OS Therapies Opens UK Regulatory Filing for Herlystic

OS Therapies has started a UK Medicines and Healthcare products Regulatory Agency review for Herlystic, its OST-HER2 therapy, aimed at reducing relapse risk after complete surgery for lung-spread osteosarcoma. The company said on November 10, 2026 that it expects to finish the CMAA process in Q4 2026. It also identified a potential early MHRA market-access decision in Q1 2027.

The filing begins a UK regulatory pathway that could expand access to Herlystic if the agency grants authorization. OS Therapies expects a possible early market-access decision from the MHRA in Q1 2027.

  • 1OS Therapies initiated a Conditional Marketing Authorisation Application process with the UK MHRA for Herlystic in pulmonary metastatic osteosarcoma.
  • 2The company expects to complete the CMAA process in Q4 2026.
  • 3OS Therapies identified a potential early MHRA market-access decision in Q1 2027.
  • 4The filing followed a scientific advice meeting with the MHRA in September 2026.

Sources