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Rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) is the current standard therapy for patients with diffuse large B-cell lymphoma (DLBCL) and is curative in ∼60% of patients. Atezolizumab is a humanized immunoglobulin G1 monoclonal antibody that targets programmed death–ligand 1 and has previously shown antitumor activity in several tumor types. In a phase 1b/2 trial (NCT02596971), we evaluated the safety and efficacy of atezolizumab in combination with R-CHOP (atezo–R-CHOP; for 6-8 cycles) in patients with previously untreated DLBCL. Patients achieving a complete response (CR) at the end of induction received consolidation therapy with atezolizumab on day 1 of each 21-day cycle for an additional 17 cycles. Overall, 42 patients with DLBCL were included in this analysis. The primary endpoint, CR rate at the end of induction, as assessed by an independent review committee (modified Lugano 2014 criteria), was 77.5% (95% confidence interval [CI], 64.0-87.7; n = 40). Investigator-assessed progression-free survival and overall survival at 3 years were 77.4% (95% CI, 59.7-88.0) and 87.2% (95% CI, 71.9-94.5), respectively. All treated patients experienced ≥1 adverse event (AE; 32 patients [76.2%] had grade 3-4 AE). One patient had a fatal AE (unconfirmed progressive multifocal leukoencephalopathy) that was considered related to atezolizumab and rituximab, and 17 patients (40.5%) experienced atezolizumab-related AEs of special interest. In previously untreated patients with DLBCL, atezo–R-CHOP demonstrated encouraging clinical efficacy and a safety profile consistent with the known toxicities of the individual drugs. This trial was registered at www.clinicaltrials.gov as #NCT02596971.

Peripheral T-cell lymphomas (PTCLs) are a heterogeneous group of aggressive non-Hodgkin lymphomas, the majority of which have high relapse rates following standard therapy. Despite use of consolidative stem cell transplant (SCT) following frontline therapy, there remains no consensus on its utility. The double-blind randomized phase 3 ECHELON-2 study (#NCT01777152; clinicaltrials.gov) demonstrated improved progression-free survival (PFS) and overall survival with frontline brentuximab vedotin plus cyclophosphamide, doxorubicin, and prednisone (A+CHP). Herein, we conducted an exploratory subgroups analysis of the impact of consolidative SCT on PFS in patients with previously untreated CD30+ PTCL (ALK− anaplastic large cell lymphoma [ALCL] and non-ALCL) who were in complete response (CR) after frontline treatment with A+CHP or cyclophosphamide, doxorubicin, vincristine, and prednisone. Median PFS follow-up was 47.57 months. The PFS hazard ratio was 0.36, equating to a 64% reduction in the risk of a PFS event in patients who underwent SCT. The median PFS in patients who underwent SCT was not reached, vs 55.66 months in patients who did not undergo SCT. PFS results favored the use of SCT in both ALK− ALCL and non-ALCL subgroups. These data support the consideration of consolidative SCT in patients with CD30+PTCL who achieve CR following treatment with A+CHP.

Obinutuzumab (G) chemoimmunotherapy demonstrated improved progression-free survival (PFS) vs rituximab-based chemoimmunotherapy in patients with previously untreated follicular lymphoma (FL) in the GALLIUM trial. Atezolizumab (atezo) is a programmed death-ligand 1 inhibitor with a complementary mechanism of action to G by restoring cytotoxic T-cell function. We evaluated the safety and efficacy of atezo-G-bendamustine in patients with previously untreated FL in a phase Ib/II trial (#NCT02596971). A safety run-in phase was followed by an expansion phase with atezo-G-bendamustine induction and atezo-G maintenance for ≤24 months. Forty patients with previously untreated FL were enrolled and treated with atezo-G-bendamustine. The primary endpoint, complete response (CR) rate, assessed by an independent review committee (IRC; modified Lugano 2014 criteria) was 75.0% (95% confidence interval [CI], 61.3% to 85.8%). Three-year investigator-assessed PFS and overall survival rates were 80.9% (95% CI, 63.9% to 90.5%) and 89.3% (95% CI, 73.9% to 95.9%), respectively. At baseline, 21/40 patients had circulating lymphoma-specific clonotypes and underwent repeat testing at end of induction; all were minimal residual disease negative (10−5 sensitivity), with 16 (76.2%) CRs, 3 (14.3%) partial responses, and 2 (9.5%) with stable disease (IRC assessed). Grade 5 (fatal) adverse events (AEs) were reported in 5 patients. The efficacy of atezo-G-bendamustine in previously untreated FL did not appear superior to G-bendamustine efficacy as seen in the GALLIUM trial, and the addition of atezo to G-bendamustine was associated with an increased risk of AEs. Particularly due to the unfavorable safety profile, this regimen cannot be recommended in patients with previously untreated FL. This trial was registered at www.clinicaltrials.gov as #NCT02596971.

Introduction Midostaurin is the only approved FLT3 inhibitor for combination with intensive induction and consolidation chemotherapy in newly diagnosed patients with FLT3 mutant AML. The FLT3 inhibitor, sorafenib, was investigated in the randomized SORAML trial (Röllig, Lancet Onc 2015), in combination with intensive chemotherapy (IC) for newly diagnosed adults with AML Methods The Australasian Leukaemia and Lymphoma Group (ALLG) conducted a randomized phase 2 study [ACTRN12611001112954] in 99 adults aged 18-65 years with newly diagnosed FLT3-ITD positive (allelic ratio (AR) ≥0.05) AML to determine whether addition of SOR to IC would improve event-free survival (EFS). The study was powered to identify a 25% increase in 2-year EFS with SOR. Patients 18-55 yrs received induction with IDAC-3 (idarubicin [IDA] 12 mg/m2 D1-3 and ara-C 1.5 g/m2 BD D1,3,5,7); patients 56-65 received 7+3 (IDA 12 mg/m2 D1-3 and ara-C 100 mg/m2 D1-7 IVI). Patients were randomized 2:1 to SOR or PBO 400 mg BD on days 4-10 of induction and each consolidation cycle. Due to the pharmacokinetic interaction between SOR and azoles, antifungal prophylaxis during induction was with AmBisome 5 mg/kg IV twice weekly. For consolidation, patients 18-55 yrs received 2 cycles of IcE (IDA 9 mg/m2 D1-2, ara-C 100 mg/m2 D1-5 IVI and etoposide 75 mg/m2 D1-5), those 56-65 yrs received 2 cycles of IDAC-2 (IDA 12 mg/m2 D1-2 and ara-C 1g/m2 BD D1,3,5). Maintenance was with SOR/PBO 400 mg bd days 1-28 for 12 cycles. Allogeneic HCT (allo-HCT) was at investigator discretion. SOR/PBO was not continued post allo-HCT. The primary endpoint was EFS without censoring for allo-HCT with events defined as failure to achieve complete remission (CR) or CR with incomplete hematologic recovery (CRi), relapse or death. Pre-specified secondary endpoints included overall response rate (ORR) defined as CR and CRi, tolerability, EFS according to FLT3-ITD AR < or ≥ 0.7 and impact of randomization on allograft outcome. Results Between Jan 2013-May 2018, 18 centers randomized 99 patients to induction with either SOR (n=65) or PBO (n=33); one patient later found to be FLT3-ITD negative was excluded. Patient characteristics are shown in Table 1. Treatment arms were balanced apart from fewer patients in the SOR arm with NPM1 mutant AML. Deliverability of therapy was comparable, with commencement of consolidation in 78% and 79% and maintenance therapy in 32% and 27% in the SOR and PBO arms, respectively. The overall response rate (ORR) was high in both arms; 91% in the SOR (CR 80%, CRi 11%) and 94% in the PBO (CR 70%, CRi 24%) arm. In the SOR arm, 5% achieved partial remission, went off study and were deemed treatment failures. With a median overall follow-up of 25 mo, there was no significant difference in EFS (HR 0.87 95% CI 0.50-1.49; P=0.61)(Fig A) or OS (HR 0.70 95% CI 0.38-1.29; P=0.26)(Fig. B), nor in a sensitivity analysis with censoring at HCT. 2 yr EFS was 47.9% (SOR) vs 45.4% (PBO) and 2-year OS 66.8% (SOR) vs 56.4% (PBO). Hematopoietic cell transplant (HCT) in CR1 was performed in 62% and 58% in the SOR and PBO arms, respectively. For patients in CR1, 2 yr OS post-HCT was 78.5% (SOR) vs 54.2% (PBO)(Fig C). Suggestive of an on-target effect against FLT3-ITD, the impact of SOR on OS appeared greater for patients with higher FLT3-ITD AR ≥0.7 (Fig. D) (Table 2). Only one early death (within 30 days) was recorded in each treatment arm. The frequency of grade 3-4 adverse events (AEs) were similar between the two arms, apart from palmar-plantar rash, reported as drug-related in 15.4% and 6.1% pts in the SOR and PBO arms, respectively. Correlative studies will be reported in a companion abstract. Conclusions SOR did not improve EFS when combined with intensive chemotherapy in adults with newly diagnosed FLT3-ITD AML. Although not powered for significance, SOR showed a trend for improved OS among patients with higher FLT3-ITD AR or receiving HCT in CR1. Further exploration of more potent FLT3 inhibitors in the pre- and post-allograft setting are warranted for patients with newly diagnosed FLT3 mutant AML. Acknowledgements: The ALLG AMLM16 trial was funded through an Australian Government NHMRC grant and a research grant from the Leukaemia Foundation of Australia. Bayer supplied sorafenib and Gilead AmBisome. Disclosures Wei: Roche: Honoraria; Servier: Consultancy, Honoraria, Research Funding; Novartis: Honoraria, Research Funding, Speakers Bureau; Amgen: Honoraria, Research Funding; Abbvie: Honoraria, Research Funding, Speakers Bureau; Pfizer: Honoraria; Bristol Myers Squibb: Honoraria, Research Funding, Speakers Bureau; Walter and Eliza Hall Institute of Medical Research: Patents & Royalties: AW is eligible for royalty payments related to venetoclax; Astra Zeneca: Honoraria, Research Funding; Janssen: Honoraria; Macrogenics: Honoraria. Enjeti:Novartis: Membership on an entity's Board of Directors or advisory committees; Alexion: Speakers Bureau; Bayer: Speakers Bureau; Sanofi: Speakers Bureau; AbbVie: Membership on an entity's Board of Directors or advisory committees; Astellas: Membership on an entity's Board of Directors or advisory committees. D'Rozario:Abbvie: Membership on an entity's Board of Directors or advisory committees; BMS/ Celgene: Membership on an entity's Board of Directors or advisory committees. Marlton:Celgene: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees; Astellas: Membership on an entity's Board of Directors or advisory committees; AbbVie: Membership on an entity's Board of Directors or advisory committees; F. Hoffmann-La Roche Ltd: Membership on an entity's Board of Directors or advisory committees; Astra-Zeneca: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees. Verner:Janssen Cilag Pty Ltd.: Research Funding. Hahn:Roche: Honoraria; Astra Zeneca: Honoraria. Hiwase:Novartis Australia: Research Funding. Anstee:Walter and Eliza Hall Institute: Patents & Royalties: milestone and royalty payments related to venetoclax.. Levis:FujiFilm: Honoraria, Research Funding; Amgen: Honoraria; Daiichi-Sankyo: Honoraria; Menarini: Honoraria; Astellas: Honoraria, Research Funding. Bajel:Abbvie: Honoraria; Astellas: Honoraria; Pfizer: Honoraria; Amgen: Honoraria, Speakers Bureau; Novartis: Honoraria. Roberts:Genentech: Patents & Royalties: for venetoclax to one of my employers (Walter & Eliza Hall Institute); I receive a share of these royalties; Janssen: Research Funding; Servier: Research Funding; AbbVie: Research Funding. OffLabel Disclosure: Sorafenib for FLT3-ITD AML

Introduction: Polatuzumab vedotin (Pola) combined with rituximab (R) demonstrated activity and tolerability in a Phase (Ph) II trial of patients (pts) with relapsed/refractory (R/R) diffuse large B-cell lymphoma (DLBCL) (Morschhauser et al. Lancet 2019). The pro-survival MCL-1 protein has been identified as a mechanism of resistance to venetoclax (Ven), a potent inhibitor of BCL-2, in non-Hodgkin lymphoma cell lines. Preclinical studies have demonstrated that concurrent treatment with Pola promotes MCL-1 degradation and enhances anti-tumor efficacy in vivo, thus providing a strong rationale for the combination with Ven (Amin et al. AACR 2020). We sought to determine whether the combination of Pola-Ven-R might further enhance anti-tumor response. Here, we present the primary efficacy and safety analysis from a Ph Ib/II study of Pola-Ven-R in pts with R/R DLBCL (GO29833; NCT02611323). Methods: GO29833 is an open-label, multicenter study of pts with R/R DLBCL who had received ≥1 prior anti-CD20 chemo-immunotherapy regimen. The recommended Ph II dose (RP2D) combination for Pola-Ven-R was initially defined in a 3+3 dose escalation phase and was then expanded into Ph II. Pts in the expansion cohort received induction therapy with six 21-day cycles of: intravenous (IV) Pola 1.8mg/kg (Cycle [C] 1-6: Day [D]1), Ven 800mg by mouth daily and R 375mg/m2 IV (C1-6: D1). Responders received consolidation therapy for 8 months (Ven 800mg daily and R 375mg/m2 on D1 every 2 months). The primary safety objectives were to determine the RP2D for Pola and Ven when given in combination with R and to evaluate the safety and tolerability of the Pola-Ven-R combination. The primary efficacy endpoint was complete response (CR) at end of induction (EOI), as determined by the Independent Review Committee (IRC) based on positron emission tomography-computed tomography (PET-CT) scans using modified Lugano 2014 response criteria. Secondary objectives included CR-rate at EOI and best overall response (BOR) determined by the investigator (INV). Exploratory objectives included INV-assessed progression-free survival (PFS) and overall survival (OS). Results: At the primary analysis (January 30, 2020), 57 pts from the Ph Ib/II populations were enrolled and received at least one study drug; the median duration of follow-up was 7.0 (range 0.2-30.4) months. Baseline characteristics of the safety-evaluable pts are shown in Table 1: median age, 65 years; male, 49%; Ann Arbor Stage III-IV, 84%; International Prognostic Index (IPI) ≥3, 54%; median prior lines of therapy, 3; refractory to last line, 83%; primary refractory, 65%. Dose limiting toxicity was not observed in Ph I and the maximum dose level was chosen as RP2D. All except two pts experienced at least one adverse event (AE), 21 (37%) had a serious AE, and 45 (79%) had a Grade 3-4 AE. The most common Grade 3-4 AEs were neutropenia (30 pts, 53%), infections (9 pts, 16%), and anemia (6 pts, 11%). AEs leading to dose reduction or interruption of any drug occurred in 10 (18%) and 35 (61%) pts, respectively; the majority of dose modifications were changes to Ven dosing. Seven (12%) pts had an AE that led to the discontinuation of any study drug (Pola [n=5]; Ven [n=7]; R [n=6]). One grade 5 AE was reported (pneumonia); however, it was not considered related to study treatment as the pt had received new anti-lymphoma therapy following disease progression. In the primary efficacy-evaluable population (n=48), the IRC-assessed modified Lugano CR rate at EOI was 29% (Table 2). The INV-assessed CR rate at EOI and BOR were 31% and 65%, respectively, with a median duration of response of 5.8 months (95% confidence interval [CI]: 3.4-6.7). The median PFS and OS were 4.4 months (95% CI: 3.0-7.1) and 11.0 months (95% CI: 6.7-not evaluable), respectively. Conclusions: Our study of the novel triplet combination, Pola-Ven-R, demonstrates a safety profile consistent with the known profiles of the individual drugs. This first report of the full efficacy population showed promising activity in a heavily pre-treated and refractory population of pts with R/R DLBCL. Further evaluation of Pola-Ven-R and the impact of consolidation therapy is warranted to address the significant unmet medical need in this patient population. Disclosures Gritti: Autolus: Consultancy; Takeda: Honoraria; F. Hoffmann-La Roche Ltd: Honoraria; Amgen: Honoraria; Kite: Consultancy; Italfarmaco: Consultancy; Jannsen: Other: Travel Support; IQVIA: Consultancy. Marlton:Astellas: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Astra-Zeneca: Membership on an entity's Board of Directors or advisory committees; F. Hoffmann-La Roche Ltd: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees; AbbVie: Membership on an entity's Board of Directors or advisory committees. Phillips:Abbvie: Consultancy, Research Funding; Pharmacyclics: Consultancy; Cardinal Health: Consultancy; Bayer: Consultancy, Research Funding; BMS: Consultancy; Seattle Genetics: Consultancy; Incyte: Consultancy, Other: travel expenses; AstraZeneca: Consultancy; Karyopharm: Consultancy; Beigene: Consultancy. Arthur:Royal North Shore Hospital: Current Employment. Bannerji:Regeneron Pharmaceuticals: Research Funding; AbbVie: Research Funding; Sanofi-Pasteur: Other: Spouse is employee; F. Hoffmann-La Roche Ltd/Genentech, Inc and Pharmacyclics LLC, an AbbVie Company: Research Funding. Corradini:Incyte: Consultancy; Celgene: Consultancy, Honoraria, Other: Travel and accommodations paid by for; Janssen: Consultancy, Honoraria; Daiichi Sankyo: Consultancy, Honoraria; Sanofi: Consultancy, Honoraria; KiowaKirin: Consultancy, Honoraria; Servier: Consultancy, Honoraria; BMS: Other; Gilead: Consultancy, Honoraria, Other: Travel and accommodations paid by for; Takeda: Consultancy, Honoraria, Other; AbbVie: Consultancy, Honoraria, Other: Travel and accommodations paid by for; Novartis: Consultancy, Honoraria, Other: Travel and accommodations paid by for; F. Hoffman-La Roche Ltd: Consultancy, Honoraria; Kite: Consultancy, Honoraria; Amgen: Consultancy, Honoraria, Other: Travel and accommodations paid by for. Johnston:MSD: Membership on an entity's Board of Directors or advisory committees; F. Hoffmann-La Roche Ltd: Membership on an entity's Board of Directors or advisory committees. Seymour:Janssen: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; AstraZeneca: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; AbbVie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; F. Hoffmann-La Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Gilead: Consultancy; Mei Pharma: Consultancy, Honoraria; Morphosys: Consultancy, Honoraria; Nurix: Honoraria. Hirata:Genentech, Inc.: Current Employment; F. Hoffmann-La Roche Ltd: Current equity holder in publicly-traded company. Musick:F. Hoffmann-La Roche Ltd: Current equity holder in publicly-traded company; Roche/Genentech, Inc.: Current Employment. Saha:Genentech, Inc.: Consultancy; Genentech, Inc.: Current Employment. Croft:Genentech, Inc.: Current Employment, Current equity holder in publicly-traded company, Divested equity in a private or publicly-traded company in the past 24 months. Flowers:OptumRx: Consultancy; Karyopharm: Consultancy; Gilead: Consultancy, Research Funding; Leukemia and Lymphoma Society: Membership on an entity's Board of Directors or advisory committees; BeiGene: Consultancy; Bayer: Consultancy; Denovo Biopharma: Consultancy; Genentech, Inc./F. Hoffmann-La Roche Ltd: Consultancy, Research Funding; Pharmacyclics/Janssen: Consultancy; Acerta: Research Funding; Spectrum: Consultancy; Millennium/Takeda: Consultancy, Research Funding; TG Therapeutics: Research Funding; Burroughs Wellcome Fund: Research Funding; Eastern Cooperative Oncology Group: Research Funding; National Cancer Institute: Research Funding; AbbVie: Consultancy, Research Funding; V Foundation: Research Funding; Cancer Prevention and Research Institute of Texas: Research Funding; Celgene: Consultancy, Research Funding; Kite: Research Funding. OffLabel Disclosure: Polatuzumab vedotin (Polivy) is approved in combination with bendamustine and rituximab or use in third-line or later treatment of relapsed/refractory (R/R) DLBCL in the USA and in second-line or later treatment in the EU. Venetoclax (Venclexta) is approved for the treatment of adult patients with CLL or SLL, and in combination with azacitidine or decitabine or low-dose cytarabine for the treatment of newly-diagnosed AML in adults >75 years, or who have comorbidities that preclude use of intensive induction chemotherapy. Rituximab (Rituxan) is approved for use in relapsed/refractory low-grade NHL and in previously untreated DLBCL with CHOP, but is not approved for use in R/R DLBCL.

Introduction The phase 3 ECHELON-2 study (NCT01777152) demonstrated that frontline treatment with brentuximab vedotin (BV) plus cyclophosphamide, doxorubicin, and prednisone (A+CHP) is superior to cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) for patients (pts) with systemic anaplastic large cell lymphoma (sALCL) or other CD30-expressing peripheral T-cell lymphomas (PTCL) (Horowitz S, et al. Lancet 2019). With a median follow-up of 36.2 months for progression-free survival (PFS), the hazard ratio (HR) (0.71 [95% confidence interval {CI}: 0.54, 0.93], P=0.01) favored A+CHP over CHOP. The median PFS was 48.2 months (95% CI: 35.2, not evaluable) versus 20.8 months (95% CI: 12.7, 47.6) for A+CHP and CHOP, respectively. With a median follow-up of 42.1 months for overall survival (OS), the HR (0.66 [95% CI: 0.46, 0.95], P=0.02) also favored A+CHP over CHOP. Median OS was not reached for either arm. With these results, A+CHP was the first treatment regimen to show an OS benefit over CHOP in this pt population. Herein, we report results with a median follow-up of 44.3 months for PFS and 55.5 months for OS. Methods ECHELON-2 is a phase 3, randomized, double-blind, double-dummy, placebo-controlled, active-comparator, multicenter study. Eligible adult pts with previously untreated CD30-positive PTCL (targeting 75% ± 5% with sALCL) were randomized to A+CHP or CHOP for six or eight cycles. Randomization was stratified by histological subtype and international prognostic index score. The primary endpoint of PFS was assessed per blinded independent central review in the primary analysis and per investigator in this updated analysis. Key secondary endpoints were OS, PFS in sALCL, complete remission (CR) rate, and objective response rate (ORR). Subsequent therapies, including BV or BV-containing regimens, were permitted. Results A total of 452 pts were enrolled and randomized 1:1 with 226 pts in each arm. The study included pts with advanced disease (Stage III [27%] and Stage IV [53%]; IPI ≥2 [78%]); given target enrollment, most pts (316 [70%]) had sALCL (218 [48%] anaplastic lymphoma kinase [ALK]-negative and 98 pts [22%] ALK-positive). With additional follow-up, the HRs for PFS per investigator (0.70 [95% CI: 0.53, 0.91], P=0.0075) (Figure 1) and OS (0.74 [95% CI: 0.54, 1.02], P=0.0688) continue to favor A+CHP over CHOP. The median PFS was 63.5 months (95% CI: 42.0, not evaluable) versus 23.8 months (95% CI: 13.6, 55.9) for A+CHP and CHOP, respectively. The estimated 5-year PFS was 50.9% (95% CI: 42.1, 59.1) for the A+CHP arm versus 42.7% (95% CI: 35.3, 49.8) for the CHOP arm. Median OS was not reached for either arm. The estimated 5-year OS was 68.7% (95% CI: 61.3, 75.0) for the A+CHP arm versus 60.3% (95% CI: 52.8, 67.0) for the CHOP arm. The PFS analyses for key prespecified subgroups were generally consistent with the overall study results (Figure 2). In the subset of pts with sALCL, the HR for PFS (0.55 [95% CI: 0.39, 0.78]) also favors A+CHP over CHOP, with an estimated 5-year PFS of 59.8% (95% CI: 48.0, 69.7) for the A+CHP arm versus 48.1% (95% CI: 39.1, 56.6) for the CHOP arm. A total of 23 pts (10%) in the A+CHP arm (16 pts with sALCL, 4 pts with PTCL not otherwise specified, and 3 pts with angioimmunoblastic T-cell lymphoma) and 51 pts (23%) in the CHOP arm received subsequent systemic therapy with BV. In the A+CHP arm, the median time to retreatment was 12.3 months (range, 3, 51); 15 pts (ORR: 65%) had CR (9 pts) or partial remission (6 pts) after retreatment with BV monotherapy (21 pts) or BV-containing regimen (2 pts). With additional follow-up in pts with treatment-emergent peripheral neuropathy (PN) (117 pts A+CHP and 124 pts CHOP), 68% of pts in the A+CHP arm had either resolution or improvement of these events compared with 77% of pts in the CHOP arm. Of the pts with ongoing PN events at last follow-up, 73% in A+CHP arm and 74% in the CHOP arm had grade 1 events, 25% and 23% of pts, respectively, had grade 2 events, and 2% of pts in each arm had grade 3 events. Conclusions At 5 years, frontline treatment with A+CHP continues to provide clinically meaningful improvement in PFS and OS versus CHOP, including ongoing remission in ~60% of pts with sALCL, with a manageable safety profile, including continued resolution or improvement of PN. Additional 5-year results, including data from prespecified subgroups, will be presented. Disclosures Horwitz: C4 Therapeutics: Consultancy; Daiichi Sankyo: Research Funding; Affirmed: Consultancy; GlaxoSmithKline: Consultancy; Janssen: Consultancy; Kura Oncology: Consultancy; Miragen: Consultancy; Myeloid Therapeutics: Consultancy; Verastem: Consultancy, Research Funding; ASTEX: Consultancy; Vividion Therapeutics: Consultancy; Beigene: Consultancy; ADCT Therapeutics: Consultancy, Research Funding; Aileron: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Forty Seven: Consultancy, Research Funding; Infinity/Verastem: Research Funding; Kyowa Hakka Kirin: Consultancy, Research Funding; Millenium/Takeda: Consultancy, Research Funding; Seattle Genetics: Consultancy, Research Funding; Trillium: Consultancy, Research Funding; Corvus: Consultancy; Innate Pharma: Consultancy; Mundipharma: Consultancy; Portola: Consultancy, Research Funding. Pro:Verastem Oncology: Research Funding. Illidge:Takeda: Current Employment, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Iyer:Legend Biotech: Consultancy; Rhizen: Research Funding; Spectrum: Research Funding; CRISPR: Research Funding; Curio Biosciences: Honoraria; Trillium: Research Funding; Target Oncology: Honoraria; Afffimed: Research Funding; Daiichi Sankyo: Consultancy; Merck: Research Funding; Seattle Genetics, Inc.: Research Funding. Advani:Astra Zeneca, Bayer Healthcare Pharmaceuticals, Cell Medica, Celgene, Genentech/Roche, Gilead, KitePharma, Kyowa, Portola Pharmaceuticals, Sanofi, Seattle Genetics, Takeda: Consultancy; Celgene, Forty Seven, Inc., Genentech/Roche, Janssen Pharmaceutical, Kura, Merck, Millenium, Pharmacyclics, Regeneron, Seattle Genetics: Research Funding. Bartlett:BTG: Consultancy; Seattle Genetics: Membership on an entity's Board of Directors or advisory committees, Research Funding; ADC Therapeutics: Consultancy; Forty Seven: Research Funding; Autolus: Research Funding; Acerta: Consultancy; Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Immune Design: Research Funding; Janssen: Research Funding; Kite, a Gilead Company: Research Funding; Merck: Research Funding; Millennium: Research Funding; Pharmacyclics: Research Funding; Seattle Genetics: Consultancy, Research Funding; Affimed Therapeutics: Research Funding; BMS/Celgene: Research Funding; Roche/Genentech: Consultancy, Research Funding. Christensen:Odense University Hospital: Current Employment; Seattle Genetics, Inc.: Research Funding. Morschhauser:Abbvie: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Epizyme: Membership on an entity's Board of Directors or advisory committees; Gilead: Consultancy, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria; Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Servier: Consultancy. Domingo-Domenech:Takeda: Consultancy, Other: Travel, accomodations and expenses , Research Funding; Bristol-Myers Squibb: Other: Travel, Research Funding; Roche: Other: Travel, accomodations and expenses ; Janssen: Other: Travel, accomodations and expenses ; Seattle Genetics, Inc.: Research Funding. Rossi:Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Other: Advisory board; Astellas: Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria; Daiichi Sankyo: Consultancy, Honoraria; Sanofi: Honoraria; Jazz: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees; Alexion: Membership on an entity's Board of Directors or advisory committees; Abbvie: Membership on an entity's Board of Directors or advisory committees. Kim:Donga: Research Funding; Joihnson & Johnson: Research Funding; Kyowa Kirin: Research Funding; Mundipharma: Research Funding; Pfizer: Research Funding; Roche: Research Funding; Takeda: Research Funding; Celltrion: Research Funding. Feldman:Celgene: Honoraria, Research Funding; Cell Medica: Research Funding; Amgen: Research Funding; Kite: Honoraria, Other: Travel expenses, Speakers Bureau; Rhizen: Research Funding; Janssen: Speakers Bureau; Pharmacyclics: Honoraria, Other, Speakers Bureau; AstraZeneca: Consultancy; Bayer: Consultancy, Honoraria; Abbvie: Honoraria; Takeda: Honoraria, Other: Travel expenses; Pfizer: Research Funding; BMS: Consultancy, Honoraria, Research Funding; Trillium: Research Funding; Portola: Research Funding; Corvus: Research Funding; Kyowa Kirin: Consultancy, Research Funding; Eisai: Research Funding; Seattle Genetics, Inc.: Consultancy, Honoraria, Other: Travel expenses, Research Funding, Speakers Bureau; Viracta: Research Funding. Menne:Daiichi Sankyo: Honoraria; Kyowa Kirin: Other: Travel expenses; Pfizer: Honoraria, Other; Roche: Honoraria; Bayer: Other: Travel expenses; Kite/Gilead: Honoraria, Other: Travel expenses; Novartis: Honoraria, Research Funding; Celgene: Honoraria, Other: Travel expenses; Takeda: Honoraria; Atara: Honoraria; AstraZeneca: Research Funding; Amgen: Honoraria, Other: Travel expenses; Janssen: Honoraria, Research Funding. Belada:Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Travel expenses, Research Funding; Roche: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Travel expenses, Research Funding; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Gilead: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Travel expenses, Research Funding; Celgene: Research Funding. Illés:Celgene, Janssen, Novartis,Roche, Takeda: Consultancy; Novartis, Janssen, Pfizer, Roche;: Other: Travel, Accommodations, Expenses; Janssen, Celgene, Takeda, Novartis Pharma SAS, Pfizer Pharmaceuticals Israel, Roche;: Consultancy, Honoraria; Takeda, Seattle Genetics: Research Funding. Tobinai:Daiichi Sankyo: Consultancy, Honoraria; Kyowa Kirin: Consultancy, Honoraria; Bristol-Myers Squibb: Honoraria; Celgene: Consultancy, Honoraria; Mundipharma: Consultancy, Honoraria; Ono Pharma: Consultancy, Honoraria; Solasia: Honoraria; SymBio: Consultancy; Takeda: Consultancy, Honoraria; HUYA Bioscience: Consultancy, Honoraria; Eisai: Honoraria; Yakult: Consultancy, Honoraria; Zenyaku Kogyo: Consultancy, Honoraria; Chugai Pharma: Consultancy, Honoraria. Tsukasaki:Ono Pharma: Consultancy; Mundy Pharma: Honoraria; HUYA: Consultancy, Research Funding; Kyowa Kirin: Honoraria, Research Funding; Celgene: Honoraria; Chugai Pharma: Honoraria, Research Funding; Daiichi Sankyo: Consultancy; Eizai: Research Funding; Seattle Genetics: Research Funding. Yeh:AbbVie: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees; Astellas: Membership on an entity's Board of Directors or advisory committees; Astex: Membership on an entity's Board of Directors or advisory committees. Shustov:Seattle Genetics: Research Funding. Hüttmann:Lead Discovery Center GmbH: Consultancy; Celgene: Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company); Gilead: Honoraria; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company); Roche: Other: Travel expenses; Seattle Genetics: Research Funding; University Hospital Essen, University of Duisburg-Essen, Essen, Germany: Current Employment. Savage:Verastem: Honoraria; Takeda: Honoraria; Servier: Consultancy; Seattle Genetics: Consultancy, Honoraria, Research Funding; Merck: Consultancy, Honoraria; Bristol-Myers Squibb: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Abbvie: Consultancy, Honoraria. Zinzani:Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; AbbVie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; TG Therapeutics, Inc.: Honoraria, Speakers Bureau; EUSA Pharma: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Merck: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Immune Design: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Kirin Kyowa: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; ADC Therapeutics: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Sanofi: Consultancy, Membership on an entity's Board of Directors or advisory committees; Verastem: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen: Consultancy, Honoraria, Speakers Bureau; Servier: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Incyte: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Kyowa Kirin: Consultancy, Speakers Bureau; Eusapharma: Consultancy, Speakers Bureau; Portola: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Immune Design: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Sandoz: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; MSD: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen-Cilag: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celltrion: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Gilead: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; BMS: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Miao:Takeda: Current equity holder in publicly-traded company. Bunn:Seattle Genetics: Research Funding; Takeda: Current Employment. Fenton:Seattle Genetics: Current Employment, Current equity holder in publicly-traded company. Fanale:Seattle Genetics: Current Employment, Current equity holder in publicly-traded company. Puhlmann:Seattle Genetics: Current Employment, Current equity holder in publicly-traded company. Truemper:Janssen: Consultancy; Mundipharma: Research Funding; Nordic Nanovector: Consultancy; Roche: Research Funding; Seattle Genetics: Research Funding; Takeda Europe: Consultancy, Research Funding.

7534 Background: Polatuzumab vedotin (Pola) + obinutuzumab (G) demonstrated activity and tolerability in a Phase 1b/2 trial of patients (pts) with R/R FL (Phillips, et al. Blood 2016). Preclinical studies with venetoclax (Ven) showed that concurrent treatment with Pola promotes MCL-1 degradation, a known mechanism of resistance to Ven, and enhances in vivo anti-tumor efficacy (Amin, et al. AACR 2020). Here, we report the primary safety/efficacy analysis with Pola-G-Ven in a Phase 1b/2 study of pts with R/R FL (GO29833; NCT02611323). Methods: Pts received induction treatment every 21 days (D) x six cycles (C) of: Pola 1.4–1.8mg/kg intravenously (IV) in dose escalation (DE) or recommended Phase 2 dose (RP2D) on D1; G 1000mg IV (C1: D1, D8, D15; C2–6: D1); and oral Ven 200–800mg (DE or RP2D; D1–21). Pts with complete response/partial response/stable disease (CR/PR/SD) at end of induction (EOI) received maintenance with G (1000mg on D1 every 2 months [mo] for 24 mo) and Ven (200–800mg daily) for 8 mo. Primary endpoints were safety/tolerability and positron emission tomography (PET)-CR rate at EOI by independent review committee (IRC) using modified Lugano criteria. Results: At the primary analysis (Oct 05, 2020), 74 pts were enrolled. Median pt age was 64 years (range 36–78); male (57%); Ann Arbor Stage III–IV (86%); FL International Prognostic Index high risk ≥3 (55%); bulky disease ≥7cm (16%); prior lines of therapy ≥2 (74%); refractory to: last prior therapy (51%), any prior anti-CD20 therapy (55%), both anti-CD20 therapy and an alkylating agent (double refractory; 55%). Grade 3–4 adverse events (AEs) were experienced by 73% of pts; most commonly, neutropenia (39%), thrombocytopenia (19%), and infections (16%; mainly pneumonia). AEs led to dose reduction in 38% and interruption in 68% of pts (mainly modifications to Ven). One fatal AE was reported (pneumonia). In total, 49 pts were treated at RP2D (Pola 1.8mg/kg + Ven 800mg) and were evaluable for efficacy. PET-CR rate at EOI by IRC was 57% (Table). With a median follow-up of 14.4 mo (range 8.2–28.4), the 12-mo progression-free survival (PFS) was 73% (95% confidence interval: 59.4–86.9). Median PFS was not reached. Conclusions: The safety profile of Pola-G-Ven is consistent with the known profiles of the individual drugs. Response rates at EOI with Pola-G-Ven are encouraging in this R/R FL patient population. Additional follow-up is needed to assess PFS benefit during maintenance treatment and beyond. Clinical trial information: NCT02611323. [Table: see text]

7510 Background: FL is the most common type of indolent non-Hodgkin lymphoma. Approved treatment options are limited for pts with R/R FL. In a phase 1b trial ( Blood Adv. 2020;4(19):4802-4811), ZO was found to be tolerable and associated with early signal of efficacy. ROSEWOOD (BGB-3111-212) is a phase 2, randomized study designed to assess efficacy and safety of ZO vs O in pts with R/R FL. Methods: Pts with R/R FL who received ≥2 lines of therapy, including an anti-CD20 antibody and an alkylating agent, were randomized 2:1 to receive either ZO or O. O was given in both arms on Days 1, 8, and 15 of Cycle 1, Day 1 of Cycles 2-6, and then every 8 weeks up to 20 doses maximum. Z (160 mg twice daily) was given until progressive disease (PD) or unacceptable toxicity; Pts with confirmed PD in the O arm were allowed to crossover to ZO. Primary endpoint was overall response rate (ORR) by independent central review. Secondary endpoints included complete response rate (CRR), duration of response (DOR), progression-free survival (PFS), overall survival (OS), and safety. Exploratory endpoint included ORR by investigator after crossover. Primary analysis cutoff was October 8, 2021. Results: A total of 217 pts were randomized to ZO (n = 145) or O (n = 72). Median study follow-up was 12.5 mo; median age was 64 yrs. Incidence of high FL International Prognostic Index score was 53% (ZO) and 51% (O). Pts received a median of 3 prior lines of therapy, with 28% (ZO) and 25% (O) of pts receiving > 3 lines. Proportion of pts refractory to rituximab, refractory to the most recent line of therapy, or with PD within 24 mo of initiation of first-line immunochemotherapy was 54%, 32% and 28% with ZO and 50%, 40% and 32% with O, respectively. The study met its primary endpoint: ORR was 68.3% with ZO vs 45.8% with O ( p= 0.0017). CRR was 37.2% (ZO) vs 19.4% (O); 18-mo DOR rate was 70.9% (ZO) vs 54.6% (O); and median PFS was 27.4 mo (ZO) vs 11.2 mo (O; hazard ratio [HR], 0.51 [95% CI, 0.32-0.81], p= 0.0040). Median time to new anti-lymphoma therapy or crossover was not evaluable (NE; ZO) vs 12.1 mo (O; HR, 0.37 [95% CI, 0.23-0.60], p< 0.0001). ORR for 29 pts who crossed over to ZO was 24.1%. Median OS was NE; 18-mo OS probability was 85.4% (ZO) vs 72.6% (O). Most common any grade AEs in the ZO arm were thrombocytopenia (34.3%), neutropenia (27.3%), diarrhea (16.1%), fatigue (14.0%), constipation (13.3%), cough (11.9%), pyrexia (11.2%), and dyspnea (10.5%). Grade ≥3 AEs with incidence > 5% with ZO were neutropenia (22.4%) and thrombocytopenia (14.0%); incidence of atrial fibrillation was 0.7% and major bleeding was 1.4%. Incidence of treatment-emergent AEs leading to death was 5.6% (ZO) and 9.9% (O). Conclusions: ZO demonstrated superior efficacy to O in treatment of pts with R/R FL. ZO had a favorable benefit-risk profile and represents a potential combination therapy for pts with R/R FL. Clinical trial information: NCT03332017.

We present a retrospective multicenter study of pralatrexate treatment outcomes in an Australian practice setting for patients with relapsed/refractory T-cell lymphoma who had failed 1+ systemic therapies, treated via a compassionate access program. Endpoints assessed included response rates, toxicities, and subsequent therapies. Progression-free survival (PFS), time to next treatment (TTNT), event-free survival (EFS), overall survival (OS), and time to best response, were assessed by Kaplan-Meier analysis. The study included 31 patients, with median age 69 years. We demonstrated ORR of 35.5% (n = 11), including 4 complete responses (13%) and 7 partial responses (23%). The predicted median OS was 10 months, with EFS of 9 months, and PFS of 9 months. Median TTNT was 8 months. Mucositis was the most commonly observed toxicity. This study - the second largest real-world cohort reported to date - underscores the importance of pralatrexate in relapsed/refractory T-cell lymphoma, as well as its acceptable toxicity profile.

Objective Brentuximab vedotin (BV) plus cyclophosphamide, doxorubicin, and prednisone (A+CHP) significantly prolonged progression-free survival (PFS) and overall survival (OS) versus cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) in patients with systemic anaplastic large-cell lymphoma (sALCL) or other CD30-positive peripheral T-cell lymphomas (PTCL) in ECHELON-2 (Horwitz S et al., Lancet 2019). We report updated results; median follow-up was 47.6 months for PFS and 66.8 months for OS. Design This phase 3, double-blind study (NCT01777152) randomized patients aged ≥18 years with previously untreated CD30-positive PTCL (targeting 75% ± 5% with sALCL) to A+CHP or CHOP for 6 or 8 cycles. Primary endpoint of PFS was assessed per investigator in this updated analysis. Key secondary endpoints included OS and PFS in sALCL. BV or BV-containing regimens were permitted as subsequent/retreatment therapies. Results 452 patients were enrolled (226 patients in each arm); 316 (70%) patients had sALCL. Patients with advanced disease were included (stage III [27%] and stage IV [53%]; International Prognostic Index ≥2 [78%]). Data continues to favor A+CHP: HRs were 0.70 (95% CI: 0.53–0.91, P=0.0077) for PFS per investigator and 0.72 (95% CI: 0.53–0.99, P=0.0424) for OS. 5-year PFS was 51.4% (95% CI: 42.8–59.4) with A+CHP versus 43.0% (95% CI: 35.8–50.0) with CHOP; median PFS was 62.3 months (95% CI: 42.0–not evaluable) with A+CHP and 23.8 months (95% CI: 13.6–60.8) with CHOP. 5-year OS was 70.1% (95% CI: 63.3–75.9) and 61.0% (95% CI: 54.0–67.3) with A+CHP and CHOP, respectively. Median OS was not reached in either arm. PFS favored A+CHP (HR: 0.55 [95% CI: 0.39–0.79]) in sALCL. 29 (13%) and 54 (24%) patients with A+CHP and CHOP received subsequent BV, respectively. Treatment-emergent peripheral neuropathy (PN), resolved/improved in 72% (n=84/117) and 78% (n=97/124) of patients with PN on A+CHP and CHOP, respectively; 98% and 97% of ongoing PN events were grade 1/2 with A+CHP and CHOP, respectively. Conclusions At this important 5-year milestone, A+CHP still provides clinically meaningful improvement in both PFS and OS versus CHOP, with a manageable safety profile, including continued resolution/improvement of PN. Funded by NIH/NCI Support Grant P30 CA008748.

Purpose: Treatment of patients with relapsed or refractory lymphoid neoplasms represents a significant clinical challenge, largely due to the genetic heterogeneity of these malignancies. Our study goal was to design a rational treatment strategy that simultaneously targets multiple disease drivers to provide safe, efficacious, and durable responses in patients with relapsed or refractory non-Hodgkin lymphoma (NHL). Experimental procedures and data summary: Venetoclax is a selective BCL-2 inhibitor that induces apoptosis and is efficacious in chronic lymphocytic leukemia; however, single-agent efficacy in other lymphoid neoplasms is limited. Using pharmacologic and genetic studies, we identified the pro-survival BCL-2 protein family member MCL-1 as a venetoclax resistance factor in NHL cell lines. We found that the monomethyl auristatin E (MMAE) payload of the antibody-drug conjugate polatuzumab vedotin promotes MCL-1 degradation via the ubiquitin/proteasome system, thus providing a strong rationale for combination with venetoclax. Mechanistically, polatuzumab vedotin combined with venetoclax promoted apoptotic NHL cell death. In NHL animal models, venetoclax, polatuzumab vedotin, and the anti-CD20 antibody obinutuzumab, that activates targeted antibody- and complement-dependent cell cytotoxicity, produced durable tumor regressions. In a phase 1b clinical trial, 33 patients with relapsed or refractory follicular lymphoma were evaluable for response over 6 dose levels with 19 complete responses and 6 partial responses (overall response rate 76%). All patients (8 of 8) treated with the recommended phase 2 regimen (venetoclax 800mg + polatuzumab vedotin 1.8mg/kg + obinutuzumab 1000mg) achieved complete responses at end of induction. The median duration of follow-up for all dose levels was 17.7 months. This triplet combination was well-tolerated by most patients and had an expected and acceptable safety profile. Conclusions: Our studies implicate MCL-1 as a key venetoclax resistance factor in NHL that can be overcome by polatuzumab vedotin, which promotes MCL-1 degradation. Pre-clinical NHL animal models and early clinical data confirmed that the combination of venetoclax, polatuzumab vedotin, and obinutuzumab is safe and promotes durable responses. Because MMAE and other anti-tubulin agents are likely not the only therapeutics that antagonize MCL-1, our study provides scientific rationale to pursue the broader strategy of identifying other therapeutics that similarly neutralize MCL-1 function. Such agents could be used in combination with venetoclax in other malignancies where MCL-1 is a venetoclax resistance factor. Our mechanism-based treatment regimen that directly targets oncogenic drivers in NHL patients may serve as a framework for treating other malignancies with complex etiologies. Citation Format: Dhara N. Amin, Rajat Bannerji, Raghuveer Singh Mali, Jason Oeh, Eva Lin, Anuradha Zindal, MaryAnn Go, Shang-Fan Yu, Maxwell Krem, Chris Arthur, Uwe Hahn, Anna M. Johnston, Vinit G. Karur, Nadia Khan, Paula Marlton, Tycel Phillips, Giuseppe Gritti, John F. Seymour, Monica Tani, Sam Yuen Yuen, Scott Martin, Matthew T. Chang, Christopher M. Rose, Victoria C. Pham, Elizabeth A. Lasater, Andrew G. Polson, YiMeng Chang, Jamie Hirata, Lisa Musick, Deepak Sampath, Christopher R. Flowers, Ingrid E. Wertz. Targeting BCL-2 and MCL-1 overcomes treatment resistance in relapsed and refractory non-Hodgkin lymphoma: Pre-clinical rationale and results from an open-label phase 1b study [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr CT133.

BACKGROUND: Based on the encouraging activity and manageable safety profile observed in a phase 1 study, the ECHELON-2 trial was initiated to compare the efficacy and safety of brentuximab vedotin, cyclophosphamide, doxorubicin, and prednisone (A+CHP) versus cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) for the treatment of CD30-positive peripheral T-cell lymphomas.METHODS: ECHELON-2 is a double-blind, double-dummy, randomised, placebo-controlled, active-comparator phase 3 study. Eligible adults from 132 sites in 17 countries with previously untreated CD30-positive peripheral T-cell lymphomas (targeting 75% with systemic anaplastic large cell lymphoma) were randomly assigned 1:1 to receive either A+CHP or CHOP for six or eight 21-day cycles. Randomisation was stratified by histological subtype according to local pathology assessment and by international prognostic index score. All patients received cyclophosphamide 750 mg/m2 and doxorubicin 50 mg/m2 on day 1 of each cycle intravenously and prednisone 100 mg once daily on days 1 to 5 of each cycle orally, followed by either brentuximab vedotin 1·8 mg/kg and a placebo form of vincristine intravenously (A+CHP group) or vincristine 1·4 mg/m2 and a placebo form of brentuximab vedotin intravenously (CHOP group) on day 1 of each cycle. The primary endpoint, progression-free survival according to blinded independent central review, was analysed by intent-to-treat. This trial is registered with ClinicalTrials.gov, number NCT01777152.FINDINGS: Between Jan 24, 2013, and Nov 7, 2016, 601 patients assessed for eligibility, of whom 452 patients were enrolled and 226 were randomly assigned to both the A+CHP group and the CHOP group. Median progression-free survival was 48·2 months (95% CI 35·2-not evaluable) in the A+CHP group and 20·8 months (12·7-47·6) in the CHOP group (hazard ratio 0·71 [95% CI 0·54-0·93], p=0·0110). Adverse events, including incidence and severity of febrile neutropenia (41 [18%] patients in the A+CHP group and 33 [15%] in the CHOP group) and peripheral neuropathy (117 [52%] in the A+CHP group and 124 [55%] in the CHOP group), were similar between groups. Fatal adverse events occurred in seven (3%) patients in the A+CHP group and nine (4%) in the CHOP group.INTERPRETATION: Front-line treatment with A+CHP is superior to CHOP for patients with CD30-positive peripheral T-cell lymphomas as shown by a significant improvement in progression-free survival and overall survival with a manageable safety profile.FUNDING: Seattle Genetics Inc, Millennium Pharmaceuticals Inc, a wholly owned subsidiary of Takeda Pharmacuetical Company Limited, and National Institutes of Health National Cancer Institute Cancer Center.

Background Peripheral T-cell lymphomas (PTCLs) are a heterogeneous group of aggressive non-Hodgkin lymphomas (NHL). PTCL accounts for approximately 10% of all NHL cases in the US and Europe, and may be as high as 24% in Asia. The most common frontline treatment of PTCL is anthracycline-based chemotherapy with CHOP or CHOP-like regimens which do not produce durable remissions in the majority of subtypes, including ALK+ systemic anaplastic large cell lymphoma (sALCL) with high International Prognostic Index (IPI) scores. Brentuximab vedotin is an antibody-drug conjugate directed against CD30 currently approved for the treatment of relapsed or refractory sALCL with demonstrated antitumor activity in frontline PTCL. A phase 1 trial combining brentuximab vedotin with cyclophosphamide, doxorubicin, and prednisone (CHP [CHOP without vincristine to eliminate additive neurotoxicity]) as frontline treatment of PTCL demonstrated estimated 5-year progression-free survival (PFS) and overall survival (OS) rates of 52% and 79% (Fanale 2018). Based on the encouraging activity and manageable safety profile of the combination, the ECHELON-2 trial was initiated to compare the efficacy and safety of brentuximab vedotin in combination with CHP (A+CHP) versus standard CHOP for the treatment of patients (pts) with PTCL (ClinicalTrials.gov No. NCT01777152). Here we report the blinded, pooled analyses per investigator of the ECHELON-2 trial. Methods ECHELON-2 is a phase 3, randomized, double-blind, active-controlled, multicenter study. Adults with newly diagnosed CD30+ (≥10% of neoplastic cells by local review) PTCL were enrolled. Pts with ALK+ sALCL were required to have an IPI ≥2. The primary endpoint of ECHELON-2 is PFS per an independent review facility. Pts were randomized 1:1 to receive 21-day cycles of either CHOP or A+CHP for 6 to 8 cycles. Consolidative SCT or radiotherapy was permitted at the investigator's discretion after end of treatment. Results A total of 452 pts across 17 countries were randomized between January 2013 and November 2016 in Europe (44%), North America (29%), and other (26%) regions including Asia and Australia. The median age was 58 years (range, 18-85) and 63% were male. Most pts were white (62%) or Asian (22%). Most pts entering the study had an ECOG performance status of 0 or 1 (39% each) and the remaining 22% of pts had a performance status of 2. Most pts had advanced-stage disease (Stage III [27%] or IV [53%]) at diagnosis and 78% had IPI scores ≥2 (2 [34%], 3 [29%], 4 [12%]. 5 [3%]). PTCL subtypes included sALCL (316 pts [70%]: ALK+ 98 pts [22%]; ALK- 218 pts [48%]), PTCL - not otherwise specified (72 pts [16%]), angioimmunoblastic T-cell lymphoma (54 pts [12%]), adult T-cell leukemia/lymphoma (7 pts [2%]), and enteropathy-associated T-cell lymphoma (3 pts [1%]). Of the 452 randomized pts, 449 received at least 1 dose of study treatment and all pts had either completed (82%) or discontinued treatment as of April 2017. Treatment was discontinued for adverse events (AEs) (7%), progressive disease (7%), investigator decision (2%), and patient decision (2%). Preliminary results by investigator assessment, show an overall blinded pooled objective response rate (ORR) following completion of the frontline treatment of 79% (95% CI: 75.4-83.1) with 64% achieving a complete response (CR) (95% CI: 59.1-68.2). With a median follow-up of 35.2 mos, the 3-year PFS and OS for all pts were 52.9% (95% CI: 47.7-57.7) and 73.1% (95% CI: 68.3-77.2). The incidence of AEs was consistent with the known safety profiles of brentuximab vedotin and CHOP chemotherapy, including the AE of interest, peripheral sensory neuropathy (43%). Grade 3 or higher AEs reported in ≥10% of pts were neutropenia (33%), febrile neutropenia (17%), and anemia (12%). Conclusions ECHELON-2 is the largest prospective, randomized, double-blind study to compare the efficacy and safety of standard CHOP with an alternative regimen that includes a CD30-targeted agent in frontline treatment of sALCL and other CD30+ PTCLs. Blinded pooled data from ECHELON-2 show that the treatment was well tolerated with encouraging 3-year PFS and OS rates. The primary analysis by treatment regimen will be unblinded prior to the meeting and presented at the conference. Disclosures Horwitz: Seattle Genetics: Consultancy, Research Funding; Aileron Therapeutics: Consultancy, Research Funding; Innate Pharma: Consultancy; Millennium/Takeda: Consultancy, Research Funding; Forty Seven: Consultancy, Research Funding; Corvus: Consultancy; Mundipharma: Consultancy; ADC Therapeutics: Consultancy, Research Funding; Trillium: Consultancy; Celgene: Consultancy, Research Funding; Portola: Consultancy; Infinity/Verastem: Consultancy, Research Funding; Spectrum: Research Funding; Kyowa-Hakka-Kirin: Consultancy, Research Funding. O'Connor:Seattle Genetics: Research Funding; Celgene: Research Funding; ADC Therapeutics: Research Funding. Pro:kiowa: Honoraria; Takeda Pharmaceuticals: Honoraria, Other: Travel expenses; Seattle Genetics: Consultancy, Other: Travel expenses, Research Funding; portola: Honoraria. Illidge:Nordic Nanovector: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Seattle Genetics: Consultancy, Research Funding; Takeda: Consultancy, Honoraria. Fanale:Amgen: Membership on an entity's Board of Directors or advisory committees; Seattle Genetics: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel expenses, Research Funding; Bristol-Myers Squibb: Consultancy, Honoraria, Other: Travel expenses, Research Funding; Merck & Co: Consultancy, Honoraria, Other: Travel expenses, Research Funding; Takeda: Honoraria, Other: Travel expenses, Research Funding. Advani:Agensys: Research Funding; Takeda: Consultancy, Honoraria, 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, Other: Participated in an advisory board, Research Funding; Astra Zeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Participated in an advisory board; Merck: Research Funding; Janssen: Research Funding; Autolus: Membership on an entity's Board of Directors or advisory committees, Other: Participated in an advisory board; Celgene: Research Funding; Kyowa: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Participated in an advisory board; Regeneron: Research Funding; Pharmacyclics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Infinity: Research Funding; Kura: Research Funding; Celgene: Research Funding; Roche/Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Participated in an advisory board, Research Funding; Gilead/Kite: Membership on an entity's Board of Directors or advisory committees, Other: Participated in an advisory board; Cell Medica: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Participated in an advisory board; Millenium: Research Funding; Seattle Genetics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Participated in an advisory board, Research Funding; Forty Seven Inc.: Research Funding; Bayer: Membership on an entity's Board of Directors or advisory committees, Other: Participated in an advisory board. Bartlett:KITE: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Research Funding; Astra Zeneca: Research Funding; Pharmacyclics: Research Funding; Seattle Genetics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; ImaginAB: Research Funding; Gilead: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Merck & Co: Research Funding; Immune Design: Research Funding; Acerta: Membership on an entity's Board of Directors or advisory committees; Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Genentech: Research Funding; Forty Seven: Research Funding; Affimed: Research Funding; Celgene: Research Funding; Novartis: Research Funding; Pharmacyclics: Research Funding; Novartis: Research Funding; Bristol-Meyers Squibb: Research Funding; Millennium: Research Funding. Christensen:Seattle Genetics: Research Funding. Morschhauser:Janssen: Other: Scientific Lectures; BMS: Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Epizyme: Consultancy; Roche: Membership on an entity's Board of Directors or advisory committees; Gilead: Consultancy, Membership on an entity's Board of Directors or advisory committees. Domingo-Domenech:Affimed: Research Funding. Rossi:Novartis: Honoraria; Jazz: Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees; Abbvie: Membership on an entity's Board of Directors or advisory committees; Sanofi: Membership on an entity's Board of Directors or advisory committees; Teva: 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 expenses; Amgen: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees, Other: Travel expenses; Janssen: Membership on an entity's Board of Directors or advisory committees, Travel expenses; Roche: Membership on an entity's Board of Directors or advisory committees; BMS: Honoraria; Mundipharma: Honoraria; Sandoz: Honoraria; Seattle Genetics: Research Funding; Alexion: Other: Travel expenses. Feldman:Portola: Research Funding; Celgene: Speakers Bureau; Pharmacyclics: Speakers Bureau; Seattle Genetics: Research Funding, Speakers Bureau; KITE: Speakers Bureau; Johnson and Johnson: Speakers Bureau; Janssen: Speakers Bureau. Lennard:Janssen: Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees; Seattle Genetics: Research Funding. Belada:Janssen-Cilag: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Roche: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Seattle Genetics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Gilead Sciences: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. Illés:Takeda: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees. Tobinai:Zenyaku Kogyo: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Research Funding; Eisai: Honoraria, Research Funding; Ono Pharmaceutical: Honoraria, Research Funding; SERVIER: Research Funding; Abbvie: Research Funding; GlaxoSmithKline: Research Funding; Takeda: Honoraria, Research Funding; Mundipharma: Honoraria, Research Funding; Kyowa Hakko Kirin: Honoraria, Research Funding; HUYA Bioscience International: Consultancy, Honoraria; Chugai Pharma: Honoraria, Research Funding; Janssen: Honoraria, Research Funding. Tsukasaki:Celgene: Honoraria; Eisai: Research Funding; Chugai Pharma: Honoraria, Research Funding; HUYA: Consultancy, Research Funding; Ono Pharma: Consultancy; Daiich-Sankyo: Consultancy; Mundy Pharma: Honoraria; Kyowa-hakko/Kirin: Honoraria; Seattle Genetics: Research Funding. Yeh:GNT Biotech & Medicals Crop.: Research Funding. Shustov:Seattle Genetics: Research Funding. Hüttmann:Roche: Other: Travel expenses; Celgene: Other: Travel expenses. Savage:Verastem: Consultancy, Honoraria; Abbvie: Consultancy, Honoraria; Seattle Genetics: Consultancy, Honoraria, Research Funding; Merck: Consultancy, Honoraria; BMS: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Honoraria; Servier: Consultancy. Yuen:Seattle Genetics: Research Funding. Zinzani:MSD: Honoraria, Speakers Bureau; Celltrion: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; SERVIER: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Astra Zeneca: Speakers Bureau; Verastem: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Merck: Honoraria, Membership on an entity's Board of Directors or advisory committees; TG Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees; PFIZER: Honoraria, Membership on an entity's Board of Directors or advisory committees; TG Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees; Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees; Bayer: Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees; PFIZER: Honoraria, Membership on an entity's Board of Directors or advisory committees; Bayer: Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Speakers Bureau; BMS: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Merck: 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. Hua:Takeda Pharmaceuticals International Co.: Employment. Little:Takeda Pharmaceuticals: Employment. Rao:Seattle Genetics: Employment, Equity Ownership. Woolery:Seattle Genetics: Employment, Equity Ownership. Manley:Seattle Genetics: Employment, Equity Ownership. Trümper:Seattle Genetics: Research Funding.

Introduction The ECHELON-2 study (NCT01777152) demonstrated significantly longer progression-free survival (PFS) and overall survival with brentuximab vedotin plus cyclophosphamide, doxorubicin, and prednisone (A+CHP) versus CHOP in the frontline treatment of patients (pts) with sALCL or other CD30-expressing PTCL and supported the 2018 FDA approval in this setting. Consistent with current guidelines, pts could have received consolidative stem cell transplant (SCT) after treatment at the discretion of the treating investigator. In all pts treated with A+CHP, only 22% (50 of 226) underwent SCT. Herein, we present outcomes from an exploratory analysis of pts in a complete remission (CR) following A+CHP who received an SCT and those who did not. Methods CR rate was defined at the end of treatment (EOT) by independent review per the Revised Response Criteria for Malignant Lymphoma. ALK+ sALCL pts were excluded because they tend to have more favorable outcomes. Consolidative transplant was not considered a PFS event. A univariate analysis of SCT versus no SCT and multivariate analyses adjusting for region and age were performed. Results Sixty-seven percent (76/113 pts) of pts with ALK- sALCL on the A+CHP arm were in CR at EOT and 36% (27/76) of them received SCT. Pts who underwent SCT were younger, with a median age of 50 years (yr) (range 18-68) compared with 59 yr (range 20-85) in those without SCT. Median PFS for pts with SCT was not reached (95% CI 36.57, not estimable [NE]) versus 55.66 mos (95% CI 23.72, 55.66) for pts without SCT. Fifty-nine percent (38/64) of pts with non-sALCL on the A+CHP arm were in CR at EOT and 29% (11/38) of them received SCT. Pts who underwent SCT were younger than those without (median age 57 yr [35-73] vs 66 yr [49-77]). Median PFS for pts who did and did not receive SCT was not reached (95% CI 20.70, NE) versus 33.22 mos (95% CI 8.08, NE), respectively. Prior to treatment start, the intent to transplant in Asian countries among ALK- sALCL and non-ALCL pts was less frequent in comparison to non-Asian countries (13% and 29% vs 49% and 57%, respectively). The proportion of pts ultimately transplanted was also less frequent (13% and 12% in Asia versus 32% and 23% in non-Asian countries). Standard PFS and multivariate proportional hazards regression analyses favored the use of SCT in PTCL pts in a CR after A+CHP (Table). Conclusions Numerical PFS estimates favor the use of SCT in PTCL pts in a CR after A+CHP; however, sample sizes are small. It is also recognized that unknown confounders may impact this post-hoc analysis. We observed that use of SCT was infrequent in Asian countries, suggesting regional practice differences. The overall impact of consolidative SCT remains unconfirmed, including in patients treated with A+CHP. Further studies are needed to establish its role in this setting. Table Disclosures Savage: BMS, Merck, Novartis, Verastem, Abbvie, Servier, and Seattle Genetics: Consultancy, Honoraria; Seattle Genetics, Inc.: Consultancy, Honoraria, Research Funding. Horwitz:Millennium/Takeda: Consultancy, Research Funding; Infinity/Verastem: Consultancy, Research Funding; Trillium: Research Funding; Infinity/Verastem: Consultancy, Research Funding; Aileron: Research Funding; Kura: Consultancy; Affimed: Consultancy; Millennium/Takeda: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Trillium: Research Funding; Portola: Consultancy; Forty-Seven: Research Funding; Mundipharma: Consultancy; Celgene: Consultancy, Research Funding; ADCT Therapeutics: Research Funding; Astex: Consultancy; Astex: Consultancy; Celgene: Consultancy, Research Funding; Infinity/Verastem: Consultancy, Research Funding; Infinity/Verastem: Consultancy, Research Funding; Innate Pharma: Consultancy; Affimed: Consultancy; Affimed: Consultancy; Kura: Consultancy; ADCT Therapeutics: Research Funding; Kyowa Hakko Kirin: Consultancy; Corvus Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Corvus Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Kyowa Hakko Kirin: Consultancy; Astex: Consultancy; Miragen: Consultancy; Celgene: Consultancy, Research Funding; Mundipharma: Consultancy; Innate Pharma: Consultancy; Kura: Consultancy; Millennium/Takeda: Consultancy, Research Funding; Astex: Consultancy; ADCT Therapeutics: Research Funding; Affimed: Consultancy; Portola: Consultancy; Miragen: Consultancy; Aileron: Research Funding; Trillium: Research Funding; Seattle Genetics: Consultancy, Research Funding; Portola: Consultancy; Innate Pharma: Consultancy; Forty-Seven: Research Funding; Miragen: Consultancy; Kyowa Hakko Kirin: Consultancy; Aileron: Research Funding; Corvus Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Seattle Genetics: Consultancy, Research Funding; Miragen: Consultancy; ADCT Therapeutics: Research Funding; Corvus Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Millennium/Takeda: Consultancy, Research Funding; Kura: Consultancy; Innate Pharma: Consultancy; Seattle Genetics: Consultancy, Research Funding; Forty-Seven: Research Funding; Mundipharma: Consultancy; Seattle Genetics: Consultancy, Research Funding; Aileron: Research Funding; Kyowa Hakko Kirin: Consultancy; Trillium: Research Funding; Forty-Seven: Research Funding; Portola: Consultancy; Mundipharma: Consultancy. Advani:Regeneron: Research Funding; Pharmacyclics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Gilead Sciences, Inc./Kite Pharma, Inc.: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celmed: Consultancy, 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, Research Funding; Millennium: Research Funding; Forty-Seven: Research Funding; AstraZeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees; Cell Medica, Ltd: Consultancy; Janssen: Research Funding; Merck: Research Funding; Bayer: Consultancy, Membership on an entity's Board of Directors or advisory committees; Infinity Pharma: Research Funding; Celgene: Research Funding; Kura: Research Funding; Roche/Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Kyowa Kirin Pharmaceutical Developments, Inc.: Consultancy; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees; Autolus: Consultancy, Membership on an entity's Board of Directors or advisory committees; Stanford University: Employment, Equity Ownership; Seattle Genetics: Consultancy, Research Funding; Agensys: Research Funding. Domingo-Domenech:Roche: Other: Travel expenses; Seattle Genetics: Research Funding; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Travel expenses; Bristol-Myers Squibb: Other: Travel expenses. Rossi:Daiichi-Sankyo: Consultancy; Celgene: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; Sanofi: Membership on an entity's Board of Directors or advisory committees; Abbvie: Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees; Jazz: Membership on an entity's Board of Directors or advisory committees; Astellas: Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria; Mundipharma: Honoraria; BMS: Honoraria; Sandoz: Honoraria; Roche: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees. Morschhauser:Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria; Gilead: Membership on an entity's Board of Directors or advisory committees; Epizyme: Membership on an entity's Board of Directors or advisory committees; Celgene: 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; Bayer: Membership on an entity's Board of Directors or advisory committees; Seattle Genetics: Research Funding. Alpdogan:Seattle Genetics, Inc.: Research Funding. Tobinai:Meiji Seika: Honoraria; Takeda Pharmaceutical: Consultancy, Honoraria, Research Funding; Mundi Pharma: Consultancy, Honoraria, Research Funding; AbbVie: Research Funding; Chugai Pharmaceutical: Honoraria, Research Funding; Eisai: Honoraria, Research Funding; Kyowa Kirin: Honoraria, Research Funding; Verastem: Honoraria; Zenyaku Kogyo: Consultancy, Honoraria; Yakult: Honoraria; Bristol-Myers Squibb: Honoraria; HUYA Bioscience: Consultancy, Honoraria; Janssen Pharmaceutical: Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Solasia: Honoraria; Daiichi Sankyo: Consultancy, Honoraria; Ono Pharmaceutical: Consultancy, Honoraria, Research Funding. Shustov:Seattle Genetics, Inc.: Research Funding. Trneny:Roche: Consultancy, Honoraria; Bristol-Myers Squibb: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Abbvie: Consultancy, Honoraria; Incyte: Consultancy, Honoraria; Gilead sciences: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Morphosys: Consultancy, Honoraria. Yuen:Seattle Genetics, Inc.: Other: Travel expenses, Research Funding. Zinzani:Verastem: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; MSD: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Eusapharma: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Sanofi: Consultancy; Celltrion: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Gilead: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen-Cilag: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; BMS: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Servier: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Sandoz: Membership on an entity's Board of Directors or advisory committees; Immune Design: 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; Portola: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Roche: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Kyowa Kirin: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; TG Therapeutics: Honoraria, Speakers Bureau. Truemper:Janssen Oncology: Consultancy; Nordic Nanovector: Consultancy; Seattle Genetics, Inc.: Research Funding; Mundipharma: Research Funding; Roche: Research Funding; Takeda: Consultancy, Research Funding. Illidge:Div of Cancer Sciences, Faculty of Biology, Medicine and Health, Univ of Manchester, National Institutes of Health and Research Biomedical Research Center, Manchester Academic Health Sciences, Christie Hospital National Health Service Foundation Trust: Employment; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Seattle Genetics, Inc.: Research Funding. O'Connor:Spectrum Pharma: Consultancy, Other: Travel expenses, Research Funding; Roche: Research Funding; Seattle Genetics, Inc.: Consultancy, Other: Travel expenses, Research Funding; Allos Therapeutics: Consultancy; Acetylon Pharma: Other: Travel expenses, Research Funding; Celgene: Research Funding; Millenium: Consultancy, Honoraria, Other: Travel expenses, Research Funding; Mundipharma: Consultancy, Honoraria, Other: Travel expenses, Research Funding; Novartis: Consultancy, Honoraria. Pro:Kyowa Hakka Kirin: Consultancy, Honoraria; Takeda: Consultancy, Honoraria, Other: Travel Expenses; Celgene: Consultancy, Honoraria; Seattle Genetics: Consultancy, Honoraria, Other: Travel Expenses, Research Funding. Little:Takeda Pharmaceuticals: Employment. Bunn:Takeda Pharmaceuticals: Employment. Fenton:Seattle Genetics, Inc.: Employment, Equity Ownership. Manley:Seattle Genetics: Employment, Equity Ownership. Iyer:Incyte: Research Funding; Bristol-Myers Squibb: Research Funding; Seattle Genetics, Inc.: Research Funding; Genentech/Roche: Research Funding; Novartis: Research Funding; Arog: Research Funding.

While clinical recognition of thrombotic thrombocytopenia purpura (TTP) has been evident for almost 90 years, the pathological basis of this disorder has only, relatively, recently been elucidated. Consequently, options for treating TTP had evolved rather slowly for many years. Despite this, current treatment practices of intensive plasma exchange often with immune modulation have seen survival rates increase dramatically. Nevertheless, the current understanding of TTP may witness the cusp of a new era for this disorder, with new and emerging treatments nearing clinical practice that specifically target the root cause of TTP. Some of these targeted approaches may even see the beginning of plasma-free treatments for TTP, with potentially faster recoveries and fewer long-term adverse effects.

Coats disease is a rare, idiopathic retinal vasculopathy that predominantly affects males in the first decade of life. We report the case of a 3-week-old boy who presented with atypical rapidly progressing disease suggestive of Coats exudative vasculopathy. The eye developed retinal fibrosis and phthisis bulbi within 4 weeks. Retinoblastoma could not be ruled out, although histopathology after enucleation revealed no retinoblastoma. To our knowledge, this is the youngest case of Coats disease to be reported in the literature. This case highlights the wide variation in the clinical presentation of Coats disease and the difficulty in differentiating it from diffuse infiltrative retinoblastoma.

Introduction FL is characterized by the translocation t(14;18), resulting in constitutive overexpression of the key anti-apoptotic protein BCL2. Ven, a selective, potent oral inhibitor of BCL2, has shown profound efficacy combined with anti-CD20 antibodies in chronic lymphocytic leukemia and is in development for treating other hematologic malignancies, including non-Hodgkin lymphoma (NHL). Preclinical and early clinical data in indolent NHL suggest addition of Ven to R or chemo may improve efficacy. The open-label CONTRALTO study (NCT02187861) assessed efficacy and safety of a chemo-free regimen with Ven+R or randomized Ven + standard chemoimmunotherapy regimen BR vs BR for treatment of R/R FL. Methods Pts ≥18 yrs, with confirmed grade (Gr) 1-3a R/R FL, ≥1 line of prior therapy for lymphoma, and adequate hematologic and organ function with no history of B-refractory disease (chemo arms), were assigned at investigators' discretion to receive Ven+R or be randomized to BR +/- Ven, with stratification by 1 vs 0 GELF criteria and ≥ vs Results 163 pts were enrolled; 52 received Ven+R, 9 in the safety run-in, 51 Ven+BR, 51 BR (Table 1). Median lines of prior treatment: 3 (1-6) in both Ven-treated arms and 2 (1-4) in BR arm. Ann Arbor stages III/IV: 88%, 73.5%, and 72.5% of pts in Ven+R, Ven+BR and BR arms, respectively. BCL2 expression by IHC and BCL2 translocations were observed in most pts (88% and 81% respectively); expression of MCL1 (1%) and BCLxL (29%) were low. 44 pts (90%) in Ven+BR arm required dose interruptions/modifications of any therapy compared with 21 (42%) in BR and 30 (58%) in Ven+R; most were of Ven: 20 (38.5%) in Ven+R arm and 43 (88%) in Ven+BR. 17 pts (35%) in Ven+BR arm and 2 (4%) in Ven+R discontinued Ven early. 30 pts (61%) in Ven+BR arm required dose interruption/modification of B versus 20 (40%) in BR; 10 pts (20%) in Ven+BR and 2 (4%) in BR discontinued B. Neutropenia and thrombocytopenia were the most common Gr 3-4 adverse events (AEs) overall (Table 2B), and led to dose interruptions/modifications. They were highest in Ven+BR arm (59% neutropenia, 45% thrombocytopenia). Serious AEs were seen more frequently with Ven+BR (Table 2A) than Ven+R or BR; most were infection/infestation events: 22% Ven+BR, 11.5% Ven+R, 8% BR. In Ven+R arm, 17% of pts reached CMR at 6 mo; 25% achieved CMR as best overall response (BOR), of whom all achieved minimal residual disease (MRD) negativity at mid-induction. A population of pts who were non-refractory to prior therapy had improved response (54% overall response rate, 35% CMR as BOR). Six-mo CMR rates were 74% and 68% with Ven+BR and BR, respectively, and were equal at 1 yr (Table 3). PFS analysis did not show a difference between these arms (adjusted HR, 0.69; p=0.2088). Although only 61.2% of pts in Ven+BR arm had ≥90% B dose intensity vs 95.8% in BR arm, efficacy in the 2 arms was comparable in CMR and PFS. Of note, pts maintaining all cycles of Ven+BR had a 6-mo CMR of 100%. Efficacy was comparable in biomarker subgroups, and did not identify clear predictors of response. Conclusion Ven+R had an acceptable toxicity in the population studied; this arm included a high number of pts with refractory status and shorter DOR to prior treatments, potentially leading to modest overall efficacy. Improved response rates and MRD negativity, and longer PFS were observed in a subgroup of pts with non-refractory FL, showing efficacy of Ven+R in FL. Addition of Ven to BR at the dose and schedule studied resulted in increased toxicity (Gr 3-4 cytopenias and gastrointestinal events), leading to dose interruptions/discontinuations, with consequent limitation of overall tolerability. However, despite lower dose intensity of BR in Ven+BR arm, efficacy remained the same between the 2 chemo-containing arms, mandating optimal dose delivery for improved efficacy in combination with chemo in future studies. Disclosures Zinzani: Merck: 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; Takeda: Membership on an entity's Board of Directors or advisory committees; Bayer: Membership on an entity's Board of Directors or advisory committees; BMS: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; SERVIER: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; MSD: Honoraria, Speakers Bureau; Celltrion: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; PFIZER: Honoraria, Membership on an entity's Board of Directors or advisory committees; Verastem: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Astra Zeneca: Speakers Bureau; Bayer: Membership on an entity's Board of Directors or advisory committees; Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees; TG Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees; PFIZER: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Merck: Honoraria, Membership on an entity's Board of Directors or advisory committees; TG Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Speakers Bureau. Flinn:Portola: Research Funding; Curis: Research Funding; Incyte: Research Funding; Genentech: Research Funding; Trillium: Research Funding; Takeda: Research Funding; Verastem: Consultancy, Research Funding; Forty Seven: Research Funding; Forma: Research Funding; Novartis: Research Funding; Kite: Research Funding; Celgene: Research Funding; ArQule: Research Funding; BeiGene: Research Funding; Infinity: Research Funding; Pharmacyclics: Research Funding; Verastem: Research Funding; Calithera: Research Funding; Agios: Research Funding; Seattle Genetics: Research Funding; Merck: Research Funding; Constellation: Research Funding; Pfizer: Research Funding; Gilead: Research Funding; TG Therapeutics: Research Funding; Janssen: Research Funding. Yuen:Seattle Genetics: Research Funding. Topp:F. Hoffmann-La Roche Ltd: Membership on an entity's Board of Directors or advisory committees, Research Funding; Boehringer Ingelheim: Research Funding; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Research Funding; Regeneron Pharmaceuticals, Inc.: Honoraria, Research Funding. Rusconi:Celgene: Honoraria, Research Funding; Takeda: Honoraria; Janssen: Honoraria; F. Hoffmann-La Roche Ltd: Honoraria. Fleury:Novartis Pharmaceuticals Corporation: Consultancy; Merck: Consultancy; Janssen: Consultancy; Seattle Genetics: Consultancy; Gilead: Consultancy; Lundbeck: Consultancy; F. Hoffmann-La Roche Ltd: Consultancy; Celgene: Consultancy. Pro:Takeda Pharmaceuticals: Honoraria, Other: Travel expenses; kiowa: Honoraria; Seattle Genetics: Consultancy, Other: Travel expenses, Research Funding; portola: Honoraria. Gritti:Autolus: Consultancy. Crump:F. Hoffmann-La Roche Ltd: Consultancy; Servier Canada: Consultancy; Jansen-Ortho: Consultancy. Samineni:Genentech Inc: Employment, Other: Ownership interests non-PLC. Sinha:F. Hoffmann-La Roche Ltd: Employment. Punnoose:Roche: Equity Ownership; Genentech Inc: Employment. Szafer-Glusman:F. Hoffmann-La Roche Ltd: Employment, Other: Ownership interests PLC. Danesi:F. Hoffmann-La Roche Ltd: Employment. Petrich:Abbvie: Employment, Other: Ownership interests PLC. Kornacker:F. Hoffmann-La Roche Ltd: Employment. Humphrey:F. Hoffmann-La Roche Ltd: Employment, Equity Ownership. Mobasher:Genentech Inc: Employment; F. Hoffmann-La Roche Ltd: Other: Ownership interests non-PLC. Hiddemann:F. Hoffman-La Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bayer: Consultancy, Research Funding; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding.

Introduction: Rituximab (R) plus CHOP (R-CHOP) is standard of care for patients (pts) with previously untreated DLBCL. Although most pts have long-term responses, up to 40% of pts fail to achieve a remission or relapse. Atezolizumab (atezo) is a fully humanized anti-programmed death-ligand 1 (PD-L1) antibody with a complementary mechanism of action to R. An ongoing Phase I/II study (NCT02596971) is evaluating the safety and efficacy of atezo in combination with R-CHOP (R-CHOP-atezo) in DLBCL pts. Results from the primary analysis are reported. Methods: This open-label, multicenter study enrolled pts (≥18 years; ECOG PS 0-2) with previously untreated advanced DLBCL (Ann Arbor Stage III/IV, International Prognostic Index [IPI] score ≥2 or Stage II with bulky disease [at least 1 lesion ≥7cm]). Pts received induction treatment with R-CHOP-atezo (8 cycles [each 21 days] of R [375mg/m2 IV on Day 1 (Cycles 1-8)] and atezo [1200mg IV on Day 1 (Cycles 2−8)], and 6 or 8 cycles of CHOP [as determined by the investigator (INV)]). Pts who achieved a complete response (CR) at end of induction (EOI) received consolidation treatment with atezo 1200mg IV on Day 1 of Cycles 9─25, every 21 days for 12 months (mo). Primary endpoints were safety, and efficacy as determined by CR rate at EOI by independent review committee (IRC) using modified Lugano 2014 criteria (if bone marrow [BM] involvement at baseline [BL], CR was confirmed with a negative BM biopsy at EOI; designation of partial response [PR] on PET required that CR or PR on CT scan were met). Secondary endpoints included CR at EOI assessed by INV (modified Lugano 2014 criteria) and by IRC and INV (Cheson et al. J Clin Oncol 2007). Minimal residual disease (MRD) was evaluated at EOI using the Adaptive ImmunoSEQ® NGS platform (v2). Results: At the data cut-off (April 11, 2018), 42 pts were enrolled and received treatment (safety population); 7 pts discontinued during the induction phase (1 protocol violation, 1 withdrawal of consent [these 2 pts discontinued after Cycle 1, Day 1 and were not treated with atezo, and were not included in the efficacy analysis], 4 adverse events [AEs], 1 progressive disease [PD]). Of 35 pts completing induction, 30 entered the consolidation phase; 5 pts discontinued at EOI (2 PD, 3 PR). Pt demographics and disease characteristics are shown in Table 1. Among 40 pts evaluable for response (efficacy population), 31 pts (77.5%) had a CR and 4 pts (10%) had a PR by IRC (modified Lugano 2014 criteria); PD occurred in 2 pts (5%), and 3 pts (7.5%) were not evaluable. Response assessments by Cheson et al. (J Clin Oncol 2007) were similar by IRC and INV; IRC assessment showed 31 (77.5%) CRs, 5 (12.5%) PRs, 2 (5%) pts with PD and 1 with SD (Table 2). MRD was evaluable in 26 pts at BL: 10 pts were MRD negative and 16 pts were MRD positive. Of the 16 MRD positive pts at BL, MRD data were available for 14 at EOI: 13 pts were negative and 1 pt was positive (PR by INV and IRC). Median dose intensity was >99% for the induction phase (median exposure 6.7 mo [range 1.5-7.3]) and 100% for the consolidation phase (median exposure 3.7 mo [range 0.7-9.3]). During induction, all 42 pts (100%) had ≥1 AE, 29 (69%) had a grade (Gr) 3-4 AE and 12 (29%) had a serious AE. No fatal AEs were reported. AEs led to any treatment discontinuation in 6 pts (14%) (Gr 3 neutropenia and Gr 3 transaminase increase, Gr 2 hyperthyroidism, Gr 3 lipase increase, Gr 1-2 peripheral neuropathy, Gr 4 thrombocytopenia), dose reduction (CHOP) in 9 pts (21%) (Gr 4 anemia, Gr 3 pancytopenia, Gr 2 paresthesia, Gr 4 neutropenia and Gr 1-2 peripheral neuropathy) and dose interruption (missed doses and dose delays) in 15 pts (36%). Five pts had AEs of interest to atezo (Gr 3 increased lipase, Gr 2 hyperthyroidism, and Gr 1 infusion-related reaction). Common Gr 3-4 AEs during induction were: neutropenia (45%), febrile neutropenia (9.5%), leukopenia (5%), anemia (5%), increased lipase (5%), and fatigue (5%), and during consolidation were: neutropenia (10%), febrile neutropenia (3%), increased lipase (14%), and syncope (7%). Conclusions: The PET-CR rate with R-CHOP-atezo at EOI is encouraging and compares favorably with that previously reported with R-CHOP. The overall safety profile of R-CHOP-atezo is manageable, with no new safety signals reported. Preliminary MRD data at EOI are encouraging and support activity. Biomarker data and duration of response will be presented. Disclosures Younes: Sanofi: Honoraria; Roche: Honoraria, Research Funding; Takeda: Honoraria; Bayer: Honoraria; J&J: Research Funding; BMS: Honoraria, Research Funding; Astra Zeneca: Research Funding; Celgene: Honoraria; Novartis: Research Funding; Pharmacyclics: Research Funding; Seattle Genetics: Honoraria; Janssen: Honoraria, Research Funding; Abbvie: Honoraria; Genentech: Research Funding; Incyte: Honoraria; Merck: Honoraria; Curis: Research Funding. Burke:Tempus Labs: Consultancy; Celgene: Consultancy; Gilead: Consultancy; Genentech: Consultancy; Abbvie: Consultancy; Bayer: Consultancy; Seattle Genetics: Consultancy, Speakers Bureau. Cheson:AbbVie, Roche/Genentech, Pharmacyclics, Acerta, TG Therapeutics: Consultancy. Diefenbach:Genentech: Consultancy; Trillium: Research Funding; Millenium/Takeda: Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; Incyte: Research Funding; Merck: Consultancy, Research Funding; Seattle Genetics: Consultancy, Research Funding; Denovo: Research Funding; Acerta: Research Funding. Hawkes:Celgene: Other: Advisory board, Research Funding; Astra Zeneca: Research Funding; Merck: Other: Advisory board; Takeda: Other: Speaker fee; Roche: Other: Speaker fee; advisory board; Bristol Myers Squibb: Other: Speaker fee, Research Funding; Merck Sharpe Dohme: Research Funding; Merck KGA: Research Funding. Khan:Roche: Honoraria; AbbVie: Honoraria. Lossos:Affimed: Research Funding. Vitolo:Takeda: Speakers Bureau; Gilead: Speakers Bureau; Roche: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Sandoz: Speakers Bureau; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Janssen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Yuen:Seattle Genetics: Research Funding. Oestergaard:Roche: Employment, Other: Ownership interests PLC. Chitra:Genentech/Roche: Employment. Wenger:F. Hoffmann-La Roche Ltd: Employment, Equity Ownership, Other: Ownership interests PLC. Nielsen:F. Hoffmann-La Roche Ltd: Employment, Other: Ownership interests PLC. Sellam:Roche: Employment. Sharman:Pharmacyclics, an AbbVie Company: Consultancy, Research Funding; Acerta: Consultancy, Research Funding.

Introduction Despite improved response and survival for patients (pts) with follicular lymphoma (FL) receiving rituximab (R) plus chemotherapy, new options are needed. FL is typically characterized by the presence of chromosomal translocation t(14;18), which results in overexpression of the anti-apoptotic protein BCL-2. BCL-2 may also contribute to resistance to chemoimmunotherapy such as bendamustine+R (BR), a regimen commonly used in FL. Venetoclax (VEN), a selective, potent oral BCL-2 inhibitor, is in development for the treatment of B-cell malignancies. Preclinical and early clinical data suggest VEN+R or VEN+BR may improve response over R or chemotherapy alone and is feasible. This open-label study will assess efficacy and toxicity of VEN+R as well as VEN+BR vs BR alone, in pts with relapsed/refractory (R/R) FL (NCT02187861). Methods R/R pts (age ≥18 yrs, confirmed Gr 1-3a FL, ECOG PS 0-2, adequate hematologic function) were assigned (at investigators' discretion) to chemotherapy-free (chemo-free) or randomized to chemotherapy-containing (chemo) arms. Those in the chemo-free Arm (Arm A) received VEN 800mg daily for 1 yr + R (cycles [C] 1, 4, 6, 8, 10 and 12). After a safety run-in (9 pts at 600mg VEN daily + 6 cycles BR), those in the chemo Arm were randomized 1:1 to Arm B (VEN 800mg + 6 cycles BR) or C (BR only). The primary endpoint was complete response (CR) rate by PET-CT. Secondary endpoints include CR rate by CT and overall response rate. Response assessment was per Lugano non-Hodgkin lymphoma assessment (Cheson et al. 2014) 6-8 wks after D1 of C6 (or the cycle non-VEN agents were permanently discontinued: whichever came first). Results One hundred sixty-four pts were enrolled as of May 13, 2016 (Table 1); 53 chemo-free (Arm A) and 111 chemo (9 run-in; 51 Arm B; 51 Arm C). 61% were refractory to prior treatment: 79% Arm A; 56% safety run-in; 43% Arm B; 62% Arm C. One hundred fifty-three of 160 safety evaluable pts (94%) experienced any AE (Table 2). Common AEs (all grades): diarrhea (37%), neutropenia (29%), nausea (25%), fatigue (25%), and IRR (25%). Common AEs for Arm B vs Arm C: nausea (61% vs 38%), neutropenia (51% vs 26%), diarrhea (41% vs 12%), thrombocytopenia (39% vs 20%) and fatigue (37% vs 24%). Neutropenia and thrombocytopenia were the most common Gr 3-4 AEs among all groups. 40 pts had serious AE (SAEs): 14 (27%) Arm A; 4 (44%) run-in; 15 (31%) Arm B; 7 (14%) Arm C. SAEs in >1 pt in any arm: febrile neutropenia (2 run-in; 5 Arm B; 1 Arm C), pneumonia (2 Arm A; 1 Arm B), and LDH increase (2 Arm A). Laboratory tumor lysis syndrome (TLS) events occurred in 2 pts (1 Arm A; 1 Arm B): both manageable and resolved with no clinical complications. Five deaths occurred on study: 3 Arm A (colitis, pulmonary hemorrhage, PD), 1 Arm B (pneumonia), 1 Arm C (PD). Pts with AEs leading to dose interruptions or modification: 28 (54%) Arm A; 7 (78%) run-in; 37 (76%) Arm B; 12 (24%) Arm C. Pts with early drug discontinuations of VEN: 29 (56%) Arm A; 5 (56%) run-in; 11 (22%) Arm B. Early R discontinuations: 28 (54%) Arm A; 3 (33%) run-in; 7 (14%) Arm B; 5 (10%) Arm C. Early B discontinuations: 3 (33%) run-in; 7 (14%) Arm B; 4 (8%) Arm C. Efficacy by PET+CT for safety evaluable patients who reached an assessment event is shown in Table 3. Arm A had 17 (33%) responders with 14% CR. Arm A was predominantly refractory to last treatment (79%): among non-refractory pts (21%), ORR was 64% with 27% CR. There was 68% ORR in Arm B with 50% CR compared with 64% ORR with 41% CR in Arm C. 55 (51%) of chemo pts have yet to reach a response-relevant event. Correlation with expression of BCL-2 family members is pending. Conclusion Early results from the first study evaluating VEN+R and VEN+BR in pts with FL show that daily VEN 800mg has an acceptable benefit/risk ratio. As expected with the known VEN safety profile, both VEN+R and VEN+BR are associated with hematologic and GI toxicity, which appears manageable. Laboratory TLS was rare ( Disclosures Zinzani: Abbvie: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees; MorphoSys: Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees; Celegene: Membership on an entity's Board of Directors or advisory committees. Topp:Amgen: Consultancy, Honoraria, Other: travel, Speakers Bureau; Roche: Honoraria, Other: travel; Pfizer: Consultancy, Other: Travel; Boehringer: Consultancy, Other: Travel, Research Funding; Jazz: Consultancy. Rusconi:Janssen: Consultancy, Other: Congress attendance; Takeda: Consultancy; Teva: Consultancy, Other: Congress attendance. Fleury:Novartis: Consultancy, Speakers Bureau; Lundbeck: Consultancy, Speakers Bureau; Gilead: Consultancy, Speakers Bureau; Roche: Consultancy, Speakers Bureau; Amgen: Consultancy, Speakers Bureau; Seattle Genetics: Consultancy, Speakers Bureau. Pro:Celegene: Honoraria; Seattle Genetics: Honoraria; Takeda: Honoraria. Hsu:Genetech, Inc.: Employment. Punnoose:Genetech, Inc.: Employment. Hilger:Genetech, Inc.: Employment. Mobasher:Genentech, Inc.: Employment. Hiddermann:Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Gilead: Research Funding.