Oxford-based biotechnology startup OMass Therapeutics announced a $310 million Series C round on 15 October, co-led by Bain Capital Life Sciences, Forbion and Novo Holdings. The company plans to use the money to take its lead experimental drug OMS1620 through Phase 2 development and fund another programme’s initial clinical data.
OMS1620 is being developed for congenital adrenal hyperplasia and ACTH-dependent Cushing’s syndrome. The other programme targets SLC15A4 for lupus and related conditions. Janus Henderson Investors, SV Health Investors and Jefferson Life Sciences also joined the oversubscribed financing, alongside existing backers. Bain’s Evan Greif and Forbion’s Audrey Cacaly will join the board. Novo Holdings’ Max Klement and SV Health Investors’ Ali Jazayeri receive board observer seats. OMass said all existing investors participated, including Syncona, Oxford Science Enterprises, GV, Northpond Ventures and Sanofi Ventures.
Syncona details its investment and holding value
Existing investor Syncona committed $10.1 million, or £7.5 million, according to its 15 October stock-exchange announcement. Syncona said the round resulted in a £4.7 million increase in the value of its OMass holding, a 9.4 per cent uplift against the June-end valuation. Including £1.7 million of new capital invested since 30 June 2026, its holding value will be £56 million. That is the value assigned to Syncona’s investment, rather than a valuation of the entire startup.
Syncona put its ownership stake at 16.1 per cent once the full Series C is drawn down. A footnote specifies that this percentage applies when all current commitments have been invested, so it should not be read as an unconditional current shareholding. Syncona co-led the company’s Series A with Oxford Science Enterprises in 2018. It said the latest round takes OMass’ total financing to approximately $475 million. The announcement uses September’s average exchange rates for its sterling equivalents.
What the registered trial actually covers
The ClinicalTrials.gov record for OMS1620-101 describes a Phase 1 study with an estimated 84 healthy participants aged 18 to 55. It is designed to examine safety, drug concentrations and effects on adrenal hormones. The planned study includes single-dose and multiple-dose groups, with placebo comparisons, plus a food-effect assessment comparing administration while fasting and after a high-fat meal. These are early clinical investigations; the record does not report a completed trial or evidence of benefit in patients.
The registry’s latest posted update is dated 9 September 2026 and lists the study as not yet recruiting. Its start date of September 2026 and completion date of June 2027 are estimates. Because that record predates the funding announcement, it cannot establish the recruitment position on 18 October. It contains no posted results. Its estimated timetable does not establish that testing has finished, and registration itself does not mean a medicine has been approved for treatment.
OMass’ earlier evidence was preclinical. In its 14 July 2025 research announcement, the company said OMS1620 was undergoing studies intended to support an investigational new drug application. It described animal experiments examining how long compounds remain bound to the MC2 receptor when ACTH levels rise. ACTH is the hormone that acts through this receptor to stimulate adrenal hormone production. The company reported receptor-inhibition findings in an acute rat model and body- and adrenal-weight changes in a chronic model. Those findings explain the research rationale, but animal results do not establish safety or effectiveness in people.
An earlier licensing deal remains separate
The new equity financing follows a different commercial transaction. On 2 September 2025, OMass announced a licensing agreement with Genentech for a preclinical oral small-molecule programme in inflammatory bowel disease. That agreement provided for a $20 million upfront payment, more than $400 million in potential milestones and tiered royalties on net sales. The potential milestone amount was conditional, rather than cash already raised in the Series C.
Under that agreement, OMass leads the initial preclinical work until a candidate is selected. Genentech takes responsibility for clinical development, regulatory activities, manufacturing and commercialisation. This allocation of work concerns the partnered bowel-disease programme; it should not be confused with the clinical-development plans for OMS1620 announced alongside the latest financing.
Related Dalimss News coverage includes Peptris’ drug-research support agreement and Sunbound’s healthcare-business funding round.
