The UK medicines regulator continues to expand treatment options for rare conditions through regulated approvals supported by clinical evidence and ongoing safety oversight. New authorisations are intended to improve patient outcomes while maintaining strict monitoring of benefits and risks.
The Medicines and Healthcare products Regulatory Agency has approved nirogacestat hydrobromide for adults with progressing desmoid tumours, authorising its use across the UK from January 2026.
The Medicines and Healthcare products Regulatory Agency approved nirogacestat hydrobromide on 7 January 2026 for the treatment of progressing desmoid tumours in adults. The decision authorises a new medicine following evidence that it can slow disease progression and reduce the need for surgery.
The approval applies across the UK and is subject to routine post-authorisation safety monitoring. Regulators say the decision provides an additional option for patients with a rare condition that can cause serious local tissue damage.
Introduction
The MHRA confirmed that nirogacestat hydrobromide, also known as Ogsiveo, has been approved for adult patients whose desmoid tumours are progressing. The approval was granted under the International Recognition Procedure, with the European Medicines Agency acting as the reference regulator.
The agency said the medicine met UK standards for quality, safety, and effectiveness at the time of authorisation. As with all licensed medicines, the MHRA stated that ongoing monitoring will continue following its introduction into clinical use.
MHRA approval decision
The MHRA approved nirogacestat hydrobromide for use in adults with progressing desmoid tumours on 7 January 2026. The decision authorises the medicine for clinical use while requiring continued safety and effectiveness review.
The approval was issued following an assessment of clinical evidence submitted to the regulator. Officials said the authorisation reflects established regulatory standards applied to medicines for rare conditions.
What desmoid tumours are
Desmoid tumours are non-cancerous growths that develop in connective tissue, commonly affecting the arms, legs, or abdomen. Although not malignant, they can grow aggressively and damage nearby structures.
As tumours enlarge, treatment can become more complex and may require repeated medical intervention. The MHRA notes that disease progression can lead to pain, functional impairment, and difficulty with surgical removal.
How nirogacestat hydrobromide works
Nirogacestat hydrobromide works by inhibiting proteins involved in tumour growth, according to the MHRA. Clinical studies reviewed by the agency showed that patients taking the medicine experienced longer periods without disease progression.
The regulator also noted evidence that treatment reduced the likelihood of patients requiring surgery. These outcomes formed part of the benefit assessment supporting approval.
Clinical outcomes reviewed by MHRA
| Disease progression | Patients lived longer without tumour growth, based on clinical studies assessed by the MHRA |
| Surgical intervention | Reduced need for surgery compared with standard management, according to trial data |
Safety, side effects, and pregnancy warnings
The MHRA identified common side effects including diarrhoea, rash, nausea, tiredness, headache, and mouth inflammation. A serious potential side effect is premature menopause, which the agency said may affect more than one in ten patients.
The regulator also warned that the medicine may harm an unborn baby and must not be taken during pregnancy. Highly effective contraception is required for patients and certain partners while using the medicine.
- Common side effects
- Pregnancy and fertility risks
Patient safety measures
| Pregnancy prevention | Patient cards provided outlining risks and required contraception measures |
| Adverse reaction reporting | Patients advised to report suspected side effects via the MHRA Yellow Card scheme |
Regulatory process and oversight
The approval was granted through the International Recognition Procedure, using an assessment by the European Medicines Agency as the reference. The MHRA said this pathway allows timely access to medicines while maintaining regulatory standards.
The agency confirmed that a full list of side effects will be published in official product information within seven days of approval. Ongoing pharmacovigilance will continue as part of routine regulatory oversight.
- International Recognition Procedure
- Post-authorisation monitoring
Stakeholder Comments
Julian Beach, MHRA Interim Executive Director, Healthcare Quality and Access said;
“Patient safety is our top priority. The approval of nirogacestat hydrobromide will benefit adults with desmoid tumours, improving health and quality of life, and we will continue to monitor its safety and effectiveness closely.”
In Conclusion
The approval of nirogacestat hydrobromide adds a new regulated treatment option for adults with progressing desmoid tumours in the UK. The MHRA said the decision reflects evidence of clinical benefit alongside established safety requirements.
With post-authorisation monitoring in place, regulators aim to ensure continued oversight as the medicine becomes available to patients. The agency has encouraged healthcare professionals and patients to report suspected side effects through established channels.
Sources: Medicines and Healthcare products Regulatory Agency.
Prepared by Ivan Alexander Golden, Founder of THX News, an independent news organisation delivering timely insights from global official sources. Combines AI-analysed research with human-edited accuracy and context.
