hVIVO runs the world's largest commercial unit for human challenge trials, in which healthy volunteers are deliberately infected with a virus so drug makers can test vaccines and antivirals quickly. After record revenue of £63m in 2024, cancelled trials and an acquisition push cut revenue to £47m in 2025 and cash from £44m to £14m. In September 2026 the company reported a contracted orderbook that had more than doubled, but it also guided 2026 revenue to about £47m, roughly flat on 2025.
Paying volunteers to catch the flu, for drug makers
hVIVO (AIM: HVO) sells early-stage clinical research to biopharma companies, and says it serves seven of the world's ten largest. Its core is the human challenge trial. Volunteers are exposed to a virus under controlled conditions in a quarantine facility at Canary Wharf in London, which the company calls the largest of its kind. The company says sponsors get efficacy data up to 3.5 times faster than from natural-infection studies.
Four service lines now sit under one hVIVO brand. Human Challenge Trials is the original business. Clinical Trials covers Phase I/II CRO work, Phase II/III site services in the UK and Germany, and volunteer recruitment through FluCamp. Laboratories offers virology, immunology and sample storage. Consulting is the Venn Life Sciences advisory arm. Challenge trials usually bring a large upfront payment on signing, which feeds cash. The company links its 2025 cash fall partly to fewer new challenge-trial awards. 15 Sep 2026 23 Sep 2025 15 Apr 2026
Record years and a £100m ambition
The company says it was co-founded in 2017, when it was called Open Orphan. Revenue rose from £49m in 2022 to £56m in 2023 and £63m in 2024. The adjusted EBITDA margin (operating profit before depreciation) reached 26% in 2024. The new Canary Wharf unit opened in 2024.
On 30 January 2024 management set a medium-term target of £100m Group revenue by 2028, to come from strong organic growth plus small bolt-on acquisitions. It repeated the target in April 2025. It also began an annual dividend of 0.2p. Clients such as Cidara showed the model working. hVIVO ran a challenge trial for Cidara's flu antiviral in 2024 and later supported its Phase II and III studies. Cidara was bought by MSD for $9.2bn in 2025. 30 Jan 2024 9 Apr 2024 10 Apr 2025 29 Jan 2025 27 Nov 2025 15 Sep 2026 15 Apr 2026
Diversify, then lose the big contracts
In early 2025 hVIVO bought two German clinical research units from CRS for €10m and the storage firm Cryostore for up to £3.2m. The aim was to reduce reliance on challenge trials. In April 2025 it guided 2025 revenue to £73m.
On 30 May 2025 it said a significant challenge trial contract had been cancelled and others postponed. The trading update cited pharmaceutical industry uncertainty and biotech financing stress. The CEO later pointed to US macroeconomic developments. Contracted revenue for 2025 stood at £47m, and the company warned of a mid-single-digit operating loss if nothing new was won. The shares, near 19p at the end of April, were 8.7p at the end of May and 5.7p by November 2025. 29 Jan 2025 27 Feb 2025 10 Apr 2025 30 May 2025 15 Apr 2026
A smaller company, lower on cash
2025 revenue came in at £46.8m. The acquired units added £13.1m but made a net adjusted EBITDA loss of £1.4m in their first year. Adjusted EBITDA was £1.4m, against £16.4m the year before. Cash fell to £14.3m, a drop the company attributes to acquisitions and weak new challenge-trial awards. The board paid no dividend for 2025. The orderbook, now counting only signed contracts, was £30m. 15 Apr 2026 29 Jan 2026
What went wrong: concentration and timing
The 2024 results rested on large, lumpy challenge-trial contracts, and the company says 92% of revenue came from its top ten customers that year. When US-driven disruption led to cancelled and postponed trials, the business had little else to fill the gap. The company describes the downturn as external. The acquisitions were meant to broaden the base, but they were paid for in cash just as new challenge-trial awards slowed.
The £100m-by-2028 target was last repeated in April 2025. The company has not repeated it in its later reports, and has not said whether it still stands. 15 Sep 2026 10 Apr 2025 15 Apr 2026 30 May 2025
New chair, new CFO, a rebuilt order intake
CEO Yamin 'Mo' Khan has stayed throughout. Co-founder Cathal Friel stepped down as chair at the 2025 AGM, and Shaun Chilton took over on 1 September 2025. Co-founder Brendan Buckley said he would not stand for re-election at the 2026 AGM. Another director, Tracey James, resigned within two months of joining in 2025. CFO Stephen Pinkerton planned to retire on 30 September 2026 after ten years. Richard Cotton, a director since December 2025, became interim CFO. Angela Hildreth is due to start as CFO on 18 November 2026.
In 2026 the company unified its brand, pushed into cardiometabolic, respiratory and laboratory work, and added customers. The top ten share of revenue fell to 75% at the half-year. The CEO sold 6.4m shares in March 2025 and bought 1.1m in June 2025. He and the CFO bought again in December 2025. Octopus Investments has raised its stake from 3% to 14% since mid-2024. 1 Sep 2025 12 May 2025 18 Jul 2025 15 Sep 2026 12 Oct 2026 7 Mar 2025 2 Jun 2025 15 Dec 2025 15 Apr 2026
More contracts signed, revenue still low
Half-year revenue to June 2026 was £16.3m, against £24.2m a year earlier. The adjusted EBITDA loss was £4.5m. Cash was £13.0m, down from £14.3m at the end of 2025. Contract signings picked up. In April the company signed its largest challenge trial to date, for ILiAD's whooping cough vaccine, billed as the first pivotal Phase III human challenge trial. It also signed two flu challenge trials, one with Traws Pharma and another worth £6m.
The contracted orderbook rose from £30m to £65m. In August 2026 hVIVO bought CRS Berlin, which works in dermatology and women's health. The upfront price was nominal, with an earnout of about €6m gross over three years. The company expects aggregate payments to the vendors of about €4m. The latest close, on 16 October 2026, was 5.8p. 15 Sep 2026 22 Apr 2026 7 May 2026 14 Apr 2026 27 Aug 2026
2026 flat, 2027 carries the hopes
For 2026 the company now expects revenue of about £47m, including about £3m from CRS Berlin. It had guided to high single-digit growth in September 2025, repeated that in April 2026, and said in July it was broadly on track. The cut reflects deferrals of some programmes into 2027 and 2028. It expects H2 revenue to be roughly double H1, positive adjusted EBITDA in H2 and a low single-digit adjusted EBITDA loss for the full year. The orderbook including CRS Berlin is £72m, and proposal volumes were up about 45% year on year in H1.
The open questions are whether signed work turns into revenue on schedule, given the deferrals, and whether H2 reaches its targets. Cash was £13.0m at 30 June. The company has not said how 2027 revenue compares with 2026 beyond calling it significant growth. 15 Sep 2026 23 Jul 2026 15 Apr 2026 23 Sep 2025
“Our record orderbook now provides us with good revenue visibility and positions the Group for significant revenue growth in 2027.” 15 Sep 2026
Written by AI from Hvivo's own announcements since Oct 2023 · every paragraph links to its sources