Capstan Raises $175 Million to Advance In Vivo CAR-T Candidate in Autoimmune Diseases

Rare Daily Staff

Capstan Therapeutics raised $175 million in a series B financing to advance in vivo reprogramming of cells through RNA delivery using targeted lipid nanoparticles.

RA Capital Management led the financing, with participation from new investors Forbion, Johnson & Johnson Innovation – JJDC, Mubadala Capital, Perceptive Advisors, and Sofinnova Investments. Capstan’s existing investors Alexandria Venture Investments, Bristol Myers Squibb, Eli Lilly and Company, Leaps by Bayer, Novartis Venture Fund, OrbiMed, Pfizer Ventures, Polaris Partners, and Vida Ventures, also participated in the round.

Capstan’s core platform technology comprises proprietary targeted lipid nanoparticles (tLNP) that are composed of LNPs conjugated with a recombinant protein binder, such as a monoclonal antibody. tLNPs are designed to deliver payloads, including mRNA or gene editing tools, capable of reprogramming specific cell types in vivo. The company says its platform technology has the potential to generate transformative therapies with possible applications across a broad range of disease areas, including autoimmune disorders, oncology, fibrosis, and monogenic blood disorders.

Proceeds from the financing will be used to advance CPTX2309, Capstan’s lead in vivo chimeric antigen receptor T cell (CAR-T) candidate to early clinical proof-of-concept in autoimmune disorders, and to further develop Capstan’s targeted lipid nanoparticle (tLNP) pipeline. CPTX2309 delivers an mRNA payload encoding for an anti-CD19 CAR to CD8-expressing T cells, effectively engineering CAR-T cells in vivo. The therapeutic goal of this approach is to achieve a reset of the immune system through rapid deep B cell depletion in both blood and lymphoid tissues, without the challenges of conventional ex vivo CAR-T.