Sanofi's rilzabrutinib promising in phase 3 immune thrombocytopenia trial

Sanofi has announced encouraging outcomes from a phase 3 trial of its investigational oral Bruton’s tyrosine kinase (BTK) inhibitor, rilzabrutinib, in individuals with immune thrombocytopenia (ITP). The findings from the LUNA 3 study, which focused on adults and adolescents with persistent or chronic cases of this rare autoimmune disorder, were disclosed at the American Society of Hematology (ASH) annual meeting.

ITP affects roughly 9.5 per 100,000 people in the United States. This condition is marked by low platelet counts, a result of both increased platelet destruction and decreased platelet production. Symptoms can include bruising and bleeding, with severe cases potentially leading to life-threatening situations such as intracranial hemorrhage or arterial and venous thrombosis.

The primary endpoint of the LUNA 3 trial was met, with rilzabrutinib administered twice daily showing a durable platelet response in 23% of adult patients with ITP, compared to none in the placebo group. This response was defined as the proportion of patients achieving platelet counts at or above 50,000/μL for at least eight out of the last 12 weeks of the 24-week treatment period without the need for rescue therapy.

Platelet response was observed in 65% of rilzabrutinib-treated patients, compared to 33% of those receiving placebo. Over the combined 24-week double-blind and 28-week open-label periods, a durable response was reached in 29% of the rilzabrutinib group by the data cutoff point.

Additionally, patients treated with rilzabrutinib experienced significant improvements compared to those on placebo. These improvements included reduced bleeding, a lower necessity for rescue therapy, and enhanced physical fatigue and quality of life indicators.

Dietmar Berger, Sanofi's chief medical officer and global head of development, commented on the findings: “These new data support the potential of rilzabrutinib to deliver robust and enduring platelet responses in ITP, providing hope for patients with few treatment alternatives. Given its ability to target BTK, an enzyme crucial in various immune cells, we believe rilzabrutinib could also enhance patient outcomes in numerous rare blood and autoimmune disorders.”

Beyond its application in ITP, rilzabrutinib is being investigated for its efficacy in treating a range of immune-mediated diseases. These include warm autoimmune hemolytic anemia, asthma, and chronic spontaneous urticaria.

Sanofi remains committed to exploring the full potential of rilzabrutinib as a treatment option, aiming to improve the quality of life for patients with these challenging conditions.