Influenza HCT contract signed with Traws Pharma

London, UK - 14 April 2026, hVIVO plc (AIM: HVO), a purpose-built, full-service international clinical development partner and the world leader in human challenge trials, announces that it has signed a Clinical Trial Agreement ("CTA") to conduct a human challenge (HCT) trial on behalf of Traws Pharma (NASDAQ: TRAW), a clinical-stage biopharmaceutical company developing novel therapies for respiratory viral diseases. The trial will test Traws' prophylactic antiviral candidate, tivoxavir marboxil ("TXM"), using the hVIVO Influenza Human Challenge Study Model. TXM is an investigational oral, small molecule CAP-dependent endonuclease inhibitor designed to be administered as a single-dose for the treatment of seasonal influenza and bird flu.

The Phase 2a, randomised, double-blinded placebo-controlled trial is planned to take place at the Company's specialist state-of-the-art quarantine facilities in Canary Wharf. The study will evaluate TXM's safety, tolerability, and effectiveness in reducing the incidence and severity of influenza-induced illness in healthy adult participants.

The study is expected to commence in H1 2026, with the majority of the revenue recognised in 2026. Approximately 150 healthy participants will be recruited through the Company's participant recruitment arm, FluCamp, and all lab work associated with the study will be conducted by hVIVO's own specialist virology laboratory in Canary Wharf.

Seasonal influenza causes significant morbidity and mortality each year, with an estimated 1 billion cases per year, 3-5 million severe cases and 290,000 - 650,000 deaths per year. To date, hVIVO has inoculated >5,000 healthy participants across 2,477 influenza, RSV and other viral HCTs, and has also helped accelerate the development of several antiviral and vaccine candidates for both Big Pharma and biotechnology clients through its consulting, laboratory and clinical trial services. This includes Cidara Therapeutics, Inc, which was acquired by Merck Sharp & Dohme LLC in January 2026, following a longstanding clinical development partnership across hVIVO's fully integrated early phase service offering.

Yamin 'Mo' Khan, Chief Executive Officer of hVIVO, said: "Through our Influenza Human Challenge Trial Model, we will be able to deliver fast, controlled, high-quality efficacy data for Traws Pharma that would not be achievable in traditional field studies, reducing development risk for TXM and improving capital efficiency. By leveraging key synergies across our integrated clinical development services and conducting participant recruitment all under one roof, this trial illustrates our unique value proposition as a true full-service clinical development partner."

Dr Andrew Catchpole, Chief Scientific Officer of hVIVO, added: "Influenza causes significant strain on global healthcare infrastructure each year and a new influenza pandemic continues to pose a worldwide threat, underlining the critical need for effective prophylactic antivirals. Our Influenza Human Challenge Study Model has been optimised by our expert team over decades, and our purpose-built, full-service offering is well placed to deliver an accelerated path to clinical proof-of-concept for TXM, and ultimately bring this and other important medicines to patients, faster."

Iain D. Dukes, Chief Executive Officer of Traws Pharma, commented: "This agreement represents an important step forward for Traws as we advance our programme and seek to generate high‑quality, efficacy clinical data efficiently. Partnering with hVIVO enables us to leverage a proven human challenge platform to support our development strategy and accelerate progress towards our next value‑inflection point."

Anthony Farrell, Niall Gilchrist