Open Orphan plc

("Open Orphan" or the "Company")

Appointment of Nominated Adviser and Joint Broker

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 further to the announcements by Arden Partners Plc on 11 and 14 April 2022 regarding the loss of its Nominated Adviser status upon the completion of its recommended takeover, the Company has appointed Liberum Capital Limited ("Liberum") as its Nominated Adviser and Joint Broker. Given the timing of the completion of the recommended takeover of Arden Partners Plc, the Exchange has agreed that subject to initial due diligence being undertaken, Liberum has until 5pm on 27 July 2022 to complete its full due diligence.

There can be no guarantee on the outcome of the full due diligence and its impact on Liberum's decision to continue to act as Nominated Adviser. Accordingly, in such circumstances there is a risk that if the Liberum does not continue to act as Nominated Adviser following completion of its full due diligence and the Company has not found an alternative Nominated Adviser, the Company's AIM securities may be suspended pursuant to AIM Rule 1. If within one month of that suspension, the Company has failed to appoint a replacement Nominated Adviser, the admission of its AIM securities will be cancelled.

Notwithstanding the extension of time provided in respect of completing full due diligence obligations at engagement, Liberum will continue to be subject to all the ongoing Nominated Adviser responsibilities under the AIM Rules for Nominated Advisers.

finnCap plc and Davy will continue to act as the Company's Joint Brokers.

Yamin 'Mo' Khan, Chief Executive Officer at Open Orphan, said: "As the market is aware, Arden Partners can no longer act as Nomad for listed companies from 29 April 2022 and as such, we thank them for their support over the past number of years. We are delighted to now be working with such a prestigious investment bank as Liberum."

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 Notes to Editors

Open Orphan plc

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, including the recently established COVID-19 model, and is developing a number of new models, such as Malaria, 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.