Martin, Thomas G.

Abstract Background: Despite many treatment options, multiple myeloma (MM) remains largely incurable with poor outcomes among patients who progress after treatment with a protease inhibitor, immunomodulatory imide drugs (IMiDs), and/or an anti-CD38 antibody. Multiple targeted therapies have been developed for different subtypes of non-Hodgkin lymphoma (NHL); however, these therapies are typically not curative for patients with relapsed/refractory (R/R) disease. IMiDs are a standard of care for treatment of MM and have shown activity in some NHL subtypes. However, given that many patients treated with these agents frequently develop disease progression, an unmet need remains. CFT7455 is a next-generation IKZF1/3 degrader, which is more potent and catalytically active than other approved agents targeting the cereblon E3 ligase complex that degrade IKZF1/3. CFT7455 is orally bioavailable and selective for IKZF1 (Ikaros) and IKZF3 (Aiolos). Depletion of these targets from malignant B cells result in tumor cell death, and depletion from the tumor microenvironment results in T-cell activation. In i n vitro and in vivo models of MM and NHL, including anaplastic large cell lymphoma, diffuse large B-cell lymphoma, and mantle cell lymphoma (MCL), CFT7455 demonstrated greater activity than other agents in similar classes. These results provided rationale for a first-in-human, phase 1 study to evaluate CFT7455. Study Design: This is an open-label, multicenter, phase 1 clinical trial with dose escalation and dose expansion phases. The dose escalation phase, beginning with a starting dose of 50 mcg daily, may include single-participant cohorts at initial dose levels, after which 3-6 patients are enrolled per cohort using a Bayesian logistic regression model. After initial exploration of single-agent CFT7455 in a mixed cohort of patients with R/R MM or select NHLs, dose escalation is split to perform dose determination in R/R MM separate NHL. Once a safe dose of CFT7455 in R/R MM is determined, the combination of CFT7455 with dexamethasone will be explored in R/R MM. CFT7455 is dosed orally in 28-day cycles, on a 21-day on, 7-day off schedule, until disease progression or intolerable toxicity. Expansion cohorts of single-agent CFT7455 and CFT7455 plus dexamethasone in R/R MM, and single-agent CFT7455 for peripheral T-cell lymphoma and MCL are planned. Primary objectives include: safety and tolerability, randomized phase 2 dose (RP2D)/maximum tolerated dose (MTD) of CFT7455, and estimation of antitumor activity of CFT7455. Secondary objectives include assessment of pharmacokinetics. Exploratory objectives include characterization of target engagement and IKZF1/3 degradation and assessing the immunomodulatory effects of CFT7455. For MM patients, key inclusion criteria include histologically/cytologically-confirmed MM that is R/R. Patients must not be candidates for regimens known to provide clinical benefit, defined as having received ≥3 prior anti-myeloma regimens including ≥2 consecutive cycles of lenalidomide, pomalidomide, a proteasome inhibitor, a glucocorticoid, and an anti-CD38 antibody. Key exclusion criteria include the presence of central nervous system malignancy, recent venous thromboembolism or inability to undergo its prophylaxis. Plasma cell leukemia is excluded. For NHL patients, key inclusion criteria include histologically/cytologically-confirmed NHL that is R/R. Patients mustn't be candidates for regimens known to provide clinical benefit, defined as the requisite prior lines of therapy according to an indication-specific basis. Key exclusion criteria include the presence of central nervous system malignancy, recent venous thromboembolism or inability to undergo its prophylaxis. Several lymphoma subtypes less likely to benefit are excluded (eg, Richter transformation, Burkitt lymphoma, Sezary syndrome, and lymphoblastic lymphoma). Approximately 164 patients at approximately 13 US sites will be enrolled. This trial is registered with clinicaltrials.gov as NCT04756726, enrollment is ongoing. Disclosures Berdeja: Legend Biotech: Consultancy; Incyte: Research Funding; Ichnos Sciences: Research Funding; Genentech: Research Funding; GlaxoSmithKline: Research Funding; Lilly: Research Funding; SecuraBio: Consultancy; EMD Serono: Research Funding; Janssen: Consultancy, Research Funding; Bluebird bio: Consultancy, Research Funding; Amgen: Research Funding; Astex Pharmaceuticals: Research Funding; Kite Pharma: Consultancy; CRISPR Therapeutics: Consultancy, Research Funding; Celularity: Research Funding; Celgene: Consultancy, Research Funding; Poseida: Research Funding; Acetylon: Research Funding; Teva: Research Funding; Novartis: Research Funding; BMS: Consultancy, Research Funding; Sanofi: Research Funding; Abbvie: Research Funding; Takeda: Consultancy. Ailawadhi: GSK: Consultancy, Research Funding; Sanofi: Consultancy; Cellectar: Research Funding; Janssen: Consultancy, Research Funding; Xencor: Research Funding; Beigene: Consultancy; Karyopharm: Consultancy; BMS: Consultancy, Research Funding; Ascentage: Research Funding; Pharmacyclics: Consultancy, Research Funding; Amgen: Consultancy, Research Funding; AbbVie: Consultancy; Takeda: Consultancy; Genentech: Consultancy; Medimmune: Research Funding. Horwitz: Millennium /Takeda: Consultancy, Research Funding; Kura Oncology: Consultancy; Janssen: Consultancy; Tubulis: Consultancy; Myeloid Therapeutics: Consultancy; Affimed: Research Funding; Aileron: Research Funding; Vividion Therapeutics: Consultancy; ONO Pharmaceuticals: Consultancy; Celgene: Research Funding; Acrotech Biopharma: Consultancy; Daiichi Sankyo: Research Funding; Forty Seven, Inc.: Research Funding; Trillium Therapeutics: Consultancy, Research Funding; C4 Therapeutics: Consultancy; Kyowa Hakko Kirin: Consultancy, Research Funding; Seattle Genetics: Consultancy, Research Funding; SecuraBio: Consultancy, Research Funding; Shoreline Biosciences, Inc.: Consultancy; ADC Therapeutics: Consultancy, Research Funding; Verastem: Research Funding. Matous: Pharmacyclics: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees. Mehta-Shah: C4 Therapeutics: Consultancy; Kiowa Hakko Kirin: Consultancy; Karyopharm: Consultancy; Ono Pharmaceuticals: Consultancy; Secura Bio: Consultancy, Research Funding; Daiichi Sankyo: Consultancy, Research Funding; AstraZeneca: Research Funding; Bristol Myers Squibb: Research Funding; Celgene: Research Funding; Innate Pharmaceuticals: Research Funding; Roche/Genentech: Research Funding; Corvus Pharmaceuticals: Research Funding; Verastem: Research Funding. Martin: GlaxoSmithKline: Consultancy; Sanofi: Research Funding; Oncopeptides: Consultancy; Amgen: Research Funding; Janssen: Research Funding. Richardson: Takeda: Consultancy, Research Funding; Sanofi: Consultancy; Secura Bio: Consultancy; Oncopeptides: Consultancy, Research Funding; GlaxoSmithKline: Consultancy; Regeneron: Consultancy; Protocol Intelligence: Consultancy; AstraZeneca: Consultancy; Karyopharm: Consultancy, Research Funding; Celgene/BMS: Consultancy, Research Funding; AbbVie: Consultancy; Janssen: Consultancy; Jazz Pharmaceuticals: Consultancy, Research Funding. Richard: Karyopharm, Janssen: Honoraria. Bhutani: Sanofi: Consultancy; Amgen, BMS, Takeda: Speakers Bureau; Janssen, MedImmune, Takeda, Celgene, BMS, Cerecor, Celularity: Research Funding. Yee: Takeda: Consultancy; Adaptive: Consultancy; Karyopharm: Consultancy; Bristol Myers Squibb: Consultancy; Oncopeptides: Consultancy; GSK: Consultancy; Amgen: Consultancy; Sanofi: Consultancy; Janssen: Consultancy. Palmer: C4 Therapeutics: Current Employment. Gorman: C4 Therapeutics: Current Employment. Schoenborn-Kellenberger: C4 Therapeutics: Current Employment. Bilic: C4 Therapeutics: Current Employment. Crystal: C4 Therapeutics: Current Employment, Current equity holder in publicly-traded company. Mahler: C4 Therapeutics: Current Employment, Current equity holder in publicly-traded company. Lonial: Merck: Honoraria; Abbvie: Consultancy, Honoraria; BMS/Celgene: Consultancy, Honoraria, Research Funding; TG Therapeutics: Membership on an entity's Board of Directors or advisory committees; Takeda: Consultancy, Honoraria, Research Funding; AMGEN: Consultancy, Honoraria; Janssen: Consultancy, Honoraria, Research Funding; GlaxoSmithKline: Consultancy, Honoraria, Research Funding.

Abstract Introduction: Belantamab mafodotin (belamaf) is a B-cell maturation antigen (BCMA)-targeting antibody-drug conjugate approved in the United States (US) and Europe as a monotherapy for triple-class refractory adult patients with relapsed or refractory multiple myeloma (RRMM). This hypothesis-generating post-hoc analysis of DREAMM-2 trial (NCT03525678) data examined relationships between corneal exam findings (superficial punctate keratopathy and/or microcyst like epithelial changes), best-corrected visual acuity (BCVA), and direct patient-reported ocular symptoms per the Ocular Surface Disease Index (OSDI) questionnaire. This approach could provide insight into the relationship between corneal exam findings, BCVA, and ocular symptoms and their impact on quality of life to help determine if BCVA decline and symptoms could guide dosing. Currently, in the US, eye exams with eye-care professionals (ECPs) are required for each belamaf treatment, which can add to patients' therapy-related burden. Identifying a surrogate marker for results from corneal exam findings would help providers determine if dosing adjustments are necessary. Methods: Eye exams (including a corneal exam and BCVA assessment using the Snellen chart) were performed on all patients receiving single-agent belamaf (2.5 mg/kg) by ECPs at baseline (BL) and before each dose, administered q3w. Corneal exam findings (keratopathy) and BCVA were assessed per protocol-defined criteria, and grade (GR) assessment was based on the worst finding in the worse eye. BCVA and keratopathy grading were relative to BL. Patient-reported ocular symptoms and vision-related functioning, as per the OSDI, were used to evaluate the impact of treatment-related ocular toxicity. The OSDI is a patient-reported outcome questionnaire that assesses eye symptoms and effects on vision-related function in the past week and was performed in all patients before each belamaf dose. Items 1-5 address the frequency of eye-related symptoms (eg, painful or sore eyes, blurred vision) while items 6-9 address the frequency of functional limitations (eg, driving at night or reading). OSDI was considered positive, clinically meaningful, and potentially associated with treatment when at least one question 1-5 (ie, sensitivity to light, gritty or painful eyes, blurred or poor vision) was reported as experienced "all of the time" and at least one question 6-9 (ie, driving at night, reading, working with PC, or watching TV) was reported as experienced "most of the time." Results: Overall, GR 3-4 (severe) keratopathy was observed only 5% of the time in patients who did not report frequent ocular symptoms as measured by the OSDI questionnaire (no items 1-9 ≥ "most of the time"). A further breakdown of the questions revealed that, in patients who reported no items 1-5 "all of the time" AND no items 6-9 ≥ "most of the time" (OSDI negative), GR 3-4 keratopathy was observed only 6% of the time (Table). When considering individual OSDI items, in patients who reported "no deterioration from BL" for any of the OSDI eye-related symptoms or functional limitations, GR 3-4 keratopathy was observed ~3%-7% of the time while GR 0-2 (mild) keratopathy was observed ~23%-34% of the time. Similar results were observed in patients with BCVA ≤20/30 at BL who reported "no deterioration from BL" for any eye-related adverse events (AEs) or functional limitations (GR 3-4 keratopathy: ~2%-6% of the time; GR 0-2 keratopathy: ~19%-28% of the time); patients with worse visual acuity at BL (BCVA >20/30) who reported "no deterioration" for items 1-9 had lower incidence of GR 3-4 and GR 0-2 keratopathy (~0%-1% and ~3%-8%, respectively). Conclusions: The results from this hypothesis-generating post-hoc analysis suggest that hematologists/oncologists may be able to use clinical indicators/tools (eg, ocular symptoms, the OSDI tool) as potential surrogate markers for eye exam results to help determine whether dosing changes are needed. This approach will be explored in trials with other belamaf dose regimens that are currently under evaluation. If the results are validated, it may be possible for hematologists/oncologists to manage belamaf dose modifications, due to ocular AEs, without a confirmatory eye exam by the ECP, reducing the patient burden. Funding Source: GSK (205678). Drug linker technology licensed from Seagen; monoclonal antibody produced using POTELLIGENT Technology licensed from BioWa. Figure 1 Figure 1. Disclosures Popat: Takeda: Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES; GlaxoSmithKline: Consultancy, Honoraria, Research Funding; AbbVie, BMS, Janssen, Oncopeptides, and Amgen: Honoraria; Abbvie, Takeda, Janssen, and Celgene: Consultancy; Janssen and BMS: Other: travel expenses. Badros: GlaxoSmithKline: Research Funding; BMS: Research Funding; Janssen: Research Funding; J&J: Research Funding. Kumar: Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Consultancy, Research Funding; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Tenebio: Research Funding; Antengene: Consultancy, Honoraria; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Carsgen: Research Funding; Roche-Genentech: Consultancy, Research Funding; Beigene: Consultancy; BMS: Consultancy, Research Funding; KITE: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bluebird Bio: Consultancy; Oncopeptides: Consultancy; Astra-Zeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Research Funding; Merck: Research Funding; Adaptive: Membership on an entity's Board of Directors or advisory committees, Research Funding; Sanofi: Research Funding. Rodríguez-Otero: Regeneron: Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Oncopeptides: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Kite: 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; Sanofi: Honoraria, Membership on an entity's Board of Directors or advisory committees; GlaxoSmithKline: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; BMS/Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel and other expenses. Cohen: BMS: Research Funding; GlaxoSmithKline: Other: Personal fees and other association with, Research Funding; Novartis: Research Funding; Celgene: Honoraria, Other: Personal fees and other association with; Janssen: Honoraria; Kite Pharma: Honoraria; Oncopeptides: Honoraria; Seattle Genetics: Honoraria; Takeda: Honoraria. Manier: Regeneron: Consultancy, Research Funding; Oncopeptides: 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, Research Funding; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Adaptive Biotechnologies: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; GSK: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Consultancy, Research Funding; Celgene - Bristol Myers Squibb: 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. Voorhees: Secura Bio: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Abbvie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; BMS: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; GlaxoSmithKline: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Karyopharm: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Oncopeptides: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Pfizer: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Sanofi: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. Gay: Amgen: 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; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees; Bristol-Myers Squibb: Honoraria; AbbVie: Honoraria, Membership on an entity's Board of Directors or advisory committees; GlaxoSmithKline: Honoraria, Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees; Adaptive Biotechnologies: Membership on an entity's Board of Directors or advisory committees; Oncopeptides: Membership on an entity's Board of Directors or advisory committees; Bluebird Bio: Membership on an entity's Board of Directors or advisory committees; Sanofi: Consultancy, Honoraria. Rifkin: Takeda: Membership on an entity's Board of Directors or advisory committees; Sanofi: Membership on an entity's Board of Directors or advisory committees; Fresenius-Kabi: Membership on an entity's Board of Directors or advisory committees; Coherus: Membership on an entity's Board of Directors or advisory committees; Bristol Myers Squibb (Celgene): Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees; McKesson: Current Employment, Current equity holder in publicly-traded company; Karyopharm: Membership on an entity's Board of Directors or advisory committees. Martin: Janssen: Research Funding; Sanofi: Research Funding; Oncopeptides: Consultancy; Amgen: Research Funding; GlaxoSmithKline: Consultancy. Chari: Oncopeptides: Consultancy, Membership on an entity's Board of Directors or advisory committees; Takeda: Consultancy, Research Funding; GlaxoSmithKline: Consultancy, Membership on an entity's Board of Directors or advisory committees; Secura Bio: Consultancy, Membership on an entity's Board of Directors or advisory committees; Shattuck Labs: 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; AbbVie: Consultancy, Membership on an entity's Board of Directors or advisory committees; Seattle Genetics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Antengene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Research Funding; Pharmacyclics: Research Funding; Millenium/Takeda: Consultancy, Research Funding; Sanofi Genzyme: Consultancy, Membership on an entity's Board of Directors or advisory committees; Karyopharm: Consultancy, Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS/Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen Oncology: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. Weisel: Bristol Myers Squibb: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Oncopeptides: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Roche: Honoraria; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Sanofi: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; GSK: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Karyopharm: 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; Adaptive Biotechnologies: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Abbvie: Consultancy; Novartis: Honoraria; Pfizer: Honoraria. Farooq: Five Prime Therapeutics/Amgen: Consultancy; GlaxoSmithKline: Consultancy. Jeng: OysterPoint: Consultancy; GlaxoSmithKline: Consultancy, Honoraria, Research Funding; Sanofi: Consultancy; Eyegate: Current equity holder in publicly-traded company. Chng: Abbvie: Consultancy; GlaxoSmithKline: Consultancy; Takeda: Consultancy; BMS/Celgene: Consultancy, Research Funding; Sanofi: Consultancy; Novartis: Research Funding; Johnson & Johnson: Consultancy, Research Funding; Amgen: Consultancy; Antengene: Consultancy; Pfizer: Consultancy; Aslan: Research Funding. Lee: Takeda Pharmaceuticals: Consultancy, Research Funding; Oncopetides: Consultancy; Sanofi: Consultancy; GlaxoSmithKline: Consultancy, Research Funding; Legend Biotech: Consultancy; Karyopharm: Consultancy; Janssen: Consultancy, Research Funding; Genentech: Consultancy; Celgene: Consultancy; Bristol Myers Squibb: Consultancy; Amgen: Consultancy, Research Funding; Regeneron: Research Funding. Berdeja: BMS: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Celularity: Research Funding; CRISPR Therapeutics: Consultancy, Research Funding; Janssen: Consultancy, Research Funding; Kite Pharma: Consultancy; Legend Biotech: Consultancy; SecuraBio: Consultancy; EMD Serono: Research Funding; Genentech: Research Funding; GlaxoSmithKline: Research Funding; Ichnos Sciences: Research Funding; Incyte: Research Funding; Novartis: Research Funding; Poseida: Research Funding; Bluebird bio: Consultancy, Research Funding; Astex Pharmaceuticals: Research Funding; Amgen: Research Funding; Abbvie: Research Funding; Takeda: Consultancy; Sanofi: Research Funding; Acetylon: Research Funding; Teva: Research Funding; Lilly: Research Funding. Jadhav: GlaxoSmithKline: Current Employment, Current equity holder in publicly-traded company. Tosolini: GlaxoSmithKline: Current Employment, Current equity holder in publicly-traded company. Eliason: GlaxoSmithKline: Current Employment, Current equity holder in publicly-traded company. Palumbo: GlaxoSmithKline: Current Employment, Current equity holder in publicly-traded company. Dimopoulos: Beigene: Honoraria; BMS: Honoraria; Amgen: Honoraria; Janssen: Honoraria; Takeda: Honoraria. Lonial: Merck: Honoraria; Janssen: Consultancy, Honoraria, Research Funding; BMS/Celgene: Consultancy, Honoraria, Research Funding; AMGEN: Consultancy, Honoraria; GlaxoSmithKline: Consultancy, Honoraria, Research Funding; Abbvie: Consultancy, Honoraria; Takeda: Consultancy, Honoraria, Research Funding; TG Therapeutics: Membership on an entity's Board of Directors or advisory committees. Trudel: Amgen: Consultancy, Honoraria, Research Funding; Takeda: Honoraria; Amgen Canada: Honoraria; Sanofi: Honoraria; Celgene: Consultancy, Honoraria, Research Funding; GlaxoSmithKline: Consultancy, Research Funding; Janssen: Honoraria, Research Funding; Genentech: Research Funding; Karyopharm: Honoraria. Richardson: Sanofi: Consultancy; Celgene/BMS: Consultancy, Research Funding; Protocol Intelligence: Consultancy; GlaxoSmithKline: Consultancy; Secura Bio: Consultancy; AbbVie: Consultancy; Karyopharm: Consultancy, Research Funding; Janssen: Consultancy; Oncopeptides: Consultancy, Research Funding; Regeneron: Consultancy; AstraZeneca: Consultancy; Takeda: Consultancy, Research Funding; Jazz Pharmaceuticals: Consultancy, Research Funding. Terpos: Celgene: Consultancy, Honoraria, Research Funding; Genesis: Consultancy, Honoraria, Research Funding; GSK: Honoraria, Research Funding; Amgen: Consultancy, Honoraria, Research Funding; BMS: Honoraria; Janssen-Cilag: Consultancy, Honoraria, Research Funding; Novartis: Honoraria; Takeda: Consultancy, Honoraria, Research Funding; Sanofi: Consultancy, Honoraria, Research Funding.

Multiple myeloma is a malignant neoplasm of plasma cells that accumulate in bone marrow, leading to bone destruction and marrow failure. This manuscript discusses the management of patients with solitary plasmacytoma, smoldering multiple myeloma, and newly diagnosed multiple myeloma.

8035 Background: Patients (pts) with relapsed and refractory multiple myeloma (RR MM) who are refractory or intolerant to both bortezomib (BTZ) and immunomodulators (IMiDs; thalidomide [Thal] or lenalidomide [Len]) (ie, “double-refractory/intolerant”), have few therapeutic options and a poor prognosis. Carfilzomib (CFZ), a next generation proteasome inhibitor (PI), has shown durable single-agent activity in clinical studies including 003-A1, an open-label, single-arm phase 2b trial in RR MM. The present analysis describes clinical activity in pts from 003-A1 with double-refractory/intolerant disease and in other groups of clinical interest including pts with disease refractory to all 5 approved classes of anti-MM tx (alkylators, anthracyclines, corticosteroids, IMiDs, and PIs) in clinical use (“refractory to all approved tx”). Methods: Pts from 003-A1 with double-refractory/intolerant disease were analyzed, as were pts with disease refractory to all approved tx. CFZ was given on days 1, 2, 8, 9, 15, 16 of 28-day cycles (C), (20 mg/m2 in C1; 27 mg/m2 in C2–12). Primary endpoint was overall response rate (ORR). Secondary endpoints included duration of response (DOR), overall survival, and safety. Results: The study ORR was 22.9% with median DOR of 7.8 mo (N=266). 228 pts (86%) with double-refractory/intolerant disease had ORRs of 20.6% and a median DOR of 7.4 mo. Conclusions: Single-agent CFZ demonstrated clinically meaningful, durable responses in pts with double-refractory/intolerant MM or disease refractory to all 5 approved classes of tx. The ORRs across groups of clinical interest were generally consistent with results for the entire study population. These results are notable for a next-generation PI and demonstrate the activity of single-agent CFZ in pts with advanced stage MM. [Table: see text]

Background: Maintenance therapy with lenalidomide post-autologous stem cell transplantation (ASCT) has shown to improve progression-free survival (PFS) in multiple myeloma (MM), and has largely become the standard of care. However, toxicity leads to early discontinuation in nearly one-third of patients and additional options are needed (McCarthy, et al, JCO, 2017). Ixazomib is another maintenance option that has been shown to improve PFS; however, studies comparing lenalidomide and ixazomib are lacking. In this randomized phase 2 study, we analyzed the safety and efficacy of using lenalidomide and ixazomib as part of consolidation and maintenance therapies after ASCT (NCT02253316). Methods: Eligible patients, age 18-70 with newly diagnosed MM undergoing ASCT during first-line treatment, were consented prior to ASCT. Approximately 4 months following ASCT, patients received 4 cycles of consolidation therapy with IRd [ixazomib 4 mg on days 1, 8 and 15 of a 28-day cycle, lenalidomide 15 mg on days 1 through 21, and dexamethasone 40 mg on days 1, 8 and 15]. Primary data on IRd consolidation were presented at ASH 2018 (Abstract 109920). One month after the last consolidation cycle, patients were randomized (1:1) to maintenance therapy with single-agent ixazomib (4 mg on days 1, 8 and 15 of a 28-day cycle) or lenalidomide (10 mg daily months 1-3 followed by 15 mg for months 4+). The arms were stratified based on MRD-status post-consolidation. In total, 237 patients were enrolled from 10 US centers. This abstract coincides with planned interim analysis 3 which is the first comparison of ixazomib and lenalidomide maintenance. While the study was not powered to compare PFS between the two arms, the sample will provide a reasonable power to estimate non-inferiority. There is a planned stopping rule for non-inferiority set at a hazard ratio of >1.3 in favor of lenalidomide. Secondary end-points include MRD-negativity following 12 cycles and toxicity. Results: At time of abstract submission, 215 patients had completed IRd consolidation and 191 had begun maintenance. 90 were randomized to ixazomib and 94 to lenalidomide. 7 patients were not randomized due to toxicity during consolidation; data from these patients are not included in the analyses. The characteristics of the two arms are summarized in Table 1. Hematologic toxicity has been infrequent with ixazomib with neutropenia and thrombocytopenia occurring in 11% and 23% of patients. In comparison, neutropenia and thrombocytopenia occurred in 45% and 35% of patients on lenalidomide. The most common non-hematologic toxicities in both arms have been GI-related and infections, both expected events. 16% of patients on ixazomib have experienced Grade 3-4 non-hematologic toxicity compared to 34% on lenalidomide. No grade 3 or higher peripheral neuropathy has been reported in either arm. 11% of patients on ixazomib have discontinued due to toxicity and another 9% have required a dose reduction to 3mg. Lenalidomide toxicity has led to discontinuation in 15% of patients and another 12% were dose reduced to 5mg. Only 45% of patients receiving 4+ cycles of lenalidomide were able to titrate to the 15mg dose. After a median follow-up of 11.2 months from randomization (19.7 months post-ASCT), 30% of patients on ixazomib have discontinued treatment due to disease progression. After a median follow-up of 12.3 months from randomization (20.2 months post-ASCT), 18% patients on lenalidomide have discontinued treatment due to disease progression. Conclusion: Ixazomib and lenalidomide maintenance have been well tolerated to date. A comparison of PFS is currently being conducted as part of interim analysis 3 and final results will be presented, representing the first report directly comparing lenalidomide and ixazomib maintenance. Table 1: Disclosures Vij: Genentech: Honoraria; Karyopharm: Honoraria; Celgene: Honoraria, Research Funding; Bristol-Myers Squibb: Honoraria, Research Funding; Takeda: Honoraria, Research Funding; Janssen: Honoraria; Sanofi: Honoraria. Martin:Amgen, Sanofi, Seattle Genetics: Research Funding; Roche and Juno: Consultancy. Fiala:Incyte: Research Funding. Deol:Novartis: Other: Advisory board; Kite: Other: Advisory board; Agios: Other: Advisory board. Kaufman:Celgene: Consultancy; Winship Cancer Institute of Emory University: Employment; Amgen: Consultancy; Bristol-Myers Squibb: Consultancy; Pharmacyclics: Membership on an entity's Board of Directors or advisory committees; AbbVie: Consultancy; Janssen: Honoraria; Incyte: Consultancy; Karyopharm: Membership on an entity's Board of Directors or advisory committees; TG Therapeutics: Consultancy; Takeda: Consultancy. Hofmeister:Karyopharm: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees; Oncopeptides: Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria; Nektar: Honoraria, Membership on an entity's Board of Directors or advisory committees; Imbrium: Membership on an entity's Board of Directors or advisory committees. Gregory:Poseida: Research Funding; Celgene: Speakers Bureau; Amgen: Speakers Bureau; Takeda: Speakers Bureau. Berdeja:AbbVie Inc, Amgen Inc, Acetylon Pharmaceuticals Inc, Bluebird Bio, Bristol-Myers Squibb Company, Celgene Corporation, Constellation Pharma, Curis Inc, Genentech, Glenmark Pharmaceuticals, Janssen Biotech Inc, Kesios Therapeutics, Lilly, Novartis, Poseida: Research Funding; Poseida: Research Funding; Amgen Inc, BioClinica, Celgene Corporation, CRISPR Therapeutics, Bristol-Myers Squibb Company, Janssen Biotech Inc, Karyopharm Therapeutics, Kite Pharma Inc, Prothena, Servier, Takeda Oncology: Consultancy. Chari:Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bristol-Myers Squibb: Consultancy; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Millennium/Takeda: 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, Research Funding; Karyopharm: Consultancy, Membership on an entity's Board of Directors or advisory committees; Array Biopharma: Research Funding; GlaxoSmithKline: Research Funding; Novartis Pharmaceuticals: Research Funding; Oncoceutics: Research Funding; Pharmacyclics: Research Funding; Seattle Genetics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Sanofi: Membership on an entity's Board of Directors or advisory committees. Rosko:Vyxeos: Other: Travel support.

Abstract Background: Isatuximab (SAR650984) is a humanized IgG1 monoclonal antibody that binds selectively to a unique epitope on the human CD38 receptor. In the dose escalation part of the Phase I portion of the trial (NCT01749969), isatuximab ≥10 mg/kg IV given every other week (q2w) or 10 mg/kg weekly (qw) induced responses in 6/19 recipients (ORR 32%). Responses were noted at doses as low as 1 mg/kg q2w. The maximum tolerated dose (up to 20 mg/kg IV qw) was not reached. The most common treatment-emergent adverse events (TEAEs) were fatigue and nausea; few serious grade 3/4 TEAEs were reported (pneumonia 6%). The most common category of drug-related TEAE involved infusion-associated reactions (IARs) occurring in half of the patients, with grade 3/4 IARs in <5% of the patients. Based on promising Phase I activity, a Phase II dose finding study was added to investigate single-agent isatuximab in patients with relapsed or refractory myeloma (RRMM). Methods: In Phase II, eligible patients were originally randomly assigned (1:1:1) to one of 3 treatment groups: 3 mg/kg q2w, 10 mg/kg q2w, and 10 mg/kg q2w x 4 doses then q4w. A 4th treatment group was enrolled at a higher isatuximab dose with an optimized schedule of 20 mg/kg qw x 4 doses then q2w. Patient assignment was stratified by prior anti-myeloma therapy (Stratum 1: prior treatment with pomalidomide (POM) and/or carfilzomib (CAR); Stratum 2: no prior POM or CAR). Patients continued therapy until disease progression, unacceptable AEs or physician/patient decision. Eligible patients had measurable disease (serum M-protein >1 g/dL or urine M-protein ≥200 mg/24 h, or serum free light chain ≥10 mg/dL), prior exposure to ≥3 lines of anti-myeloma therapy or were double-refractory to immunomodulatory drugs (IMiDs) and proteasome inhibitors (PIs), prior treatment with an alkylating agent, and adequate baseline bone marrow reserve and organ function. Enrollment of 24 patients was planned for each treatment group. An interim efficacy analysis is planned when all patients have completed ≥2 disease assessments, with central review of these data currently ongoing. Enrollment has now been completed and all patients who completed at least 1 cycle of isatuximab at the cutoff date (5/29/15) are included in this preliminary analysis. Results: Patient characteristics (n=96): median age 62.5 yrs (range 38-85); median time from initial diagnosis to study treatment 5.85 yrs (1.2-24.1); 76% had IgA/G MM; 24% had light-chain only disease; and 22%, 22%, and 44% had Stage I, II, and III disease, respectively. The median number of prior lines of therapy was 5 (2-14) with 100%, 99%, and 98% having prior exposure to PIs, IMiDs, and alkylator-containing therapy, respectively. Overall, 78% of patients had previously received POM and/or CAR; 55% had been exposed to both of these agents. At data cut-off, 36.5% of patients remained on therapy and 53.1%, 6.3%, and 4.2% had discontinued therapy due to disease progression, AEs, or other reason, respectively. The median number of cycles received was 3 (1-9), with a median duration of treatment of 11.7 wks. Approximately 17% of patients required at least 1 dose delay and 7.3% of isatuximab infusions were interrupted. TEAEs occurred in 93% of patients, with 51% being grade ≥3. Drug-related TEAEs occurred in 61% of patients (grade ≥3, 10%). The most common drug-related TEAEs (>5% of patients) were nausea (14.6%), chills (14.6%), dyspnea (13.5%), chest discomfort (10.4%), flushing (7.3%), headache (7.3%), cough (6.3%), and vomiting (5.2%). The majority of the symptoms occurred within 24 h of isatuximab infusion and were attributed to an IAR. IARs occurred in 50% of patients, were predominantly grade 1/2 (grade ≥3, 3.1%), and were mostly limited to Cycle 1 (2 patients had IARs in Cycle 2). Pneumonia (6.3%) and sepsis (5.2%) were the most common serious TEAEs. Six deaths have occurred within 30 days of last dose, 4 due to disease progression, and 2 due to serious AEs unrelated to study therapy (cardiopulmonary arrest and cerebral hemorrhage). Conclusion: Isatuximab administered to heavily pre-treated patients with RRMM appears well tolerated. IARs are common in Cycle 1, but typically do not recur. Results by treatment arm, including interim analysis response data, will be presented. Disclosures Martin: Sanofi: Research Funding. Richter:Takeda: Speakers Bureau; Celgene: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen: Speakers Bureau; Amgen: Speakers Bureau; Novartis: Speakers Bureau. Vij:Millennium: Honoraria, Speakers Bureau; Onyx: Consultancy, Honoraria, Research Funding, Speakers Bureau; Celgene: Consultancy, Honoraria, Research Funding, Speakers Bureau; BMS: Consultancy; Takeda: Consultancy, Research Funding; Novartis: Consultancy; Sanofi: Consultancy; Janssen: Consultancy; Merck: Consultancy. Zonder:Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS, Amgen, Prothena, Seattle Genetics: Membership on an entity's Board of Directors or advisory committees. Kaufman:Spectrum: Consultancy; Merck: Research Funding; Onyx: Consultancy, Research Funding; Novartis: Consultancy; Celgene: Consultancy, Research Funding; Millenium: Consultancy. Bensinger:Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding; Acetylon: Research Funding; Sanofi: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Onyx: Research Funding, Speakers Bureau; Millenium: Research Funding; BMS: Membership on an entity's Board of Directors or advisory committees, Research Funding. Dimopoulos:Novartis: Honoraria; Amgen: Honoraria; Genesis: Honoraria; Janssen: Honoraria; Celgene: Honoraria; Onyx: Honoraria; Janssen-Cilag: Honoraria. San Miguel:Millennium, Celgene, Novartis, Janssen, Onyx, BMS, MSD: Membership on an entity's Board of Directors or advisory committees. Zimmerman:Onyx: Honoraria; Celgene: Honoraria, Speakers Bureau; Millennium: Honoraria, Speakers Bureau; Amgen: Honoraria, Speakers Bureau. Hari:Celgene: Consultancy; Takeda: Consultancy; BMS: Consultancy; Janssen: Consultancy; Novartis: Consultancy; Spectrum: Consultancy; Sanofi: Consultancy. Gasparetto:Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Onyx: Honoraria; Millennium: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Kumar:Skyline, Noxxon: Honoraria; Celgene, Millennium, Onyx, Janssen, Noxxon, Sanofi, BMS, Skyline: Consultancy; Celgene, Millennium, Onyx, Novartis, Janssen, Sanofi: Research Funding. Hsu:Sanofi: Employment. Charpentier:Sanofi: Employment. Strickland:Alexion Pharmaceuticals: Other: Advisory Board Particpation; Amgen: Other: Advisory Board Particpation; Daiichi-Sankyo: Other: Advisory Board Particpation; Boehringer-Ingelheim: Other: Advisory Board Particpation; Sunesis Pharmaceuticals: Other: Steering Committee and Advisory Board Participation. Mikhael:Sanofi: Research Funding; Onyx: Research Funding; Celgene: Research Funding; AbbVie: Research Funding.

Background: Multiple myeloma (MM) treatment has advanced considerably with proteasome inhibitors, immunomodulatory drugs (IMiDs), and, most recently, monoclonal antibodies. However, treatment response is quite heterogeneous, and many patients still progress even with novel combination therapies. Thus, understanding the factors that underlie response to treatment is a priority. Several somatic genomic aberrations and mutations predict poor response to therapy. However, germline variation has not previously been investigated as a predictor of treatment response in MM. We used genome-wide association and transcriptome-wide association approaches to identify germline genetic predictors of treatment response in MM. Methods: We included 510 MM patients from Mayo Clinic and 324 MM patients from UCSF diagnosed from 1999-2015. Basic demographics, laboratory values and pathology at diagnosis, type of initial therapy, duration of therapy, and follow-up were ascertained by chart review. Patients were grouped into categories of treatment based on their first line therapy: proteasome inhibitor-based regimen, IMiD based regimen, combination proteasome and IMiD based regimen, or other. Response was assessed using International Myeloma Working Group (IMWG) response criteria after 4-6 cycles of induction. As such, response was categorized into progressive disease (PD), minimal response (MR), partial response (PR), very good partial response (VGPR), or complete response (CR). Germline samples were genotyped using Illumina or Affymetrix arrays and were imputed based on the Haplotype Reference Consortium (HRC). For the genome-wide association study (GWAS), we included all SNPs with minor allele frequency >0.01 and imputation r2 of >0.5. We tested each SNP for association with treatment response using a linear regression model that adjusted for age, gender, and genetic ancestry (from principal components analysis (PCA)). To perform the transcriptome-wide association study (TWAS), we calculated predicted gene expression data using PREDIXCAN software on a reference cohort of 922 individuals with genotype and RNA expression data from peripheral blood. We then tested the association between predicted gene expression and response to therapy using linear regression models. Both the GWAS and TWAS were performed on subgroups of patients who received either proteasome inhibitors or IMiD therapies. The analyses of patients on proteasome inhibitors were adjusted for IMiD use as a covariate and analyses of patients on IMiDs were adjusted for proteasome inhibitor use. The threshold for genome-wide significance loci was set at P = 5 x 10-8 and the threshold for suggestive loci was set at P = 10-6. The threshold for significance for TWAS was set at P = 4 x 10-6 by using a Bonferroni correction for the number of genes for which genetic models of expression could be developed by PREDIXCAN. Results: Overall, 42.7% (59 of 138) of patients on proteasome inhibitors alone, 32.5% (66 of 203) of patients on IMiDs alone, and 58.1% (50 of 86) of patients on combination achieved at least a VGPR. There were no significant differences in response across centers in analyses that adjusted for age, sex and types of therapy. There were no genome wide significant loci to predict for response. We identified 8 suggestive SNPs associated with proteasome inhibitor response and 4 suggestive SNPs associated with IMiD response. TWAS identified ZNF622 as a candidate genetic modifier of proteasome inhibitor effect that was significant after correction for multiple hypothesis testing (P = 1.6 x 10-6). Higher genetically predicted expression was associated with improved response to proteasome inhibitor therapy. Among patients above the median of predicted expression of ZNF622 on proteasome inhibitors, 62.6% achieved at least VGPR; among patients at or below the median of expression, only 37.6% achieved at least VGPR. Conclusions: We identified an association between predicted expression of ZNF622 and clinical response to proteasome inhibitor therapy among MM patients. ZNF622 is a zinc finger binding protein which is known to be co-activator of B Myb activity and to affect apoptosis in response to oxidative stress. Our work highlights the potential importance of pharmacogenetic modifiers of treatment response in MM. Disclosures Shah: Nkarta: Consultancy, Membership on an entity's Board of Directors or advisory committees; Indapta Therapeutics: Equity Ownership; University of California, San Francisco: Employment; Celgene, Janssen, Bluebird Bio, Sutro Biopharma: Research Funding; Genentech, Seattle Genetics, Oncopeptides, Karoypharm, Surface Oncology, Precision biosciences GSK, Nektar, Amgen, Indapta Therapeutics, Sanofi: Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Poseida: Research Funding; Bristol-Myers Squibb: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Kite: Consultancy, Membership on an entity's Board of Directors or advisory committees; Teneobio: Consultancy, Membership on an entity's Board of Directors or advisory committees. Wong:Celgene: Research Funding; Janssen: Research Funding; Roche: Research Funding; Fortis: Research Funding. Martin:Roche and Juno: Consultancy; Amgen, Sanofi, Seattle Genetics: Research Funding. Kumar:Celgene: Consultancy, Research Funding; Takeda: Research Funding; Janssen: Consultancy, Research Funding.

Abstract Abstract 1876 Carfilzomib (CFZ), a next-generation proteasome inhibitor that selectively and irreversibly binds to its target, resulting in sustained inhibition absent of off-target effects relative to bortezomib, is being evaluated in MM patients. The selectivity of CFZ for the proteasome may explain the low rates of peripheral neuropathy (PN) relative to historical data for bortezomib (BTZ). Safety data have been compiled for >700 patients who received CFZ in 9 Phase (Ph) 1 or 2 trials, 4 of which are completed. The majority of patients had relapsed and refractory (R/R) MM, and many had comorbidities including baseline PN and renal insufficiency. This abstract updates and summarizes mature safety data for single-agent CFZ in 526 patients with R/R MM who took part in 1 of 3 Ph 2 studies and is a follow-up with more mature data compared with those presented at ASH 2010. Patients enrolled and treated with CFZ in the following trials are included in this analysis: PX-171-003 (conducted in 2 parts, a pilot study, PX-171-003-A0 [R/R MM], followed by PX-171-003-A1 [R/R MM]), PX-171-004 (relapsed MM), and PX-171-005 (R/R MM with varying degrees of renal function). In all studies, CFZ was dosed on Days 1, 2, 8, 9, 15, and 16 of a 28-day cycle (C). Doses were 20 mg/m2 in C1, escalating to 27 mg/m2 in C2 for all studies with the exception of 005 (15 mg/m2 in C1, 20 mg/m2 in C2, and 27 mg/m2 in C3). Overall, CFZ had a favorable safety profile in these studies. The most frequently reported adverse events (AEs) occurring in ≥30% of patients included fatigue (55%), anemia (47%), nausea (45%), thrombocytopenia (36%), dyspnea (35%), diarrhea (33%), and pyrexia (30%). The most common (≥10% of patients overall) ≥G3 AEs were thrombocytopenia (23%), anemia (22%), lymphopenia (18%), pneumonia (11%), and neutropenia (10%). The assessment of PN was based on a pooled aggregate of PN preferred terms, including neuropathy peripheral, neuropathy, peripheral sensory neuropathy, and peripheral motor neuropathy. PN was reported infrequently (14% overall) across all studies. Although 378 (72%) patients had baseline PN (≤G 2), only 13% reported treatment-emergent symptoms during the study. PN was generally mild to moderate in severity (1.3% G3 PN with no G4 PN), and only 5 patients (1%) required dose modification or discontinuation due to PN. Renal AEs (mainly ≤G2) were reported in 174 (33%) patients, and CFZ was discontinued because of a renal AE in only 21 patients (4%). A summary of CFZ exposure and discontinuation rates is reported in the table. There were a total of 37 (7%) deaths on study, including within 30 days of the last dose of study drug. The primary cause of death was due to disease progression in 22/37 patients (4.2%); however, AEs, including in order of frequency, cardiac events, hepatic failure, and infection, contributed to 14 of these deaths.No. of Patients (%) in Ph 2 MM Studies Who Received Carfilzomib003-A0 (N = 46)003-A1 (N = 266)004 (N = 164)005 (N = 50)All Patients (N = 526)Cycles, mean, n (SD)4.4 (3.4)5.3 (4.1)7.0 (4.4)5.5 (3.7)5.7 (4.2)Completed ≥12 cycles4 (8.7)40 (15.0)47 (28.7)3 (6.0)94 (17.9)Reason for not completing 12 cycles Progressive Disease23 (50.0)157 (59.0)64 (39.0)24 (48.0)268 (51.0) Adverse Event13 (28.3)33 (12.4)26 (15.9)6 (12.0)78 (14.8) Withdrew Consent2 (4.3)22 (8.3)9 (5.5)4 (8.0)37 (7.0) Other4 (8.7)14 (5.3)10 (6.1)028 (5.3) Of the 526 patients included in these analyses, >50% were treated on the 003-A1 dose and schedule (20/27 mg/m2), and fewer than 10% required dose reduction. 18% of patients completed ≥12 cycles (∼1 y) and were eligible to participate in an ongoing, multicenter, open-label Ph 2 study (PX-171-010) to monitor long-term single-agent CFZ safety. To date, patients in this extension trial have not shown evidence of cumulative toxicity. In summary, these data confirm and extend results that were previously presented, namely that single-agent CFZ has an acceptable safety profile in heavily pretreated patients with R/R MM, including those with pre-existing renal dysfunction and PN. Disclosures: Singhal: Onyx Pharmaceuticals: Research Funding, Speakers Bureau; Millennium: Speakers Bureau; Celgene: Speakers Bureau. Siegel:Millennium: 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. Martin:Celgene: Honoraria; Onyx Pharmaceuticals: Consultancy. Vij:Onyx Pharmaceuticals: Consultancy, Research Funding; Celgene: Research Funding, Speakers Bureau; Millennium: Speakers Bureau. Wang:Onyx Pharmaceuticals: Research Funding. Jakubowiak:Ortho Biotech: Consultancy, Honoraria, Speakers Bureau; Celgene: Consultancy, Honoraria, Speakers Bureau; Millennium: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Onyx Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees; Bristol-Myers Squibb: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Exelixis: Consultancy, Honoraria. Lonial:Millennium: Consultancy; Celgene: Consultancy; Novartis: Consultancy; BMS: Consultancy; Onyx Pharmaceuticals: Consultancy; Merck: Consultancy. Kukreti:Celgene: Honoraria. Zonder:Millennium: Consultancy, Research Funding, Speakers Bureau; Celgene: Speakers Bureau; Medtronics: Honoraria; Amgen: Consultancy. Wong:Onyx Pharmaceuticals: Employment, Equity Ownership. McCulloch:Onyx Pharmaceuticals: Employment. Niesvizky:Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Millennium Pharmaceuticals, Inc.: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Onyx: Research Funding; Seattle Genetics Inc: Research Funding, Speakers Bureau. Orlowski:Onyx Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees. Stewart:Celgene: Consultancy, Research Funding; Millennium: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; BMS: Consultancy, Research Funding; Onyx: Consultancy, Research Funding. Kotlovker:Onyx Pharmaceuticals: Employment. Jagannath:Millennium: Honoraria; Celgene: Honoraria; Onyx Pharmaceuticals: Honoraria; Merck: Honoraria; OrthoBiotec. Imedex: Membership on an entity's Board of Directors or advisory committees; Medicom World Wide: Membership on an entity's Board of Directors or advisory committees; Optum Health Education: Membership on an entity's Board of Directors or advisory committees; PER Group: Membership on an entity's Board of Directors or advisory committees.

Abstract Hematological malignancies such as multiple myeloma (MM) have an increased reliance on the ubiquitin proteasome system (UPS) presumably as a consequence of their high protein synthetic and secretory burden. Chemical agents that target the proteasome, such as bortezomib and carfilzomib, have been successful in treating multiple myeloma; however patients treated with these drugs ultimately relapse. The AAA-ATPase p97/VCP (p97) facilitates ATP-dependent extraction and degradation of ubiquitinated proteins destined for proteasomal elimination. In addition to ubiquitin-dependent protein degradation, p97 is also closely involved in other aspects of protein homeostasis, including endoplasmic reticulum-associated degradation (ERAD) and autophagy. Pharmacologic inhibition of p97 provides a compelling therapeutic approach for hematological malignancies that rely on tight regulation of protein homeostasis as a component of their survival. CB-5083 is a novel small molecule inhibitor of p97 ATPase activity with nanomolar enzymatic and cellular potency. Treatment of cancer cells with CB-5083 causes a dramatic increase in poly-ubiquitinated proteins as well as an accumulation of substrates of the UPS and ERAD. CB-5083 causes a profound induction of the unfolded protein response (UPR) with consequent activation of the DR5 death receptor, caspase 8, caspase 3/7 and ultimately cell death. Induction of the UPR occurs to a greater magnitude with CB-5083 when compared to the proteasome inhibitor, bortezomib, suggesting the potential for increased efficacy in cancers with sensitivity to UPR-mediated cell death. In addition, activation of apoptosis and cell death occur more rapidly with CB-5083 than with bortezomib. Sequencing of cell lines made resistant to CB-5083 reveals missense mutations mapping to the D2 ATPase site in p97, supporting on-target association with cytotoxicity. In an expanded panel of MM cell lines there is no correlation between the cytotoxic sensitivity to CB-5083 and the cytotoxic sensitivity to proteasome inhibitors, suggesting differential mechanisms of cytotoxicity and potential activity of CB-5083 in proteasome inhibitor resistant settings. Compared to myeloma cell lines, CB-5083 has reduced cytotoxic potency in immortalized stromal cell lines and in patient-derived CD138-negative bone marrow mononuclear cells. Furthermore, unlike the reduced potency demonstrated by carfilzomib in the context of MM cell-bone marrow stromal cell (BMSC) interactions, the cyto-reductive potential of CB-5083 is unaffected in co-cultures of MM cells with patient-derived BMSCs or immortalized BMSCs from healthy donors. In vivo, CB-5083 is orally bioavailable, shows a pharmacodynamic effect in tumor tissue (as measured by poly-ubiquitin accumulation) and demonstrates robust anti-tumor activity across several MM models. CB-5083 treatment of mice bearing subcutaneous xenografts leads to tumor stasis and regression in RPMI8226 and AMO1 MM models, respectively. In advanced models of disseminated, ortho-metastatic disease, intermittent oral administration of CB-5083 demonstrates significant inhibition of myeloma burden and improves survival, with an overall efficacy profile that compares favorably to that of clinically approved proteasome inhibitors. Furthermore, in the Vk*Myc genetically engineered mouse model of MM, treatment with CB-5083 results in a significant reduction in M-spike by 55%. Combination treatment of mice bearing the RPMI8226 subcutaneous xenograft model with CB-5083, dexamethasone and lenalidomide results in tumor regression. Taken together, these data demonstrate that CB-5083 is a potent and selective inhibitor of the p97 ATPase with robust activity in vitro and in vivo in numerous MM models and strongly support clinical evaluation. Based on these observations, a phase 1 dose-escalation trial has recently been initiated and is currently underway in patients with relapsed/refractory multiple myeloma. Disclosures Anderson: Cleave Biosciences: Employment. Le Moigne:Cleave Biosciences: Employment. Djakovic:Cleave Biosciences: Employment. Rice:Cleave Biosciences: Employment. Wong:Cleave Biosciences: Employment. Kumar:Cleave Biosciences: Employment. Valle:Cleave Biosciences: Employment. Menon:Cleave Biosciences: Employment. Kiss von Soly:Cleave Biosciences: Employment. Wang:Cleave Biosciences: Employment. Yao:Cleave Biosciences: Employment. Soriano:Cleave Biosciences: Employment. Bergsagel:ONYX: Consultancy; Janssen: Consultancy; BMS: Consultancy; Novartis: Research Funding. Yakes:Cleave Biosciences: Employment. Zhou:Cleave Biosciences: Employment. Wustrow:Cleave Biosciences: Employment. Rolfe:Cleave Biosciences: Employment.

The NCCN Guidelines for Multiple Myeloma provide recommendations for diagnosis, workup, treatment, follow-up, and supportive care for patients with monoclonal gammopathy of renal significance, solitary plasmacytoma, smoldering myeloma, and multiple myeloma. These NCCN Guidelines Insights highlight some of the important updates and changes in the 1.2020 version of the NCCN Guidelines for Multiple Myeloma.