OMass Therapeutics has closed an oversubscribed $310 million Series C, the Oxford, UK biotech’s largest round yet and, by one trade estimate, the second-largest financing for any European biotech so far in 2026, trailing only Isomorphic Labs’ $2.1 billion Series B. The money is earmarked chiefly for Phase 2 development of OMS1620, an oral blocker of the ACTH receptor the company is testing in congenital adrenal hyperplasia and Cushing's syndrome — and, in smaller part, for a second, earlier-stage program aimed at lupus.
The Series C in four figures
Figures from OMass’ 15 October 2026 announcement, as reported by the BioIndustry Association and Fierce Biotech.
A direct blocker for a receptor glucocorticoids can't reach
Congenital adrenal hyperplasia leaves patients unable to make enough cortisol, so the adrenal gland is driven by chronically elevated ACTH to overproduce androgens instead — and the standard treatment, lifelong high-dose glucocorticoid replacement, controls the androgens only by oversuppressing the patient’s own cortisol axis, a trade-off that itself causes harm over decades. OMass says OMS1620 works further downstream: a small-molecule antagonist of the melanocortin-2 receptor — the ACTH receptor itself, expressed on the adrenal cortex — intended to blunt the androgen-driving signal directly rather than by suppressing ACTH production upstream, the mechanism Neurocrine Biosciences’ already-approved Crenessity (crinecerfont) uses.
What a 70-year-old category is suddenly worth
$20M → $700M
DelveInsight’s congenital-adrenal-hyperplasia market valuation (2023) against its own projected peak sales for Neurocrine Biosciences’ Crenessity (crinecerfont), the first new CAH drug in seven decades, approved December 2024.
Sources: DelveInsight, Congenital Adrenal Hyperplasia Market Insights
Regulatory News outlook
We read DelveInsight’s own 35x gap between the pre-Crenessity 2023 market and its 2034 peak-sales estimate for that one drug as evidence a mechanism beyond glucocorticoid replacement can take real revenue in congenital adrenal hyperplasia once approved — the competitive opening OMS1620 is still years from testing in its own Phase 2 and Phase 3 trials.
How we got here: DelveInsight’s own figures value the whole CAH market at just over $20 million in 2023, before Crenessity’s approval, yet project $700 million in 2034 peak sales for Crenessity alone; we take that implied 35-fold expansion, driven by one approved mechanism, as the scale a second, differentiated mechanism like OMS1620 would be competing to share if its own Phase 2 and Phase 3 trials succeed.
OMS1620 against the field treating CAH
| Candidate | Mechanism | Stage | Status |
|---|---|---|---|
| OMS1620 (OMass Therapeutics) | MC2 (ACTH) receptor antagonist — blocks the adrenal receptor directly | Phase 1 single-ascending-dose complete; Phase 2 next | Investigational, privately held |
| Crenessity / crinecerfont (Neurocrine Biosciences) | CRF1 receptor antagonist — reduces ACTH production upstream | Approved | FDA-approved December 2024 |
| Atumelnant (Crinetics Pharmaceuticals) | CRF1 receptor antagonist (oral) | Mid-stage trials | Investigational |
| Glucocorticoid replacement (standard of care) | Suppresses the entire HPA axis, not androgens specifically | Established | Decades-old standard treatment |
From each company’s own announcements and public regulatory records; not a clinical comparison.
Two programs off one mass-spectrometry platform
OMass traces its origin to the native mass-spectrometry research of Professor Dame Carol Robinson at Oxford, technology the company says lets it see how small molecules bind complex membrane-protein targets — what OMass calls “target ecosystems” — that have historically resisted conventional drug discovery. OMS1620, the ACTH-receptor antagonist advancing to Phase 2, is the platform’s most advanced output; the Series C also funds initial clinical data for a second, earlier program, an inhibitor of SLC15A4, a transporter implicated in the excess interferon signalling behind lupus and related autoimmune diseases.
Three things this round changes
A direct ACTH-receptor blocker
OMS1620 antagonizes the MC2 receptor itself, downstream of where Neurocrine’s approved Crenessity and Crinetics’ atumelnant act — both block CRF1 upstream, reducing ACTH production rather than its effect on the adrenal gland.
Two programs, one platform
The same native mass-spectrometry platform that produced OMS1620 is now funded to generate early clinical data on a structurally unrelated SLC15A4 inhibitor for lupus, a bet on the underlying technology rather than a single molecule.
New transatlantic lead investors
Bain Capital Life Sciences, Forbion and Novo Holdings co-led as new investors, joined by Janus Henderson Investors, SV Health Investors and Jefferson Life Sciences — alongside UK-rooted returning backers Syncona, Oxford Science Enterprises and the British Business Bank.
From a 2018 spin-out round to Britain's second-biggest raise
CEO Ros Deegan, who joined OMass in May 2019 after serving as President and Chief Business Officer of Bicycle Therapeutics’ U.S. subsidiary, called the financing a milestone the company arrives at “at an exciting point in OMass’ evolution as we advance OMS1620 into the clinic, with our SLC15A4 inhibitor poised to follow,” according to the company’s own announcement. In press interviews she went further, describing the round as a “fantastic milestone” on the company’s path toward what she has called becoming “Britain’s Big Biotech” and said the company is “entering our next phase of growth.”
“[This financing comes] at an exciting point in OMass’ evolution as we advance OMS1620 into the clinic, with our SLC15A4 inhibitor poised to follow.” Ros Deegan, Chief Executive Officer, OMass Therapeutics — 15 October 2026 announcement
From OMass Technologies to a $310 million Series C
- 2016
Company founded
Founded as OMass Technologies, an Oxford spin-out applying Professor Dame Carol Robinson’s native mass-spectrometry research to drug discovery, initially as a research-services consultancy.
- November 2018
£14 million Series A
Led by Syncona with Oxford Sciences Innovation participating, funding the company’s shift from a services consultancy to its own drug pipeline.
- May 2019
Ros Deegan named CEO
Joins from Bicycle Therapeutics, where she was President and Chief Business Officer of its U.S. subsidiary.
- 2022
$100 million Series B
GV, Northpond Ventures and Sanofi Ventures join as new investors, with Syncona, Oxford Science Enterprises and the University of Oxford returning.
- 15 October 2026
$310 million Series C
Oversubscribed round co-led by Bain Capital Life Sciences, Forbion and Novo Holdings, bringing total capital raised to roughly $475 million.
- Ahead
Phase 2 for OMS1620
Proceeds are earmarked to take OMS1620 through Phase 2 trials in congenital adrenal hyperplasia and ACTH-dependent Cushing's syndrome; no trial start date has been announced.
What Phase 2 still has to show
A $310 million round buys OMass years of runway, not a finished drug. OMS1620 has cleared only the single-ascending-dose portion of its Phase 1 trial; Phase 2 efficacy data in congenital adrenal hyperplasia and Cushing's syndrome patients, the readout that will actually test whether blocking the ACTH receptor directly beats blocking it upstream, has not yet begun as of this announcement. Crinetics’ atumelnant, by contrast, has already reported mid-stage data that one account says outperformed Neurocrine’s approved Crenessity head-to-head — a reminder that OMass is not alone in chasing the ground Crenessity opened, and that OMS1620’s differentiated mechanism is, for now, a hypothesis rather than a demonstrated clinical advantage.
- Trial timing: no Phase 2 start date has been announced for OMS1620 in either indication.
- Regulatory filing: neither an IND-equivalent milestone date nor a target approval year has been disclosed.
- Head-to-head data: no trial has directly compared OMS1620 to Crenessity or atumelnant; the mechanistic distinction is the company's own characterization, not yet a demonstrated clinical outcome.
- SLC15A4 program: described only as advancing toward “initial clinical data” for lupus; no trial registry entry was identified for it as of this writing.
Sources & further reading
- OMass Therapeutics, announcement of $310 million Series C financing, 15 October 2026, as republished by the BioIndustry Association. bioindustry.org
- Fierce Biotech, “Why OMass’ $310M series C marks ‘fantastic milestone’ on journey to become ‘Britain’s Big Biotech’,” October 2026. fiercebiotech.com
- RARE Daily (Global Genes), “OMass Raises $310 Million to Advance Endocrine and Immunology Drugs,” October 2026. globalgenes.org
- pharmaphorum, “Could OMass become the UK’s ‘big biotech’ company?”, October 2026. pharmaphorum.com
- Goodwin, “Goodwin Advises OMass Therapeutics on $310 Million Series C,” October 2026. goodwinlaw.com
- OMass Therapeutics, “OMass Therapeutics Announces £14 Million Series A Financing to Build a Pipeline of Proprietary Medicines,” 21 November 2018. omass.com
- Endpoints News, “University of Oxford spinoff nets a nine-figure Series B, but it won’t beeline toward the clinic,” 2022. endpts.com
- Fierce Pharma, “Neurocrine Biosciences scores FDA nod for rare genetic adrenal disease,” on Crenessity's December 2024 approval. fiercepharma.com
- DelveInsight, Congenital Adrenal Hyperplasia Market Insights. delveinsight.com
Regulatory News reports on public regulatory documents. It is not legal advice, and the primary sources above govern. If we have made an error, we will say so in public: see corrections.
Frequently asked questions
How much did OMass Therapeutics raise, and from whom?
An oversubscribed $310 million (£230 million) Series C, announced 15 October 2026, co-led by new investors Bain Capital Life Sciences, Forbion and Novo Holdings, with Janus Henderson Investors, SV Health Investors and Jefferson Life Sciences also joining. Existing backers Syncona, Oxford Science Enterprises, GV, Northpond Ventures, Sanofi Ventures, British Business Bank and the University of Oxford also participated.
What will the money fund?
Primarily Phase 2 development of OMS1620, an MC2 (ACTH) receptor antagonist, in congenital adrenal hyperplasia and ACTH-dependent Cushing's syndrome. Some proceeds will also fund initial clinical data for a second, earlier-stage program, an SLC15A4 inhibitor for lupus and other interferon-driven diseases.
Is OMS1620 approved or in late-stage trials?
No. OMS1620 has completed only the single-ascending-dose stage of its Phase 1 trial; the Series C funds its advance into Phase 2. It is not approved anywhere and has no announced regulatory filing date.
How much has OMass raised in total?
Approximately $475 million (£360 million) across all rounds since the company's 2016 founding, including a £14 million Series A in 2018 and a $100 million Series B in 2022, according to the company's Series C announcement as reported by Fierce Biotech and the BioIndustry Association.
