As with any medicine, the MHRA will keep the safety and effectiveness of Nirogacestat hydrobromide under close review.
The Medicines and Healthcare products Regulatory Agency (MHRA) has today (7 January 2026) approved the medicine Nirogacestat hydrobromide (Ogsiveo) for the treatment of progressing desmoid tumours in adults.
Desmoid tumours are tumours that form in connective tissue in the body, usually the arms, legs or abdomen. Whilst they are not cancerous, as they grow, they can cause damage in nearby tissue and become difficult to remove.
Nirogacestat hydrobromide works by inhibiting the activity of certain proteins which are involved in the growth of the tumours. Studies have shown that patients taking nirogacestat hydrobromide benefitted from living longer without their condition getting worse and avoiding the need for potential surgery.
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.
As with all licensed medicines, we will continue to monitor its safety and effectiveness closely.
The most common side effects of taking nirogacestat hydrobromide include diarrhoea, rash, nausea (feeling sick), tiredness, hypophosphataemia (low blood levels of phosphates), headache, and stomatitis (inflammation of the lining of the mouth). A serious side effect can be premature menopause, which may affect more than 1 in 10 people.
Nirogacestat hydrobromide may cause harm to an unborn baby if taken during pregnancy. It is uncertain how it may damage ovaries and testicles, and how it may affect men and women's fertility. Therefore, nirogacestat hydrobromide must not be taken during pregnancy, and highly effective contraception must be used.
A patient card will be provided to support pregnancy prevention in female patients taking nirogagestat hydrobromide, and in female partners of male patients taking this drug. The card contains important information on the risks and the measures that must be followed to minimise potential harm.
A full list of side effects can be found in the Patient Information Leaflet (PIL) or the Summary of Product Characteristics (SmPC), which will be published on the MHRA website within 7 days of approval.
Anyone who suspects they are having a side effect from this medicine are encouraged to talk to their doctor, pharmacist or nurse and report it directly to the Yellow Card scheme, either through the website ( https://yellowcard.mhra.gov.uk/ ) or by searching the Google Play or Apple App stores for MHRA Yellow Card.
Notes
The approval was granted on 7 January 2026 under the International Recognition Procedure (IRP). The Reference Regulator was the European Medicines Agency (EMA) EMEA/H/C/006071/0000.
