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").

Open Orphan plc

("Open Orphan" or the "Company")

£7.2m RSV human challenge study contract

Open Orphan plc (AIM: ORPH), 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 hVIVO, a subsidiary of Open Orphan, has signed a £7.2m contract with an existing top 5 global pharmaceutical company to test its orally administered antiviral product, using hVIVO's respiratory syncytial virus ("RSV") Human Challenge Study Model.

The Phase 2a double-blinded placebo-controlled human challenge study will take place at the Company's specialist quarantine facilities in Whitechapel and will evaluate the safety and efficacy profile of the antiviral against RSV. The study will commence in June 2022, with the revenue being recognised in 2022 and 2023. As part of the study, hVIVO will recruit healthy volunteers via the Company's dedicated volunteer recruitment arm, FluCamp.

The client's antiviral is presently in Phase III clinical trials for another infectious disease indication and the client will use human challenge to assess the efficacy of their antiviral drug candidate against RSV quickly and efficiently, highlighting the value that human challenge studies can bring within the drug development process. The repeat business from this top 5 global pharmaceutical company underlines the Company's world leading expertise and its ability to attract additional contracts from its existing Big Pharma clients.

Yamin 'Mo' Khan, Chief Executive Officer of Open Orphan, said: "We're delighted to be working with this top 5 global pharmaceutical client again to test their antiviral candidate using the hVIVO RSV Human Challenge Study Model. I am especially proud that our world-class offering and customer service has secured repeat business from another Big Pharma client, and that we are seen as the 'go-to' partner for an increasing number of global drug developers. The client's drug has already been shown to be an effective antiviral in certain disease indications, and we're pleased to now test its efficacy against RSV infection. RSV continues to be a serious global health threat causing an estimated 100,000 annual deaths in children under the age of five."

Dr Andrew Catchpole, Chief Scientific Officer of hVIVO, said: "This contract is a strong example of where human challenge studies can provide significant value. With a drug that has existing safety data and has been approved for one indication, human challenge studies can provide fast, cost-effective efficacy data within a new indication. The data will then indicate whether the candidate is viable for a wider Phase II study, providing substantial time and financial savings compared to traditional field-based studies."

Interested in becoming a volunteer?

hVIVO recruits many of its volunteers for its challenge study clinical trials through its dedicated volunteer recruitment website, www.flucamp.com. By volunteering to take part in one of our studies in a safe, controlled, clinical environment under expertly supervised conditions you are playing your part to further medical research and help increase the understanding of respiratory illnesses.

Individuals interested in taking part in COVID-19 human challenge study research can learn more at www.UKCovidChallenge.com.

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Notes to Editors

Open Orphan plc (London and Euronext: ORPH) is a rapidly growing contract research company that is a world leader in testing infectious and respiratory disease products using human challenge clinical trials. The Company provides services to Big Pharma, biotech, and government/public health organisations.

The Company has a leading portfolio of human challenge study models for infectious and respiratory diseases and is developing a number of new models, such as malaria and COVID-19, to address the dramatic growth of the global infectious disease market. The Paris and Breda offices have over 25 years of experience providing drug development services such as biometry, data management, statistics CMC, PK and medical writing to third party clients as well as supporting the London-based challenge studies.

Open Orphan 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 newly opened 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. The newly opened facilities have expanded the scope of the business to enable the offering of Phase I and Phase II vaccine field trials, PK studies, bridging studies, and patient trials as part of large international multi-centre studies.

Building upon its many years of challenge studies and virology research, the Company is developing an in-depth database of infectious disease progression data. Based on the Company's Disease in Motion® platform, this unique dataset includes clinical, immunological, virological, and digital (wearable) biomarkers.

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 an estimated 100,000 deaths in children under the age of 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.