The Medicines and Healthcare products Regulatory Agency has approved vimseltinib, marketed as Romvimza, for use in adults with tenosynovial giant cell tumour on 14 August 2026. The indication covers patients whose disease affects movement or for whom surgery is not an option. The decision gives UK clinicians a new medicine route in a condition that is uncommon but can still be functionally disabling. The MHRA said the marketing authorisation was granted to Deciphera Pharmaceuticals and presented the approval as part of its duty to support access to safe and effective medicines while maintaining oversight.
Tenosynovial giant cell tumour, or TGCT, is a rare non-cancerous tumour that develops around a joint and its tendons. It usually affects a single joint and is most often seen in the knee or ankle of young and middle-aged adults. Although the tumour is not malignant, the clinical effect can still be significant. Pain, swelling, stiffness and reduced movement are among the main symptoms, which is why the approval is likely to matter most in cases where day-to-day function has already been affected.
According to the MHRA, the active substance vimseltinib works by blocking the proteins that cause these tumours to grow. In practical terms, the medicine is intended to slow tumour growth in patients who need a non-surgical option. The product is supplied as a capsule and should be swallowed whole with water twice each week. It may be taken with or without food, but patients are expected to follow the prescribed schedule exactly rather than alter the dosing pattern themselves.
The safety wording attached to the approval is a material part of the announcement. The MHRA states that vimseltinib is subject to additional monitoring and should not be used in pregnancy. The most common side effects, affecting more than one in five people, include tiredness, swelling around the eyes, ankles and feet, itching, rashes, high blood pressure, raised liver enzymes, higher cholesterol, increased creatinine and reduced neutrophil levels. For prescribing teams, that profile points to the need for close attention to both symptoms and blood-based safety markers during treatment.
For patients, the immediate guidance is straightforward. The MHRA advises that vimseltinib should be taken exactly as prescribed and that any suspected side effects should be discussed with a doctor, pharmacist or nurse. The regulator is also directing patients and professionals to the Yellow Card scheme for direct reporting of suspected adverse reactions. That reporting route is a routine part of post-authorisation pharmacovigilance, but it carries added weight when a medicine has additional monitoring status.
Further prescribing detail will follow through the Summary of Product Characteristics and the Patient Information Leaflet, which the MHRA said will be published on its products website within seven days of approval. Those documents are likely to be the main reference point for clinicians, pharmacists and medicines governance teams because they set out the authorised terms of use. Julian Beach, the MHRA's Executive Director for Healthcare Quality and Access, said the approval provides a new treatment option for patients with TGCT who have symptoms and are unsuitable for surgery. He also said the agency would continue to keep the safety of vimseltinib under close review.
For policy readers, the route to authorisation is also notable. The application was submitted and approved through the International Recognition Procedure, Route B, which places this decision within the MHRA's current framework for medicines regulation after EU exit. That procedural detail does not change what patients receive in clinic, but it does show how the UK regulator is combining access pathways with ongoing domestic safety surveillance. In this case, the approval brings together three standard features of the current system: a defined legal route to authorisation, publication of formal product information, and a clear mechanism for reporting harms once the medicine enters routine use.