Efficacy and safety of isatuximab plus pomalidomide and dexamethasone in East Asian patients with relapsed/refractory multiple myeloma: A subgroup analysis of ICARIA-MM study

Abstract

Background: The phase 3 ICARIA study demonstrated that isatuximab (Isa) plus pomalidomide and dexamethasone (Pd) significantly improved progression free survival (PFS) compared with Pd in patients (pts) with relapsed/refractory multiple myeloma (RRMM) (HR = 0.596, 95%CI 0.44‐0.81, P = 0.001). We evaluated the efficacy/ safety ofIsa‐Pd in the East Asian pts (13 Japanese, 9 Korean and 14 Taiwanese pts) of ICARIA. Methods: RRMM pts who had received >2 prior lines of therapies, including lenalido‐mide (len) and at least a proteasome inhibitor (PI), and were refractory to their last therapy were enrolled. Pts were randomized into either Isa‐Pd arm who received Isa 10 mg/kg IV weekly for the first 4 weeks (wks) followed by biweekly or Pd arm, and all pts received Pom (4mgPO days 1‐21) anddex(40mg [20mg if older than 75yrs] PO or IV weekly) in 28 day cycle until disease progression or unacceptable toxicity. Results: Data from 36 East Asian pts (21 Isa‐Pd, 15 Pd) including Japanese pts (9 Isa‐Pd, 4 Pd) were analyzed. Patient's characteristics were similar in the East Asian subgroup and the entire population of ICARIA study (n = 307). Of these pts, median age: 65 (range, 41‐85) yrs; median prior lines of therapy: 3 (range, 2‐7); 91.7% and 69.4% were refractory to len and PI, respectively; and 13.9% had high‐risk cytogenetics. After median follow‐up of 11.6 months, median PFS was not reached yet in Isa‐Pd arm and was 7.9 months in Pd arm (HR 0.517 [95% CI 0.19‐1.39]). ORR (>PR) was 71.4% in Isa‐Pd arm 60% inPdarm. The VGPR rate or better was 61.9% and 13.3% in Isa‐Pd and Pd arm, respectively. Median time to first response was 32 days and 59 days for Isa‐ Pd and Pd arm, respectively. Grade >3 AEs were observed in 90.5% and 73.3% pts in Isa‐Pd and Pd arm, respectively and which caused 9.5% pts in the Isa‐Pd arm and 0 % in Pd arm to discontinue their treatment. Infusion associated reactions were reported in 57.1% pts receiving Isa‐Pd but none of them were grade 3‐4. Conclusions: This subgroup analysis of ICARIA demonstrates that the efficacy and safety of Isa‐Pd in East Asian population, including Japanese pts, are comparable with the entire population of ICARIA. Isa‐Pd is a novel treatment option for East Asian pts with RRMM.