Apeximmune Therapeutics

Apeximmune Therapeutics is a South San Francisco / Burlingame-area biotechnology company developing next-generation antibody therapeutics that harness the immune system to treat cancer and autoimmune disease. Using a proprietary target-discovery platform built on bioinformatic analysis of thousands of tumor RNA-seq transcriptomes, the company has identified more than 30 novel immune targets. Its lead program, AI-306, is a first-in-class antagonist antibody against the novel immune checkpoint AIM-103, and its MEBA platform builds bispecific antibodies that engage macrophages to kill tumor cells. The company closed a $21.3 million Series A in 2025 led by PharmaEssentia.