SAREUM HOLDINGS PLC

("Sareum" or "the Company")

Reference to Potential SRA737 Clinical Development Timeline in Sierra Oncology Investor Presentation at 2021 Cantor Virtual Global Healthcare Conference

Cambridge, UK, 29 September 2021 - Sareum Holdings plc (AIM: SAR), the specialist drug development company, notes that Sierra Oncology, the licence holder for SRA737 (a novel Chk1 inhibitor), presented at 21.00 BST on 28 September at the 2021 Cantor Virtual Global Healthcare Conference in a Fireside Chat. During this conference and included in a slide of recent and upcoming milestones, Sierra Oncology's CEO, Stephen Dilly, referred to the initiation of additional clinical studies with pipeline agents including SRA737 in other haematologic and solid tumour indications in the first half of 2022.

Specifically, reference was made to a potential role for SRA737 in combination studies in solid tumours, including pancreatic cancer, where patients have become resistant to PARP inhibitors.

In a previous discussion, noted by Sareum on 6 August 2021, of the rationale for in-licensing BET inhibitor AZD5153, now known as SRA515, from AstraZeneca, Sierra referred to possible pipeline expansion opportunities in other haematologic or solid tumour indications. These included potential combinations with SRA737, immune-oncology agents, PARP inhibitors and drugs with other mechanisms of action. Sierra has also noted that SRA515 has shown preclinical efficacy in combination with a diverse range of agents, and that synergy between SRA515 and a family of DNA damage response agents, known as ATR inhibitors, suggested potential utility in combination with SRA737.

SRA737 was discovered and initially developed by scientists at The Institute of Cancer Research in collaboration with Sareum, and with funding from Sareum and Cancer Research UK. SRA737 was licensed to Sierra in September 2016.

Sareum's CEO, Dr Tim Mitchell, commented:

"This timeline for the possible initiation of combination studies by Sierra including SRA737 in the first half of 2022 is very encouraging and would represent a significant advance in the development of the SRA737 programme. We look forward to further updates on the clinical development of SRA737, a molecule that has shown great promise in clinical trials and preclinical studies, particularly in combination with other types of cancer therapy."

A recording of Sierra Oncology's fireside chat at the 2021 Cantor Virtual Global Healthcare Conference can be found at www.sierraoncology.com 

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About Sareum

Sareum is a specialist drug development company delivering targeted small molecule therapeutics to improve the treatment of cancer and autoimmune diseases. The Company aims to generate value through licensing its candidates to international pharmaceutical and biotechnology companies at the preclinical or early clinical trials stage.

Sareum is advancing internal programmes focused on distinct dual tyrosine kinase 2 (TYK2) / Janus kinase 1 (JAK1) inhibitors through preclinical development as therapies for autoimmune diseases, including the 'cytokine storm' immune system overreaction to Covid-19 and other viral infections, (SDC-1801) and cancer immunotherapy (SDC-1802).

Sareum also has an economic interest in SRA737, a clinical-stage oral, selective Checkpoint kinase 1 (Chk1) inhibitor that targets cancer cell replication and DNA damage repair mechanisms. Preliminary Phase 2 and comprehensive preclinical data suggest SRA737 may have broad application in combination with other oncology and immune-oncology drugs in genetically defined patients.

SRA737 was discovered and initially developed by scientists at The Institute of Cancer Research in collaboration with Sareum, and with funding from Sareum and Cancer Research UK. SRA737 was licensed by CRT Pioneer Fund (CPF) to Sierra Oncology Inc. Sierra continues to explore options that would enable the development of SRA737 to advance.

Sareum Holdings plc is listed on the AIM market of the London Stock Exchange, trading under the ticker SAR. For further information, please visit the Company's website at www.sareum.com 

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