Mipletamig Delivers 100% Remission Rate in Cohort 3 of RAINIER Trial for AML

No dose-limiting toxicities or cytokine release syndrome observed in RAINIER to date; mipletamig shows consistently favorable safety and tolerability Trial progressing efficiently, Cohort 4 open for enrollment SEATTLE, WA / ACCESS Newswire / September 16, 2025 / Aptevo Therapeutics ("Aptevo" or "the Company") (NASDAQ:APVO), a clinical-stage biotechnology company developing novel bispecific and trispecific immuno-oncology therapeutics, today announced a 100% remission rate in Cohort 3 of its Phase 1b/2 RAINI ...