MHRA Approves Sanofi’s Rilzabrutinib for Adults with Chronic ITP

The UK Medicines and Healthcare products Regulatory Agency (MHRA) has granted marketing authorization to Sanofi’s rilzabrutinib (Wayrilz) for adults with chronic immune thrombocytopenia (ITP) who have not achieved adequate benefit from prior therapies. The approval, issued on May 29, 2026, was granted through the International Recognition Procedure (IRP), which enables faster UK access to medicines previously assessed by recognized international regulators.

Disease Context

ITP is a rare autoimmune bleeding disorder in which the immune system destroys platelets, increasing the risk of bruising, bleeding, and fatigue. Platelets play a critical role in blood clotting, and low platelet counts can lead to serious bleeding complications. Current therapies often fail to provide durable disease control, leaving many patients at continued clinical risk.

First-in-Class Mechanism

Rilzabrutinib is an oral Bruton’s tyrosine kinase (BTK) inhibitor that modulates immune pathways involved in platelet destruction. By reducing immune-mediated platelet loss, the therapy helps restore platelet counts and lower bleeding risk.

Administered twice daily, rilzabrutinib becomes one of the first BTK-targeting therapies approved for ITP in the UK, introducing a novel treatment approach for patients with persistent disease.

Pivotal Phase 3 Trial

The approval was supported by a randomized, double-blind, placebo-controlled phase 3 LUNA-3 trial (NCT04562766) that enrolled 202 adults with persistent or chronic ITP whose previous treatments had provided insufficient benefit. After 24 weeks, 23% of patients receiving rilzabrutinib achieved a sustained platelet response, defined as platelet counts of at least 50,000/µL without rescue therapy, compared with no patients in the placebo group.

The results demonstrated a meaningful platelet response in patients whose disease remained inadequately controlled despite prior treatment, supporting rilzabrutinib’s potential role in a difficult-to-treat population.

Safety Profile

Safety findings were consistent with the established profile of rilzabrutinib. The most commonly reported adverse events included diarrhea, upper respiratory tract infections, nausea, headache, abdominal pain, and arthralgia.

MHRA Executive Director of Healthcare Quality and Access Julian Beach said the agency concluded that rilzabrutinib’s benefits outweigh its risks and noted that its safety and effectiveness will continue to be closely monitored following approval.

Strategic Impact

The authorization expands treatment options for patients with chronic ITP who continue to face bleeding risks despite existing therapies. By introducing a first-in-class oral BTK inhibitor to the UK market, rilzabrutinib adds a new mechanism to the ITP treatment landscape and strengthens Sanofi’s growing immunology portfolio.

Reference

Rilzabrutinib authorised to treat adults with immune thrombocytopenia when prior treatments have been insufficient – GOV.UK