OMass Therapeutics closed an oversubscribed $310M Series C to advance its rare endocrinology and immunology pipeline toward the clinic. The round is designed to fund OMS1620 through Phase II development, with the company also supporting earlier clinical work on a second candidate, SLC15A4. The financing was co-led by Bain Capital Life Sciences, Forbion, and Novo Holdings, bringing new investors in while existing backers—including Syncona, Sanofi Ventures, and the University of Oxford—participated. Management said the capital is meant to generate “meaningful data” across both programs. The deal positions OMass among the largest UK biotech financings in recent years and signals continued investor appetite for endocrine and interferon-linked biology—areas where patient stratification and biomarkers are often key to trial efficiency. For the sector, the round also highlights a pattern: large, late-stage preclinical-to-Phase II funding is increasingly used to de-risk clinical execution rather than just extend runway.