Nowakowski, Grzegorz S.

Background: Progress in genome technology allows analysis of previously completed trials to identify subgroups potentially benefiting from therapy. Enzastaurin is a potent inhibitor of protein kinase C beta (PKC-β) and suppresses the phosphoinositide 3-kinase (PI3K)/AKT pathway. The safety and efficacy of Enzastaurin has been tested in more than 60 clinical trials including 2 major studies in DLBCL: (1) PRELUDE (A phase III maintenance trial of Enzastaurin vs Placebo, N=758) (Crump, 2016), and (2) S028 (A randomized phase II study of Enzastaurin/R-CHOP vs R-CHOP in frontline intermediate/high-risk DLBCL, N=101) (Hainsworth, 2016). DNA samples extracted from blood of patients from PRELUDE were retrospectively genotyped using whole genome SNP arrays. From the genome wide screening a novel genetic biomarker, DGM1, was identified showing high correlation with response to Enzastaurin treatment (Luo, ASH 2018). Importantly, these findings were replicated in the phase II S028 study. In the S028 study the hazard ratio (HR) for OS in high-risk (IPI ≥ 3) DGM1 positive (+) patients who received Enzastaurin/R-CHOP was 0.28 (0.1-0.81) when compared to subjects who received R-CHOP, a benefit favoring Enzastaurin (p=0.018). These data suggest that addition of Enzastaurin to R-CHOP may significantly improve outcome in frontline high-risk DGM1 (+) DLBCL. The ENGINE study was initiated to validate this finding in a prospective study. Study Design and Methods: Adult patients must have untreated CD20+ DLBCL, IPI ≥ 3. Patients are randomized 1:1 to Enzastaurin/R-CHOP or Placebo/R-CHOP for 6 cycles during combination phase. Each subject's treatment assignment will be unblinded after response assessment at the end of the combination phase. Subjects randomized to the investigational arm who have a complete or partial response will have the option to continue in the single agent phase to receive Enzastaurin for up to 2 additional years. The study intends to enroll approximately 235 patients with primary endpoint of OS in DGM1 (+) patients. The study is ongoing with 57 sites open in the US and China. As of 20 July 2019, 128 patients have been randomized. Clinical trial information: NCT03263026. Disclosures Nowakowski: Genentech, Inc.: Research Funding; Curis: Research Funding; Bayer: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; F. Hoffmann-La Roche Ltd: Research Funding; Selvita: Membership on an entity's Board of Directors or advisory committees; NanoString: Research Funding; MorphoSys: Consultancy, Research Funding. Brody:Acerta Pharma: Research Funding; Merck: Research Funding; Celldex Therapeutics: Research Funding; Genentech: Research Funding; Oncovir, Inc.: Research Funding; BMS: Research Funding; Kite Pharma: Research Funding. Lue:Kymera Therapeutics: Honoraria; Astex Pharmaceuticals: Honoraria. Luo:Denovo Biopharma LLC: Employment, Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties. Zhang:Denovo Biopharma LLC: Employment. Han:Denovo Biopharma LLC: Employment. Jivani:TRACON Pharmaceuticals, Inc.: Other: Stock; Denovo Biopharma LLC: Employment. Liu:Denovo Biopharma LLC: Employment. Li:Denovo Biopharma LLC: Employment. Sun:Novartis: Other: Stock; Denovo Biopharma LLC: Employment.

Introduction and Purpose IRAK4 kinase activity is essential for signaling downstream of toll-like receptors (TLR) and the interleukin-1 receptor (IL-1R) family in a variety of myeloid and lymphoid cell types. Dysregulated signaling in these pathways is frequently observed in NHL, particularly in ABC-subtype of Diffuse Large B-Cell Lymphoma (DLBCL) and Waldenström macroglobulinemia (WM). A phase 1 trial in patients with NHL is being conducted to determine safety, pharmacokinetics, and preliminary efficacy of CA-4948 as monotherapy. Patients and Methods At the 18-Jul-2019 data cut-off date, 22 patients have been treated with single-agent CA-4948. Five dose-escalation cohorts from 50 mg QD to 200 mg BID have been tested and cleared; a cohort of patients treated at 400 mg BID dose is currently being evaluated. Patients were diagnosed with relapsed or refractory NHL, including DLBCL (n=13), FL (n=5), HGBL with MYC and BCL2 and/or BCL6 rearrangement (n=1), WM (n=1), LPL (n=1) and MCL (n=1), had a performance status of 0 or 1 (ECOG) at baseline, and were treated in 21-day cycles until progression of disease or unacceptable toxicity, lost to follow-up or death. 5 patients had prior autologous bone marrow transplants. Results CA-4948 has been generally well tolerated. Grade 3/4 treatment-related adverse events included amylase/lipase increased, diarrhea, neutrophil count decreased, rash, rhabdomyolysis. Pharmacokinetics has shown favorable characteristics with dose-proportional increases in exposure. Five patients have been on treatment through the end of Cycle 4, including one patient in Cycle 10 on study for over 7 months. Five patients experienced overall tumor burden decreases of ≥20% from baseline, including at least 2 of 4 patients treated at 200 mg BID. Downstream pharmacodynamic markers of IRAK4 activity are being evaluated. Molecular characteristics including cell-of-origin will be presented. Conclusion CA-4948 demonstrates preliminary clinical activity. Enrollment is on-going and the MTD has not been reached. These encouraging results warrant further clinical testing in patients with advanced hematological malignancies. Clinical trial: NCT03328078. Disclosures Younes: Roche: Consultancy, Honoraria, Research Funding; Takeda: Honoraria; Genentech: Research Funding; Pharmacyclics: Research Funding; Janssen: Honoraria, Research Funding; Merck: Honoraria, Research Funding; Curis: Honoraria, Research Funding; Biopath: Consultancy; Xynomics: Consultancy; Celgene: Consultancy, Honoraria; HCM: Consultancy; BMS: Research Funding; AstraZeneca: Research Funding; Syndax: Research Funding; Abbvie: Honoraria; Epizyme: Consultancy, Honoraria. Nowakowski:Selvita: Membership on an entity's Board of Directors or advisory committees; NanoString: Research Funding; MorphoSys: Consultancy, Research Funding; Genentech, Inc.: Research Funding; F. Hoffmann-La Roche Ltd: Research Funding; Curis: Research Funding; Bayer: Consultancy, Research Funding; Celgene: Consultancy, Research Funding. Tun:Mundi-pharma: Research Funding; DTRM Biopharma: Research Funding; BMS: Research Funding; Celgene: Research Funding; Curis: Research Funding; TG Therapeutics: Research Funding. Lunning:Janssen Scientific Affairs, LLC: Consultancy, Research Funding; Curis: Research Funding; Juno Therapeutics: Consultancy, Research Funding; MiRagen: Research Funding; TG Therapeutics: Consultancy, Research Funding; Spectrum: Consultancy; VANIUM: Consultancy; Verastem: Consultancy; DAVA: Consultancy; Bayer: Consultancy; AbbVie: Consultancy; Kite: Consultancy; Gilead Sciences, Inc.: Consultancy; Seattle Genetics: Consultancy; Portola: Consultancy; OncLive: Consultancy; Novartis: Consultancy. Isufi:Celgene: Consultancy; Novartis: Consultancy; Astra Zeneca: Consultancy. Martell:Curis, Inc.: Employment. Patel:AstraZeneca: Consultancy, Research Funding, Speakers Bureau; Celgene: Consultancy, Speakers Bureau; Genentech: Consultancy, Speakers Bureau; Pharmacyclics/Janssen: Consultancy, Speakers Bureau; Sunesis: Consultancy.

Background: Neurolymphomatosis (NL) is a highly rare disorder defined as infiltration of peripheral nervous system by a lymphoproliferative neoplasm, both presented as the first manifestation of the malignancy (primary NL) or as a site of disease progression or relapse (secondary NL). Due to rarity of this disorder data on clinical features, best approach and outcome are limited. Furthermore diagnosis of this disease is often uncertain and based on radiological images only. Methods: We retrospectively reviewed clinical records of all histologically confirmed-NL, diagnosed and treated at the Division of Hematology of Mayo Clinic in Rochester, MN between January 2002 and December 2018. Clinical features and outcome were analyzed. Responses to therapy were assessed by post-treatment radiological changes and clinical symptoms improvement. Survival analysis such as progression free survival (PFS) and overall survival (OS) were estimated using Kaplan Meier curves with log-rank test. Comparison between subgroups was investigated using Fisher's exact test and Wilcoxon test for categorical and continuous variables, respectively. Results: Over a 16-year period 40 patients with biopsy-proven NL were included in study. Primary and secondary NL were 19 (48%) and 21 (52%) respectively, with a median age of 60.5 years (range 37-83) and male sex 24/40 (60%). The predominant histology was represented by B-cell lymphomas (39/40, 97%) with a vast majority large B-cell lymphoma (LBCL) 27/40 (67%) and only 1 case of T-cell lymphoma. The affected structures included brachial plexus (12/40, 35%), lumbosacral plexus (5/40, 12%), cauda equine and nerve roots (14/40, 35%), sciatic nerve (12/40, 30%), femoral nerve (4/40, 10%), cranial nerves (8/40, 20%), multiple nerves involved in 23/40 (57%). Four out of 40 cases had brain involvement and cerebrospinal fluid (CSF) was positive in 7/29 (24%). NL clinical manifestations included muscular weakness (33/4, 82%), sensory deficit (32/40, 80%), pain (28/40, 70%) and autonomic dysfunction (3/40, 7%). Magnetic resonance imaging (MRI) detected neural abnormalities in 35/36 cases (97%), CT imaging identified disease in 3/8 (37%) and FDG-PET scan was positive in 22/31 (71%); electromyography showed some grade of neuropathy in 28/29 (97%). Treatment included systemic chemotherapy in 38/40 (95%) cases, containing high dose methotrexate (HD-MTX) in 26/40 (65%) and rituximab in 20/40 (50%); 11/39 (28%) patients underwent consolidative autologous stem cell transplant (ASCT); 4/40 received consolidative radiotherapy (RT), 1/40 was treated with RT alone; intrathecal chemotherapy was infused in 1/40 cases; one patient with solely great auricular nerve NL involvement was cured with surgery only. Treatment efficacy evaluated by imaging and clinical improvement consisted with an overall response rate (ORR) of 73% (27/37) with a 24% (9/37) of complete remission (CR); No statistical difference in rate of response was observed by different systemic treatments. Of note, patients undergoing HDC-ASCT consolidation obtained 100% of ORR (n=10) versus 61.5% (n=16) achieved by others (P=0.03). With a median follow up of 45.1 months (range 0.5-186.7) a 36 months-OS of 77% (95% CI, 60-88) was observed for the whole cohort. A trend of longer survival rate for primary NL was observed, with a 36-month OS of 95% (95% CI, 72-99) vs. 55% (95% CI, 30-77) for secondary NL (p 0.134). A strong benefit in terms of outcome was observed for patients receiving rituximab-containing regimens with a 36 months-PFS of 72% (95% CI, 55-92) vs 28% (95% CI, 12-53) (P=0.001), and a 36 months-OS of 87% (CI 95%, 60-98) vs. 65% (95% CI , 41-84) (P=0.04) (figure 1); no survival difference was observed for patients treated with systemic therapy containing HD-MTX vs. others. ASCT consolidation was associated with a trend of improved survival with a 36 months-PFS of 69% (95% CI, 35-90) vs. 47% (95% CI, 29-66) for others (P=0.09). Conclusions: With the limit of a retrospective analysis, LBCL represent the predominant histologic subtype of NL; MRI and FGD-PET appeared to be the most accurate radiological tools to detect neural disease. Systemic treatments including rituximab should be preferred, HD-MTX seems to be not so effective while ASCT consolidation may be considered in selected patients. Due to the spare number of cases treated with RT its role cannot be clarified by our study. Disclosures Nowakowski: NanoString: Research Funding; MorphoSys: Consultancy, Research Funding; Genentech, Inc.: Research Funding; F. Hoffmann-La Roche Ltd: Research Funding; Curis: Research Funding; Bayer: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Selvita: Membership on an entity's Board of Directors or advisory committees.

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

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

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

Background: Diffuse large B-cell lymphomas (DLBCL) are a heterogeneous group of aggressive B-cell non-Hodgkin lymphomas (NHL). Primary mediastinal B-cell lymphoma (PMBCL) is often grouped and managed as DLBCL, yet PMBCL is biologically and clinically different. Although about two-third of patients are cured with initial therapy, those who are refractory or progress within the first two years do poorly and will die from their disease. There is an unmet need for effective therapeutic approaches in this patient population. Evasion of the host immune responses is an important mechanism for inducing resistance to cancer therapy. Strategies to block molecular and cellular mediators of cancer induced immunosuppression such as programmed death -1 receptor (PD-1) have been explored. Targeting PD-1 immune checkpoints has the potential to play a major role in cancer therapy by reversing tumor immune escape. Trials using PD-1 blockers in advanced hematological malignancies demonstrated remarkable activity in Hodgkin lymphoma. Unfortunately, results in the DLBCL cohort with nivolumab were marginal and short lived. A phase 1b trial in heavily pre-treated relapsed/refractory (RR) PMBCL using pembrolizumab (a PD-1 blocker) showed that it was safe and active with an ORR of 41%. In recent years, several signaling pathways implicated in DLBCL pathogenesis have been targeted, including the PI3K-AKT-mTOR pathway. Copanlisib, a pan-PI3K inhibitor, with particularly potent PI3K-α/PI3K-δ inhibition, showed activity in both indolent and aggressive NHL, with a safer toxicity profile than the FDA-approved agent idelalisib. In a preclinical DLBCL mouse model, treatment with copanlisib resulted in effective down regulation of tumor‐infiltrating T-regulatory cells (Tregs). In the same model, copanlisib, when combined with a surrogate anti‐mouse PD‐1, showed in vivo responses in 75% vs 0% in the monotherapy groups. These data support the rational for the combination of copanlisib and checkpoint blockade in DLBCL. We developed a phase 2 prospective study with two RR cohorts (DLBCL and PMBCL), treated with the combination of copanlisib and nivolumab. Study Design: copanlisib hydrochloride 60 mg is given IV on days 1, 8 and 15 of cycles 1-8 and days 1 and 15 of subsequent cycles. Nivolumab 240 mg IV is given on days 1 and 15 of cycles 1-8 and 480 mg on day 1 of subsequent cycles. Cycles repeat every 28 days for up to 2 years in the absence of disease progression or unacceptable toxicity. Copanlisib dose will be determined using a safety cohort in 6 patients. The primary outcome is to assess ORR defined as complete and partial responses (CR+PR). Secondary outcomes are to evaluate safety of the combination; to assess progression free survival (PFS), duration of response (DOR), CR rate, and overall survival (OS). Exploratory objectives are to characterize the effects of the copanlisib and nivolumab combination regimen on tumor cells, tumor microenvironment and the immune response in RR DLBCL and PMBCL. We will also do Lymph3CX assay as an integrated biomarker to distinguish between DLBCL and PMBCL. Key inclusion criteria: adult patients with RR DLBCL and PMBCL who have measurable disease with at least one lesion that is >15mm in the longest diameter on cross-sectional imaging; After failure of ASCT or after failure of frontline therapy in subjects who declined or are not ASCT candidates; and have appropriate organ function. Key exclusion criteria: High grade B-cell lymphomas; Active, known or suspected autoimmune disease or patients on any prohibited therapies; History of active CNS involvement or leptomeningeal involvement This study is expected to enroll a maximum of 96 (6 safety cohort, 44 DLBCL and 46 PMBCL) evaluable patients. We anticipate accruing 10 additional patients to account for ineligibility, cancellation, or other reasons. Therefore, the study is expected to accrue a maximum of 106 patients. The largest success proportion where the proposed treatment regimen would be considered ineffective in DLBCL is 25% and 30% in PMBCL. The smallest success proportion that would warrant subsequent studies with the proposed regimen is 45% in DLBCL and 50% in PMBCL. This design has a 90% power with a 1-sided 10% level test. This study is conducted through NCI-CTEP (NCI Protocol #10193; NCT03484819) and is funded by Bayer. The study is to open in fall of 2019 at 11 ECTCN sites, and is available to interested sites to join in. Figure. Disclosures Bennani: Kite Pharma: Other: Advisory board; Seattle Genetics: Other: Advisory board; Purdue Pharma: Other: Advisory board; Seattle Genetics: Other: Advisory board; Bristol-Myers Squibb: Research Funding; Purdue Pharma: Other: Advisory board; Adicet Bio: Other: Advisory board; Adicet Bio: Other: Advisory board; Purdue Pharma: Other: Advisory board; Bristol-Myers Squibb: Research Funding; Bristol-Myers Squibb: Research Funding; Kite Pharma: Other: Advisory board; Kite Pharma: Other: Advisory board; Seattle Genetics: Other: Advisory board; Adicet Bio: Other: Advisory board. Nowakowski:Celgene: Consultancy, Research Funding; Selvita: Membership on an entity's Board of Directors or advisory committees; NanoString: Research Funding; MorphoSys: Consultancy, Research Funding; Genentech, Inc.: Research Funding; F. Hoffmann-La Roche Ltd: Research Funding; Curis: Research Funding; Bayer: Consultancy, Research Funding. Rimsza:NanoSting: Patents & Royalties: Named inventor on a patent licensed to NanoSting [Institution]. Ansell:Bristol-Myers Squibb: Research Funding; Mayo Clinic Rochester: Employment; Seattle Genetics: Research Funding; Seattle Genetics: Research Funding; Regeneron: Research Funding; Bristol-Myers Squibb: Research Funding; LAM Therapeutics: Research Funding; Regeneron: Research Funding; Regeneron: Research Funding; Mayo Clinic Rochester: Employment; Affimed: Research Funding; Bristol-Myers Squibb: Research Funding; Seattle Genetics: Research Funding; Trillium: Research Funding; Regeneron: Research Funding; Bristol-Myers Squibb: Research Funding; LAM Therapeutics: Research Funding; Regeneron: Research Funding; Bristol-Myers Squibb: Research Funding; Trillium: Research Funding; Trillium: Research Funding; Regeneron: Research Funding; Mayo Clinic Rochester: Employment; Trillium: Research Funding; LAM Therapeutics: Research Funding; Mayo Clinic Rochester: Employment; Affimed: Research Funding; LAM Therapeutics: Research Funding; Regeneron: Research Funding; LAM Therapeutics: Research Funding; Bristol-Myers Squibb: Research Funding; Trillium: Research Funding; Affimed: Research Funding; Seattle Genetics: Research Funding; LAM Therapeutics: Research Funding; Bristol-Myers Squibb: Research Funding; Trillium: Research Funding; LAM Therapeutics: Research Funding; Mayo Clinic Rochester: Employment; Seattle Genetics: Research Funding; Trillium: Research Funding; Mayo Clinic Rochester: Employment; Affimed: Research Funding; Trillium: Research Funding; Mayo Clinic Rochester: Employment; Mayo Clinic Rochester: Employment; Mayo Clinic Rochester: Employment; Seattle Genetics: Research Funding; Affimed: Research Funding; Trillium: Research Funding; Seattle Genetics: Research Funding; Affimed: Research Funding; Seattle Genetics: Research Funding; Regeneron: Research Funding; Affimed: Research Funding; LAM Therapeutics: Research Funding; Bristol-Myers Squibb: Research Funding; Affimed: Research Funding; LAM Therapeutics: Research Funding; Bristol-Myers Squibb: Research Funding; Affimed: Research Funding; Regeneron: Research Funding; Seattle Genetics: Research Funding.

Background: While there is evidence in the literature of increased prevalence of hypogammaglobulinemia in chronic lymphocytic leukemia (CLL), there are no studies evaluating the prevalence of hypogammaglobulinemia in newly diagnosed diffuse large B cell lymphoma (DLBCL) or the relationship between hypogammaglobulinemia and presentation or outcomes. The objective of this study was to examine the prevalence of hypogammaglobulinemia in newly diagnosed DLBCL patients and to test the hypothesis that DLBCL patients with baseline hypogammaglobulinemia have a distinct clinical profile and outcome. Methods: We obtained banked frozen sera from 200 newly diagnosed, treatment-naïve, DLBCL patients from the Lymphoma SPORE Molecular Epidemiology Resource (MER), a prospective cohort study conducted at the Mayo Clinic and the University of Iowa. IgG/A/M levels were measured using immunoturbidimetric assay whereas IgE level was measured using electrochemiluminescence immunoassay; deficiency was defined using standard reference ranges. IgE levels were considered deficient if &lt;2 UI/ml. The associations between Ig deficiencies and clinical factors were evaluated with Wilcoxon rank sum and chi-squared (Fisher's exact, where appropriate) tests. Event-free survival (EFS) was defined as time from diagnosis to progression, relapse, retreatment, or death, and EFS24 was defined as EFS at 24 months after diagnosis (achieve or failure to achieve EFS24). The association of Ig levels with EFS24 was estimated using odds ratios (OR) and 95% confidence intervals (CI) from logistic regression, and with EFS, overall survival (OS), and lymphoma-specific survival (LSS) was estimated using Kaplan-Meier curves and hazard ratios (HR) and 95% CI from Cox regression. Results: The mean age (SD) of the cohort was 65.6 (13.4) years, 54% were males and 98% of the patients were white. Over a median follow-up of five years, there were 59 (29.5%) deaths. The prevalence of hypogammaglobulinemia, defined as any deficiency, in newly diagnosed, treatment-naïve DLBCL was 22.1% (44/199) in our cohort, and the most common Ig deficiency was for IgG (&lt;700 mg/dL, 13.5%), followed by IgM (&lt;40 mg/dL, 9.0%), IgE (&lt;2 UI/ml, 7.5%) and IgA (&lt;70 mg/dL, 4.0%) (Table1). There were no statistically significant differences between Ig deficient and non-deficient patients in terms of age at diagnosis, gender, stage, cell of origin, or MYC double hit status. However, median LDH levels were higher in Ig deficient patients (228 vs 194, p&lt;0.01). Any immunoglobulin deficiency was associated with inferior EFS (HR 1.94, 95% CI 1.16-3.24) (Figure 1) and OS (HR 2.02, 95% CI 1.17-3.49), and these associations were not attenuated after adjustment for the international prognostic index (IPI). Any Ig deficiency was also associated with failure to achieve EFS24 (OR=2.13, 95% CI 1.00-4.60) after adjusting for IPI. Conclusions: To the best of our knowledge, this is the first study to report the prevalence of hypogammaglobulinemia in treatment naïve DLBCL. We found that any Ig deficiency was not uncommon in our cohort and it was associated with an inferior EFS and OS in DLBCL patients. The prevalence of hypogammaglobulinemia in DLBCL patients seems to be lower than has been described in CLL patients. While the underlying relationship between these two immunologic disorders deserves further study, our findings highlight the interaction between global immune dysfunction and emergence of a clonal B cell process. Disclosures Nowakowski: Genentech, Inc.: Research Funding; F. Hoffmann-La Roche Ltd: Research Funding; Curis: Research Funding; Bayer: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Selvita: Membership on an entity's Board of Directors or advisory committees; NanoString: Research Funding; MorphoSys: Consultancy, Research Funding. Farooq:Celgene: Honoraria; Kite Pharma: Research Funding. Cerhan:NanoString: Research Funding; Celgene: Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees.

Introduction: Waldenström macroglobulinemia (WM) is characterized by circulating monoclonal IgM and bone marrow infiltration with lymphoplasmacytic lymphoma (LPL) cells. Presently, there is limited data to guide prognosis or treatment options of WM based on the proportion of lymphocytes or plasma cells in the LPL population on the pathology. In this study, we aim to look at differing clinical features and outcomes of patients with WM based on the plasma cell (PC) percentage in the diagnostic bone marrow biopsy. Methods Patients with WM seen at Mayo Clinic, Rochester, MN between January 2001 and December 2017, with a bone marrow biopsy and a corresponding serum free light chain (FLC) examination at diagnosis of WM were included. The percentage of lymphocytes and PCs in the marrow biopsy was determined based on morphology ± immunohistochemistry. On immunohistochemistry, CD138 and/or MUM-1 positivity was used to quantify PCs, whereas CD20 and/or PAX5 were used to quantify lymphocytes. Patients with ≥10% PC component in the lymphoplasmacytic (LPL) cells on bone marrow biopsy were considered to have WM with excess plasma cells (WMEPC), while those with &lt;10% PCs were considered to have lymphocytic WM (LWM). Continuous variables were compared using Wilcoxon test and categorical variables were compared using Chi square test or Fisher's exact test. Time-to-next therapy (TTNT) was defined as the period from initiation of first line therapy to start of second line therapy or death due to any cause before second line therapy. Time-to-event analyses were conducted using Kaplan Meier method. Results: Of 228 evaluable patients, 147 (64%) had ≥ 10% PCs in the initial marrow biopsy. The median follow-up was 3.4 years (95% CI: 2.3-4.3 years) for LWM and 4.3 years (95% CI: 3.4-4.8 years) for WMEPC (p=0.33). The baseline characteristics of WMEPC versus LWM are depicted in Table 1. Patients with WMEPC had lower bone marrow involvement by LPL (30%) compared to LWM (60%; p&lt;0.001) at diagnosis, but the rate of symptomatic hyperviscosity was higher in WMEPC during the disease course (Table 1). The TTNT was shorter for WMEPC [2.6 years (95% CI: 1.8-4.5 years)] compared to LWM [4.5 years (95% CI 3.2-8.2)], although it did not reach statistical significance (p=0.09, Figure 1). There was a trend towards shorter OS for WMEPC [Not reached (95% CI 7.2- NR)] compared to LWM [10.7 years (95% CI 7.3 -12.1 years); p=0.28], Figure 2. Of the 228 patients, 79% (n=182) had data available for systemic therapy. The rate of PR or better with frontline therapy was higher in rates in LWM compared to WMEPC (61 % vs 42% p=0.02, Table 1). Among WMEPC cohort, patients receiving either a proteasome inhibitor (PI)-based or an immunomodulatory (IMiD)-based combination as frontline therapy (n=16) had higher rates of partial response or better (68%) compared to non-PI/non-IMiD based therapy (n=114), p=0.04. Conclusion: WM with excess plasma cells at diagnosis is associated with a trend towards shorter TTNT and OS compared to WM with &lt;10% plasma cells in the lymphoplasmacytic population at diagnosis. Our preliminary data shows higher rates of partial response or better with the use of PI/IMiD based therapy, but the small cohort size limits the strength of this finding which needs to be validated externally. Disclosures Ansell: Bristol-Myers Squibb: Research Funding; Trillium: Research Funding; Bristol-Myers Squibb: Research Funding; Bristol-Myers Squibb: Research Funding; LAM Therapeutics: Research Funding; Mayo Clinic Rochester: Employment; Regeneron: Research Funding; Trillium: Research Funding; Bristol-Myers Squibb: Research Funding; Affimed: Research Funding; Seattle Genetics: Research Funding; Regeneron: Research Funding; Bristol-Myers Squibb: Research Funding; Affimed: Research Funding; LAM Therapeutics: Research Funding; Trillium: Research Funding; Mayo Clinic Rochester: Employment; Seattle Genetics: Research Funding; Mayo Clinic Rochester: Employment; Bristol-Myers Squibb: Research Funding; Seattle Genetics: Research Funding; Mayo Clinic Rochester: Employment; Trillium: Research Funding; LAM Therapeutics: Research Funding; Affimed: Research Funding; Affimed: Research Funding; Bristol-Myers Squibb: Research Funding; Regeneron: Research Funding; Mayo Clinic Rochester: Employment; Trillium: Research Funding; Bristol-Myers Squibb: Research Funding; Seattle Genetics: Research Funding; Regeneron: Research Funding; LAM Therapeutics: Research Funding; LAM Therapeutics: Research Funding; Regeneron: Research Funding; Mayo Clinic Rochester: Employment; Affimed: Research Funding; Mayo Clinic Rochester: Employment; Trillium: Research Funding; Regeneron: Research Funding; Regeneron: Research Funding; Seattle Genetics: Research Funding; Affimed: Research Funding; Seattle Genetics: Research Funding; Mayo Clinic Rochester: Employment; Trillium: Research Funding; Trillium: Research Funding; Bristol-Myers Squibb: Research Funding; Trillium: Research Funding; LAM Therapeutics: Research Funding; LAM Therapeutics: Research Funding; Regeneron: Research Funding; Regeneron: Research Funding; Affimed: Research Funding; Seattle Genetics: Research Funding; LAM Therapeutics: Research Funding; Seattle Genetics: Research Funding; Seattle Genetics: Research Funding; Affimed: Research Funding; Mayo Clinic Rochester: Employment; LAM Therapeutics: Research Funding; Affimed: Research Funding. Gertz:Spectrum: Honoraria, Research Funding; Janssen: Honoraria; Celgene: Honoraria; Prothena: Honoraria; Alnylam: Honoraria; Ionis: Honoraria. Dingli:alexion: Consultancy; Janssen: Consultancy; Millenium: Consultancy; Rigel: Consultancy; Karyopharm: Research Funding. Nowakowski:Selvita: Membership on an entity's Board of Directors or advisory committees; NanoString: Research Funding; MorphoSys: Consultancy, Research Funding; Genentech, Inc.: Research Funding; F. Hoffmann-La Roche Ltd: Research Funding; Curis: Research Funding; Bayer: Consultancy, Research Funding; Celgene: Consultancy, Research Funding. Dispenzieri:Alnylam: Research Funding; Celgene: Research Funding; Takeda: Research Funding; Pfizer: Research Funding; Janssen: Consultancy; Intellia: Consultancy; Akcea: Consultancy. Lacy:Celgene: Research Funding. Kumar:Celgene: Consultancy, Research Funding; Janssen: Consultancy, Research Funding; Takeda: Research Funding. Kapoor:Janssen: Research Funding; Cellectar: Consultancy; Glaxo Smith Kline: Research Funding; Amgen: Research Funding; Takeda: Honoraria, Research Funding; Sanofi: Consultancy, Research Funding; Celgene: Honoraria.

Background Diffuse large B-cell lymphoma (DLBCL) is the most common non-Hodgkin's lymphoma (NHL) in adults. R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone) remains the standard of care for newly diagnosed DLBCL, with cure rates of 60-70%. However, more effective front-line options are needed to further improve outcomes, particularly in high-risk patients (Sehn LH, Gascoyne RD. Blood 2015;125:22). Approximately 15-20% of treatment-naïve patients with DLBCL have CD20-low expressing tumors, while CD19 is expressed in >90% of DLBCL. CD20-low DLBCL is associated with poor response to rituximab-based regimens (Johnson NA, et al. Blood 2009;113:3773; Prevodnik VK, et al. Diagnostic Pathol 2011;6:33). CD19 is a B-lymphocyte lineage-specific surface antigen that is widely expressed in mature B-cell malignancies, including DLBCL. CD19 functions as a positive regulator of B-cell receptor signaling and is important for B-cell activation and proliferation, and is, therefore, an attractive therapeutic target in addition to CD20. Tafasitamab (MOR208) is a humanized anti-CD19 monoclonal antibody with an engineered constant region (Fc) that enhances Fc-γ receptor binding affinity on effector cells, thereby enhancing antibody-dependent cellular cytotoxicity (ADCC) and phagocytosis (ADCP). Preliminary data in DLBCL cell lines suggest that combined targeting of CD19 and CD20 with tafasitamab and rituximab, respectively, could have synergistic cytotoxic effects. Monotherapy with tafasitamab has shown clinical activity and acceptable safety in a Phase I study in relapsed/refractory (R/R) chronic lymphocytic leukemia/small lymphocytic lymphoma (NCT01161511) and in a Phase IIa study in R/R NHL (NCT01685008). In patients with R/R DLBCL, treatment with single agent tafasitamab until progression led to a 26% objective response rate (ORR) with several long-term responses (Jurczak W, et al. Ann Oncol 2018; 29:1266). Preclinical in vitro and in vivo data have demonstrated increased combinatorial antitumor effects with tafasitamab and the immunomodulatory agent lenalidomide (LEN). In the Phase II, single-arm L-MIND study (NCT02399085) in patients with R/R DLBCL, treatment with tafasitamab/LEN achieved an ORR of 60%, a complete response (CR) rate of 42.5% and a median progression-free survival (PFS) of 12.1 months (Salles GA, et al. ICML 2019; Abstr 124). This combination received breakthrough therapy designation by the US Food and Drug Administration. Study design and methods First-MIND is a Phase Ib, open-label, multicenter, randomized trial of tafasitamab/R-CHOP or tafasitamab/LEN/R-CHOP in patients with newly diagnosed DLBCL (Figure 1). Patients must be aged ≥18 years, treatment naïve, with histologically confirmed DLBCL not otherwise specified and have intermediate- to high-risk disease (International Prognostic Index 2-5). Key exclusion criteria include known double- or triple-hit lymphoma, and transformed or composite lymphoma. Treatment consists of six 21-day cycles of tafasitamab (12 mg/kg intravenously [IV], on Days [D] 1, 8 and 15) in addition to R-CHOP (Arm A) or tafasitamab (12 mg/kg IV, on D1, 8 and 15) and LEN (25 mg orally, on D1-10) in addition to R-CHOP (Arm B). The trial includes a safety run-in phase and a main phase. In the safety run-in phase, 12 patients will be enrolled in each arm. If no unexpected safety signals suspected to be related to the addition of tafasitamab ± LEN to R-CHOP are observed, an additional 18 patients will be enrolled in each arm in the main phase. The primary objective of the trial is to assess safety; secondary objectives include evaluation of efficacy (ORR and PET-assessed CR rate at end of treatment, PFS, overall survival, event-free survival, time to next anti-lymphoma treatment), long-term safety and pharmacokinetics, and immunogenicity of tafasitamab in each arm. Exploratory objectives will include the assessment of biomarkers in peripheral blood (natural killer [NK] cell count, cell-free circulating tumor DNA) and tumor tissue (DLBCL cell of origin, NK cell or macrophage count/gene expression profile, CD19 and CD20 expression) that may be relevant to the mechanism of action and/or response to study treatment. As this is a Phase Ib study to primarily explore safety, no formal statistical hypothesis is considered for the sample size calculation; approximately 60 patients will be recruited across Europe and the US. Disclosures Burke: Gilead: Consultancy; Roche/Genentech: Consultancy; Celgene: Consultancy. André:Celgene: Other: Travel grants, Research Funding; Chugai: Research Funding; Takeda Millenium: Research Funding; Johnson & Johnson: Research Funding; Amgen: Other: Travel grants, Research Funding; Roche: Other: Travel grants, Research Funding; Abbvie: Membership on an entity's Board of Directors or advisory committees; Seattle Genetics: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding; Takeda: Membership on an entity's Board of Directors or advisory committees; Bristol-Myers-Squibb: Membership on an entity's Board of Directors or advisory committees; Karyopharm: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees, Other: Travel grants. Cheson:Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Gilead: Research Funding; Acerta: Consultancy, Research Funding; Kite: Research Funding; Epizyme: Research Funding; Morphosys: Membership on an entity's Board of Directors or advisory committees; AstraZeneca: Membership on an entity's Board of Directors or advisory committees; Pharmacyclics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Symbios: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Trillium: Research Funding; TG Therapeutics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Seattle Genetics: Research Funding; Bristol Myers Squibb: Research Funding; Portola: Research Funding; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. Duell:Regeneron Pharmaceuticals, Inc.: Research Funding. Nowakowski:Genentech, Inc.: Research Funding; F. Hoffmann-La Roche Ltd: Research Funding; Selvita: Membership on an entity's Board of Directors or advisory committees; NanoString: Research Funding; MorphoSys: Consultancy, Research Funding; Curis: Research Funding; Bayer: Consultancy, Research Funding; Celgene: Consultancy, Research Funding. Rosenwald:MorphoSys: Consultancy. Salles:Roche, Janssen, Gilead, Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Educational events; BMS: Honoraria; Novartis, Servier, AbbVie, Karyopharm, Kite, MorphoSys: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Educational events; Autolus: Consultancy, Membership on an entity's Board of Directors or advisory committees; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Educational events; Epizyme: Consultancy, Honoraria; Amgen: Honoraria, Other: Educational events; Merck: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. Sharman:Acerta: Consultancy, Honoraria, Research Funding; TG Therapeutics: Consultancy, Honoraria, Research Funding; Pharmacyclics LLC, an AbbVie Company: Consultancy, Honoraria, Research Funding; AbbVie: Consultancy, Honoraria, Research Funding; Genentech: Consultancy, Honoraria, Research Funding; AstraZeneca: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Research Funding. Staber:Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Takeda-Millenium: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Janssen: Honoraria, Speakers Bureau; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; Gilead: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; MSD: Honoraria, Speakers Bureau; AbbVie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Trněný:Abbvie: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Gilead Sciences: Consultancy, Honoraria; Incyte: Consultancy, Honoraria; MorphoSys: Consultancy, Honoraria; Bristol-Myers Squibb: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; F. Hoffmann-La Roche: Consultancy, Honoraria; Celgene: Consultancy; Janssen: Consultancy, Honoraria. Westin:Novartis: Other: Advisory Board, Research Funding; Juno: Other: Advisory Board; Unum: Research Funding; Curis: Other: Advisory Board, Research Funding; Genentech: Other: Advisory Board, Research Funding; Kite: Other: Advisory Board, Research Funding; Celgene: Other: Advisory Board, Research Funding; 47 Inc: Research Funding; MorphoSys: Other: Advisory Board; Janssen: Other: Advisory Board, Research Funding. Brugger:MorphoSys: Employment; AstraZeneca: Equity Ownership. Fingerle-Rowson:MorphoSys AG: Employment. Klanova:MorphoSys AG: Employment. Würth:MorphoSys AG: Employment. Truemper:Janssen Oncology: Consultancy; Nordic Nanovector: Consultancy; Takeda: Consultancy, Research Funding; Seattle Genetics, Inc.: Research Funding; Roche: Research Funding; Mundipharma: Research Funding.