The UK's Medicines and Healthcare products Regulatory Agency has approved vimseltinib, also called Romvimza, for some adults with tenosynovial giant cell tumor.This rare, non-cancerous tumor forms around a joint and nearby tendons. It can cause pain, swelling, stiffness, and difficulty moving.The new option is for adults whose tumor affects movement or who are not able to have surgery. Vimseltinib works by blocking proteins that help these tumors grow.The medicine is subject to additional monitoring, and the agency says its safety and effectiveness will continue to be reviewed. Patients are advised to use it only as prescribed and discuss side effects with a doctor or pharmacist.