Development and commercialisation licence SRA737

Cambridge, UK, 2 Jan 2024 - Sareum Holdings plc (AIM: SAR), a clinical-stage biotechnology company developing next-generation kinase inhibitors for autoimmune disease and cancer, today announces that the Company's co-development partner, the CRT Pioneer Fund ("CPF"), has entered into a development and commercialisation licence agreement for SRA737 (the "Licensing Agreement") with a private biopharma company based in the United States (the "Licensee Company").

Under the terms of the Licensing Agreement, an immediate upfront payment of US$0.5 million is due to CPF. An additional fee made up of up to US$1.0 million cash and 500,000 shares in the Licensee Company (the "Consideration Shares") may be payable upon the sooner of 12 months following the signing of the Licensing Agreement, or the event of the Licensee Company achieving certain commercial and material financing objectives. A further announcement regarding any future income, including any Consideration Shares which may be issued, will be made at the appropriate time.

Additional payments to the aggregate amount of up to US$289 million may become payable to CPF under the Licensing Agreement, subject to achievement of certain development, regulatory and commercial milestones which may or may not be achieved. The Licensee Company will also pay tiered high single digit royalties to CPF on the net sales of any product successfully developed and commercialised.

Under the terms of Sareum's co-development agreements with CPF and Cancer Research Technology Ltd, Sareum is entitled to receive 27.5% of any income arising from this licensing of the SRA737 programme. Therefore, Sareum is entitled to receive US$137,500 from the upfront fee payable under the Licensing Agreement, as well as 27.5% of any future payments payable by the Licensee Company (including any Consideration Shares received), under the terms of the Licensing Agreement.

Dr Tim Mitchell, CEO of Sareum, commented: "SRA737 has shown considerable promise in earlier clinical studies, demonstrating a robust safety profile and preliminary efficacy, in particular in combination with low dose chemotherapy. With CPF, we are very pleased a partner has been identified to advance this exciting molecule into further development and believe this licensing agreement offers the best path forward for SRA737.

"Sareum is entitled to a share of income from potential development and sales milestones from this agreement for SRA737 which have the potential to support Sareum's TYK2/JAK1 development pipeline. The team at Sareum is now focused on our lead programme, SDC-1801, which is progressing in clinical studies in Australia, and more broadly on TYK2/JAK1 inhibitors, a class which we believe has significant potential in autoimmune diseases and cancer."

About SRA737

SRA737 is a clinical-stage oral, selective Checkpoint Kinase 1 inhibitor that targets cancer cell replication and DNA damage repair mechanisms. It was discovered and initially developed by scientists at the Institute of Cancer Research in collaboration with Sareum, with funding from Sareum and Cancer Research UK.

SRA737 was licensed by CPF to Sierra in September 2016. Sierra progressed SRA737 through Phase 1/2 clinical development and, at the 2019 American Society of Clinical Oncology (ASCO) Annual meeting, reported positive preliminary efficacy and safety data from two clinical trials evaluating SRA737 as a monotherapy and in combination with chemotherapy.

Following the acquisition of Sierra by GSK in July 2022, primarily for Sierra's momelotinib myelofibrosis asset, the rights to SRA737 were returned to CPF in January 2023.