Isatuximab (Isa, anti-CD38 monoclonal antibody) is approved in combination with carfilzomib (K) and dexamethasone (d), for relapsed multiple myeloma (MM) patients (pts) after ≥1 prior therapy. Final progression free survival (PFS) analysis after 2 years showed mPFS of 35.65 mo (Isa-Kd) vs 19.15 mo (Kd). Here, we report the final overall survival (OS) from IKEMA planned 3 years after the primary PFS analysis.

Pts with 1−3 prior lines of therapy were randomized 3:2 to receive Isa-Kd (n=179) or Kd (n=123). Treatment (tx) was given until progressive disease, unacceptable toxicity, or pt wish. Safety was assessed in all treated pts.

As of 7 Feb 2023, 23.5% (Isa-Kd) and 5.7% (Kd) pts were on tx. Median follow-up: 56.61 mo. OS benefit was more in Isa-Kd pts (mOS was NR; [95% CI: 52.172−NR] vs 50.6 mo [95% CI: 38.932−NR]; HR: 0.855; nominal one-sided p=0.1836). Isa-Kd had longer TTNT vs Kd (median 43.99 vs 25.0 mo; nominal one-sided p=0.0002), as was PFS2 (median 47.18 vs 32.36 mo; nominal one-sided p=0.0035). The safety profiles were comparable to interim and final PFS analyses. Grade ≥3 TEAEs: 84.2% (Isa-Kd) vs 73.0% (Kd).

This final OS analysis shows a meaningful trend for OS benefit with Isa-Kd vs Kd despite subsequent tx with anti-CD38 agents, introduction of tx with novel mechanism of action among further therapies, and the COVID-19 pandemic. Improvements in TTNT and PSF2 were observed and sustained PFS benefit still observed at PFS2. The Isa-Kd safety profile was consistent with previous analyses, supporting it as a standard-of-care therapy for relapsed MM pts.