Aptevo Therapeutics initiates Phase 1b/2 ‘RAINIER’ AML trial

Aptevo Therapeutics announced initiation of the Company’s Phase 1b/2 dose optimization trial, “RAINIER,” as part of its ongoing program to evaluate APVO436 in combination with venetoclax + azacitidine for frontline patients with acute myeloid leukemia. RAINIER will be conducted in two parts. First, a Phase 1b frontline AML study followed by a Phase 2 study. The Company also announced that APVO436 has received its generic name, mipletamig and will refer to its lead candidate by this name moving forward. This frontline AML study is a multi-center, multi-cohort, open label dose finding study of up to 39 patients across five dose levels ranging from 9 mcg – 140 mcg in combination with venetoclax and azacitidine. Subjects will be adults aged 18 or older, newly diagnosed with AML who are not eligible for intensive induction chemotherapy. Phase 1b consists of 28-day cycles of treatment in five sequential cohorts. Aptevo has partnered with Prometrika, a premier contract research organization, for the RAINIER trial. Primary endpoints: Evaluate the safety, tolerability, and maximum tolerated dose of increasing doses of APVO436 in combination with venetoclax and azacitidine in patients with newly diagnosed AML; Determine the recommended Phase 2 dose; Assess incidence of cytokine release syndrome at each dose level. Secondary Endpoint: Determine the efficacy of increasing doses of APVO436 in combination with venetoclax and azacitidine in patients with newly diagnosed AML.