Addition

Addition Therapeutics is a private genomic medicine company developing all-RNA, non-viral, lipid nanoparticle-based one-time therapies for chronic and rare diseases. Its proprietary PRINT platform, short for Precise RNA-Mediated Insertion of Transgenes, is designed to insert therapeutic genetic payloads into specific genomic safe harbor sites without using viral vectors. The company is advancing a preclinical pipeline of "PRINTed" medicines, including both wholly owned and partnered programs, and has indicated initial disease-related non-human primate studies in 2026. Addition emerged from stealth in December 2025 with $100 million in funding and is positioning its approach as a potentially safer, more durable, and more scalable alternative to conventional gene therapy and gene editing approaches.