Addition Therapeutics announced it has raised $100 million in financing to date, highlighting progress toward developing one-time genomic medicines for chronic and rare diseases. Based in South San Francisco, the company is building around an all-RNA, non-viral approach that uses lipid nanoparticles (LNPs) to deliver its PRINT platform, short for Precise RNA-Mediated Insertion of Transgenes.
The company said its PRINT platform is designed to overcome the limitations of existing genetic medicine modalities by enabling durable transgene insertion without the use of viral vectors. Addition’s therapeutic concept centers on leveraging retrotransposition: a retrotransposase encoded in the medicine converts a template RNA into a DNA transgene, which is then directed to a conserved ribosomal DNA “safe-harbor” site. According to the company, this enables precise insertion while avoiding disruption of other genes or cellular functions. Delivery is handled through a clinically validated LNP formulation that Addition said has demonstrated low immunogenicity.
Addition said it is advancing a pipeline of “PRINTed” therapeutics across chronic and rare indications, with initial disease-related non-human primate studies planned for 2026. While the company did not disclose lead program details, it said multiple pipeline efforts have been advanced through research initiatives with undisclosed pharmaceutical partners.
The financing syndicate includes SR One, Pivotal Life Sciences, Abingworth, Osage University Partners, the Gates Foundation, and BEVC. The company also pointed to non-dilutive support, noting that the Gates Foundation has provided a grant for a PRINTed program intended to enable endogenous antibody production from a single dose, with the stated goal of providing lifetime protection against HIV. Addition positioned the initiative as part of a broader effort to make potential genomic-medicine-based interventions viable and affordable for high-risk populations in low- and middle-income countries.
Addition is a spin-out of Professor Kathleen Collins’ laboratory at the University of California, Berkeley. The company said the foundational technology underlying PRINT draws on Collins’ retrotransposase expertise and was supported by entrepreneurship funding from UC Berkeley’s Bakar Fellows Program and an NIH Director’s Pioneer Award. Pivotal Life Sciences seeded the company at the time of its spin-out, Addition said.
Addition’s senior leadership team includes CEO Ron Park, M.D., MBA; CSO Francine Gregoire, Ph.D.; CBO Priya Parameswaran, MBA; VP of People and Culture Joy Branford, MS; VP and Distinguished Scientific Fellow Greg Cost, Ph.D.; VP of Operations Grady Snyder, MBA; and Executive Director of IP and Legal and Corporate Secretary Lawrence Kong, Ph.D., JD.
The board is chaired by Matthew Patterson, a venture partner at SR One, and includes representation from Pivotal Life Sciences and Abingworth, alongside Collins. Board observers include Matt Cohen, Ph.D., of Osage University Partners and Graham Mills, Ph.D., of Abingworth.
Addition said it plans to share more about its lead programs and pipeline in the future as it progresses toward 2026 primate studies and broader preclinical development.
KEY QUOTES
Ron Park, M.D., MBA: “Our bold vision at Addition Therapeutics is to achieve genomic medicine’s powerful, long-held promise for patients and forge new frontiers for what’s possible in the treatment of disease.”
Ron Park, M.D., MBA: “Bolstered by our team of top-tier scientists and engineers and our high-caliber investors, we have built a world-class technology platform and a pipeline of novel chronic and rare disease programs. Today, we’re excited to start sharing our progress and momentum.”
Matt Patterson: “Addition brings together an extraordinary platform, a highly skilled team, and disciplined planning and execution.”
Matt Patterson: “The external support Addition has received from this outstanding group of funders and several top pharma companies will enable the continued advancement of its patient-centric mission. I look forward to Addition’s progress in the years ahead.”
Kathleen Collins, Ph.D.: “While we’ve seen important progress over the last decade, gene therapy modalities approaching or in the clinic are limited in their technical capabilities and restricted in their applicability and adoption.”
Kathleen Collins, Ph.D.: “Harnessing retrotransposon machinery to achieve precise transgene insertion to the ideal genomic safe-harbor site is an elegant and versatile new drug mechanism.”
Kathleen Collins, Ph.D.: “It’s thrilling to see the Addition team’s evolution of this technology into a powerful platform and a pipeline that has the potential to help usher in a new era of genomic medicines.”
