Exercise of Warrants

11 June 2021

Open Orphan plc

("Open Orphan", the "Company")

Exercise of Warrants

Open Orphan plc (AIM: ORPH), a rapidly growing specialist pharmaceutical services clinical research organisation (CRO) and a world leader in vaccine and antiviral testing using human challenge clinical trials, has received notice of exercise of warrants by investors, who participated in the Venn loan note financing in December 2018, over 404,806 ordinary shares of 0.1 pence each in the capital of the Company ("Ordinary Shares") at a price of 0.1 pence per share for 143,312 Ordinary Shares and at a price of 2.2 pence per share for 261,494 Ordinary Shares. The gross proceeds of this exercise received by the Company amount to £5,896.18.

Following this exercise, the warrants issued to investors in connection with the 2018 Venn loan note have been substantially exercised with only the Chairman's 657,285 warrants outstanding.

The total outstanding warrants over Ordinary Shares are as follows:

The Company has made application for 404,806 new Ordinary Shares, to be issued and allotted as a result of the warrant exercise set out above, to be admitted to trading on AIM and Euronext Growth. Admission is expected to occur at 8.00 a.m. on 16 June 2021.

Total Voting Rights

Following the admission of the 404,806 new Ordinary Shares, the Company's total issued ordinary share capital will consist of 670,855,002 Ordinary Shares. This figure may be used by shareholders as the denominator for the calculations by which they will determine if they are required to notify their interest in, or a change to their interest in, the Company under the Financial Conduct Authority's Disclosure Guidance and Transparency Rules.

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.

If you are interested in being contacted and provided with details about future COVID-19 human challenge study research, please leave your contact details at www.UKCovidChallenge.com.

For further information, please contact:

Notes to Editors

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

Open Orphan runs challenge studies in London from both its 19-bedroom Whitechapel quarantine clinic, opened in February 2021, and its 24-bedroom QMB clinic which also has a highly specialised virology and immunology laboratory on-site. Open Orphan has a leading portfolio of eight human challenge study models for conditions such as RSV, flu, asthma and COPD. In addition, Open Orphan is also developing the world's first COVID-19 human challenge study model as part of the Human Challenge Programme and has signed a reservation contract with the UK Government for the first three COVID-19 vaccine challenge 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. The Disease in Motion platform has many potential applications across a wide variety of end users including big technology, wearables, pharma and biotech companies. Following COVID-19 there is now a renewed interest and investment in infectious diseases.

Open Orphan's Paris office has been providing biometry, data management and statistics to its many European pharmaceutical clients for over 20 years. For over 15 years, the Company's Netherlands office has been providing drug development consultancy and services, including CMC (chemistry, manufacturing and controls), PK and medical writing, to a broad range of European clients. Both offices are now also fully integrated with the London office and working on challenge study contracts as well as supporting third party trial contracts.