Aptevo Therapeutics

Aptevo Therapeutics is a Seattle-based clinical-stage immuno-oncology company developing monospecific, bispecific, and multi-specific antibody candidates on its ADAPTIR and ADAPTIR-FLEX platforms. Its lead clinical candidate is mipletamig, in a Phase 1b/2 trial for acute myelogenous leukemia, with ALG.APV-527 (developed with Alligator Bioscience) in Phase 1 across multiple solid tumors. In mid-2026 the company pivoted its solid-tumor strategy toward a Nectin-4 x PD-L1 dual-targeting backbone and raised $4.5 million via a warrant exercise and PIPE, followed by a resale-registration effectiveness in September 2026 that expanded tradable share supply.