OMass Therapeutics is developing experimental small-molecule drugs for people with rare endocrine disorders and immune diseases. The Oxford company said on October 15 that it had announced a $310 million Series C, co-led by Bain Capital Life Sciences, Forbion and Novo Holdings. The money is meant to move its lead drug through Phase 2 and produce the first clinical data for a second program.
Its OdyssION platform combines native mass spectrometry, biochemistry and custom chemistry to examine drug targets and the molecular complexes around them outside whole cells. That setup is intended to retain the target’s biological context while giving researchers the precision of a cell-free experiment. The company grew out of University of Oxford research and uses the platform to build its own drug pipeline.
OMS1620 is the first clinical test of that approach. It blocks MC2, the receptor through which ACTH drives adrenal-hormone production. In congenital adrenal hyperplasia, low cortisol disrupts a feedback loop and causes ACTH to rise. OMass designed OMS1620 to remain on the receptor longer and maintain activity as ACTH increases, but that is the drug’s proposed distinction rather than a demonstrated patient outcome.
Fierce Biotech reported that OMS1620 had reached only the single-ascending-dose portion of a Phase 1 trial in healthy volunteers. The Series C is designed to carry it through Phase 2 in congenital adrenal hyperplasia and ACTH-dependent Cushing’s syndrome. The financing therefore supports the move from early human testing into patient studies; no patient-efficacy result was disclosed.
OMass also plans to use the round to generate initial clinical data for an SLC15A4 inhibitor. It is pursuing the preclinical small molecule for lupus and other diseases associated with excess interferon signaling and harmful B-cell activation. That gives the financing a second clinical objective instead of leaving it entirely dependent on the adrenal program.
The clinical push is also changing how OMass operates. Chief Executive Ros Deegan told Fierce Biotech that the company would add development capabilities on both sides of the Atlantic as it moves toward multi-region work. OMass has used partnerships before: Genentech paid $20 million upfront in 2025 to license a preclinical inflammatory-bowel-disease program, while this round is directed at two programs OMass discovered internally.