups. We observed an initial decline in overall QoL in the first 3 months across both groups, driven primarily by physical and functional well-being. QoL gradually improved and was above baseline by month 12. Patients reported highest improvement in the functional well-being subdomain. Patients in both groups reported high satisfaction with the quality of care received, and there were no differences in overall satisfaction, communication with team, or access to care. At baseline, 16%-19% of patients reported financial burden, which increased to a peak of 33% in the CT group and to 49% in the non-CT group over the course of 1 year. There was no significant difference in financial burden in the two groups overall. Most of the patients reported getting all the care that was deemed medically necessary in both groups. However, a significant proportion of patients reported having to make other kinds of financial sacrifices because of their cancer (CT group: 33% of patients at baseline and 21%-40% over 1 year; non-CT group: 19% at baseline and 25%-36% over 1 year). CONCLUSION: Patients treated on CTs reported comparable QoL and quality of care with the non-CT group. A high proportion of patients reported financial burden over time in both groups. Our findings can serve as a guide to educate patients regarding CT participation and highlight the need to address the significant financial burden experienced by patients with cancer.

Abstract A recent systematic review reported that trials involving patients with marginal zone lymphoma (MZL) show marked heterogeneity both in the choice and definitions of primary and secondary endpoints, thus hampering comparability between trials. The main objective of this study was to reach consensus, through a Delphi process, on the definitions of four time‐to‐event endpoints in MZL trials, by surveying clinicians and methodologists involved in the conduct of clinical trials including patients with MZL. We polled a panel of leading international experts involved in MZL trials by means of self‐administered sequential questionnaires in 2021. Of these 105 experts, 62 responded to the Round 1 questionnaire regarding the definitions of progression‐free survival (PFS), event‐free survival (EFS), time‐to‐failure (TTF), and time‐to‐next‐treatment (TTNT). Afterward, we therefore focused the Round 2 and 3 questionnaires among principal investigators, coinvestigators, and trial methodologists. Consensus was reached when there was a >80% agreement on all potential events (11 choices) of each endpoint. Participants in our survey reached consensus on three of the four time‐to‐event endpoints definitions. Consensus was reached on the definitions of PFS and TTNT after Round 1, of TTF after Round 2, and was not reached for EFS after Round 3. The disagreement concerned the event “treatment discontinuation” in EFS definition. The main interest of our study was to elicit investigator's interest in the importance of consistently defining endpoints in MZL trials and to highlight that composite endpoints should not be encouraged. Fifteen years after the last consensus statement on time‐to‐event endpoints definitions issued in Lugano (2007), both the review of literature and survey of international investigators agree on the inconsistency of endpoints definitions used within the MZL community. Hopefully, revised standardized definitions of endpoints shall be provided at the upcoming International Conference on Malignant Lymphoma in 2023.

Abstract Purpose: To report on the first-in-human phase I study of VIP152 (NCT02635672), a potent and highly selective cyclin-dependent kinase 9 (CDK9) inhibitor. Patients and Methods: Adults with solid tumors or aggressive non–Hodgkin lymphoma who were refractory to or had exhausted all available therapies received VIP152 monotherapy as a 30-minute intravenous, once-weekly infusion, as escalating doses (5, 10, 15, 22.5, or 30 mg in 21-day cycles) until the MTD was determined. Results: Thirty-seven patients received ≥ 1 VIP152 dose, with 30 mg identified as the MTD based on dose-limiting toxicity of grade 3/4 neutropenia. The most common adverse events were nausea and vomiting (75.7% and 56.8%, respectively), all of grade 1/2 severity. Of the most common events, grade 3/4 events occurring in > 1 patient were neutropenia (22%), anemia (11%), abdominal pain (8%), increased alkaline phosphatase (8%), and hyponatremia (8%). Day 1 exposure for the MTD exceeded the predicted minimum therapeutic exposure and reproducibly achieved maximal pathway modulation; no accumulation occurred after multiple doses. Seven of 30 patients with solid tumors had stable disease (including 9.5 and 16.8 months in individual patients with pancreatic cancer and salivary gland cancer, respectively), and 2 of 7 patients with high-grade B-cell lymphoma with MYC and BCL2/BCL6 translocations (HGL) achieved durable complete metabolic remission (ongoing at study discontinuation, after 3.7 and 2.3 years of treatment). Conclusions: VIP152 monotherapy, administered intravenously once weekly, demonstrated a favorable safety profile and evidence of clinical benefit in patients with advanced HGL and solid tumors.

Abstract Background: Event-free survival at 24 months (EFS24) is an important clinical endpoint in newly diagnosed diffuse large B-cell lymphoma and follicular lymphoma, and patients who achieve EFS24 with frontline immunochemotherapy have minimal loss of lifetime compared to age- and sex-matched general population. However, the prognostic role of EFS24 in mantle cell lymphoma (MCL) has not been well studied, possibly due to the perception of continued relapse pattern and poor survival outcome of MCL historically. A recent study from our group demonstrated evolving frontline therapy pattern from 2002-2009 ("Era 1") to 2010-2015 ("Era 2") which was associated with improved EFS and overall survival (OS) in Era 2. In the current study, we sought to explore the prognostic role of EFS24 in the two eras. Methods: Patients with newly diagnosed MCL from 9/2002 through 6/2015 were identified from Molecular Epidemiology Resource (MER), a prospective cohort study of the University of Iowa/Mayo Clinic Lymphoma SPORE. OS was defined as time from diagnosis (or the EFS24 defining event where applicable) to death from any cause and was analyzed using the Kaplan-Meier method. Expected OS accounting for age and sex was generated in R by using the general US population as the reference group. Observed versus expected OS was summarized by using standardized mortality ratio (SMR) and 95% confidence intervals (CI) of observed to expected deaths. Cumulative incidence of lymphoma-specific death was analyzed using Gray's test, with deaths from all other causes treated as competing events. Results: A total of 343 patients were included, 175 from Era 1 (median follow-up 13.0 years) and 168 from Era 2 (median follow-up 6.9 years). Age, sex and simplified MIPI score were similar between the 2 groups. Patients diagnosed in Era 2 had better OS, with a 5-year OS of 68.4% vs 59.2% (simplified MIPI-adjusted hazard ratio 0.68, 95% CI 0.50-0.93). Patients diagnosed in both eras had inferior OS compared to the general population, with an SMR of 3.26 (95% CI 2.70-3.89, P<0.001) in Era 1 and 2.63 (95% CI 2.03-3.36, P<0.001) in Era 2. Patients diagnosed in Era 1 who achieved EFS24 (n=98) still had inferior OS compared to the general population, with an SMR of 2.23 (95% CI 1.67-2.92, P<0.001) (Figure 1A). In contrast, for patients diagnosed in Era 2 who achieved EFS24 (n=99), no evidence of OS difference was found compared to the general population, with an SMR of 1.31 (95% CI 0.78-2.07, P=0.31) (Figure 1B). The primary cause of death after diagnosis was lymphoma-related for patients diagnosed in both eras. The 5-year rate of lymphoma-related death was 28.8% in Era 1 and 20.5% in Era 2. In patients who were diagnosed in Era 1 and achieved EFS24, the primary cause of death after achieving EFS24 remained to be lymphoma-related, with a 5-year rate of 19.8% compared to 6.2% for lymphoma-unrelated causes (Figure 1C). In contrast, in patients who were diagnosed in Era 2 and achieved EFS24, the rate of lymphoma-related death was no longer higher than that of lymphoma-unrelated death, with a 5-year rate of 2.1% vs 5.5%, respectively (Figure 1D). In a sensitivity analysis restricted to only patients who received standard frontline immunochemotherapy, similar results were obtained. For example, in patients who achieved EFS24, the SMR compared to the general population was 2.89 (95% CI 2.00-4.04, P<0.001) in Era 1 and 0.89 (95% CI 0.43-1.64, P=0.82) in Era 2. The 5-year rates of deaths due to lymphoma-related vs lymphoma-unrelated causes were 20.7% vs 6.2% in Era 1 and 1.3% vs 4.9% in Era 2. Conclusions: MCL survival outcome has improved for patients first diagnosed in the more recent era (2010-2015, compared to 2002-2009), likely due to improved frontline therapy as well as better salvage treatments (such as lenalidomide and BTK inhibitors). In the more recent treatment era, patients who achieved EFS24 had survival approaching the age- and sex-matched general population. In addition, these patients had a low risk of dying from lymphoma and were more likely to die from other causes. Longer follow-up (e.g., in Era 2) and external validation in other series are necessary to confirm the prognostic role of EFS24. With more efficacious salvage treatment options and likely continued improvement of OS in MCL, EFS24 may become an important clinical endpoint in frontline therapy of MCL. Figure 1 Figure 1. Disclosures Wang: TG Therapeutics: Membership on an entity's Board of Directors or advisory committees; Eli Lilly: Membership on an entity's Board of Directors or advisory committees; Novartis: Research Funding; InnoCare: Research Funding; LOXO Oncology: Membership on an entity's Board of Directors or advisory committees, Research Funding; Genentech: Research Funding; Incyte: Membership on an entity's Board of Directors or advisory committees, Research Funding; MorphoSys: Research Funding. Maurer: Morphosys: Membership on an entity's Board of Directors or advisory committees, Research Funding; Genentech: Research Funding; Pfizer: Membership on an entity's Board of Directors or advisory committees; Kite Pharma: Membership on an entity's Board of Directors or advisory committees; BMS: Research Funding; Nanostring: Research Funding. Link: Novartis, Jannsen: Research Funding; Genentech/Roche: Consultancy, Research Funding; MEI: Consultancy. Farooq: Kite, a Gilead Company: Honoraria. Paludo: Karyopharm: Research Funding. Witzig: Celgene/BMS, Acerta Pharma, Kura Oncology, Acrotech Biopharma, Karyopharm Therapeutics: Research Funding; Karyopharm Therapeutics, Celgene/BMS, Incyte, Epizyme: Consultancy, Membership on an entity's Board of Directors or advisory committees. Habermann: Seagen: Other: Data Monitoring Committee; Tess Therapeutics: Other: Data Monitoring Committee; Incyte: Other: Scientific Advisory Board; Morphosys: Other: Scientific Advisory Board; Loxo Oncology: Other: Scientific Advisory Board; Eli Lilly & Co.,: Other: Scientific Advisor. Cerhan: Regeneron Genetics Center: Other: Research Collaboration; Celgene/BMS: Other: Connect Lymphoma Scientific Steering Committee, Research Funding; NanoString: Research Funding; Genentech: Research Funding. Nowakowski: Celgene, NanoString Technologies, MorphoSys: Research Funding; Celgene, MorphoSys, Genentech, Selvita, Debiopharm Group, Kite/Gilead: Consultancy, Membership on an entity's Board of Directors or advisory committees.

Abstract Background: While extranodal involvement by mantle cell lymphoma (MCL) is relatively common, involvement of the central nervous system (CNS) is rare (<5% of cases), with limited treatment options. We report the outcomes of 36 patients (pts) with CNS involvement compared to 72 matched control MCL pts without CNS involvement. Methods: MCL pts with CNS involvement seen at Mayo Clinic between 1/1995-9/2020 were identified using the Mayo Data Explorer tool. CNS involvement was defined by tissue biopsy confirmed CNS MCL, CSF analysis demonstrating lymphoma cells, and/or neuroimaging findings compatible with CNS involvement. A 2:1 control group of MCL pts without CNS involvement, matched by age (+/- 2 years) and year of diagnosis (+/- 1 year), was selected among all MCL cases. Medical records were reviewed for baseline characteristics, treatment modalities, and outcomes. Kaplan-Meier method was used for time to event analysis. Wilcoxon test was used to compare continuous variables and Chi square test was used for categorical variables. Results: Out of 1,753 pts with MCL, 36 (2%) had evidence of CNS involvement, including 4 pts with CNS involvement at initial MCL diagnosis. Baseline characteristics of pts with CNS involvement (CNS MCL group) and those without CNS involvement (control group) are shown in Table 1. At MCL diagnosis, non-CNS extranodal involvement was seen in 30 (83%) pts in the CNS MCL group (24 pts with 1 site and 6 pts with ≥ 2 sites), with bone marrow being the most common extranodal site of involvement (n=24, 67%). For the control group, 54 (75%) pts had extranodal involvement (44 pts with 1 site and 10 pts with ≥ 2 sites), and bone marrow was also the most common extranodal site of involvement (n=50, 69%). Notably, advanced stage disease (stage 3-4) was more commonly seen in the CNS MCL group (n=32, 97%) than in the control group (n=59, 83%) (p=0.04) at MCL diagnosis. Blastoid variant was present in a higher proportion of pts in the CNS MCL group (n=11, 31%) compared to the control group (n=8, 11%) (p=0.02). The CNS MCL group also presented with a higher median serum LDH at diagnosis (239 U/L [range 153-1901] vs. 187 U/L [range 124-588], p=0.02), and higher Ki-67 (40% [range 15-100] vs. 30% [range 10-90], p=0.04) compared to the control group. The most common frontline treatment regimen was anthracycline-based therapies (i.e. R-CHOP, Nordic regimen, R-hyperCVAD) for both groups (58% in CNS MCL group and 56% in control group). 14 (39%) pts in the CNS MCL group underwent autologous stem cell transplant in CR1 vs. 31 pts (43%) in the control group. Similar use of rituximab maintenance was seen in both groups (31% in CNS MCL group and 25% in control group). Median total lines of therapy from initial MCL diagnosis was 3 (range 1-9) in CNS MCL group and 2 (range 1-9) in the control group. The median follow-up from MCL diagnosis was 134 months (95% CI:119-163) for the entire cohort. Median OS from MCL diagnosis was 50.3 months (95% CI: 20.9-71.1) for the CNS MCL group compared to 97.1 months (95% CI: 82.6-192.7; p=<0.001) for the control group (Figure 1). Median time from MCL diagnosis to CNS involvement was 25 months (range 0-167). Median OS from CNS involvement was 4.7 months (95% CI: 2.3-6.7). At last follow up, 31 (86%) pts were deceased from the CNS MCL group, compared to 38 (52%) pts in the control group. For the CNS MCL group, the causes of death were CNS lymphoma in 10 (32%) pts, systemic lymphoma in 9 (29%) pts, treatment-related complication in 7 (23%) pts, and other/unknown in 5 (16%) pts. For the control group, the causes of death were systemic lymphoma in 15 (39%) pts, treatment-related in 2 (5%) pts, and other/unknown in 21 (55%) pts. Conclusion: In pts with MCL, CNS involvement is associated with worse outcomes as evident by a shorter median OS from initial MCL diagnosis (50 months vs. 97 months). Involvement of the CNS by lymphoma is an important contributor for the shorter OS as suggested by the median OS of only 5 months from CNS involvement. Advanced stage, blastoid variant, elevated LDH, and elevated Ki67 at MCL diagnosis were features more commonly seen in the CNS MCL cohort. Validation of risk factors at initial MCL diagnosis associated with CNS involvement and exploring the role of CNS prophylaxis are important topics for further investigation. Figure 1 Figure 1. Disclosures Paludo: Karyopharm: Research Funding. Wang: Novartis: Research Funding; TG Therapeutics: Membership on an entity's Board of Directors or advisory committees; MorphoSys: Research Funding; InnoCare: Research Funding; Eli Lilly: Membership on an entity's Board of Directors or advisory committees; LOXO Oncology: Membership on an entity's Board of Directors or advisory committees, Research Funding; Incyte: Membership on an entity's Board of Directors or advisory committees, Research Funding; Genentech: 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. Nowakowski: Celgene, MorphoSys, Genentech, Selvita, Debiopharm Group, Kite/Gilead: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene, NanoString Technologies, MorphoSys: Research Funding. Witzig: Karyopharm Therapeutics, Celgene/BMS, Incyte, Epizyme: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene/BMS, Acerta Pharma, Kura Oncology, Acrotech Biopharma, Karyopharm Therapeutics: Research Funding. Habermann: Seagen: Other: Data Monitoring Committee; Tess Therapeutics: Other: Data Monitoring Committee; Incyte: Other: Scientific Advisory Board; Morphosys: Other: Scientific Advisory Board; Loxo Oncology: Other: Scientific Advisory Board; Eli Lilly & Co.,: Other: Scientific Advisor. Ansell: Bristol Myers Squibb, ADC Therapeutics, Seattle Genetics, Regeneron, Affimed, AI Therapeutics, Pfizer, Trillium and Takeda: Research Funding.

Abstract With the development of various strategies of anti-CD19 immunotherapy for treatment of B cell malignancies, it remains to be elucidated whether CD19 targeting with a monoclonal antibody impairs subsequent CD19 targeted chimeric antigen receptor T cell (CART19) therapy. In this study, we evaluated the potential interference between the CD19 targeting monoclonal antibody tafasitamab and CART19 treatment (using a construct similar to the FDA approved therapy, FMC63-41BBζ, tisagenlecleucel) in preclinical lymphoma and leukemia models. For in vitro assays, the CD19 + cell lines JeKo-1 (mantle cell lymphoma), Nalm6 (acute lymphoblastic leukemia), and OCI-Ly7 (diffuse large B cell lymphoma) were used. When CART19 were co-cultured with CD19 + tumor cells in the presence of increasing concentrations of tafasitamab (10-400 µg/mL) or the isotype control, an impairment of CART19 functions at the highest concentration of tafasitamab was observed. However, when tafasitamab was cocultured with tumor cells overnight and removed from the culture by washing, there was no impairment of CART19 anti-tumor activity or effector functions compared to a pre-culture with isotype control. We then aimed to validate these findings in xenograft mouse models by determining whether prior tafasitamab treatment impairs subsequent CART cell function. First, a two-step JeKo-1 xenograft model was created through inoculation of 1x10 6 luciferase + JeKo-1 cells to immunocompromised NOD-SCID-γ -/- (NSG) mice via tail vein injection. One week later, tumor burden was assessed by bioluminescence imaging (BLI) and mice were randomized to receive either 1) PBS (Group 1) or 2) 10 mg/kg of tafasitamab (Group 2) (Fig. 1A). Treatment was performed until the mice reached the endpoint due to the high tumor load. When reaching the endpoint, mice were euthanized and spleen was harvested. Splenic cells were then injected to naïve NSG mice. Two weeks after the inoculation of splenic cells (PBS or tafasitamab treated), mice were imaged with BLI and randomized according to their tumor burden to receive 2x10 6 of 1) untransduced T cells (UTD) or 2) CART19 (i.v.) (Fig. 1B). Mice, treated with CART19 demonstrated potent anti-tumor effects and showed prolonged survival compared to UTD control mice. Interestingly, CART19-treated mice inoculated with Group 2 splenic cells (pretreated with tafasitamab) showed a significantly better tumor control and overall survival compared with mice engrafted Group 1 splenic cells (PBS pretreatment) (Fig. 1C). This finding led us to further investigate the effects of prior tafasitamab therapy on subsequent CART19 treatment. In this context, we studied the sequential treatment with tafasitamab and CART19 in an additional JeKo-1 xenograft model (Fig. 1D). In brief, NSG mice were inoculated with luciferase + JeKo-1 on day -14. On day -8, mice were imaged and randomized to the PBS (Group I) or tafasitamab (10 mg/kg) group. On day -1 tafasitamab treated mice were imaged again, randomized to the tafasitamab discontinuation (Group II) or continuation (Group III). Treatment with PBS was continued in Group I. All groups were administered with 1x10 6 of CART19 on day 0. Cotreatment of JeKo-1 xenografts with tafasitamab and CART19 led to impaired anti-tumor activity presumably as a result of CD19 binding competition between tafasitamab and CART19 (Group III). Mice treated with tafasitamab followed by CART19 had improved tumor control compared to mice treated with PBS followed by CART19 (Fig. 1E-F). Serial peripheral blood analysis demonstrated that mice from Group I showed the highest CART19 expansion on day 10. Strikingly, Group II exhibited weak CART19 expansion at day 10, but strongest expansion on day 23 (Fig. 1G). We therefore hypothesized that prior treatment with tafasitamab results in modulation of CART19 cell activation. To test this hypothesis, spleens of satellite mice were harvested 24 hours after CART19 administration. Flow cytometric analysis revealed that the mice from Group II showed significantly lower CD69 and HLA-DR expression on CART19 cells compared with Group I, and reduced apoptosis as measured by the Annexin assay (Fig. 1H-I). In summary, concomitant treatment of tafasitamab and CART19 led to impaired anti-tumor activity while, in contrast, sequential treatment of tafasitamab and CART19 did not inhibit CART19 anti-tumor activity but rather promoted anti-tumor effects in xenograft models. Figure 1 Figure 1. Disclosures Sakemura: Humanigen: Patents & Royalties. Augsberger: MorphoSys AG: Current Employment. Schanzer: MorphoSys AG: Current Employment. Patra-Kneuer: MorphoSys AG: Current Employment. Heitmüller: MorphoSys AG: Current Employment. Steidl: MorphoSys AG: Current Employment. Endell: MorphoSys AG: Current Employment. Ding: DTRM: Research Funding; Merck: Membership on an entity's Board of Directors or advisory committees, Research Funding; Octapharma: Membership on an entity's Board of Directors or advisory committees. Parikh: Pharmacyclics, MorphoSys, Janssen, AstraZeneca, TG Therapeutics, Bristol Myers Squibb, Merck, AbbVie, and Ascentage Pharma: Research Funding; Pharmacyclics, AstraZeneca, Genentech, Gilead, GlaxoSmithKline, Verastem Oncology, and AbbVie: Membership on an entity's Board of Directors or advisory committees. Kay: Acerta Pharma: Research Funding; Targeted Oncology: Membership on an entity's Board of Directors or advisory committees; Oncotracker: Membership on an entity's Board of Directors or advisory committees; Juno Therapeutics: Membership on an entity's Board of Directors or advisory committees; Morpho-sys: Membership on an entity's Board of Directors or advisory committees; Pharmacyclics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Dava Oncology: Membership on an entity's Board of Directors or advisory committees; TG Therapeutics: Research Funding; Behring: Membership on an entity's Board of Directors or advisory committees; CytomX Therapeutics: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Rigel: Membership on an entity's Board of Directors or advisory committees; MEI Pharma: Research Funding; AstraZeneca: Membership on an entity's Board of Directors or advisory committees; Abbvie: Membership on an entity's Board of Directors or advisory committees, Research Funding; Bristol Meyer Squib: Membership on an entity's Board of Directors or advisory committees, Research Funding; Tolero Pharmaceuticals: Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees; Agios Pharm: Membership on an entity's Board of Directors or advisory committees; Genentech: Research Funding; Sunesis: Research Funding. Nowakowski: Celgene, NanoString Technologies, MorphoSys: Research Funding; Celgene, MorphoSys, Genentech, Selvita, Debiopharm Group, Kite/Gilead: Consultancy, Membership on an entity's Board of Directors or advisory committees. Cox: Humanigen: Patents & Royalties. Kenderian: Humanigen, Inc.: Consultancy, Honoraria, Research Funding.

Abstract Introduction: DNA mismatch repair (MMR) is a major mechanism cells use to repair erroneous insertion or deletion of bases during DNA replication. MMR deficiency (MMR-d), including rare germline mutations (Lynch syndrome) and somatic inactivation, has been extensively studied in solid tumors, such as colon, endometrial, pancreatic, and ovarian cancers. The prevalence of MMR-d in solid tumors ranges from 1% - 20% of somatic defects, and patients with MMR-d tumors have a longer overall survival. It is also well-known that MMR is an integral part of activation-induced cytidine deaminase (AID)-mediated somatic hypermutation and immunoglobulin class switch processes in normal mature B lymphocytes, while mice deficient in the MMR genes are prone to develop T and B cell lymphomas. It is also known that follicular lymphoma (FL) carries a high degree of somatic hypermutation with some heterogeneity induced by AID. Our understanding of MMR status in human blood cancers, especially in FL remains very limited. One could hypothesize that MMR-d status could permit cells to acquire and sustain high-degree of mutation rates, better sensitivity to DNA damaging chemotherapy while hindering rapid cell proliferation, which could manifest to a better prognosis in patients. Herein, we conducted an exploratory analysis to understand the frequency of MMR-d status and its prognostic significance in FL. Methods: Following approval of the Institution Review Board, we assessed the expression of MMR proteins; MLH1, PMS2 and MSH6 on formalin fixed paraffin embedded (FFPE) lymph node tissue obtained from patients with FL by immunohistochemistry (IHC) using standard methods on Ventana Benchmark XT automated stainers (Ventana Medical Systems, Tucson, AZ). Dako (clone ES05), Cell Marque (clone EPR3947) and Biocare (clone BC/44) antibodies were used to stain MLH1, PMS2 and MSH6, respectively. Fifty cases of FL with existing FFPE blocks were selected randomly. The expression of MLH1, PMS2 and MSH6 proteins in the tumor cells was scored as 0, +1 or +2, (Figure 1A). Cases with absence of the IHC signal (score of 0) in any one of the three proteins were classified as MMR-d. Progression free survival at 12 months (PFS12) or 24 months (PFS24) was defined as being free from disease progression or death at 12 or 24 months, respectively. All time-to-event analyses were done from the time of diagnosis. Results: Fifty patients with FL were included in the study. The median age at diagnosis was 65 years (range 34-85) and 58% were females. At initial diagnosis, 36 (72%) patients had advanced stage (stage 3, n=8, stage 4, n=28) disease. Of the 50 patients, 26 (52%) required treatment; chemotherapy (n=14), radiation treatment alone (n=9), surgery alone (n=3). Out of the 50 patients, 23 (46%) were classified as MMR-d due to lack of expression of one of the three assessed proteins: MLH1 (n=1, 2%), PMS2 (n=11, 22%) and MSH6 (n=19, 38%). The patient who had MLH1 loss had concomitant PMS2 loss. Stage IV disease was observed in 52% of the MMR-d patients and 59% in the MMR proficient (MMR-p) patients, p=0.77. Median age at diagnosis was 62 (range: 34-84) years and 67 (range: 34-85) years in MMR-d and MMR-p patients, respectively, p=0.1. FLIPI score was similar between the MMR-d [low n=10 (43%), intermediate n=9 (39%), high n=4 (18%)] and MMR-p [low n=5 (18%), intermediate n=14 (52%), high n=8 (30%)] patients, p=0.16. Fourteen (61%) of MMR-d patients required initiation of therapy upon diagnosis compared to 12 (44%) of MMR-p patients, p=0.27. The median follow-up for the entire cohort was 17 years [95% confidence interval (CI): 11.7-29.4]. The median overall survival (OS) of MMR-d patients was 10 years (95%CI: 7.8-20.7) compared to 6 years (95%CI: 4.5-NR) in MMR-p patients, p=0.036, Figure 1B. In patients with MMR-d and MMR-p, 83% and 55% achieved PFS12, p=0.04 and 65% and 41% achieved PFS24, p=0.08, respectively. After adjusting for FLIPI score, MMR status remained associated with OS (MMR-d HR: 0.51, 95%CI: 0.2-1.02, p=0.05). Discussion and Conclusion: In this pilot study, MMR-d in the FL tumors was common (46%) and, as predicted, was associated with a favorable OS. Association of MMR-d status with PFS in general and patients with early progression (short PFS12 and PFS24) and relationship of MMR-d with types of therapy need further study in large FL datasets. Figure 1 Figure 1. Disclosures Paludo: Karyopharm: Research Funding. King: Celgene/BMS: Research Funding. Maurer: Celgene: Research Funding; Genentech: Research Funding; Kite Pharma: Membership on an entity's Board of Directors or advisory committees; Morphosys: Membership on an entity's Board of Directors or advisory committees, Research Funding; Nanostring: Research Funding; Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees. Nowakowski: Celgene, NanoString Technologies, MorphoSys: Research Funding; Celgene, MorphoSys, Genentech, Selvita, Debiopharm Group, Kite/Gilead: Consultancy, Membership on an entity's Board of Directors or advisory committees. Witzig: Karyopharm Therapeutics, Celgene/BMS, Incyte, Epizyme: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene/BMS, Acerta Pharma, Kura Oncology, Acrotech Biopharma, Karyopharm Therapeutics: Research Funding.

Abstract Background The majority of patients with relapsed/refractory (R/R) DLBCL who relapse after hematopoietic stem cell transplantation (HSCT) or chimeric antigen receptor T-cell (CAR-T) therapy, or who are not candidates for HSCT or CAR-T, have poor outcomes and need novel therapies (Crump 2017). Brentuximab vedotin (BV) was the first antibody-drug conjugate to be approved in multiple cancer types (Gauzy-Lazo 2020). The combination of a CD30-directed monoclonal antibody, a protease-cleavable linker, and the microtubule-disrupting agent monomethyl auristatin E drives the anticancer activity of BV by inducing cell cycle arrest and apoptosis (Sutherland 2006). Lenalidomide may enhance the activity of BV through immune-mediated mechanisms. In a phase 1 trial (NCT02086604) in which 37 patients with R/R DLBCL were treated with BV + lenalidomide, the objective response rate (ORR) was 56.7% (73.3% in CD30+ patients). The median duration of remission was 13.2 months in patients with a complete response (CR) or partial response (PR) and 11.7 months in patients with a CR, PR, or stable disease (SD) >6 months. The median progression-free survival (PFS) and overall survival (OS) were 10.2 months and 14.3 months, respectively, and results were similar in the CD30+ and CD30 <1% groups (manuscript submitted). The clinical activity and manageable safety profiles of BV, lenalidomide, and rituximab as single agents provide a strong rationale for this combination in multiple relapsed and heavily pretreated patients with R/R DLBCL. Study Design and Methods ECHELON-3 (NCT04404283) is a randomized, double-blind, placebo-controlled, active-comparator, multicenter phase 3 study designed to evaluate the efficacy of BV versus placebo, in combination with lenalidomide and rituximab, in patients with R/R DLBCL. Key eligibility criteria will include patients ≥18 years of age with R/R DLBCL with an eligible subtype, ≥2 prior lines of systemic therapy and ineligible for stem cell transplant or CAR-T therapy, Eastern Cooperative Oncology Group performance status 0 to 2, fluorodeoxyglucose-avid disease by positron emission tomography (PET), and bidimensional measurable disease of at least 1.5 cm by computed tomography (CT). Patients with a history of another malignancy within the past 2 years, any uncontrolled Grade ≥3 infection, Grade ≥2 peripheral neuropathy, or previous exposure to BV or lenalidomide will not be eligible. After completing the safety run-in period, patients (n=400) will be randomized 1:1 to receive either BV (1.2 mg/kg intravenously every 3 weeks [Q3W]) or placebo (intravenously Q3W) in combination with lenalidomide (20 mg orally daily) and rituximab (1400 mg subcutaneously Q3W from Cycle 2, with 375 mg/m 2 intravenously on Cycle 1 Day 1). Treatment may continue while there is clinical benefit (SD or better) without progression or unacceptable toxicity. Patients will be stratified by CD30 expression (≥1% [positive] vs <1% [negative]), prior allogeneic or autologous stem cell transplant therapy (received or not), prior CAR-T therapy (received or not), and cell of origin (germinal center B-cell [GCB] or non-GCB). The dual primary endpoints are PFS per blinded independent central review (BICR) in the intention-to-treat (ITT) and CD30+ populations. Key secondary endpoints are OS in the ITT and CD30+ populations, and ORR per BICR. Other secondary endpoints include CR rate, duration of objective response, and safety and tolerability of the combination. Disease response will be assessed by BICR and the investigator according to the Lugano Classification Revised Staging System for nodal non-Hodgkin and Hodgkin lymphomas (Cheson 2014). Radiographic disease evaluations, including contrast-enhanced CT and PET, will be assessed at baseline, then every 6 weeks from randomization until Week 48, then every 12 weeks thereafter. PET is not required after CR is achieved For the analyses of PFS per BICR, the stratified log-rank test will be used to compare PFS between the 2 treatment groups. Hazard ratios will be estimated using the stratified Cox regression model. PFS will also be summarized using the Kaplan-Meier method. Similar methods will be used to estimate OS and other time-to-event efficacy endpoints. The study is currently enrolling and will be open in 16 countries. Disclosures Bartlett: Merck: Research Funding; Kite, a Gilead Company: Research Funding; Janssen: Research Funding; Genentech: Research Funding; Forty Seven: Research Funding; Celgene: Research Funding; Bristol Myers Squibb: Research Funding; Autolus: Research Funding; Seagen: Consultancy, Research Funding; Roche/Genentech: Consultancy; ADC Therapeutics: Consultancy, Research Funding; Millennium: Research Funding; Pharmacyclics: Research Funding. Yasenchak: Seagen Inc.: Research Funding. Harwin: Sarah Cannon Research Institute: Other: Grants, Research Funding. Sims: Seagen Inc.: Current Employment. Nowakowski: Celgene, MorphoSys, Genentech, Selvita, Debiopharm Group, Kite/Gilead: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene, NanoString Technologies, MorphoSys: Research Funding.

Abstract Introduction Tafasitamab is a humanized, Fc-modified, anti-CD19 monoclonal antibody (mAb) shown to enhance antibody-dependent cellular cytotoxicity and phagocytosis. It is approved by the FDA under accelerated approval (July 2020) in combination with lenalidomide (LEN) for treatment of relapsed/refractory diffuse large B-cell lymphoma (R/R DLBCL) in adult patients ineligible for autologous stem cell transplantation. To evaluate if newly diagnosed DLBCL patients would also benefit from this regimen, this Phase Ib study (First-MIND; NCT04134936) was designed to first assess the safety and tolerability of tafasitamab ± LEN in addition to rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone (R-CHOP) in newly diagnosed DLBCL patients. Methods Eligible patients were ≥18 years old, with treatment-naïve DLBCL, international prognostic index (IPI) 2-5 and Eastern Cooperative Oncology Group performance status (ECOG PS) 0-2. Patients with known double- or triple-hit and transformed lymphoma were excluded. Patients were randomized 1:1 to either six 21-day [D] cycles of R-CHOP (R-CHO, D1; P, D1-5) + tafasitamab (12 mg/kg IV, D1, 8, 15) (Arm A) or R-CHOP + tafasitamab + LEN (25 mg orally, D1-10) (Arm B). Granulocyte colony-stimulating factor and venous thromboembolism prophylaxis was mandatory. The primary safety endpoint was incidence of treatment-emergent adverse events (TEAEs); secondary endpoints included overall response rate (ORR), positron emission tomography (PET)-complete response (CR) rate, and partial response (PR) rate at end of treatment (EOT). Tumor measurements by PET/CT or PET/MRI at EOT were performed according to Lugano 2014 criteria within 6±2 weeks after Day 21 of the last treatment cycle the patient started. Results From December 2019 to August 2020, 83 patients were screened in nine countries across 34 sites in Europe and the US; 66 were randomized (Arm A, n=33; Arm B, n=33). Data cut-off for this analysis: 13 March 2021. Median age was 64.5 years (range 20-86). Many patients had high-risk disease: IPI 2: 24/66 (36.4%), IPI 3: 29/66 (43.9%), IPI 4: 11/66 (16.7%), IPI 5: 2/66 (3.0%); ECOG PS ≥2: 6/66 (9.1%). Most patients had Stage III/IV disease 62/66 (93.9%); 29/66 (43.9%) had bulky disease. All patients experienced at least one TEAE. The most frequent Grade ≥3 TEAEs by system organ class were blood and lymphatic disorders (81.8% patients overall), experienced by 24 patients (72.7%) in Arm A and 30 patients (90.9%) in Arm B. Grade ≥3 neutropenia and thrombocytopenia occurred in 19/33 (57.6%) and 4/33 (12.1%) (Arm A), and 28/33 (84.8%) and 12/33 (36.4%) (Arm B) patients, respectively; Grade ≥3 febrile neutropenia was experienced by 6/33 (18.2%) patients in each arm. Grade ≥3 infusion-related reactions to both rituximab and tafasitamab occurred in no patients in Arm A and one patient (3.0%) in Arm B, and 7/33 (21.2%) (Arm A) and 9/33 (27.3%) (Arm B) patients had a Grade ≥3 infection and/or infestation (Figure 1). Serious TEAEs occurred in 14/33 (42.4%) patients in Arm A and 17/33 (51.5%) patients in Arm B. Two out of 33 (6.1%) and one out of 33 (3.0%) patients discontinued study treatment due to TEAEs in Arms A and B, respectively. There were four deaths unrelated to tafasitamab and/or LEN (COVID-19 pneumonia, sepsis, and urosepsis). The average relative dose intensity of R-CHOP in each cycle was maintained in both arms. ORR at EOT was observed in 25/33 patients (75.8%; 95% confidence interval [CI]: 57.7-88.9) in Arm A and 27/33 patients (81.8%; 95% CI: 64.5-93.0) in Arm B. Conclusion These data suggest that both regimens are tolerable and do not impair dosing and scheduling of R-CHOP. Toxicities were similar to those expected with R-CHOP with or without LEN. With tumor follow-up still ongoing, the ORR at EOT suggests that patients with treatment-naïve DLBCL may achieve clinically meaningful efficacy tafasitamab and LEN in addition to standard treatment. A Phase III, multicenter, randomized, double-blind, placebo-controlled trial will assess efficacy and safety of R-CHOP + tafasitamab + LEN vs R-CHOP in newly diagnosed patients with high intermediate and high risk DLBCL, and is currently recruiting (frontMIND study; NCT04824092). Funding: MorphoSys AG. Figure 1 Figure 1. Disclosures Belada: Roche: Consultancy, Other: Travel, Accommodations, Expenses, Research Funding; Gilead Sciences: Consultancy, Other: Travel, Accommodations, Expenses, Research Funding; Janssen-Cilag: Consultancy, Research Funding; Takeda: Consultancy, Other: Travel, Accommodations, Expenses, Research Funding; MorphoSys AG: Consultancy, Research Funding; Debiopharm Group: Consultancy; Pharmacyclics: Research Funding; Archigen Biotech: Research Funding; Reddys: Research Funding. André: Johnson & Johnson: Research Funding; Roche: Other: Travel/accomodation/expenses, Research Funding; Incyte: Consultancy; Gilead: Consultancy, Other: Travel/Accommodations/Expenses; Karyopharm: Consultancy; Bristol-Myers-Squibb: Consultancy, Other: Travel/Accommodations/Expenses; Takeda: Consultancy, Research Funding; Celgene: Other: Travel/accomodation/expenses; AbbVie: Other: Travel/accomodation/expenses. Pérez Persona: Amgen: Consultancy, Other: Support for attending meetings and/or travel, Speakers Bureau; BMS/Celgene: Consultancy, Other: Support for attending meetings and/or travel, Speakers Bureau; AbbVie: Other: Support for attending meetings and/or travel, Speakers Bureau; Takeda: Speakers Bureau; Sanofi: Consultancy, Speakers Bureau; AstraZeneca: Speakers Bureau; GSK: Consultancy; Incyte: Consultancy. Staber: Roche: Consultancy, Honoraria, Research Funding; AbbVie: Consultancy, Honoraria; Gilead: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Astra Zeneca: Consultancy, Honoraria; Takeda: Consultancy, Research Funding; MSD: Consultancy, Honoraria; BMS: Consultancy, Honoraria; Incyte: Consultancy, Honoraria, Research Funding; Beigene: Consultancy, Honoraria. Trneny: AbbVie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses; Amgen: Consultancy, Honoraria; Bristol-Myers Squibb: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses; Gilead Sciences: Consultancy, Honoraria, Other: Travel, Accommodations, Expenses; Incyte: Consultancy, Honoraria, 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, Other: Travel, Accommodations, Expenses; MorphoSys: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses; Celgene: Consultancy; 1st Faculty of Medicine, Charles University, General Hospital in Prague: Current Employment; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Portola: Honoraria, Membership on an entity's Board of Directors or advisory committees; AstraZeneca: Honoraria. Brackertz: MorphoSys AG: Current Employment. Shah: MorphoSys AG: Current Employment. Sporchia: MorphoSys AG: Current Employment. Burke: MorphoSys: Consultancy; Adaptive Biotechnologies: Consultancy; Verastem: Consultancy; AstraZeneca: Consultancy; Bristol Myers Squibb: Consultancy; Kymera: Consultancy; X4 Pharmaceuticals: Consultancy; AbbVie: Consultancy; SeaGen: Consultancy, Speakers Bureau; Kura: Consultancy; Roche/Genentech: Consultancy; Epizyme: Consultancy; Beigene: Consultancy, Speakers Bureau. Nowakowski: Celgene, NanoString Technologies, MorphoSys: Research Funding; Celgene, MorphoSys, Genentech, Selvita, Debiopharm Group, Kite/Gilead: Consultancy, Membership on an entity's Board of Directors or advisory committees. OffLabel Disclosure: Tafasitamab is a humanized Fc-modified cytolytic CD19 targeting monoclonal antibody. In combination with lenalidomide (LEN), it received accelerated approval in July 2020 for adult patients with relapsed/refractory (R/R) diffuse large B-cell lymphoma (DLBCL) not otherwise specified (NOS), including arising from lowâ€'grade lymphoma, who are ineligible for autologous stem cell transplant (ASCT). Following FDA approval, we are now evaluating the safety and efficacy of tafasitamab in combination with LEN as an add-on to first-line therapy with R-CHOP in newly diagnosed patients with DLBCL.

Abstract Introduction: The clinical presentation of mantle cell lymphoma (MCL) is heterogeneous, ranging from indolent disease that does not require immediate treatment to rapidly progressive disease that responds poorly to aggressive immunochemotherapy. Several small retrospective studies suggested that active surveillance or delayed treatment is feasible in select patients with an indolent disease course. A shorter diagnosis-to-treatment interval (DTI) is a strong predictor for inferior survival in patients with aggressive non-Hodgkin lymphomas such as diffuse large B-cell lymphoma (DLBCL) and peripheral T-cell lymphoma (PTCL), which likely correlates with an aggressive disease biology and clinical presentation. However, the impact of DTI on survival has not been well studied in patients with MCL. In this study, we utilized the National Cancer Database to investigate the feasibility of active surveillance or delayed treatment in patients with MCL and to explore the potential impact of DTI on survival of MCL patients requiring treatment. Methods: The National Cancer Database was used to identify adult patients (≥ 18 years) with MCL diagnosed from 2004 through 2017. Patients were divided into three groups based on their time to initial treatment: early treatment [ET] (treatment started within 3 months), delayed treatment [DT] (treatment started after 3 months) and surveillance [SUR] (watch and wait without treatment). Baseline clinical characteristics were compared between the 3 groups using Chi-square test. Survival analysis was performed using the Kaplan-Meier method and log-rank test. Statistical analysis was performed using SPSS version 25. Results: A total of 27,867 patients with newly diagnosed MCL were included in this study, 995 patients (4%) in the SUR group, 21,425 patients (77%) in the ET group, and 1,052 patients (4%) in the DT group. There were no major differences in the baseline characteristics among the three groups including demographics (age, sex, ethnicity), socioeconomic factors (annual income, insurance status, place of residence), comorbidity scores, and Ann Arbor stage. Compared to patients in the SUR and DT groups, patients in the ET group were more likely to have B symptoms (ET=27% vs DT=16% vs SUR=8%, p<0.001) and were less likely to be managed at an academic center (ET=40% vs DT=53% vs SUR= 51%, p<0.001) (Table 1). The median follow-up was 38.2 months for the entire cohort. There was a significant difference in OS among the three groups, with a median OS of 107 months (95% CI = 92.7-122.7) in the SUR group, 84.9 months (95% CI = 74.2-95.7) in the DT group, and 68.9 months (95% CI = 66.8-70.9) in the ET group (p=0.001) (Figure 1A). Among patients in the DT group, a shorter DTI was associated with a trend of inferior OS, with a median OS of 82 months (95% CI = 73.2-90.8) for those with a DTI of 3-12 months and not reached (95% CI not calculable) for those with a DTI > 12 months (p=0.095) (Figure 1B). Among the ET group, a shorter DTI was associated with shorter OS, with a median OS of 53 months (95% CI = 50.2-55.8) for patients with a DTI ≤ 15 days, 71.7 months (95% CI = 67.1-76.3) for those with a DTI of 16-30 days, and 87.1 months (95% CI= 82.8-91.4) for patients with a DTI of 31-90 days (p<0.001) (Figure 1C) Conclusion: In this retrospective analysis, patients with newly diagnosed MCL who were managed with an active surveillance strategy or delayed therapy had a better survival compared to patients who underwent early therapy. These findings validate the feasibility of delayed therapy in select patients with MCL. In patients who undergo early therapy, a shorter DTI is associated with an inferior survival outcome, mirroring findings in DLBCL and PTCL. A shorter DTI is likely associated with more aggressive disease biology and clinical presentation. Figure 1 Figure 1. Disclosures Munoz: Pharmacyclics/Abbvie, Bayer, Gilead/Kite Pharma, Pfizer, Janssen, Juno/Celgene, BMS, Kyowa, Alexion, Beigene, Fosunkite, Innovent, Seattle Genetics, Debiopharm, Karyopharm, Genmab, ADC Therapeutics, Epizyme, Beigene, Servier: Consultancy; Gilead/Kite Pharma, Kyowa, Bayer, Pharmacyclics/Janssen, Seattle Genetics, Acrotech/Aurobindo, Beigene, Verastem, AstraZeneca, Celgene/BMS, Genentech/Roche.: Speakers Bureau; Millennium: Research Funding; Janssen: Research Funding; Seattle Genetics: Research Funding; Pharmacyclics: Research Funding; Genentech: Research Funding; Incyte: Research Funding; Portola: Research Funding; Merck: Research Funding; Celgene: Research Funding; Gilead/Kite Pharma: Research Funding; Bayer: Research Funding; Physicians' Education Resource: Honoraria; Seattle Genetics: Honoraria; Targeted Oncology: Honoraria; OncView: Honoraria; Kyowa: Honoraria. Paludo: Karyopharm: Research Funding. Habermann: Seagen: Other: Data Monitoring Committee; Incyte: Other: Scientific Advisory Board; Tess Therapeutics: Other: Data Monitoring Committee; Morphosys: Other: Scientific Advisory Board; Loxo Oncology: Other: Scientific Advisory Board; Eli Lilly & Co.,: Other: Scientific Advisor. Nowakowski: Nanostrings: Research Funding; Blueprint Medicines: Consultancy; TG Therapeutics: Consultancy; Kymera Therapeutics: Consultancy; Incyte: Consultancy; Zai Labolatory: Consultancy; Daiichi Sankyo: Consultancy; Bantham Pharmaceutical: Consultancy; Karyopharm Therapeutics: Consultancy; Curis: Consultancy; Selvita: Consultancy; Ryvu Therapeutics: Consultancy; Kyte Pharma: Consultancy; Genentech: Consultancy, Research Funding; Roche: Consultancy, Research Funding; Celgene/Bristol Myers Squibb: Consultancy, Research Funding; MorphoSys: Consultancy. Wang: TG Therapeutics: Membership on an entity's Board of Directors or advisory committees; Eli Lilly: Membership on an entity's Board of Directors or advisory committees; MorphoSys: Research Funding; Genentech: Research Funding; Novartis: Research Funding; LOXO Oncology: Membership on an entity's Board of Directors or advisory committees, Research Funding; Incyte: Membership on an entity's Board of Directors or advisory committees, Research Funding; InnoCare: Research Funding.