Sareum Holdings plc, a clinical stage small molecule drug development company, engages in the discovery and development of therapeutic drugs for cancer and autoimmune diseases. The company's lead product is SDC-1801, a TYK2/JAK1 inhibitor which has completed Phase 1 clinical trial for the treatment of autoimmune diseases. It also develops SDC-1802, a TYK2/JAK1 inhibitor, that is in preclinical stage for cancer and cancer-immunotherapy applications; and SRA737, a clinical-stage oral, selective Chk 1 inhibitor, which has completed Phase II clinical trials that targets cancer cell replication and DNA damage repair mechanisms. The company has strategic collaboration with Receptor.AI launched in August 2025 to accelerate discovery and optimisation of BBB-permeable TYK2/JAK1 inhibitors; and completion of initial stage expected Q4 2025. Sareum Holdings plc was formerly known as Keepfast plc and changed its name to Sareum Holdings plc in July 2004. The company was incorporated in 2004 and is headquartered in Cambridge, the United Kingdom.