Aptevo Therapeutics Inc., a clinical-stage research and development biotechnology company, focuses on developing immunotherapeutic candidates for the treatment of various forms of cancer in the United States. The company develops its products using ADAPTIR and ADAPTIR-FLEX platforms to generate monospecific, bispecific, and multi-specific antibody candidates capable of enhancing the human immune system against cancer cells. Its lead clinical blood cancer candidate is mipletamig that is in Phase 1b/2 clinical trial for the treatment of acute myelogenous leukemia. The company also develops ALG.APV-527, a novel investigational bispecific ADAPTIR candidate that is in Phase 1 clinical trial for the treatment of non-small cell lung cancer, head and neck, colorectal, pancreatic, breast, and other solid tumors; APVO603, a preclinical dual agonist bispecific ADAPTIR candidate to treat multiple solid tumors; APVO442, a preclinical bispecific candidate based on the ADAPTIR-FLEX platform technology for the treatment of multiple solid tumors; and APVO711, a preclinical dual mechanism bispecific ADAPTIR candidate to treat prostate cancer. It has a collaboration and option agreement with Alligator Bioscience AB to develop ALG.APV-527. Aptevo Therapeutics Inc. was incorporated in 2016 and is headquartered in Seattle, Washington.