Monohan, Gregory

Abstract Proteins in the antiapoptotic B-cell lymphoma 2 (BCL-2) family play a role in the pathophysiology of multiple myeloma (MM). Venetoclax is a highly selective, potent, oral BCL-2 inhibitor that induces apoptosis of MM cells, and its efficacy may be potentiated through combination with agents that increase BCL-2 dependency or have complementary mechanisms of action. The safety, tolerability, pharmacokinetics, and antitumor activity of venetoclax in combination with carfilzomib and dexamethasone (VenKd) in adults with relapsed/refractory MM (RRMM) were investigated in this phase 2 dose-escalation study. Oral venetoclax (400 or 800 mg) was administered daily in combination with intravenous carfilzomib (27, 56, or 70 mg/m2) and oral dexamethasone (20 or 40 mg) in 4 dose-finding cohorts. The expansion cohort received venetoclax 800 mg, carfilzomib 70 mg/m2, and dexamethasone 40 mg. Forty-nine patients received treatment. Median prior lines of therapy was 1 (range, 1-3), and median time in the study was 27 months. The most common treatment-emergent adverse events were diarrhea (65%), fatigue (47%), nausea (47%), and lymphopenia (35%). Serious adverse events occurred in 26 (53%) patients. Of 3 treatment-emergent deaths, 1 was considered treatment related. The overall response rate was 80% in all patients, 92% in patients with t(11;14) (n = 13), and 75% in patients without (n = 36). The rate of complete response or better was 41%. Median progression-free survival was 22.8 months. Treatment with VenKd was well tolerated and showed promising response rates in this RRMM patient population, with greater responses observed in patients with t(11;14). This trial is registered at www.clinicaltrials.gov as #NCT02899052.

Abstract Introduction: Venetoclax (Ven), an oral agent that targets the antiapoptotic protein, BCL-2, has demonstrated efficacy, as monotherapy and combined with proteasome inhibitor (PI) bortezomib, in relapsed/refractory (R/R) multiple myeloma (MM). We report preliminary safety and efficacy data for Ven combined with the second generation PI carfilzomib (K) and dexamethasone (VenKd) in R/R MM. Methods: In this ongoing phase 2, dose escalation study (NCT02899052), patients with R/R MM and no prior K exposure received VenKd on 28-d cycles in 4 dose finding and one expansion cohorts: Ven 400 mg/day + K 27 mg/m2 Day 1, 2, 8, 9, 15, 16 + dex 40 mg Day 1, 8, 15, 22 (Cohort 1), same regimen but with Ven 800 mg/day (Cohort 2), Ven 800 mg/day + K 70 mg/m2 Day 1, 8, 15 + dex 40 mg Day 1, 8, 15, 22 (Cohort 3/expansion cohort), or Ven 800 mg + K 56 mg/m2 Day 1, 2, 8, 9, 15, 16 + dex 40 mg Day 1, 2, 8, 9, 15, 16, 22, 23 (Cohort 4). Treatment continued until progressive disease (PD) or unacceptable toxicity. Results: As of June 11, 2018, 42 patients were enrolled. The median age was 66.5 years (min, max: 37, 79), 63% had ISS II/III disease, and 8 patients (19%) had t(11;14). Patients received a median of 2 prior therapies (range: 1 - 3), 93% had received prior PI (50% refractory), 62% were refractory to immunomodulatory therapies, and 33% double refractory. At the data cut off, 29 patients were still active and had completed ≥2 cycles and 13 patients discontinued with the primary reason being disease progression (n=4), death (n=3), physician decision (n=2), withdrawal of consent (n=2), lack of efficacy (n=1), and AE (n=1). All patients experienced at least one AE, and grade 3/4 AEs experienced by >10% of subjects included: decreased lymphocyte count (26%), decreased neutrophil count (14%), and hypertension (12%). Thirteen subjects experienced at least one serious AE. Maximum tolerated dose was not reached and Ven 800 mg/day + K 70 mg/m2 was selected for expansion. Ven mean (% coefficient of variation) maximum plasma concentration (Cmax) and area under the plasma concentration-time curve over 24 hours (AUC24) on Cycle 1 Day 15 were 2.7 (57) mg/mL and 33.1 (54) mg×h/mL, respectively, at 400 mg venetoclax (n=4); and were 2.42 (53) mg/mL and 38.7 (51) mg×h/mL, respectively, at 800 mg venetoclax (n=13) in the dose escalation cohorts. The overall response rate (ORR) was 78% and the very good partial response (VGPR) or better rate was 56% (Table). Median time from first dose to the data cut or discontinuation was 5.7 months (range: 0.9 - 16.3) and the median time to first response was 1.9 months (95% CI: 0.9, 9.2). ORRs for subgroups of interest are reported in the Table. Conclusions: The combination of VenKd appears tolerable with no new safety signals or changes in Ven pharmacokinetics. VenKd shows promising preliminary efficacy in R/R MM patient subgroups. Response rates were comparable in all high risk subgroups and overall population. However, the subset of patients with t(11;14) had the highest response. Overall, these results demonstrate that VenKd is a safe and efficacious regimen in R/R MM and support the continued study of VenKd. Disclosures Costa: Abbvie: Research Funding; BMS: Research Funding; Karyopharm: Research Funding; Amgen: Honoraria, Research Funding; Sanofi: Honoraria; Celgene: Honoraria, Research Funding; Janssen: Research Funding. Stadtmauer:Celgene: Consultancy; AbbVie, Inc: Research Funding; Janssen: Consultancy; Takeda: Consultancy; Amgen: Consultancy. Morgan:Bristol-Myers Squibb: Consultancy, Honoraria; Janssen: Research Funding; Takeda: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Research Funding. Kovacsovics:Amgen: Honoraria, Research Funding; Abbvie: Research Funding. Jakubowiak:Takeda: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Bristol-Myers Squibb: Consultancy, Honoraria; SkylineDx: Consultancy, Honoraria; Adaptive Biotechnologies: Consultancy, Honoraria; AbbVie: Consultancy, Honoraria; Karyopharm: Consultancy, Honoraria; Celgene: Consultancy, Honoraria. Kaufman:Roche: Consultancy; BMS: Consultancy; Karyopharm: Other: data monitoring committee; Janssen: Consultancy; Abbvie: Consultancy. Mobasher:Genentech Inc: Employment; F. Hoffmann-La Roche Ltd: Other: Ownership interests non-PLC. Freise:AbbVie, Inc: Employment, Equity Ownership. Ross:AbbVie, Inc: Employment, Equity Ownership. Pesko:AbbVie, Inc: Employment, Equity Ownership. Munasinghe:AbbVie, Inc: Employment, Equity Ownership. Gudipati:AbbVie, Inc: Employment, Equity Ownership. Mudd:AbbVie, Inc: Employment, Equity Ownership. Bueno:AbbVie, Inc: Employment, Equity Ownership. Kumar:Oncopeptides: Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees; AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding; Roche: Research Funding; Merck: Membership on an entity's Board of Directors or advisory committees, Research Funding; KITE: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; KITE: 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; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding.

Background:Venetoclax (Ven) is a highly selective, potent, oral BCL‐2 inhibitor that induces apoptosis in malignant cells dependent on BCL‐2 for survival. Proteasome inhibitors (PIs) and dexamethasone (d) were shown to increase BCL‐2 dependence in multiple myeloma (MM) cells, and preclinical studies showed enhanced inhibition of MM tumor growth with Ven+PI compared to either alone. Moreover, d has been shown to indirectly promote BCL‐2 dependency in MM cells. Clinical trials have since demonstrated efficacy of Ven in combination with the PI bortezomib in patients (pts) with relapsed/refractory MM (RRMM).Aims:We report interim data for Ven combined with second‐generation PI carfilzomib (K) and d in pts with RRMM.Methods:In this ongoing Phase 2 study (NCT02899052), pts with RRMM (1–3 prior lines of therapy) and no prior K exposure received VenKd on 28‐day cycles in 4 dose‐finding and 1 expansion cohort: Ven 400 mg/day + K 27 mg/m2 Day 1, 2, 8, 9, 15, 16 + d 40 mg Day 1, 8, 15, 22 (Cohort 1); same regimen but with Ven 800 mg/day (Cohort 2); Ven 800 mg/day + K 70 mg/m2 Day 1, 8, 15 + d 40 mg Day 1, 8, 15, 22 (Cohort 3/expansion cohort); or Ven 800 mg + K 56 mg/m2 Day 1, 2, 8, 9, 15, 16 + d 40 mg Day 1, 2, 8, 9, 15, 16, 22, 23 (Cohort 4). Treatment continued until progressive disease or unacceptable toxicity.Results:As of the clinical data cut‐off of 1 Feb 2019, 43 pts were enrolled. Median age was 67 (range, 37–79), 26 (62%) pts had ISS II/III disease, and 8 (19%) were t (11;14)+. Median number of prior lines of therapy was 2 (range, 1–3). Forty (93%) pts received prior PI (49% refractory), 33 (77%) received prior immunomodulatory drug (IMiD, 61% refractory), and 33 (77%) received prior PI+IMiD (33% double refractory).All pts had at least 1 adverse event (AE). The most common AEs of any grade were diarrhea (65%), nausea (49%), fatigue (47%), cough (35%), insomnia, dyspnea, vomiting, upper respiratory infection (33% each), lymphopenia (28%), thrombocytopenia, and dyspepsia (26% each). Thirty‐six (84%) pts had a Grade 3/4 AE, the most common being lymphopenia (23%), pneumonia, hypertension (16% each), and hypophosphatemia (12%).The overall response rate (ORR) was 79%, complete response or better (≥CR) rate was 40%, and very good partial response or better (≥VGPR) rate was 64% for all pts (Table). Median follow‐up for 42 pts was 10.4 months (95% CI = 8.0–13.8); 15 pts had progression‐free survival (PFS) events, with median PFS yet to be achieved. Baseline bone marrow core biopsy samples from 25 pts were evaluated for BCL‐2 expression by immunohistochemistry, with high expression (≥50% of tumor cells with moderate or higher cytoplasmic staining) seen in 23 (92%) samples. Pts with high BCL‐2 expression had response rates similar to the overall study population. Other correlative biomarker analyses are ongoing.Summary/Conclusion:The combination of VenKd was found to be tolerable with no new safety signals. VenKd demonstrates promising efficacy in pts with RRMM. The study remains ongoing with an additional 60 pts with RRMM enrolling to assess efficacy and safety in a larger group of pts with similar eligibility (Cohort 6) and t (11;14)+ pts (Cohort 7).image