Sanofi Unveils ITP Response Data to Support Rilzabrutinib Approval in US, EU

Sanofi announced significant findings from its pivotal trial on rilzabrutinib for treating immune thrombocytopenia (ITP). The French pharmaceutical company first revealed in April that the BTK inhibitor met the primary endpoint of the Phase III LUNA 3 study. With promising results, Sanofi aims to submit regulatory applications in the United States and Europe by the end of the year. This development could validate Sanofi's $3.7-billion acquisition of Principia Biopharma in 2020, potentially bringing a crucial product to market from its immunology and inflammation pipeline, a sector that is becoming increasingly vital for the company as it reduces its focus on oncology.

Sanofi remains cautious due to previous setbacks with the BTK inhibitor in clinical studies for pemphigus and atopic dermatitis. Nonetheless, the promising results from the LUNA 3 study, which were shared in an abstract ahead of the American Society of Hematology (ASH) meeting in December, offer optimism.

The LUNA 3 study involved 202 adults with persistent or chronic ITP, who were randomized to receive either rilzabrutinib twice daily or a placebo. The primary endpoint was a durable platelet response. Rilzabrutinib achieved this endpoint, with 23% of patients reaching platelet counts of at least 50,000/μL for eight or more of the final 12 weeks of the 24-week treatment phase, without needing rescue therapy. In contrast, no patients in the placebo group met this criterion. Combining data from both the double-blind and open-label phases of the study, the durable response rate increased to 29%.

Additionally, rilzabrutinib significantly reduced the need for rescue therapy by 52% compared to placebo. The treatment also led to notable improvements in patients' physical fatigue and bleeding symptoms. In terms of safety, the therapy was well-tolerated, with a comparable percentage of adverse events (AEs) in both the rilzabrutinib and placebo groups. The most common treatment-related Grade 1/2 AEs for rilzabrutinib were diarrhea (23%), nausea (17%), headache (8%), and abdominal pain (6%).

Sanofi also reported a serious adverse event: one patient with multiple risk factors experienced a treatment-related Grade 3 peripheral embolism. Additionally, another participant in the study passed away due to pneumonia, which was deemed unrelated to the treatment.

In summary, the detailed results from the LUNA 3 trial provide a positive outlook for rilzabrutinib as a treatment for ITP. Sanofi's commitment to advancing its immunology and inflammation pipeline appears to be paying off, potentially enhancing its market position while it streamlines its oncology portfolio. The drug's ability to boost platelet counts, reduce the need for rescue therapy, and improve patient well-being without significant safety concerns underscores its potential as a new treatment option for ITP. As Sanofi prepares for regulatory submissions, the successful advancement of rilzabrutinib could mark a significant milestone for the company and the patients who may benefit from this novel therapy.