Pomalidomide and Dexamethasone with or without Subcutaneous Daratumumab in Patients with Relapsed or Refractory Multiple Myeloma: Updated Analysis of the Phase 3 Apollo Study

Abstract

Introduction: Daratumumab (DARA) is a human IgGκ monoclonal antibody targeting CD38 with a direct on-tumor and immunomodulatory mechanism of action. DARA is approved as monotherapy or in combination with standard-of-care regimens for the treatment of relapsed or refractory multiple myeloma (RRMM). In the primary analysis (median follow-up, 16.9 months) of the phase 3 APOLLO study (NCT03180736), the addition of DARA to pomalidomide and dexamethasone (D-Pd) showed a significant progression-free survival (PFS) improvement over pomalidomide and dexamethasone (Pd) alone in patients (pts) with RRMM (Dimopoulos MA, et al. Lancet Oncol. 2021;22[6]:801-812). Here, we report results from the APOLLO study, including outcomes of pts refractory to lenalidomide based on the last dose of lenalidomide received. Methods: Eligible pts were ≥18 years of age, had RRMM, had received ≥1 prior line of therapy (including both a proteosome inhibitor and lenalidomide), and had responded to prior treatment; pts with only 1 prior line of therapy were required to be refractory to lenalidomide. Pts were randomized 1:1 to Pd ± DARA, stratified via International Staging System disease stage (I vs II vs III) and number of lines of prior therapy (1 vs 2-3 vs ≥4). All pts received 28-day cycles of pomalidomide (4 mg PO daily on Days 1-21) and dexamethasone (40 mg [20 mg for pts ≥75 years of age], PO daily on Days 1, 8, 15, and 22). Pts in the D-Pd group received DARA subcutaneously (DARA SC; 1,800 mg; co-formulated with recombinant human hyaluronidase PH20 [rHuPH20; ENHANZE ® drug delivery technology, Halozyme, Inc.]) or, prior to a protocol amendment, intravenously (DARA IV; 16 mg/kg; n=7) weekly in Cycles 1-2, every 2 weeks in Cycles 3-6, and every 4 weeks thereafter. Pts receiving DARA IV were allowed to switch to DARA SC starting on Day 1 of Cycle 3 or later. All pts were treated until disease progression or unacceptable toxicity. The primary endpoint was PFS. Results: In total, 304 pts were randomized (D-Pd, n=151; Pd, n=153). At the time of randomization, 120 (79.5%) pts in the D-Pd group and 122 (79.7%) pts in the Pd group were refractory to lenalidomide. Among pts refractory to lenalidomide, the last dose of lenalidomide received was 5-10 mg in 30 (25.0%) pts in the D-Pd group and 31 (25.4%) pts in the Pd group and was 15-25 mg in 86 (71.7%) pts in the D-Pd group and 89 (73.0%) pts in the Pd group. With a median follow-up of 16.9 months, the median PFS in the overall population was 12.4 months in the D-Pd group versus 6.9 months in the Pd group (hazard ratio [HR], 0.63; 95% confidence interval [CI], 0.47-0.85; P=0.0018); the estimated 18-month PFS rate was 42.1% for the D-Pd group and 25.5% for the Pd group. Among pts refractory to lenalidomide, the median PFS was 9.9 months in the D-Pd group and 6.5 months in the Pd group (HR, 0.66; 95% CI, 0.49-0.90). For lenalidomide-refractory pts who last received a dose of 5-10 mg lenalidomide, the median PFS was 10.3 months for the D-Pd group and 8.5 months for the Pd group (HR, 0.75; 95% CI, 0.41-1.36); for lenalidomide-refractory pts who last received a dose of 15-25 mg lenalidomide, the median PFS was 10.7 months for the D-Pd group and 6.1 months for the Pd group (HR, 0.61; 95% CI, 0.42-0.88) (Figure). Grade 3/4 treatment-emergent adverse events occurred in 130 (87.3%) pts in the D-Pd group and 123 (82.0%) pts in the Pd group; the most frequently reported (≥15% in both groups) were neutropenia (67.8% vs 50.7%), thrombocytopenia (17.5% vs 18.0%), and anemia (16.8% vs 21.3%). Grade 3/4 pneumonia occurred in 20 (13.4%) pts in the D-Pd group and 10 (6.7%) of pts in the Pd group. Serious adverse events occurred in 75 (50.3%) pts in the D-Pd group and 59 (39.3%) pts in the Pd group. Conclusion: The addition of DARA to Pd provided a PFS benefit in the overall pt population and among pts refractory to lenalidomide. The safety profile observed in the APOLLO trial was consistent with previous reports for DARA SC and Pd. Additional analyses for lenalidomide-refractory pts, as well as efficacy and safety data for the overall population at longer follow up, will be presented. Figure 1 Figure 1. Disclosures Sonneveld: Celgene/BMS: Consultancy, Honoraria, Research Funding; SkylineDx: Honoraria, Research Funding; Janssen: Consultancy, Honoraria, Research Funding; Karyopharm: Consultancy, Honoraria, Research Funding; Amgen: Consultancy, Honoraria, Research Funding; Takeda: Consultancy, Honoraria, Research Funding. Terpos: Celgene: Consultancy, Honoraria, Research Funding; Genesis: Consultancy, Honoraria, Research Funding; GSK: Honoraria, Research Funding; Janssen-Cilag: Consultancy, Honoraria, Research Funding; Novartis: Honoraria; Takeda: Consultancy, Honoraria, Research Funding; Sanofi: Consultancy, Honoraria, Research Funding; BMS: Honoraria; Amgen: Consultancy, Honoraria, Research Funding. Boccadoro: Sanofi, Celgene, Amgen, Janssen, Novartis, Bristol-Myers Squibb, and AbbVie: Honoraria; Janssen and GSK: Membership on an entity's Board of Directors or advisory committees; Sanofi, Celgene, Amgen, Janssen, Novartis, Bristol-Myers Squibb, and Mundipharma: Research Funding. Delimpasi: Takeda: Honoraria, Speakers Bureau; Janssen: Honoraria, Speakers Bureau; Amgen: Honoraria, Speakers Bureau. Beksac: Amgen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; BMS: 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; Sanofi: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Oncopeptides: 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. Katodritou: GSK, Amgen, Karyopharm, Abbvie, Janssen-Cilag, Genesis Pharma, Sanofi: Honoraria, Research Funding. Moreau: Celgene BMS: Honoraria; Sanofi: Honoraria; Oncopeptides: Honoraria; Janssen: Honoraria; Amgen: Honoraria; Abbvie: Honoraria. Symeonidis: Gilead: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; GSK: Research Funding; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; MSD: Consultancy, Research Funding; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pfizer: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Roche: 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, Research Funding; Sanofi/Genzyme: 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; Demo: Research Funding; WinMedica: Research Funding; GenesisPharma: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Astellas: Consultancy, Research Funding; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Bila: Janssen, Takeda, AMGEN: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Oriol: Sanofi: 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; BMS/Celgene: 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; Oncopeptides: 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. Mateos: Sanofi: Honoraria, Membership on an entity's Board of Directors or advisory committees; AbbVie: Honoraria; Oncopeptides: Honoraria; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees; Bluebird bio: Honoraria; Adaptive Biotechnologies: Honoraria, Membership on an entity's Board of Directors or advisory committees; GSK: Honoraria; Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees; Regeneron: Honoraria, Membership on an entity's Board of Directors or advisory committees; Sea-Gen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene - Bristol Myers Squibb: 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; Oncopeptides: Honoraria, Membership on an entity's Board of Directors or advisory committees. Einsele: Janssen, Celgene/BMS, Amgen, GSK, Sanofi: Consultancy, Honoraria, Research Funding. Orfanidis: Health Data Specialists: Current holder of individual stocks in a privately-held company. Kampfenkel: Janssen: Current Employment. Qiu: Janssen: Current Employment. Amin: Janssen: Current Employment, Current equity holder in publicly-traded company. Kosh: Janssen: Current Employment. Tran: Janssen: Current Employment, Current equity holder in publicly-traded company. Carson: Janssen: Current Employment. Dimopoulos: Beigene: Honoraria; Takeda: Honoraria; Janssen: Honoraria; Amgen: Honoraria; BMS: Honoraria. OffLabel Disclosure: The regimen is approved for patients who have received at least two prior therapies, whereas the APOLLO study included patients who have received at least 1 prior therapy.

Quadruplet therapy for newly diagnosed myeloma: Comparative analysis of sequential cohorts with triplet therapy lenalidomide, bortezomib and dexamethasone (RVd) vs daratumamab with RVD (DRVd) in transplant-eligible patients

“…In the PERSEUS study, the 48-month PFS rate was 84.3% in the D-RVd arm and 67.7% in the RVd arm (HR 0.42; 95% CI 0.30-0.59, p <0.001), and in the GRIFFIN trial, the 4-year PFS was 87% in the D-RVd arm and 70% in the RVd arm (HR 0.45, 95% CI 0.23-0.95). [5,6] In our analysis, the results were quite similar with what was seen in the phase 2 and 3 setting with an estimated 4-year PFS rate of 85% in the D-RVd arm and 61% in the RVd arm. This consistency provides further confidence in the validity of our data.…”

“…In sum, this randomized data is quite convincing and supports quadruplet induction therapy as the new standard of care. [6] Recognizing the potential benefit of daratumumab in induction, we modified our standard of care treatment to Dara-RVd for NDMM patients at our institution in 2018.…”

Autologous hematopoietic stem cell transplantation for multiple myeloma in the age of CAR T cell therapy

“…The phase II GRIFFIN trial tested Dara-VRd as induction with AHCT and showed similarly excellent 2-year PFS at 95.8% (68). The recently published phase III PERSEUS trial compared Dara-VRd vs VRd in induction and post-AHCT consolidation, and demonstrated a significant improvement in PFS with the addition of Dara (84.3% 4-year PFS, vs 67.7% in the VRd only group) (6). Importantly PERSEUS reported a powerful depth of response with 75.2% of patients in the D-VRd group achieving MRD-negativity.…”

“…For 2023, an estimated 35,730 new cases will be diagnosed in the United States which represents 1.8% of all cancers and 19% of all hematologic malignancies (1). The advent of high doses of melphalan with autologous hematopoietic stem cell transplantation (AHCT) was a major advance and led to improved response rates (RR), progression free survival (PFS), and, in some trials, prolonged overall survival (OS) in patients with newly diagnosed MM (NDMM) and has been a cornerstone of treatment in eligible patients for the last 20 years (2)(3)(4)(5)(6). While there are no universally agreed upon transplant eligibility criteria and several risk stratification tools have been proposed, factors such as age, baseline performance status, and comorbidities are important tenets in determining a patient's eligibility (7)(8)(9)(10).…”