Change of Adviser

(AIM:SAR) 16 August 2019

Sareum Holdings PLC

("Sareum" or the "Company")

Appointment of Nominated Adviser

Sareum Holdings plc (AIM: SAR), the specialist small molecule drug development business, is pleased to announce the appointment of Strand Hanson Limited as Nominated & Financial Adviser to the Company with immediate effect.

This announcement contains inside information for the purposes of Article 7 of Regulation (EU) 596/2014.

For further information, contact:

Notes to editor:

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

Sareum's leading clinical-stage programme, SRA737, a novel Checkpoint kinase 1 (Chk1) inhibitor licensed to NASDAQ-listed Sierra Oncology, is in Phase 2 clinical trials targeting multiple advanced cancers. The key role of Chk1 in cancer cell replication and DNA damage repair suggests that SRA737 may have broad application as a targeted therapy 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, London, UK in collaboration with Sareum, and with funding from Cancer Research UK. SRA737 was licensed to Sierra Oncology for up to $328.5 million plus royalties by Sareum's co-investment partner, CRT Pioneer Fund. Sareum is eligible to receive up to $88 million in milestone payments, plus sales royalties as SRA737 advances.

Notable highlights from the Phase 1/2 preliminary results reported by Sierra at ASCO (June 2019) were:

SRA737 + low dose gemcitabine (LDG) combination

·; Striking anti-tumour activity was observed in patients with anogenital cancer, including examples where metastatic disease was cleared from liver and lung.

·; Tumour size decreased by more than a third in 30% of the evaluable anogenital cancer patients and a further 30% had durable stable disease.

·; Sierra outlined a potential route to market for SRA737+LDG in anogenital cancer via a registration-intent Phase 2 trial.

SAR737 monotherapy

High-grade serous ovarian cancers (HGSOC) appeared to be the most sensitive tumour to SRA737, with the disease being controlled (stable disease) in 54% of evaluable patients.

Sareum is also advancing internal programmes focused on distinct dual tyrosine kinase 2 (TYK2) /Janus kinase 1 (JAK1) inhibitors through preclinical development as therapies for autoimmune diseases (SDC-1801) and cancers (SDC-1802). TYK2 and JAK1 have roles in pro-inflammatory responses in autoimmune diseases (e.g. psoriasis, rheumatoid arthritis, inflammatory bowel diseases and lupus) and tumour cell proliferation in certain cancers (e.g. T-cell acute lymphoblastic leukaemia and some solid tumours). The Company is targeting first human clinical trials in each indication in 2020.

The Company also has an Aurora+FLT3 inhibitor targeting haematological cancers, which is at the preclinical development stage.

Sareum Holdings plc is listed on the AIM market of the London Stock Exchange, trading under the ticker SAR. For further information, please visit www.sareum.co.uk