Addition Therapeutics has raised $100 million in Series A funding to develop an RNA‑to‑DNA gene‑medicine platform derived from UC Berkeley research. Using lipid nanoparticles to deliver RNA bound to an enzyme that converts it into DNA, the company aims to reduce reliance on viral vectors and improve safety, durability, and cost. Addition is collaborating with the Gates Foundation on an HIV program and is advancing multiple pipeline programs with unnamed pharma partners.
Addition Therapeutics Raises $100M to Build RNA‑to‑DNA Gene Medicines for Rare and Chronic Diseases
Addition Therapeutics has emerged from stealth with $100 million in Series A funding to develop a new class of genetic medicines spun out of research at the University of California, Berkeley. The startup says its platform is designed to avoid several limitations of conventional viral gene therapies and current gene‑editing approaches.
How the Platform Works
Addition uses lipid nanoparticles (LNPs) — fatty, nonviral delivery shells — to carry a specialized form of RNA bound to an enzyme into target cells. Once inside, the enzyme converts the RNA message into DNA, which the company says is then directed to a specific site in the genome. By avoiding engineered viral vectors, the approach aims to reduce immune reactions and manufacturing complexity.
Potential Advantages
The company and its scientific leadership say the technology could offer three main benefits compared with many existing methods: lower production costs, greater durability of effect, and improved safety by minimizing immune responses tied to viral vectors. Addition's CSO, Francine Gregoire, says the platform is intended to be applicable not only to rare monogenic diseases but also to more common chronic conditions — a feature that could broaden patient impact and improve commercial viability.
“It’s really tough and expensive to develop your therapies, and for the end of it, the patient population that it can address is relatively small,” said Ron Park, Addition’s CEO. “That creates a business model for traditional gene therapy approaches that is just very, very difficult.”
Pipeline, Partners and Financing
Addition confirmed a collaboration with one of its investment partners, the Bill & Melinda Gates Foundation, to develop an HIV program intended to prompt long‑term expression of protective antibodies. The company also said multiple additional pipeline programs are being advanced via research collaborations with unnamed pharmaceutical partners. Formed in 2021, Addition closed about a half dozen investors in this round, including SR One, Pivotal Life Sciences and Abingworth.
Outlook
While early-stage and not yet disclosing all target indications, Addition positions its RNA‑to‑DNA approach as a potential middle ground between transient mRNA therapies and permanent but riskier gene edits. If successful, the platform could expand genetic-medicine options for both rare and more prevalent diseases, while addressing manufacturing and immune‑response challenges tied to viral vectors.
