Ahmadi, Tahamtan

Abstract Purpose: AXL, a receptor tyrosine kinase related to oncogenic processes, is aberrantly expressed in various cancers and associated with treatment resistance. Enapotamab vedotin (EnaV), a novel anti-AXL human IgG1 and monomethyl auristatin E antibody–drug conjugate, demonstrated antitumor activity in preclinical models, including non–small cell lung cancer (NSCLC). This phase 1/2 study assessed the safety and preliminary efficacy of EnaV in solid tumors. Patients and Methods: This study comprised dose-escalation and dose-expansion phases; both phases investigated EnaV once every 3 weeks (Q3W) and EnaV on days 1, 8, and 15 of a 28-day cycle (3Q4W). Primary objectives determined the maximum tolerated dose (dose escalation) and safety (dose expansion). Pharmacokinetic profile, antitumor activity, and AXL expression were also assessed. Results: During dose escalation, 32 patients received EnaV Q3W; 15 received EnaV 3Q4W. The maximum tolerated dose and recommended phase 2 dose were 2.2 mg/kg in Q3W and 1.0 mg/kg in 3Q4W schedules. In dose expansion, 189 patients received EnaV Q3W; 70 received EnaV 3Q4W. Common adverse events in dose expansion included fatigue, constipation, nausea, decreased appetite, and diarrhea. Overall response rates ranged from 4.5% to 12.5% with Q3W dose schedule and from 9.1% to 11.5% with 3Q4W dose schedule. Disease control rates for NSCLC cohorts were 40.9% to 50.0%. NSCLC subset analysis demonstrated correlation between radiomics signature and disease control. The relationship between clinical activity and AXL expression was not apparent. Conclusions: EnaV had an acceptable safety profile; however, because the evaluation of antitumor activity did not show clinically meaningful responses, clinical development of EnaV was discontinued. Significance: EnaV, an anti-AXL human IgG1 and monomethyl auristatin E antibody–drug conjugate, showed single-agent antitumor activity in preclinical models. This phase 1/2 study of EnaV demonstrated a manageable safety profile and antitumor activity in selected tumor types. Further studies exploring alternative targeting modalities, patient selection, and/or combinations are needed.

Introduction: High-risk smoldering multiple myeloma (SMM) is an asymptomatic precursor disorder to active multiple myeloma (MM) without approved treatment options. However, recent evidence suggests patients at high risk of progression to MM may benefit from early treatment. Daratumumab (DARA) is a human IgGκ monoclonal antibody targeting CD38 with direct on-tumor and immunomodulatory mechanisms of action. DARA is approved as monotherapy for relapsed/refractory MM (RRMM) and in combination with standard-of-care regimens for RRMM and newly diagnosed MM. Based on the encouraging activity and tolerability observed with DARA monotherapy in patients with intermediate- or high-risk SMM in the phase 2 CENTAURUS study, the phase 3 AQUILA study sought to determine if DARA could delay progression to MM versus active monitoring. Here we report the primary analysis from the AQUILA study. Methods: Eligible patients had a confirmed diagnosis of high-risk SMM for ≤5 years, defined as clonal bone marrow plasma cells (BMPCs) ≥10% and ≥1 risk factor (serum M protein ≥30 g/L, IgA SMM, immunoparesis with reduction of 2 uninvolved Ig isotypes, serum involved:uninvolved free light chain ratio ≥8 and <100, and/or clonal BMPCs >50% to <60%). Focal and lytic lesion assessment was performed in screening by CT and MRI and centrally reviewed prior to study enrollment. Patients were randomized 1:1 to receive DARA SC versus active monitoring. DARA (QW in Cycles 1 and 2, Q2W in Cycles 3-6, and Q4W thereafter) was given in 28-day cycles until cycle 39, 36 months, or disease progression, whichever came first. The primary endpoint was progression-free survival (PFS), defined as progression to active MM as assessed by an independent review committee and according to IMWG diagnostic criteria for MM (SLiM-CRAB) or death. Major secondary endpoints included overall response rate (ORR), PFS on first-line MM treatment (PFS2), and overall survival (OS). Results: A total of 390 patients (DARA, n = 194; active monitoring, n = 196) were randomized. Median (range) age (64 [31-86] years) and time from initial SMM diagnosis to randomization (0.72 [0-5.0] years) were balanced between treatment groups. Median treatment duration in the DARA group was 38 cycles (35.0 months). At a median (range) follow-up of 65.2 (0-76.6) months, PFS was significantly improved with DARA versus active monitoring (HR, 0.49; 95% CI, 0.36-0.67; P <0.0001). Median PFS was not reached in the DARA group versus 41.5 months for active monitoring; estimated 60-month PFS rates were 63.1% versus 40.8%, respectively. Prespecified analyses showed generally consistent PFS improvement with DARA versus active monitoring across subgroups. ORR was 63.4% with DARA versus 2.0% with active monitoring (P <0.0001). As of the clinical cutoff, 64 (33.0%) patients in the DARA group and 102 (52.0%) patients in the active monitoring group had started first-line MM treatment. Median time from randomization to the date of first-line MM treatment was not reached with DARA versus 50.2 months with active monitoring (HR, 0.46; 95% CI, 0.33-0.62; nominal P <0.0001). There was a positive trend in favor of DARA for PFS2 (HR, 0.58; 95% CI, 0.35-0.96) and OS (60-month OS rates: DARA, 93.0%; active monitoring, 86.9%; HR, 0.52; 95% CI, 0.27-0.98). A total of 41 deaths were observed, 15 for the DARA group and 26 for the active monitoring group. Grade 3/4 treatment-emergent adverse events (TEAEs) occurred in 40.4% and 30.1% of patients in the DARA and active monitoring groups, respectively. The most common (≥5% in either group) grade 3/4 TEAE was hypertension (DARA, 5.7%; active monitoring, 4.6%). The frequency of TEAEs leading to DARA discontinuation was low (5.7%), as was the incidence of fatal TEAEs in both groups (DARA, 1.0%; active monitoring, 2.0%). Conclusions: DARA monotherapy was well tolerated and demonstrated a clinically meaningful and significant benefit in preventing or delaying progression to active MM compared with active monitoring in patients with high-risk SMM. ORR was significantly higher and time to first-line MM treatment was prolonged with DARA compared with active monitoring. This was accompanied by positive trends for PFS2 and OS in favor of DARA. These results strongly support the benefit of early intervention with DARA monotherapy versus active monitoring, the current standard of care, in patients with high-risk SMM.

PURPOSE At the primary analysis of CASTOR (median follow-up, 7.4 months), daratumumab plus bortezomib and dexamethasone (D-Vd) significantly prolonged progression-free survival versus bortezomib and dexamethasone (Vd) alone in relapsed or refractory multiple myeloma (RRMM). We report updated efficacy and safety results at the final analysis for overall survival (OS). METHODS CASTOR was a multicenter, randomized, open-label, phase III study during which eligible patients with ≥ 1 line of prior therapy were randomly assigned to Vd (up to eight cycles) with or without daratumumab (until disease progression). After positive primary analysis and protocol amendment, patients receiving Vd were offered daratumumab monotherapy after disease progression. RESULTS At a median (range) follow-up of 72.6 months (0.0-79.8), significant OS benefit was observed with D-Vd (hazard ratio, 0.74; 95% CI, 0.59 to 0.92; P = .0075). Median OS was 49.6 months with D-Vd versus 38.5 months with Vd. Prespecified subgroup analyses demonstrated an OS advantage with D-Vd versus Vd for most subgroups, including patients age ≥ 65 years and patients with one or two prior lines of therapy, International Staging System stage III disease, high-risk cytogenetic abnormalities, and prior bortezomib treatment. The most common (≥ 10%) grade 3/4 treatment-emergent adverse events with D-Vd versus Vd were thrombocytopenia (46.1% v 32.9%), anemia (16.0% v 16.0%), neutropenia (13.6% v 4.6%), lymphopenia (10.3% v 2.5%), and pneumonia (10.7% v 10.1%). CONCLUSION D-Vd significantly prolonged OS in patients with RRMM, with the greatest OS benefit observed in patients with one prior line of therapy. To our knowledge, our results, together with the OS benefit observed with daratumumab plus lenalidomide and dexamethasone in the phase III POLLUX study, demonstrate for the first time an OS benefit with daratumumab-containing regimens in RRMM (ClinicalTrials.gov identifier: NCT02136134 [CASTOR]).

Abstract Introduction Lenalidomide-based therapies are a standard of care for patients with newly diagnosed, transplant-ineligible MM. Daratumumab (DARA) is a human, CD38-targeted, IgG1κ monoclonal antibody which has single-agent activity in heavily pretreated MM patients. As previously reported in 3 phase 3 studies, the addition of DARA to standards of care in both relapsed refractory (D-Rd, DARA plus bortezomib and dexamethasone [D-Vd]) or transplant-ineligible NDMM (DARA plus bortezomib, melphalan, and prednisone [D-VMP]) resulted in a ≥50% reduction in the risk of disease progression or death (Palumbo A, et al. N Engl J Med 2016;375:754-766; Dimopoulos MA, et al. N Engl J Med 2016;375:1319-1331; Mateos MV, et al. N Engl J Med 2018;378:518-528). Of these, the POLLUX study with D-Rd showed the greatest benefit with a 63% reduction in risk of disease progression or death in patients with MM who had at least one prior line of therapy. Based on the efficacy and tolerable safety profile of D-Rd, we conducted a phase 3 study (MAIA) to evaluate D-Rd vs Rd in transplant-ineligible NDMM. Here we report the prespecified interim analysis of the MAIA study. Methods Patients ineligible for high-dose chemotherapy with autologous stem cell transplantation due to age ≥65 years or comorbidities were randomized 1:1 to Rd ± DARA. Stratification was based on International Staging System stage (ISS [I, II, III]), region (North America vs other), and age (<75 vs ≥75 years). All patients received 28-day cycles of treatment with Rd ± DARA. R: 25 mg (oral) QD on Days 1-21; d: 40 mg (oral) on Days 1, 8, 15 and 22. In the D-Rd arm, DARA was given at 16 mg/kg (intravenously) QW for Cycles 1-2, Q2W for Cycles 3-6, and Q4W thereafter. In both arms, patients were treated until disease progression or unacceptable toxicity. The primary endpoint was progression-free survival (PFS). Key secondary endpoints included overall response rate (ORR), minimal residual disease (MRD)-negativity rate (10-5 sensitivity, clonoSEQ® version 2.0), and safety. Results This international study randomized 737 patients (368 to D-Rd; 369 to Rd) from 14 countries. Key baseline characteristics were well balanced between the two arms. The median (range) age was 73 (45-90) years with 44% of patients ≥75 years, and 52% were male. Two thirds of patients had ECOG scores ≥1: ECOG score 0, 34%; 1, 50%; ≥2, 17%. Overall, 27%, 43%, and 29% were ISS stage I, II, and III, respectively. Of 642 patients evaluable for FISH/karyotyping analysis, 86% and 14% were standard and high cytogenetic risk, respectively. The prespecified interim analysis occurred after 239 PFS events on 24 September 2018 with a median follow up of 28 months. For the primary endpoint, the hazard ratio was 0.55 (95% CI, 0.43 to 0.72; P <0.0001), representing a 45% reduction in the risk of progression or death in patients treated with D-Rd (Figure). The median PFS for the Rd arm was 31.9 months and not reached for the D-Rd arm. Adding DARA to Rd resulted in deeper responses with a complete response (CR) or better rate of 47.6% in the D-Rd arm compared with 24.7% in the Rd arm (odds ratio [OR] 2.75, 95% CI, 2.01 to 3.76; P <0.0001). The very good partial response (VGPR) or better rate was 79.3% in the D-Rd arm compared with 53.1% in the Rd arm (OR 3.4, 95% CI, 2.45 to 4.72; P <0.0001). A total of 19% of patients have died and the HR for OS was 0.78 (95% CI, 0.56 to 1.1); follow-up is ongoing. Higher rates (5% or more difference) of grade 3/4 pneumonia, neutropenia, and leukopenia were observed in the D-Rd arm. The safety profile is consistent with previously reported DARA studies. The complete topline data set will be presented with additional efficacy endpoints, including MRD negativity rate. Conclusion The addition of DARA to Rd in patients with transplant-ineligible NDMM significantly reduced the risk of progression or death by 45%. There are no new safety signals using DARA plus Rd in NDMM. These data together with the phase 3 ALCYONE study (D-VMP vs VMP) support the addition of DARA to standard of care combinations in patients with NDMM ineligible for transplant. Disclosures Facon: Sanofi: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Takeda: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Amgen: Membership on an entity's Board of Directors or advisory committees; Karyopharm: Membership on an entity's Board of Directors or advisory committees; Oncopeptides: Membership on an entity's Board of Directors or advisory committees. Kumar:KITE: 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; 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. Plesner:Celgene: Other: Independent Response Assessment Comittee; Janssen: Consultancy. Orlowski:Bristol-Myers Squibb: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Kite Pharma: Consultancy, Membership on an entity's Board of Directors or advisory committees; Sanofi-Aventis: Consultancy, Membership on an entity's Board of Directors or advisory committees; Takeda: Consultancy; Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; BioTheryX: Research Funding; Spectrum Pharma: Research Funding. Moreau:Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Bahlis:Amgen: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding. Hulin:Celgene: Honoraria, Research Funding; Amgen: Honoraria; Takeda: Honoraria; Janssen: Honoraria, Research Funding. Goldschmidt:Adaptive Biotechnology: 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; Bristol Myers Squibb: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Sanofi: 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; Chugai: Honoraria, Research Funding; Mundipharma: Research Funding; Novartis: Honoraria, Research Funding; ArtTempi: Honoraria. O'Dwyer:Janssen: Consultancy. Perrot:Janssen: Consultancy, Equity Ownership, Honoraria. Venner:Janssen: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; Amgen: Honoraria; Takeda: Honoraria. Weisel:Celgene: Consultancy; Angeb: Consultancy, Honoraria, Research Funding; Juno: Consultancy; Takeda: Consultancy, Honoraria; Sanofi: Consultancy, Research Funding; Bristol Myers SquibbMS: Consultancy, Honoraria; Janssen: Consultancy, Honoraria, Research Funding. Ahmadi:Genmab: Employment, Equity Ownership. Chiu:Janssen Research & Development, LLC: Employment, Equity Ownership. Wang:Janssen Research & Development, LLC: Employment. Van Rampelbergh:Janssen: Employment. Uhlar:Janssen: Employment. Kobos:Janssen Research & Development: Employment. Qi:Janssen Research & Development, LLC: Employment. Usmani:Abbvie, Amgen, Celgene, Genmab, Merck, MundiPharma, Janssen, Seattle Genetics: Consultancy; Amgen, BMS, Celgene, Janssen, Merck, Pharmacyclics,Sanofi, Seattle Genetics, Takeda: Research Funding.

LBA4 Background: Daratumumab (D), a human anti-CD38 IgGκ mAb, induces deep and durable responses with a favorable safety profile in RRMM pts. We report a pre-specified interim analysis of the first randomized controlled study of D (CASTOR; NCT02136134). Methods: Pts with ≥1 prior line of therapy were randomized (1:1) to 8 cycles (q3w) of bortezomib (V)/dexamethasone (d) (V: 1.3 mg/m2sc on Days 1, 4, 8, 11; d: 20 mg po on Days 1, 2, 4, 5, 8, 9, 11, 12) ± D (16 mg/kg iv qw in Cycles 1-3, Day 1 of Cycles 4-8, then q4w until progression). Primary endpoint was PFS. Results: 498 pts (DVd, 251; Vd, 247) were randomized. Baseline demographics and disease characteristics were well balanced. Pts received a median of 2 prior lines of therapy (range 1-10). 66% received prior V; 76% received prior IMiD; 48% received prior PI and IMiD; 33% were IMiD-refractory; 32% were refractory to last line of prior therapy. With median follow-up of 7.4 months, D significantly improved median PFS (61% reduction in risk of progression) and TTP for DVd vs Vd (Table). D significantly increased ORR (83% vs 63%, P <0.0001), and doubled rates of ≥VGPR (59% vs 29%, P <0.0001), and ≥CR (19% vs 9%, P= 0.0012) for DVd vs Vd, respectively; median duration of response was NR vs 7.9 months, respectively. Most common (>25%) AEs (DVd/Vd) were thrombocytopenia (59%/44%), peripheral sensory neuropathy (47%/ 38%), diarrhea (32%/22%) and anemia (26%/31%). Most common grade 3/4 AEs (>10%) were thrombocytopenia (45%/33%), anemia (14%/16%), neutropenia (13%/4%). 7%/9% of pts discontinued due to a TEAE. D-associated infusion-related reactions (45% of pts) mostly occurred during the first infusion; most were grade 1/2 (grade 3/4, 9%/0%). Conclusions: D significantly improved PFS, TTP, and ORR in combination with Vd vs Vd alone. DVd doubled both VGPR and sCR/CR rates vs Vd alone. Safety of DVd is consistent with the known safety profile of D and Vd. The addition of D to Vd should be considered a new standard of care for RRMM pts currently receiving Vd alone. Clinical trial information: NCT02136134. [Table: see text]