THIS ANNOUNCEMENT CONTAINS INSIDE INFORMATION FOR THE PURPOSES OF ARTICLE 7 OF THE UK VERSION OF THE MARKET ABUSE REGULATION (EU) NO.596/2014, WHICH FORMS PART OF UK LAW BY VIRTUE OF THE EUROPEAN UNION (WITHDRAWAL) ACT 2018 ("UK MAR").

hVIVO plc

("hVIVO" or the "Company")

£13.6m RSV human challenge study contract with biopharma client

Study cohort sizes increase as clients recognise the benefits of human challenge

hVIVO plc (AIM & Euronext: HVO) (formerly Open Orphan plc), a rapidly growing specialist contract research organisation (CRO) and world leader in testing infectious and respiratory disease products using human challenge clinical trials, announces that it has signed a £13.6m contract with a US-based biopharmaceutical client to test its respiratory syncytial virus ("RSV") antiviral candidate, using hVIVO's established RSV Human Challenge Study Model.

The Phase 2a double-blinded placebo-controlled human challenge trial will take place at the Company's specialist quarantine facilities in Whitechapel and will evaluate the efficacy profile of the antiviral against RSV infection. The study is expected to commence in Q3/Q4 2023, with the revenue being recognised in 2023 and 2024. As part of the study, hVIVO will recruit healthy volunteers via the Company's dedicated volunteer recruitment arm, FluCamp.

This contract highlights hVIVO's world leading expertise in its field and its ability to execute sizable contracts as well as the industry's renewed focus on developing new treatments for RSV. The Company continues to see growing demand for larger challenge studies from both new and existing clients as they seek greater clarity of data and pursue lower frequency endpoints in an effort to further de-risk their programmes ahead of later stage field studies.

Yamin 'Mo' Khan, Chief Executive Officer of hVIVO, said: "We're delighted to be working with this biopharma client to test their antiviral candidate using our established hVIVO RSV Human Challenge Study Model. We continue to see an increase in the size of our studies as new benefits of challenge study data are continually realised by both new and existing biotech and pharma clients."

Alex Mann, Senior Director Clinical Science of hVIVO said: "RSV continues to be a serious global health threat causing an estimated 100,000 annual deaths in children under the age of five and we are currently seeing a significant jump in cases around the world as we enter the winter months.

"This contract is a strong example of where human challenge studies can provide great value for our clients, with access to fast, cost-effective efficacy data which can provide a 'go/no-go' decision ahead of a larger Phase 2 study, allowing our clients to ensure that their candidates have the best possible chance of advancing through the rest of the development pathway."

For further information please contact:

Notes to Editors

hVIVO plc (ticker: HVO) (formerly Open Orphan plc) is a rapidly growing specialist contract research organisation (CRO) and the world leader in testing infectious and respiratory disease vaccines and therapeutics using human challenge clinical trials. The Group provides end-to-end early clinical development services to its large, established and growing repeat client base, which includes four of the top 10 largest global biopharma companies.

The Group's fast-growing services business includes a unique portfolio of 10+ human challenge models to test a broad range of infectious and respiratory disease products, world class challenge agent manufacturing, specialist drug development and clinical consultancy services via its Venn Life Sciences brand, and a lab offering via its hLAB brand, which includes virology, immunology biomarker and molecular testing. The Group offers additional clinical field trial services such as patient recruitment and clinical trial site services.

hVIVO runs challenge studies in London from its Whitechapel quarantine clinic, its state-of-the-art QMB clinic with its highly specialised on-site virology and immunology laboratory, and its clinic in Plumbers Row. To recruit volunteers / patients for its studies, the Company leverages its unique clinical trial recruitment capacity via its FluCamp volunteer screening facilities in London and Manchester.

About RSV

RSV is the main cause of childhood lower respiratory infections and is responsible for a significant burden of disease in the elderly and in adults with chronic medical problems, such as COPD. Globally it affects an estimated 50-million people annually, leading to 4 million hospitalisations and approximately 60,000 in-hospital deaths in children younger than 5 years. There is a lack of understanding and insight into RSV disease, especially in adult groups, despite its considerable impact on society and its high degree of infectivity.