Brander, Danielle M.

Targeted agents have greatly improved outcomes for patients (pts) with chronic lymphocytic leukemia (CLL) and other B cell lymphomas; however, single agents have been limited by intolerance, resistance and depth/durability of responses. Current novel targeted agent combinations may improve depth of response, but such "full dose" strategies have been associated with significant AEs, dose reductions/interruptions and discontinuations. Our in vitro & in vivo screening/optimization studies identified that concurrent inhibition of BTK & mTOR targets plus IMiD at low doses of each inhibitor can synergistically kill B-cell malignancies and may address drug-resistance. DTRM-555 is an optimized oral triplet combination of a novel BTK inhibitor DTRMWXHS-12 (DTRM-12) with everolimus (EV) & pomalidomide (POM). This once daily therapy was tested in a stepwise, phase I, US multicenter study in patients with highest unmet medical needs including r/r CLL, Richter's transformation (RT) of CLL, DLBCL, transformed B-cell lymphomas. We conducted a 3+3 design phase I, first human trial exploring DTRM-555 in pts ≥18 years, ECOG PS ≤1 with CLL, B-cell NHL, or Hodgkin lymphoma (HL) with no available standard therapy (NCT02900716). Our goal was to determine optimal doses for triplet combination therapy through 3 escalating phases of study: DTRM-12 in escalating doses (50, 100, 200, & 300 mg/day) in Part Ia, DTRM-12 at 200 mg or 300 mg & EV at 5 mg (doublet or DTRM-505) in Part Ib Arm A while DTRM-12 at 200 mg or 300 mg, EV at 5 mg & POM at 2 mg in Part Ib Arm B. For all arms, treatment was administered for 21 consecutive days of a 28-day cycle, until disease progression or unacceptable toxicity. Safety was the primary endpoint, and the dose-limiting toxicity (DLT) period was cycle 1. Secondary endpoints included response (iwCLL 2018 or Cheson 2014), progression free survival, duration of response and pharmacokinetics. Intra-patient migration between arms (Mono to doublet to triplet) was permitted if subsequent doses were tolerated. The trial commenced 9/27/2016 and completed enrollment 7/25/2019. Thirty-three pts were enrolled, including 2 screen failures and 4 intra-cohort migrations, with r/r DLBCL (n=8), CLL/SLL (n=5), RT (n=6), FL (n=5), MCL (n=4), MZL/LPL (n=3), HL (n=2). 30 of 31 treated pts were evaluated: 8 pts participated in phase Ia (DTRM-12) while 23 pts were treated on phase Ib combinations (DTRM-505 & DTRM-555). Baseline characteristics: 70% male (n=23), median age 70 years (range 46-94) and 94% white. Median prior therapies were 3 (range 1-10), 53% had been treated with ≥1 prior targeted agent (i.e., CD19/CD3 bispecific antibody, obtinutuzumab, pembrolizumab, nivolumab, ibrutinib, venetoclax, PI3k-i), CAR-T or HSCT. 35% pts were previously treated with ibrutinib. Table 1 describes Grade (Gr) 3 and 4 AEs (all causality, stratified by treatment arm). Regarding safety, AEs were manageable, with a total of 5 DLTs were observed: 2 (Gr 3 febrile neutropenia, URI) in part Ib arm A, 3 (Gr 4 thrombocytopenia, Gr 3 diarrhea, G3 febrile neutropenia) in Part Ib arm B. No MTD was reached for the mono & doublet arms, with the MTD of the triplet determined to be DTRM-12 200 mg, EV 5 mg, & POM 2 mg. Spider plot (Figure 1a) shows the clinical response for individual CLL and lymphoma pts treated with mono, doublet and triplet therapies. Depth and durability of response improved with combination therapies (vs. mono). Of note, 48% of all patients had a ≥50% reduction in sum of the products of lymph node diameters. Representative PET-CT scans are in Figure 1b-c. Responses in multi-refractory pts are ongoing (including 15+ mos in a pt with r/r DLBCL and 5+ mos PR in a pt aged > 90 yrs with r/r DLBCL; 4+ & 13+ mos PRs in two pts with RT). DTRM-12 plasma concentrations were unaffected by EV & POM (Once Daily Oral Therapies) in Figure 1d. The clinical trial met its primary endpoint as the triple combination DTRM-555 had an acceptable safety profile. Dose dependent drug levels with minimal inter-pt variations were observed in all arms, supporting once daily oral administration of this low-dose combination therapy. Encouraging clinical activity was observed in several high-risk, multi-refractory CLL and lymphoma pts, including those previously treated with ibrutinib. Thus synthetic lethality is a viable treatment approach. A phase II US expansion study is underway targeting pts with transformed lymphomas (follicular or prior CLL) and r/r DLBCL cohorts. Table 1. Disclosures Mato: AbbVie: Consultancy, Research Funding; Sunesis: Consultancy, Research Funding; Genentech: Consultancy, Research Funding; Johnson & Johnson: Consultancy, Research Funding; Celgene: Consultancy; AstraZeneca: Consultancy, Research Funding; Pharmacyclics: Consultancy, Research Funding; Gilead: Research Funding; Acerta: Consultancy; Janssen: Consultancy; TG Therapeutics: Consultancy, Other: DSMB member , Research Funding; LOXO: Consultancy, Research Funding; DTRM Biopharma: Research Funding. Schuster:DTRM Biopharma: Research Funding. Foss:Mallinckrodt: Consultancy; Acrotech: Consultancy; miRagen: Consultancy; Seattle Genetics: Consultancy, Other: fees for non-CME/CE services ; Eisai: Consultancy; Spectrum: Other: fees for non-CME/CE services . Isufi:Novartis: Consultancy; Astra Zeneca: Consultancy; Celgene: Consultancy. Ding:Merck: Research Funding; DTRM Biopharma: Research Funding. Brander:Novartis: Consultancy; MEI: Research Funding; Pharmacyclics LLC, an AbbVie Company: Consultancy; BeiGene: Research Funding; AstraZeneca: Consultancy, Research Funding; Acerta: Research Funding; Tolero: Research Funding; AbbVie: Consultancy, Honoraria, Research Funding; Genentech: Consultancy, Honoraria, Research Funding; Teva: Consultancy, Honoraria; TG Therapeutics: Consultancy, Honoraria, Research Funding; DTRM Biopharma: Research Funding. Tun:Mundi-pharma: Research Funding; TG Therapeutics: Research Funding; Curis: Research Funding; DTRM Biopharma: Research Funding; Celgene: Research Funding; BMS: Research Funding. He:DTRM Biopharma: Employment, Equity Ownership. Kearney:DTRM Biopharma: Employment, Equity Ownership. Gui:DTRM Biopharma: Employment, Equity Ownership. Anderson:Theradex: Employment. Roeker:AbbVie: Equity Ownership; Abbott Laboratories: Equity Ownership. Huntington:Bayer: Consultancy, Honoraria; AbbVie: Consultancy; Celgene: Consultancy, Research Funding; Genentech: Consultancy; Pharmacyclics: Honoraria; DTRM Biopharm: Research Funding. OffLabel Disclosure: Everolimus in B cell lymphomas and CLL Pomalidomide in B cell lymphomas and CLL

Abstract Introduction: Given the availability of several active treatment (tx) options for CLL, providers frequently make tx recommendations based on their interpretation of objective data from consensus criteria and clinical trials. There are limited data describing patient (pt) experience, values, and insights when encountering multiple tx choices. The CLL Society, a pt-driven, physician-curated nonprofit organization focused on the unmet needs of the CLL community, sought to explore how CLL pts make tx decisions. Methods: A 64 question survey was distributed online and in paper to CLL pts from Oct-Dec 2017. The survey was developed by CLL experts. The research was IRB-approved. Chi square was used for statistical comparison; all other analyses are descriptive in nature. Results: 1147 pts from 48 states completed the survey. Median age was 65 (range 28-86), 46% male, 96% Caucasian. Who Influences Tx: Of the 79% of pts who have seen a CLL expert, defined as a provider focused on CLL at an academic/research center, 95% rated their provider as very/extremely influential. 83% of pts rated their own opinions as influential, and 59% rated the opinion of a general hematologist/oncologist (gen heme/onc), a provider who sees a variety of cancer types, as influential. Only 27% let their provider unilaterally decide on tx. Of these pts, 19% trusted their provider to select the best tx and 5% didn't have enough understanding to be involved in the decision. 64% were influenced by outside sources of information, such as family members, live CLL support groups, or online sources including pt experts and forums. Factors in Deciding Tx: Of the 67% pts surveyed who have been treated, 73% were offered > 1 tx choice by their provider. In deciding on a specific tx, 94% of respondents stated that it was very/extremely important to know there were tx options beyond their current regimen. The most important factors in selecting tx were response rate (91%), overall survival (88%), progression-free survival (86%), long-term side effects (82%), ability to achieve undetectable MRD (80%), cost/insurance coverage (66%), and location of tx (50%) with significant differences between subgroups (Table 1). Tx was impacted by cost or insurance issues for 16% (n=104). Of these 104 pts, cost/insurance issues resulted in tx delay for 34 and change in tx plan for 24 pts. 16 pts reported that an appeal led to coverage and 16 pts received financial assistance. Pts' willingness to accept potentially curable but high-risk tx was heavily influenced by availability of alternate options. For example, 18% of pts would be willing to consider cytotoxic chemotherapy if alternate options were available vs. 72% if no options were available. Similar patterns were seen with CAR-T tx (28% vs. 79%) and bone marrow transplantation (BMT) (15% vs. 66%) with significant differences between subgroups (Table 2). 82% were willing to take a life-long tx for long-term control without potential for cure. Willingness to accept long-term tx was significantly higher in treated vs. untreated pts (84% vs. 77%, p=.006) and men vs. women (84% vs. 78%, p=.008). Clinical Trial Education: Of those treated by a gen heme/onc, 31% received no education on clinical trials. Only 15% reported good understanding of trial opportunities vs. 52% treated by a CLL expert (p<.001). 9% of pts treated by gen heme/onc were offered clinical trial participation vs. 47% treated by a CLL expert (p<0.001). Pts who declined or would have declined participation cited reasons including preference for "proven" tx (38%), distance from trial site (29%), fear (20%), frequent imaging (20%), overall lack of understanding about trials (15%), and lack of information (14%). Summary: Most respondents want to be and are involved in tx decisions. While providers are influential in decision making, CLL pts also rely on outside sources. Gender, age, and tx status influence which factors drive decision making. Pts select tx based on response rate, survival, side effects, and ability to achieve deep response and want a plan in place for sequencing tx. The majority are willing to consider long-term tx without cure. Few want chemotherapy, CAR-T, or BMT unless they have no other options. A significant opportunity for improvement in education on clinical trial opportunities was identified. This description of pt experience, values, and preferences enriches the informed consent process and may lead to more tailored and patient-centered care. Disclosures Kennard: AbbVie, Gilead, Verastem: Consultancy. Furman:TG Therapeutics: Consultancy; Loxo Oncology: Consultancy; Sunesis: Consultancy; Verastem: Consultancy; Incyte: Consultancy, Other: DSMB; Genentech: Consultancy; Acerta: Consultancy, Research Funding; Gilead: Consultancy; Janssen: Consultancy; Pharmacyclics LLC, an AbbVie Company: Consultancy; AbbVie: Consultancy. Pagel:Pharmacyclics, an AbbVie Company: Consultancy; Gilead: Consultancy. Davids:Sunesis: Membership on an entity's Board of Directors or advisory committees; Roche: Consultancy; Astra-Zeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS: Research Funding; Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Astra-Zeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; MEI Pharma: Consultancy, Research Funding; Surface Oncology: Research Funding; Gilead: Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy; Merck: Consultancy; Merck: Consultancy; MEI Pharma: Consultancy, Research Funding; TG Therapeutics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Astra-Zeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; MEI Pharma: Consultancy, Research Funding; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy; Sunesis: Membership on an entity's Board of Directors or advisory committees; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees; TG Therapeutics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pharmacyclics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Gilead: Membership on an entity's Board of Directors or advisory committees; Verastem: Consultancy, Research Funding; Surface Oncology: Research Funding; Gilead: Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Pharmacyclics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy; Roche: Consultancy; Pharmacyclics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees; BMS: Research Funding; Verastem: Consultancy, Research Funding; BMS: Research Funding; Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Surface Oncology: Research Funding; Verastem: Consultancy, Research Funding; TG Therapeutics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Sunesis: Membership on an entity's Board of Directors or advisory committees; Merck: Consultancy; Roche: Consultancy. Nabhan:Cardinal Health: Employment, Equity Ownership. Kay:Acerta: Research Funding; Tolero Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees; Morpho-sys: Membership on an entity's Board of Directors or advisory committees; Pharmacyclics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Agios Pharm: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; Infinity Pharm: Membership on an entity's Board of Directors or advisory committees; Cytomx Therapeutics: Membership on an entity's Board of Directors or advisory committees. Siddiqi:Juno Therapeutics: Other: Steering committee. Brander:Genentech: Consultancy, Honoraria, Other: Institutional research funding for non investigator initiated clinical trial, Research Funding; Pharmacyclics, an AbbVie Company: Consultancy, Honoraria, Research Funding; AbbVie: Consultancy, Honoraria, Other: Institutional research funding for non investigator initiated clinical trial, Research Funding; Teva: Consultancy, Honoraria; Novartis: Consultancy, Other: DSMB; TG Therapeutics: Consultancy, Honoraria, Other: Institutional research funding for non investigator initiated clinical trial, Research Funding; BeiGene: Other: Institutional research funding for non investigator initiated clinical trial, Research Funding; Acerta: Other: Institutional research funding for non investigator initiated clinical trial, Research Funding; DTRM: Other: Institutional research funding for non investigator initiated clinical trial, Research Funding. Wierda:AbbVie, Inc: Research Funding; Genentech: Research Funding. Hill:Abbvie: 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; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; Seattle Genetics: Honoraria, Membership on an entity's Board of Directors or advisory committees; Genentech: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees; Seattle Genetics: Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; Pharmacyclics: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Research Funding; Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees; Pharmacyclics: Honoraria, Membership on an entity's Board of Directors or advisory committees. Cheson:AbbVie, Roche/Genentech, Pharmacyclics, Acerta, TG Therapeutics: Consultancy. Choi:Pharmacyclics: Consultancy, Research Funding, Speakers Bureau; Gilead: Speakers Bureau; Rigel: Consultancy; Genentech: Speakers Bureau; AbbVie, Inc: Consultancy, Speakers Bureau. Mato:AstraZeneca: Consultancy; Prime Oncology: Honoraria; Portola: Research Funding; Johnson & Johnson: Consultancy; Medscape: Honoraria; Celgene: Consultancy; TG Therapeutics: Consultancy, Research Funding; Acerta: Research Funding; Pharmacyclics, an AbbVie Company: Consultancy, Research Funding; AbbVie: Consultancy, Research Funding; Regeneron: Research Funding.

Abstract Introduction: The most effective initial therapy for older adults with CLL has not yet been established due to the lack of comparison of chemoimmunotherapy (CIT) and targeted therapy with the Bruton's Tyrosine Kinase (BTK) inhibitor ibrutinib. CIT has been the gold standard since studies showing that addition of CD20 antibody to chemotherapy prolongs survival. Bendamustine plus rituximab (BR) is one standard, more aggressive CIT regimen for patients (pts) age 65 or older. While ibrutinib has been FDA approved for untreated CLL since 2016, it has only been compared to chlorambucil, which is relatively ineffective, and never before to aggressive CIT. Additionally, the benefit of the addition of rituximab to ibrutinib in this setting has not been prospectively studied in a phase 3 trial. As part of a randomized phase 3 trial, the Alliance sought to answer these important clinical questions. Pts and Methods: Alliance A041202 is a multicenter NCI National Clinical Trials Network phase 3 study comparing BR (Arm 1) with ibrutinib (Arm 2) and the combination of ibrutinib plus rituximab (Arm 3) to determine whether ibrutinib-containing regimens are superior to CIT in terms of PFS. Additionally, this study sought to determine if adding rituximab to ibrutinib would prolong PFS over ibrutinib alone. At time of progression, pts on Arm 1 could cross over to Arm 2. Eligible pts were those age ≥ 65 years with previously untreated, symptomatic CLL. Pts had a CrCl ≥ 40 mL/min, bilirubin ≤ 1.5 x ULN, and no significant life-limiting intercurrent illness or need for warfarin treatment. Pts were stratified based upon Rai stage, Zap-70 methylation performed centrally, and del(17)(p13.1) or del(11)(q22.3) by local interphase cytogenetics and were randomized 1:1:1 to each arm. With 166 pts per arm, the trial was powered to detect an improvement in 2-year PFS from 61% in Arm 1 to 75% in Arms 2 or 3 (HR=0.586) using two one-sided log-rank tests with type I error rate of 2.5% and 90% power. The Alliance Data and Safety Monitoring Board approved the data release after meeting the protocol-defined efficacy threshold at a planned interim analysis with a one-sided critical value of 0.001538. These data were locked July 2, 2018; updated results will be presented at the meeting. Results: Between 12/9/2013 and 5/16/2016, 547 pts were registered and randomized (Arms 1: 183, 2: 182, and 3: 182). Median age was 71 years and 67% of pts were men. High-risk Rai stage (stage III/IV) was seen in 54%, unmethylated Zap-70 in 53%, and del(17p) or del(11q) by local FISH in 28%. Local vs centralized FISH was performed for del(11q) and del(17p) with agreement between local and central results in 94% (Kappa=0.80) and 97% (Kappa=0.76) of pts, respectively. 525 (96%) pts were eligible and included in the primary PFS analysis (Arms 1: 176, 2: 178, and 3: 171). With median follow-up of 32 months (mo), median PFS was 41 mo in Arm 1 and has not been reached in Arms 2 or 3 (HR comparing Arm 2 to 1 is 0.40 with one-sided p&lt;0.0001; HR comparing Arm 3 to 1 is 0.41 with one-sided p&lt;0.0001; HR comparing Arm 3 to 2 is 1.01 with one-sided p=0.48). 2-year PFS estimates were 74%, 87% in 2, and 88% in Arms 1, 2, and 3 respectively. At this time, there are no significant differences in overall survival (OS) among arms (p=0.87), median OS has not been reached for any arm, and 2-year OS estimates were 95%, 90%, and 94% in Arms 1, 2, and 3, respectively. Adverse events (AEs) were compared among arms using Fisher's exact tests. Grade 3+ treatment-emergent AEs were seen in 428 of 537 evaluable pts with 61%, 41%, and 38% of pts experiencing Grade 3+ heme AEs (p&lt;0.0001) and 60%, 72%, and 71% of pts experiencing Grade 3+ non-heme AEs (p=0.03) in Arms 1, 2, and 3 respectively. Grade 5 AEs were seen in 5 (2.8%), 14 (7.8%), and 14 (7.7%) pts (p=0.07). Unexplained or unwitnessed death over the entire observation period was seen in 2 (1.1%), 7 (3.9%), and 4 (2.2%) pts (p=0.24) in Arms 1, 2, and 3 respectively. Conclusions: This international phase 3 trial demonstrates that ibrutinib produces superior PFS to standard CIT in older pts with CLL and justifies it as a standard of care treatment for pts age 65 and older. The addition of rituximab does not prolong PFS with ibrutinib. While ibrutinib represents a major therapeutic advance, toxicities and also cost justify future efforts to reduce the need for long-term continuous treatment. Support: K23CA178183, R01CA183444, U10CA180821, U10CA180882, U24CA196171, Clinicaltrials.gov identifier: NCT01886872 Figure. Figure. Disclosures Ding: Merck: Research Funding. Bartlett:Astra Zeneca: Research Funding; ImaginAB: Research Funding; Seattle Genetics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pharmacyclics: Research Funding; Bristol-Meyers Squibb: Research Funding; Gilead: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Genentech: Research Funding; Pharmacyclics: Research Funding; Affimed: Research Funding; Janssen: Research Funding; Novartis: Research Funding; Merck & Co: Research Funding; KITE: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Acerta: Membership on an entity's Board of Directors or advisory committees; Celgene: Research Funding; Immune Design: Research Funding; Forty Seven: Research Funding; Novartis: Research Funding; Millennium: Research Funding. Brander:BeiGene: Other: Institutional research funding for non investigator initiated clinical trial, Research Funding; TG Therapeutics: Consultancy, Honoraria, Other: Institutional research funding for non investigator initiated clinical trial, Research Funding; Genentech: Consultancy, Honoraria, Other: Institutional research funding for non investigator initiated clinical trial, Research Funding; Novartis: Consultancy, Other: DSMB; AbbVie: Consultancy, Honoraria, Other: Institutional research funding for non investigator initiated clinical trial, Research Funding; Pharmacyclics, an AbbVie Company: Consultancy, Honoraria, Research Funding; Teva: Consultancy, Honoraria; Acerta: Other: Institutional research funding for non investigator initiated clinical trial, Research Funding; DTRM: Other: Institutional research funding for non investigator initiated clinical trial, Research Funding. Barr:AbbVie, Gilead: Consultancy. Parikh:Gilead: Honoraria; Pharmacyclics: Honoraria, Research Funding; MorphoSys: Research Funding; Janssen: Research Funding; AstraZeneca: Honoraria, Research Funding; Abbvie: Honoraria, Research Funding. Coutre:Celgene: Research Funding; Janssen: Consultancy, Honoraria, Research Funding; Pharmacyclics LLC, an AbbVie Company: Honoraria, Research Funding; Gilead: Research Funding; Beigene: Consultancy; AbbVie: Consultancy, Research Funding. Lozanski:Novartis: Research Funding; BI: Research Funding; Genentech: Research Funding; Stem Line: Research Funding; Coulter: Research Funding; Beckman: Research Funding. Larson:Ariad/Takeda: Consultancy, Research Funding; BristolMyers Squibb: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding; Novartis: Consultancy, Research Funding. Erba:Amgen: Research Funding; Juno: Research Funding; Daiichi Sankyo: Consultancy, Research Funding; Daiichi Sankyo: Consultancy, Research Funding; MacroGenics: Consultancy; Juno: Research Funding; Janssen: Research Funding; Seattle Genetics: Consultancy, Research Funding; Janssen: Research Funding; Juno: Research Funding; Agios: Consultancy, Speakers Bureau; MacroGenics: Consultancy; Incyte: Consultancy, Speakers Bureau; Seattle Genetics: Consultancy, Research Funding; Takeda/Millenium: Research Funding; Novartis: Consultancy, Speakers Bureau; Takeda/Millenium: Research Funding; Incyte: Consultancy, Speakers Bureau; MacroGenics: Consultancy; Celgene: Consultancy, Speakers Bureau; Janssen: Research Funding; Novartis: Consultancy, Speakers Bureau; Celgene: Consultancy, Speakers Bureau; Astellas: Research Funding; Glycomimetics: Consultancy, Other: Chair, Data and Safety Monitoring Committee; MacroGenics: Consultancy; Daiichi Sankyo: Consultancy, Research Funding; Pfizer: Consultancy, Other: grant; Astellas: Research Funding; Juno: Research Funding; Janssen: Research Funding; Novartis: Consultancy, Speakers Bureau; Amgen: Research Funding; Agios: Consultancy, Speakers Bureau; Astellas: Research Funding; Agios: Consultancy, Speakers Bureau; Novartis: Consultancy, Speakers Bureau; Amgen: Research Funding; Pfizer: Consultancy, Other: grant; Pfizer: Consultancy, Other: grant; Astellas: Research Funding; Amgen: Research Funding; Agios: Consultancy, Speakers Bureau; Incyte: Consultancy, Speakers Bureau; Incyte: Consultancy, Speakers Bureau; Jazz: Consultancy, Speakers Bureau; Immunogen: Consultancy, Research Funding; Jazz: Consultancy, Speakers Bureau; Immunogen: Consultancy, Research Funding; Glycomimetics: Consultancy, Other: Chair, Data and Safety Monitoring Committee; Pfizer: Consultancy, Other: grant; Jazz: Consultancy, Speakers Bureau; Immunogen: Consultancy, Research Funding; Seattle Genetics: Consultancy, Research Funding; Jazz: Consultancy, Speakers Bureau; Seattle Genetics: Consultancy, Research Funding; Celgene: Consultancy, Speakers Bureau; Immunogen: Consultancy, Research Funding; Takeda/Millenium: Research Funding; Glycomimetics: Consultancy, Other: Chair, Data and Safety Monitoring Committee; Celgene: Consultancy, Speakers Bureau; Takeda/Millenium: Research Funding; Daiichi Sankyo: Consultancy, Research Funding; Glycomimetics: Consultancy, Other: Chair, Data and Safety Monitoring Committee. Owen:Janssen: Honoraria, Research Funding; Celgene: Research Funding; AstraZeneca: Honoraria, Research Funding; Pharmacyclics: Research Funding; F. Hoffmann-La Roche Ltd: Honoraria, Research Funding; AbbVie: Research Funding; Merck: Honoraria; Teva: Honoraria. Abramson:Bayer: Consultancy; Novartis: Consultancy; Merck: Consultancy; Karyopharm: Consultancy; Seattle Genetics: Consultancy; Verastem: Consultancy; Humanigen: Consultancy; Juno Therapeutics: Consultancy; Gilead: Consultancy; Celgene: Consultancy; Amgen: Consultancy.

Abstract Introduction Transformation of chronic lymphocytic leukemia (CLL) into Hodgkin lymphoma (HL) is a rare, but recognized complication of CLL. The prognosis of CLL with HL Transformation (HT) appears significantly worse than de novo HL, but most series are small and there are limited published data. These reports have prompted several groups to recommend aggressive therapy with stem cell transplantation (SCT) in first complete remission (CR1). We describe the largest reported series of HT patients (pts) with analyses of the clinicobiologic characteristics, treatment patterns, and clinical outcomes based upon our multi-institutional clinical experience. Methods Pts diagnosed with HT from 01/2000 - 01/2018 were retrospectively identified in 13 tertiary cancer centers. Clinicobiologic characteristics, treatment type, and survival outcomes for each pt were analyzed. Overall survival (OS) was measured from the time of HT diagnosis until time of death. OS estimates were calculated using the Kaplan-Meier method. The log-rank test was used to calculate differences in survival. Results Ninety-four pts with HT were identified. Median age at HT was 67 years (yrs; range, 38-85) and 81% of the pts were male. Median time from CLL diagnosis to HT was 5.5 yrs (range, 0-20.2; 7 pts with simultaneous diagnosis of CLL and HL). At initial CLL diagnosis, 31%, 34%, 21%, 10%, and 4% were Rai Stage 0, 1, 2, 3, and 4, respectively. At CLL diagnosis, 67% (25/37) had an un-mutated IgVH gene, 36% (21/59) had del(13q), 32% (14/44) had trisomy 12, 24% (14/59) had del(11q), and 15% (9/61) had del(17p). Prior to HT diagnosis, pts had a median of 2 (range, 0-12) therapies for CLL. Seventeen (18%) had no prior CLL treatments. Forty-three (46%) and 25 (27%) patients had received purine analogue- and ibrutinib-based therapy prior to HT, respectively. Baseline characteristics at HT are described in Table 1. As initial therapy for HL, the majority of pts (61%, n = 62) received ABVD-based regimens (adriamycin, bleomycin, vinblastine, and dacarbazine) at full (n = 48) or reduced (n = 14) doses. Of these, CD20 monoclonal antibody was added in 6 and Bruton-tyrosine kinase inhibitor was added in 2. Ten (11%) received a brentuximab-based regimen. Seven (7%) received an RCHOP-based regimen (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone). Six patients (6%) received no therapy for HT due to frailty. Subsequent therapy included autologous SCT and allogeneic SCT in 7 (7%) and 11 (12%) of patients, respectively. Two (2%) and 5 (5%) pts received their autologous and allogeneic SCT while in CR1, respectively. The median number of treatments for HT per pt was 1 (range, 0-5) with 59 (61%) pts only receiving one line of therapy. After HT diagnosis, pts had a median follow-up of 1.6 yrs (range, 0.0 - 15.1). Two-yr OS after HT diagnosis was 72% (95%CI 62 - 83%). The pts who received any CLL directed therapy (n = 80) prior to HT had a significantly lower estimated 2-yr OS of 69% (95%CI 58 - 82%) compared with pts who did not receive any prior CLL-directed therapy (n = 17; 93%; 95%CI 82-100%; p 0.02; Figure 1). Pts who received purine-analogue-based therapy for their CLL prior to HT had a significantly lower estimated 2-yr OS of 60% (95%CI 46 - 79%) compared with pts who did not receive purine-analogue-based CLL-directed therapy prior to HT (n = 51; 83%; 95%CI 73 - 96%; p 0.009; Figure 2). Although limited by small sample size, the pts who underwent SCT for HT in CR1 had a similar 2-yr OS (n = 7; 67%; 95%CI 38-100%) to pts who did not undergo SCT for HT in CR1 (n = 87; 72%; 95%CI 63 - 84%; p 0.46; Figure 3). Conclusions In this retrospective analysis, we describe the largest reported series of pts with HT from CLL. Two-yr survival in pts with HT was shorter than what is historically expected in patients with de novo HL, but longer than what is expected in CLL pts who transform to diffuse large B-cell lymphoma. Pts with HT who have received prior CLL-directed therapies (specifically purine-analogue-based treatments) are estimated to have a shorter 2-yr OS, likely due to underlying immunosuppression. The majority of pts (61%) only received 1 line of HL therapy and only 20% went on to receive SCT (7% while in CR1), indicating that these patients can have prolonged OS after achieving response to first-line therapy for HT and may not require SCT in CR1. Further study of this rare population is required to determine optimum management. Disclosures Kander: AstraZeneca: Consultancy. Parikh:Gilead: Honoraria; AstraZeneca: Honoraria, Research Funding; Abbvie: Honoraria, Research Funding; Janssen: Research Funding; MorphoSys: Research Funding; Pharmacyclics: Honoraria, Research Funding. Shadman:Acerta Pharma: Research Funding; Verastem: Consultancy; Celgene: Research Funding; Gilead Sciences: Research Funding; Mustang Biopharma: Research Funding; Pharmacyclics: Research Funding; AstraZeneca: Consultancy; Beigene: Research Funding; Genentech: Research Funding; Qilu Puget Sound Biotherapeutics: Consultancy; AbbVie: Consultancy; TG Therapeutics: Research Funding; Genentech: Consultancy. Pagel:Pharmacyclics, an AbbVie Company: Consultancy; Gilead: Consultancy. Mato:Portola: Research Funding; AstraZeneca: Consultancy; Acerta: Research Funding; Prime Oncology: Honoraria; Regeneron: Research Funding; Celgene: Consultancy; Pharmacyclics, an AbbVie Company: Consultancy, Research Funding; Medscape: Honoraria; TG Therapeutics: Consultancy, Research Funding; Johnson & Johnson: Consultancy; AbbVie: Consultancy, Research Funding. Hill:Amgen: Research Funding; Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees; Seattle Genetics: Honoraria, Membership on an entity's Board of Directors or advisory committees; Pharmacyclics: Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; Genentech: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees; Pharmacyclics: 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; Seattle Genetics: Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: 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. Danilov:Verastem: Consultancy, Research Funding; Aptose Biosciences: Research Funding; Takeda Oncology: Research Funding; Genentech: Consultancy, Research Funding; TG Therapeutics: Consultancy; Bayer Oncology: Consultancy, Research Funding; Astra Zeneca: Consultancy; Gilead Sciences: Consultancy, Research Funding. Phillips:Abbvie: Research Funding; Bayer: Consultancy; Gilead: Consultancy; Genentech: Consultancy; Pharmacyclics: Consultancy, Research Funding; Seattle Genetics: Consultancy. Brander:Pharmacyclics, an AbbVie Company: Consultancy, Honoraria, Research Funding; AbbVie: Consultancy, Honoraria, Other: Institutional research funding for non investigator initiated clinical trial, Research Funding; Acerta: Other: Institutional research funding for non investigator initiated clinical trial, Research Funding; Novartis: Consultancy, Other: DSMB; Teva: Consultancy, Honoraria; TG Therapeutics: Consultancy, Honoraria, Other: Institutional research funding for non investigator initiated clinical trial, Research Funding; DTRM: Other: Institutional research funding for non investigator initiated clinical trial, Research Funding; Genentech: Consultancy, Honoraria, Other: Institutional research funding for non investigator initiated clinical trial, Research Funding; BeiGene: Other: Institutional research funding for non investigator initiated clinical trial, Research Funding. Smith:BMS: Consultancy; Portola: Honoraria. Davids:Surface Oncology: Research Funding; Roche: Consultancy; Sunesis: Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy; Sunesis: Membership on an entity's Board of Directors or advisory committees; Verastem: Consultancy, Research Funding; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Surface Oncology: Research Funding; Astra-Zeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Gilead: Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Roche: Consultancy; MEI Pharma: Consultancy, Research Funding; Astra-Zeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Verastem: Consultancy, Research Funding; Roche: Consultancy; Sunesis: Membership on an entity's Board of Directors or advisory committees; Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS: Research Funding; BMS: Research Funding; MEI Pharma: Consultancy, Research Funding; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees; Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees; Pharmacyclics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pharmacyclics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; TG Therapeutics: Membership on an entity's Board of Directors or advisory committees, Research Funding; TG Therapeutics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Pharmacyclics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; TG Therapeutics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Merck: Consultancy; Merck: Consultancy; Celgene: Consultancy; Astra-Zeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Gilead: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; Merck: Consultancy; Celgene: Consultancy; BMS: Research Funding; Surface Oncology: Research Funding; MEI Pharma: Consultancy, Research Funding; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Verastem: Consultancy, Research Funding.

Abstract Background: Synthetic lethality (SL) is characterized by the chemical inhibition of multiple aberrant genes to differentially kill malignant cells. We investigated small-molecule combinations for SL through in vitro and in vivo screening and optimization studies (as in the granted patents in USA and China) and demonstrated the synergistic potential of best-in-class combinations of targeted agents, drug repositioning, immune modulation and low-dose combinations. We hypothesize that BTK and mTOR inhibition coupled with an IMID will target multiple key signaling pathways, improve differential apoptosis and target acquired drug resistance. DTRM-555, an optimized mechanism-based combination, consists of the clinically differentiated BTK inhibitor DTRMWXHS-12 (or DTRM-12), everolimus (EV) and pomalidomide (POM). In xenograft tumor models, DTRM-555 administered orally has demonstrated superior efficacy over monotherapy at very low dose combinations of the three agents (1/18 of DTRM-12, 1/6 of EV, and 1/6 of POM). DTRM-12 monotherapy has been safe and well tolerated in simultaneous phase Ia trials (US and China) with preliminary efficacy across 50 mg through 400 mg once daily (QD). Here we report the US clinical results of the oral combination therapies DTRM-505 (DTRM-12 plus EV) and DTRM-555 (DTRM-12 plus EV plus POM) for the first time (NCT02900716). Methods: The safety and anti-tumor activity of the oral doublet therapy DTRM-505 and the oral triplet therapy DTRM-555 are evaluated using a "3+3" study design. Enrollment was conducted concurrently with a phase Ia study of DTRM-12 monotherapy; with DTRM-505 opened for accrual when monotherapy DTRM-12 cleared the 200-mg dose level. Eligible patients are at least 18 years old, having ECOG performance status less than 2 with relapsed/refractory chronic lymphocytic leukemia (CLL), diffuse large B cell lymphoma (DLBCL), mantle cell lymphoma (MCL), follicular lymphoma (FL) or classical Hodgkin lymphoma (cHL). Study treatment is administered daily for 21 consecutive days over a 28-day cycle. The dose-limiting toxicity (DLT) period was defined during the first cycle of therapy, and treatment was continued until disease progression or unacceptable toxicity. Patients underwent tumor evaluations every 2 months and response was recorded using revised response criteria (IWCLL and Cheson 2014). Results: Between 9/2016 and 7/2018, 19 patients have been treated with DTRM-12 monotherapy in the USA (6 pts, 50-300 mg) and China (13 pts, 50-400 mg). Patients have tolerated up to 23+ cycles of DTRM-12 monotherapy. Seven patients, including DLBCL, CLL, MCL, FL and cHL, have been treated with oral doublet therapy DTRM-505 for 2 to 12 cycles. Three patients (2 DLBCL, 1 FL) have been treated with oral triplet therapy DTRM-555, including one patient transitioned from the doublet DTRM-505 under an exploratory arm. No patient has discontinued due to an adverse event (AE) and no DLT has occurred. Recurring AEs are mostly grade 1 or 2 and responses have been seen with DTRM-505 and DTRM-555 across diverse lymphoma histologies (See Tables). All patients evaluable for response demonstrated partial response to DTRM-505 and DTRM-555, with 2/7 (doublet) and 3/3 (triplet) patients remaining on therapy. Conclusion: The maximum tolerated dose has not been reached for DTRM-12 monotherapy and for the current fixed dose doublet and triplet combinations. Toxicities have been mild and repeated cycles of study treatment have been well tolerated without delays of subsequent treatment cycles. Enrollment continues for refractory lymphoma patients to demonstrate the safety and efficacy for the first-in-class oral triplet therapy DTRM-555. Disclosures Huntington: Janssen: Consultancy; Bayer: Consultancy; Celgene: Consultancy. Schuster:Merck: Consultancy, Honoraria, Research Funding; Genentech: Honoraria, Research Funding; Pfizer: Membership on an entity's Board of Directors or advisory committees; OncLive: Honoraria; Dava Oncology: Consultancy, Honoraria; Physician's Education Source, LLC: Honoraria; Nordic Nanovector: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis Pharmaceuticals Corporation: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Gilead: Membership on an entity's Board of Directors or advisory committees. He:Zhejiang DTRM Biopharma Co. Ltd.: Other: Founder and CEO; Zhejiang DTRM Biopharma LLC: Other: Founder and CEO. Shen:Zhejiang DTRM Biopharma LLC: Other: Clinical Operations Director. Kennard:AbbVie, Gilead, Verastem: Consultancy. Dwivedy Nasta:Incyte: Research Funding; Takeda/Millenium: Research Funding; Debiopharm: Research Funding; Pharmacyclics: Research Funding; Rafael/WF: Research Funding; Aileron: Research Funding; Roche: Research Funding; Merck: Other: DSMC; Celgene: Membership on an entity's Board of Directors or advisory committees. Landsburg:Takeda: Consultancy; Curis: Consultancy, Research Funding. Porter:Novartis: Other: Advisory board, Patents & Royalties, Research Funding; Genentech: Other: Spouse employment; Kite Pharma: Other: Advisory board. Svoboda:Bristol-Myers Squibb: Consultancy, Research Funding; TG Therapeutics: Research Funding; Kyowa: Consultancy; Regeneron: Research Funding; Merck: Research Funding; Seattle Genetics: Consultancy, Research Funding; Pharmacyclics: Consultancy, Research Funding; KITE: Consultancy. Song:Peking University Cancer Hospital (Beijing Cancer Hospital): Employment. Zhu:Beijing Cancer Hospital: Employment. Brander:Pharmacyclics, an AbbVie Company: Consultancy, Honoraria, Research Funding; AbbVie: Consultancy, Honoraria, Other: Institutional research funding for non investigator initiated clinical trial, Research Funding; TG Therapeutics: Consultancy, Honoraria, Other: Institutional research funding for non investigator initiated clinical trial, Research Funding; Novartis: Consultancy, Other: DSMB; Genentech: Consultancy, Honoraria, Other: Institutional research funding for non investigator initiated clinical trial, Research Funding; Teva: Consultancy, Honoraria; Acerta: Other: Institutional research funding for non investigator initiated clinical trial, Research Funding; DTRM: Other: Institutional research funding for non investigator initiated clinical trial, Research Funding; BeiGene: Other: Institutional research funding for non investigator initiated clinical trial, Research Funding. Ding:Merck: Research Funding. Mato:Pharmacyclics, an AbbVie Company: Consultancy, Research Funding; AstraZeneca: Consultancy; Regeneron: Research Funding; Celgene: Consultancy; Acerta: Research Funding; TG Therapeutics: Consultancy, Research Funding; AbbVie: Consultancy, Research Funding; Portola: Research Funding; Johnson & Johnson: Consultancy; Prime Oncology: Honoraria; Medscape: Honoraria.

7505 Background: Novel agents (NA) targeting B cell receptor kinases and Bcl-2 have substantially improved outcomes in CLL; however, the development of RS in CLL patients (pts) on NAs has been observed, and has not been systematically evaluated. Methods: We retrospectively reviewed pts at 9 academic centers diagnosed with pathologically-confirmed RS from 2011-16. Informed consent was provided through IRB-approved protocols. Descriptive statistics were utilized and overall survival (OS) was calculated from RS diagnosis (dx) to death or last follow-up by Kaplan-Meier. Results: 71 pts who developed RS on NAs for CLL were identified. Median age at CLL dx was 55 yrs (range 21-82), median of 3 therapies (range 0-12) prior to the NA. 68% pts were fludarabine-refractory, and 5 pts (7%) had relapsed post alloHCT. Median time from CLL dx to initiation of NA was 68.5 mo. (range 1.1-246.2). FISH at NA initiation: del(17p) 30/61 (49%), del(11q) 15/61 (25%), trisomy 12 15/61 (25%). Complex karyotype was present in 40/53 (75%). 46/52 (88%) were IGHV unmutated, VH1-69 10/43 (23%), VH4-39 4/43 (9%). 59 (83%) pts were on a BTK inhibitor, 6 (8%) PI3K inhibitor, 6 (8%) venetoclax. RS histology: DLBCL (87%), plasmablastic (6%), Hodgkin (4%), 3% other. RS Ki-67%: >90 (23%), 75-90 (25%), 50-75% (25%), <50% (28%). Median time from start of NA to RS dx was 9.1 mo (range 0.9-48.2), with 65% developing RS within 12 mo. of starting NA. In 56 pts, 19 different regimens were used as initial RS therapy, including: R-EPOCH (36%), R-CHOP (20%), checkpoint blockade (9%), OFAR (7%), or a different NA (7%). Of the 48 pts evaluable for response, ORR was 42% (15% CR, 27% PR). In 29 evaluable pts receiving R-EPOCH/CHOP, ORR was 48% (21% CR). With a median follow-up of 10.6 mo., median OS was only 3.3 mo. (95%CI 2.2-6.0), though none of the 7 pts who achieved CR has died. Conclusions: We report to our knowledge the largest series of CLL pts developing RS on NAs. Pts often had high risk CLL, particularly complex cytogenetics, and RS frequently developed within the first year of NA therapy. Substantial variation exists in treatment, and outcomes are poor for those who do not achieve CR. Identification of molecular drivers of RS and development of novel treatment strategies are urgently needed.