12 July 2023

Oncimmune Holdings plc

("Oncimmune" or the "Company")

Appointment of new leadership team

Changes to the Board

Oncimmune Holdings plc (AIM: ONC.L), the leading autoantibody profiling company to the pharmaceutical and biotechnology industry, is pleased to announce changes to its leadership team and its Board of Directors.

As previously announced on 23 June 2023, following the divestment of Oncimmune Limited, which now allows the Company to focus on its ImmunoINSIGHTS business, Dr Adam M Hill stepped down as the Company's Chief Executive Officer and as a director of the Company. Oncimmune is now pleased to announce that Martin Gouldstone will be joining Oncimmune as its new Chief Executive Officer on 1 August 2023. Martin has over 25 years of experience in the life science sector, including senior commercial roles at a major CRO and most recently as Global Senior Vice President at Owkin Inc., an AI biotech company. Martin's commercial experience and connections will be a valuable asset in driving the Company's future business development activities. Martin will also join the Company's Board of Directors and regulatory disclosures in relation to his appointment as required under Schedule 2(g) of the AIM Rules for Companies can be found at the foot of this announcement.

In addition, after more than five years as Oncimmune's Chief Financial Officer, Matthew Hall has decided to leave his role at Oncimmune. Oncimmune has recruited Martin Hudson to a new role of Finance Director, who will head the Company's finance function and support the new Chief Executive Officer. Martin is a CIMA qualified finance professional with over 19 years' post-qualified international experience in large multinational and smaller entrepreneurial environments. Martin has spent most of his career to date in engineering and service companies, including more than seven years with the McLaren Group and over four years at Williams Advanced Engineering. Martin will be joining Oncimmune on 4 September 2023 and will be transitioning from Matthew over the coming months.

Finally, after more than nine years with Oncimmune, Andrew Unitt will be stepping down as an Independent Non-Executive Director of the Company and as Chair of the Audit Committee on
30 September 2023. Andrew joined Oncimmune as non-executive director in 2014 and has chaired the Audit Committee since Oncimmune's IPO in 2016. The Company has begun a search for a new Independent Non-Executive Director and Chair of the Audit Committee.

Alistair Macdonald, Oncimmune's Chairman, said:

"On behalf of myself and the whole Board I would like to thank Andrew and Matthew for their service to the Company over many years. I am very pleased to welcome Martin Gouldstone and Martin Hudson to the leadership team. Martin Gouldstone brings considerable experience in commercialising products and services in the life science industry and will be leading our business development efforts. With these changes to the leadership team, we believe that Oncimmune is now poised to begin FY2024 with the right leadership and resources to deliver on its plan for growth, which is based on our strong intellectual property portfolio, our master services agreements with major pharma companies and our recently announced long term relationship with Freenome, Inc.

"Since our last announcement in June we have continued to engage with our shareholders to understand their views on the Company's leadership and direction. We will continue to engage all of our stakeholders as we move forward, and we are excited to see the impact of a more focussed and commercially orientated leadership team on the business."

Matthew Hall, Oncimmune's outgoing Chief Financial Officer, said:

"I would like to thank the Board for their support over the past five years, as we transitioned the Company from a single asset diagnostic company to a leading autoantibody profiling pharma services business. I wish the new management team every success as they now capitalise on Oncimmune's industry leading position."

Martin Gouldstone, Oncimmune's incoming Chief Executive Officer, said:

"I am delighted to be joining Oncimmune at such a pivotal time for its business. I look forward to bringing my skills, experience and contacts in the sector to drive the business development efforts and deliver for stakeholders."

For further information:

Oncimmune Holdings plc

Ron Kirschner, Chief Executive Officer

contact@oncimmune.co.uk

Singer Capital Markets (Nominated Adviser and Broker)

Phil Davies, Harry Gooden, George Tzimas, James Fischer

+44 (0)20 7496 3000

Zeus (Joint Broker)

Dominic King, Victoria Ayton, Dan Bate

+44 (0)20 3829 5000

+44 (0)20 3727 1000

About Oncimmune

Oncimmune is a specialist pharmaceutical services company, primarily focused on the growing fields of immuno-oncology, autoimmune disease and infectious diseases. Oncimmune has a contract discovery and development service business whose ImmunoINSIGHTS platform delivers actionable insights into therapies to the Company's pharmaceutical and biotech partners.

Our understanding of the immune system enables us to harness its sophisticated response to disease to detect cancer earlier and to support the development of better therapies. The key to improving cancer survival is early detection and better selection for therapy. As a company, we are driven by our passion to improve cancer survival and to give people extra time.

Oncimmune's ImmunoINSIGHTS platform enables life science organisations to optimise drug development and delivery, leading to more effectively targeted and safer treatments for patients. Oncimmune's ImmunoINSIGHTS service business at its discovery research centre in Dortmund, Germany. The ImmunoINSIGHTS business development team are based in the US and Europe.

For more information, visit www.oncimmune.com

Regulatory Disclosures

The following information regarding the appointment of Martin Gouldstone, aged 56, is disclosed under Schedule 2(g) of the AIM Rules for Companies:

As at the date of this announcement, Martin Gouldstone does not hold any ordinary shares in the Company.

Save as set out above there are no further disclosures pursuant to Rule 17 or Schedule 2(g) of the AIM Rules for Companies in respect of the appointment of Martin Gouldstone.