Sareum Holdings plc (SAR.L) is a United Kingdom-based clinical-stage biotechnology company focused on the discovery and development of next-generation small-molecule kinase inhibitors for autoimmune diseases and cancer. Founded in 2004 and headquartered in Cambridge, the company leverages its proprietary Sareum Kinase Inhibitor Library (SKIL) technology to advance drug candidates to preclinical or early clinical stages for licensing to pharmaceutical and biotechnology partners. Its core pipeline includes SDC-1801, a potent and selective TYK2/JAK1 inhibitor in development for autoimmune conditions such as psoriasis, rheumatoid arthritis, lupus, and inflammatory bowel disease following completion of a Phase 1 clinical trial demonstrating favorable safety and pharmacokinetics; SDC-1802, a TYK2/JAK1 inhibitor targeted at cancer and cancer immunotherapy applications; and SRA737, a clinical-stage oral Checkpoint kinase 1 (Chk1) inhibitor with a 63.5% net economic interest held by Sareum for potential monotherapy or combinations including low-dose gemcitabine, BET/PARP/Wee1 inhibitors, or immunotherapy in solid tumors such as ovarian, prostate, lung, and colorectal cancers. Recent developments include the acquisition of the SRA737 license from CRT Pioneer Fund in March 2025 after its reversion from a prior U.S. licensee, enhancing Sareum's control and revenue share; initiation of toxicology studies for SDC-1801 in May 2025 to support Phase 2 readiness, with an update in October 2025 noting a pause due to control-group findings; a strategic collaboration with AI-driven drug discovery firm Receptor.AI announced in August 2025 to accelerate development of blood-brain-barrier permeable TYK2/JAK1 inhibitors using AI for compound optimization and virtual screening; multiple equity fundraises such as institutional placements in March 2025 and subscriptions in 2024 totaling over £3 million to extend cash runway; and broker appointments including a joint corporate broker in October 2025 and sole broker changes earlier in the year. Sareum operates primarily from the UK with global research partnerships, including historical collaborations with the Institute of Cancer Research and Cancer Research UK, and targets licensing opportunities in major pharmaceutical markets.