Voorhees, Peter M.

TPS8075 Background: Standard of care for SMM includes active monitoring until progression to multiple myeloma (MM); however, recent evidence suggests pts with high-risk features may benefit from early treatment. DARA is a human IgGκ monoclonal antibody targeting CD38 that is approved as monotherapy for relapsed/refractory MM (RRMM) or in combination with standard of care for RRMM or newly diagnosed MM. Results from the phase 3 COLUMBA study showed that DARA SC demonstrated similar efficacy to intravenous (IV) DARA but with a lower rate of infusion-related reactions and shorter administration time. Based on the promising single-agent activity observed with IV DARA in intermediate- or high-risk SMM pts during the phase 2 CENTAURUS study, we hypothesized that DARA SC may delay progression to MM versus active monitoring in pts with high-risk SMM. Methods: AQUILA is an ongoing, randomized, open-label, multicenter phase 3 study of DARA SC versus active monitoring in pts with high-risk SMM. DARA SC (DARA 1,800 mg + recombinant human hyaluronidase PH20 [rHuPH20; 2,000 U/mL; Halozyme]) is administered by manual injection over approximately 5 minutes at alternating locations on the abdomen weekly in Cycles 1 and 2, every 2 weeks in Cycles 3-6, and every 4 weeks thereafter until 39 cycles (28 days/cycle), up to 36 months, or until disease progression. Eligibility criteria include confirmed diagnosis of SMM for ≤5 years, factors indicating high risk of progression to MM (clonal bone marrow plasma cells [BMPCs] ≥10% and ≥1 of the following: serum M protein ≥30 g/L, IgA SMM, immunoparesis with reduction of 2 uninvolved Ig isotypes, serum involved:uninvolved free light chain ratio ≥8 to < 100, or clonal BMPCs > 50% to < 60% with measurable disease), and ECOG performance status ≤1. The primary endpoint is progression-free survival (PFS), assessed by an independent review committee, with disease progression defined according to International Myeloma Working Group diagnostic criteria for MM. Secondary endpoints include time to biochemical or diagnostic (SLiM-CRAB) progression, overall response rate, complete response rate, duration of response, time to response, time to first-line treatment for MM, PFS on first-line treatment for MM (PFS2), overall survival, and incidence of MM with adverse prognostic features. The study completed enrollment on May 6, 2019; 390 pts have been randomly assigned to DARA SC or active monitoring. The primary efficacy analysis will be performed after approximately 165 PFS events have been observed. Clinical trial information: NCT03301220.

8054 Background: The introduction of immunomodulatory agents, proteasome inhibitors, and autologous stem cell transplantation (ASCT) has improved outcomes for patients with multiple myeloma (MM), but those with high risk MM (HRMM) have a poor long-term prognosis. Herein we provide survival outcomes on the first randomized trial in newly diagnosed HRMM, S1211, to follow-up on the previously reported progression-free survival (PFS) (NCT01668719, Usmani SZ et al, Lancet Haem 2021). Methods: S1211 is a randomized phase II trial comparing 8 cycles of lenalidomide, bortezomib and dexamethasone (RVd) induction followed by dose-attenuated RVd maintenance until disease progression with or without elotuzumab (RVd-Elo). Stem cell collection was allowed, but ASCT was deferred until progression. HRMM was defined by one of the following: gene expression profiling high-risk (GEPhi), t(14;16), t(14;20), del(17p), amplification 1q21, primary plasma cell leukemia (pPCL), or elevated serum LDH (> 2X ULN). Median PFS was the primary endpoint, using a one-sided stratified log-rank test at a one-sided significance level of 0.1. Secondary endpoints included overall response rate (ORR), adverse events (AE), serious adverse events (SAE) and OS. Response was assessed using the IMWG 2009 criteria. Results: S1211 enrolled 103 evaluable patients, RVd n=54, RVd-Elo n=49. 74% had ISS II/III, 48% amp1q21, 38% del(17p), 11% t(14;16), 9% GEPhi, 7% pPCL, 5% t(14;20) and 4% elevated LDH (17% >1 feature). With median follow-up of 72 months (mos.), no difference in median PFS was observed [RVd-Elo=29 mos., RVd= 34 mos., HR = 1.11 (80% CI=0.82, 1.49, p=0.66]. No difference in OS was observed [RVd-Elo = median not reached (NR), RVd= 68 mos., HR = 0.85 (80% CI: 0.59, 1.23), p-value = 0.58]. 76% pts had >Grade 3 AEs, no differences in the safety profile were observed. Amongst patients with gain/amp 1q21, median PFS was [RVd-Elo=31 mos., RVd= 37 mos., HR = 1.48 (80% CI= 0.95, 2.31), p=0.25], median OS was [RVd-Elo = 61 mos., RVd= 68 mos., HR = 1.23 (80% CI: 0.72, 2.10), p-value = 0.63]. In patients with del(17p), median PFS was RVd-Elo=41 mos., RVd= 30 mos.[HR = 0.98 (80% CI= 0.60, 1.58), p=0.95], median OS RVd-Elo = NR, RVd= 72 mos., [HR = 0.77 (80% CI: 0.40, 1.48), p-value = 0.61]. Conclusions: In the first randomized HRMM study reported to date, the addition of Elo to RVd induction and maintenance did not improve PFS and OS with a median follow-up of 6 years. Although the median PFS for Del17p subgroup on RVd-Elo arm is higher than RVd, it did not achieve statistical significance. The PFS and OS observed for gain/amp 1q21 and del17p in the RVd control arm may serve as important benchmarks for future enrichment design HRMM clinical trials. The PFS and OS in both arms of the study exceeded the original statistical assumptions and support the role for PI/IMiD combination induction/maintenance therapy for this population. Clinical trial information: NCT01668719.

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 &gt;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.

Abstract Background Prognosis is poor for patients (pts) with relapsed/refractory multiple myeloma (RRMM; median overall survival: &lt;1 year), indicating a clear need to identify agents with novel mechanisms of action. B-cell maturation antigen (BCMA) has recently emerged as a novel treatment target for MM due to its highly selective expression in plasma cells. TNB-383B, a BCMA x CD3 T-cell engaging bispecific antibody, was designed to overcome the toxicity limitations of existing BCMA therapies and has demonstrated promising results in an ongoing first-in-human phase 1 study in pts with RRMM (Rodriguez C, et al. Blood 2020;136[suppl 1]:43-44). Herein, we report the updated efficacy and safety outcomes of this phase 1 study. Methods This multicenter, phase 1, open-label, dose-escalation/expansion study (NCT03933735) enrolled pts with RRMM (≥3 prior lines of therapy that included a proteasome inhibitor, an immunomodulatory drug, and an anti-CD38 monoclonal antibody), estimated glomerular filtration rate ≥30 mL/min as calculated by the Modification of Diet in Renal Disease formula, and ECOG performance status ≤2. Prior BCMA-targeted therapy is prohibited. Primary objectives include safety/tolerability, pharmacokinetics (PK), and determination of recommended phase 2 dose (RP2D); secondary objectives include assessment of clinical activity (per IMWG criteria 2016). TNB-383B is administered intravenously over 1-2 hours every 3 weeks (Q3W) with the first dose administered inpatient. The study uses a 3+3 design with backfilling for dose and permits intrapatient dose escalation to highest safe dose. Dose expansion was initiated on selection of RP2D. Pts are treated until progression, unacceptable toxicity, or other discontinuation criteria are met. The efficacy-evaluable population includes all pts who received at least 1 dose of TNB-383B and have at least 1 postdose assessment. The safety population includes all pts who received at least 1 dose of study drug; adverse events (AEs) are graded according to NCI CTCAE v5.0. Results As of 10 May 2021, 103 pts (dose escalation, n=73; dose expansion, n=30) have been treated with TNB-383B (0.025-120 mg). The RP2D of 60 mg Q3W was selected on the basis of tolerability, safety, PK, and clinical activity. Pt demographics and baseline characteristics are summarized in Table 1. Three dose-limiting toxicities were reported in dose escalation (platelet count decreased: grade [Gr] 4, 60 mg; cytokine release syndrome [CRS]: Gr 3, 90 mg and 120 mg); none were reported as serious. Treatment-related AEs (TRAEs) were reported in 79 (77%) pts, with Gr ≥3 and serious AEs occurring in 33 (32%) and 23 (22%) pts, respectively. The most common TRAEs (Table 2) include CRS (n=54, 52%), neutropenia (n=18, 17%), and fatigue (n=14, 14%). At the RP2D (n=39), the Gr ≥3 CRS rate was 3% (n=1). Onset of CRS typically occurred on the same or next day following the first dose and all pts recovered using tocilizumab or standard supportive care measures. Treatment-emergent AEs (TEAEs) of infusion-related reactions were reported in 8 (8%) pts and infections occurred in 29 (28%) pts; pneumonia (n=5, 5%) and upper respiratory tract infection (n=4, 4%) were the most common. Five deaths from TEAEs were reported; all were unrelated to study drug. Forty-two (40%) pts discontinued treatment due to disease progression. In the dose-escalation cohorts of ≥40 mg Q3W (n=24), the objective response rate (ORR) was 79% (19/24), with a very good partial response or better (≥VGPR) rate of 63% (15/24), and a complete response (CR) rate of 29% (7/24) at the data cutoff date; these pts have the longest follow-up (ie, mature data) with median time on study of 6.1 months (Figure 1). At doses ≥40 mg in the combined dose-escalation and -expansion cohorts (n=44), the observed ORR, ≥VGPR, and CR rates were 64% (28/44), 43% (19/44), and 16% (7/44), respectively; these pts have shorter follow-up (ie, immature data) with median time on study of 3.1 months. Twenty-nine (66%) of the 44 pts administered ≥40 mg were triple-class refractory and reported an ORR of 55% (16/29). Conclusions TNB-383B in pts with RRMM is well tolerated with an ORR of 79% observed at doses ≥40 mg in the dose-escalation cohorts. Despite having a shorter follow-up period, this trend was also observed at doses ≥40 mg in the combined dose-escalation/expansion cohorts (ORR: 64%). Enrollment into the dose-expansion arm is ongoing; updated data will be presented at the meeting. Figure 1 Figure 1. Disclosures Kumar: Novartis: Research Funding; Carsgen: Research Funding; KITE: 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; Astra-Zeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Merck: Research Funding; Roche-Genentech: Consultancy, Research Funding; Bluebird Bio: Consultancy; Janssen: 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; Amgen: Consultancy, Research Funding; Beigene: Consultancy; Oncopeptides: Consultancy; Antengene: Consultancy, Honoraria; Tenebio: Research Funding; BMS: Consultancy, Research Funding; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Adaptive: Membership on an entity's Board of Directors or advisory committees, Research Funding; Sanofi: Research Funding. D'Souza: Imbrium, Pfizer, BMS: Membership on an entity's Board of Directors or advisory committees; Sanofi, Takeda, Teneobio, CAELUM, Prothena: Research Funding; Janssen, Prothena: Consultancy. Shah: Oncopeptides: Consultancy; Nektar: Research Funding; Poseida: Research Funding; Janssen: Research Funding; Indapta Therapeutics: Consultancy; GSK: Consultancy; CareDx: Consultancy; BMS/Celgene: Research Funding; Bluebird Bio: Research Funding; CSL Behring: Consultancy; Teneobio: Research Funding; Kite: Consultancy; Sutro Biopharma: Research Funding; Karyopharm: Consultancy; Amgen: Consultancy; Precision Biosciences: Research Funding; Sanofi: Consultancy. Rodriguez: Takeda: Consultancy, Speakers Bureau; Karyopharm: Consultancy, Speakers Bureau; Janssen: Consultancy, Speakers Bureau; BMS: Consultancy, Speakers Bureau; Oncopeptides: Consultancy, Honoraria; Amgen: Consultancy, Speakers Bureau. Voorhees: AbbVie Inc, Bristol-Myers Squibb Company; Consulting Agreement: GlaxoSmithKline, Novartis, Oncopeptides: Other: Advisory Committee; Bristol-Myers Squibb Company.: Other: Data Safety & Monitoring. Bueno: AbbVie: Current Employment, Current equity holder in publicly-traded company. Buelow: Teneobio, Inc.: Current Employment, Current holder of stock options in a privately-held company. Freise: Abbvie, Inc.: Current Employment, Current equity holder in publicly-traded company, Current holder of individual stocks in a privately-held company. Yue: Abbvie, Inc.: Current Employment, Current equity holder in publicly-traded company, Current holder of individual stocks in a privately-held company. Pothacamury: AbbVie: Current Employment, Current equity holder in publicly-traded company, Current holder of individual stocks in a privately-held company. Polepally: Abbvie, Inc.: Current Employment, Current equity holder in publicly-traded company, Current holder of individual stocks in a privately-held company. Vij: BMS: Research Funding; Takeda: Honoraria, Research Funding; Sanofi: Honoraria, Research Funding; BMS: Honoraria; GSK: Honoraria; Oncopeptides: Honoraria; Karyopharm: Honoraria; CareDx: Honoraria; Legend: Honoraria; Biegene: Honoraria; Adaptive: Honoraria; Harpoon: Honoraria.

Abstract The multiple myeloma treatment landscape has evolved considerably over the last 20 years with the development of multiple therapies with novel mechanisms of action and new combination regimens. However, the recent failure of several large phase III trials, coupled with an increased understanding of the mutational landscape of multiple myeloma has provided opportunities to explore optimal strategies for future multiple myeloma drug development. The Office of Oncologic Diseases at the FDA held an educational symposium, “Drug Development in MM-Project 2025,” in November 2019. The symposium brought together select U.S.-based academic thought leaders in the field of multiple myeloma to explore issues relevant to regulatory science in the field, including considerations for trial design, combination strategies, control arms, and precision medicine. This article summarizes the highlights of this educational symposium held at the FDA, including discussions on the future development of novel drugs and drug combinations and biomarker-directed therapies for patients with multiple myeloma.

Abstract Castleman disease (CD) includes a group of rare and heterogeneous disorders with characteristic lymph node histopathological abnormalities. CD can occur in a single lymph node station, which is referred to as unicentric CD (UCD). CD can also involve multicentric lymphadenopathy and inflammatory symptoms (multicentric CD [MCD]). MCD includes human herpesvirus-8 (HHV-8)–associated MCD, POEMS-associated MCD, and HHV-8−/idiopathic MCD (iMCD). The first-ever diagnostic and treatment guidelines were recently developed for iMCD by an international expert consortium convened by the Castleman Disease Collaborative Network (CDCN). The focus of this report is to establish similar guidelines for the management of UCD. To this purpose, an international working group of 42 experts from 10 countries was convened to establish consensus recommendations based on review of treatment in published cases of UCD, the CDCN ACCELERATE registry, and expert opinion. Complete surgical resection is often curative and is therefore the preferred first-line therapy, if possible. The management of unresectable UCD is more challenging. Existing evidence supports that asymptomatic unresectable UCD may be observed. The anti–interleukin-6 monoclonal antibody siltuximab should be considered for unresectable UCD patients with an inflammatory syndrome. Unresectable UCD that is symptomatic as a result of compression of vital neighboring structures may be rendered amenable to resection by medical therapy (eg, rituximab, steroids), radiotherapy, or embolization. Further research is needed in UCD patients with persisting constitutional symptoms despite complete excision and normal laboratory markers. We hope that these guidelines will improve outcomes in UCD and help treating physicians decide the best therapeutic approach for their patients.

Background: BCMA targeted immunotherapy has yielded promising results for relapsed/refractory multiple myeloma (RRMM). TNB-383B is a BCMA x CD3 bispecific T-cell redirecting antibody incorporating a unique anti-CD3 moiety that preferentially activates effector over regulatory T-cells and uncouples cytokine release from anti-tumor activity, as well as 2 heavy-chain-only anti-BCMA moieties for a 2:1 tumor associated antigen to CD3 stoichiometry. Results from the ongoing phase 1 dose escalation and expansion First-in-Human (FIH) study of TNB-383B are presented (NCT03933735). Methods: Eligible patients have RRMM and have been exposed to at least 3 prior lines of therapy including a proteasome inhibitor, an immunomodulatory drug, and an anti-CD38 monoclonal antibody. Patients have been treated with escalating doses of TNB-383B infused IV over 1-2 hours Q3W (without step-up dosing). The primary objectives are to determine the safety/tolerability and clinical pharmacology of TNB-383B and to identify the MTD/RP2D. The study used a 3+3 design for dose escalation, with additional patients enrolled on cleared dose levels. Patients on earlier dose cohorts were allowed to increase to the highest cleared dose with investigator consensus. Responses were assessed by IMWG criteria and Adverse Events (AEs) were graded according to CTCAE v5.0. Minimal residual disease (MRD) assessment was performed via NGS on bone marrow samples in patients achieving a complete response (CR). Results: As of 13 July 2020, 38 subjects have been dosed with TNB-383B (0.025 - 40 mg). Demographics and disease characteristics at study entry are summarized in Table 1. The most common Gr 3/4 AEs were anemia (6/38; 16%) and thrombocytopenia (5/38; 13%). The most common drug-related AEs were CRS (8/38; 21%) and headache (5/38; 13%). One case of Gr 2 CRS was observed at 0.075 mg; all other CRS events were seen at 5.4 mg and above. Cases of CRS were grade 1 (5/8) or 2 (3/8) and occurred only after the first dose of TNB-383B. All but 3 subjects were managed with fluids and acetaminophen (the other 3 received 1 dose each of tocilizumab). One DLT, Gr3 confusion that resolved within 6 hours without sequelae was seen at the 20 mg dose in an additional patient enrolled on this cohort. No IRRs were observed. Dose modification was necessary in 1 subject for Gr 3 neutropenia associated with CRS; the subject escalated to their full dose after tolerating subsequent doses without incident. 5 subjects died from their underlying disease during follow-up. 15 subjects discontinued treatment, all of them for progressive disease. Preliminary PK data support Q3W dosing of TNB-383B. Activity was observed in one patient each at 0.2 mg and 1.8 mg; at doses of 5.4 - 40 mg an ORR of 52% (12/23) was observed. Depth and duration of response are summarized in Table 2. Conclusions: TNB-383B is well tolerated at doses up to 40 mg, without the need for step/split dosing. A preliminary ORR of 52% (12/23) was observed at doses ≥ 5.4 mg, including deep (6 PR / 3 VGPR / 3 CR) and durable (up to 24 weeks) responses despite dosing only every 3 weeks. Enrollment into the dose escalation arm is ongoing; updated data will be presented at the meeting. Disclosures Rodriguez: BMS, Takeda, Amgen: Consultancy, Speakers Bureau. D'Souza:Amgen: Research Funding; Akcea: Consultancy; Pfizer: Consultancy; Teneobio: Research Funding; Imbrium: Consultancy; Merck: Research Funding; Janssen: Consultancy. Shah:GSK, Amgen, Indapta Therapeutics, Sanofi, BMS, CareDx, Kite, Karyopharm: Consultancy; BMS, Janssen, Bluebird Bio, Sutro Biopharma, Teneobio, Poseida, Nektar: Research Funding. Voorhees:Bristol-Myers Squibb: Other: Personal fees; Adaptive Biotechnologies: Other: Personal fees; Novartis: Other: Personal fees; Celgene: Other: Personal fees; Janssen: Other: Personal fees; Oncopeptides: Other: Personal fees; TeneoBio: Other: Personal fees; Levine Cancer Institute, Atrium Health: Current Employment. Buelow:Teneobio, Inc.: Current Employment, Current equity holder in private company. Kumar:Karyopharm: Consultancy; Tenebio: Other, Research Funding; Sanofi: Research Funding; Oncopeptides: Consultancy, Other: Independent Review Committee; IRC member; AbbVie: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Genecentrix: Consultancy; Dr. Reddy's Laboratories: Honoraria; Adaptive Biotechnologies: Consultancy; Merck: Consultancy, Research Funding; Takeda: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; BMS: Consultancy, Research Funding; Cellectar: Other; Janssen Oncology: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Carsgen: Other, Research Funding; Amgen: Consultancy, Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments, Research Funding; Celgene/BMS: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Novartis: Research Funding; MedImmune: Research Funding; Genentech/Roche: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Kite Pharma: Consultancy, Research Funding.

8507 Background: The introduction of immunomodulatory agents, proteasome inhibitors, and autologous stem cell transplantation (ASCT) has improved outcomes for patients with multiple myeloma (MM), but those with high risk MM (HRMM) have a poor long-term prognosis. To date, no trials have addressed optimal treatment for these patients. Methods: S1211 is a randomized phase II trial (NCT01668719) comparing 8 cycles of lenalidomide, bortezomib and dexamethasone (RVd) induction followed by dose-attenuated RVd maintenance until disease progression with or without elotuzumab. Stem cell collection was allowed, but ASCT was deferred until progression. HRMM was defined by one of the following: gene expression profiling high-risk (GEPhi), t(14; 16), t(14; 20), del(17p) or amplification 1q21, primary plasma cell leukemia (pPCL) and elevated serum LDH (> 2X ULN). Median progression-free survival (PFS) was the primary end-point, using a one-sided stratified log-rank test at a one-sided significance level of 0.1. Secondary endpoints included overall response rate (ORR), adverse events (AE), serious adverse events (SAE) and OS. Response was assessed using the IMWG 2009 criteria. Results: S1211 enrolled 103 evaluable patients, RVd n = 54, RVd-Elo n = 49. 75% had ISS II/III, 47% amp1q21, 38% del17p, 12% t(14; 16), 9% GEPhi, 7% pPCL, 5% t(14; 20) and 4% elevated serum LDH (18.5% > 1 feature). With median follow-up of 53 months (mos.), no difference in median PFS was observed [RVd-Elo = 31 mos., RVd = 34 mos.,HR = 0.968 (80% CI = 0.697-1.344), p = 0.449]. No difference in OS was observed [RVd-Elo = 68 mos, RVd = not reached, HR = 1.279 (80% CI: 0.819, 2.000), p-value = 0.478]. 72% pts had > Grade 3 AEs, no differences in the safety profile were observed except >Grade 3 infections (RVd 8%, RVd-Elo 16%), >Grade 3 sensory neuropathy (RVd 8%, RVd-Elo 13%). Conclusions: In the first randomized HRMM study reported to date, the addition of elotuzumab to RVd induction and maintenance did not improve patient outcomes. However, the PFS and OS seen in both arms of the study exceeded the original statistical assumptions and support the role for PI/IMiD combination maintenance therapy for this patient population. The S1211 data will serve as an important benchmark for future HRMM clinical trials. Clinical trial information: NCT01668719 .

Abstract Purpose: Treatment of multiple myeloma has evolved tremendously and optimal utilization of available therapies will ensure maximal patient benefits. Patients and Methods: We report the Southwest Oncology Group randomized phase II trial (S1304) comparing twice weekly low-dose (27 mg/m2; arm 1) to high-dose carfilzomib (56 mg/m2; arm 2), both with dexamethasone, administered for 12 cycles (11 months) for relapsed and/or refractory multiple myeloma with up to six prior lines of therapy (NCT01903811). The primary endpoint was progression-free survival (PFS), and patients on arm 1 could cross-over to arm 2 after progression on treatment. Results: Among 143 enrolled patients, of whom 121 were eligible and analyzable, the overall response rate was 42.8%, with no significant difference between the arms (P = 0.113). Also, neither the median PFS [5 months and 8 months, respectively; HR, 1.061; 80% Wald confidence interval (CI), 0.821–1.370; P = 0.384] nor the median overall survival were significantly different (26 and 22 months, respectively; HR, 1.149, 80% Wald CI, 0.841–.571; P = 0.284). Sixteen patients crossed over to arm 2 with a median PFS benefit of 3 months. Certain adverse events (AE) were more frequent in arm 2, including fatigue, thrombocytopenia, and peripheral neuropathy, but there was no significant difference in cardiopulmonary AEs. Conclusions: This randomized trial did not support a benefit of fixed duration, twice weekly 56 mg/m2 dosing of carfilzomib over the 27 mg/m2 dose for the treatment of relapsed and/or refractory multiple myeloma. However, treatment to progression in earlier patient populations with high-dose carfilzomib using different schedules should still be considered as part of the standard of care.