As with any medicine, the MHRA will keep the safety and effectiveness of rilzabrutinib under close review.
The Medicines and Healthcare products Regulatory Agency (MHRA) has today (29 May 2026) granted a marketing authorisation for the medicines rilzabrutinib (Wayrilz) to treat adults with immune thrombocytopenia (ITP) when prior treatments for ITP have not worked well enough.
ITP is a rare autoimmune disease, in which the body´s own immune system attacks and destroys platelets in the blood, causes fatigue, and increases risk of bleeding. Platelets are needed to help create clots and stop bleeding.
Rilzabrutinib works by blocking Bruton's tyrosine kinase, a protein in the body that plays a role in the immune system. By blocking this protein, the medicine can decrease the destruction of blood platelets and thus increase the number of healthy platelets in the body. This helps reduce the risk of bleeding.
Julian Beach, MHRA Executive Director, Healthcare Quality and Access, said:
Keeping patients safe and enabling their access to high quality, safe, and effective medical products are key priorities for us.
The MHRA has decided that the benefits of rilzabrutinib are greater than its risks and that it can be authorised for use in the UK.
As with all products, we will keep the safety and effectiveness of rilzabrutinib under close review.
Rilzabrutinib is available as tablets to be taken by mouth twice a day.
This approval is based on a pivotal phase 3 study of 202 patients with ITP whose prior treatments had been insufficient. After 24 weeks, 23 per cent of patients receiving rilzabrutinib achieved a stable, adequate platelet count to prevent excessive bleeding, compared with 0 per cent on placebo.
The most common side effects of the medicine (which may affect more than 1 in 10 people) include diarrhoea, nose and throat infections, nausea, headache, stomach pain, and joint pain.
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 new marketing authorisation was granted on 29 May 2026 to Sanofi B.V
