Sanofi Announces Positive Phase 1/2 Study Results of Rilzabrutinib in People with Immune Thrombocytopenia

Sanofi has announced the positive results from the Phase 1/2 dose-finding study evaluating the safety, pharmacokinetics and clinical activity of rilzabrutinib, an investigational oral Bruton’s tyrosine kinase (BTK) inhibitor, in adults with heavily pre-treated immune thrombocytopenia (ITP) were published in the New England Journal of Medicine.

Results demonstrate treatment with rilzabrutinib led to a rapid and durable increase in platelet count and support an acceptable safety profile. Sanofi is investigating the safety and efficacy of twice daily rilzabrutinib (400 mg) for adults and adolescents with chronic ITP in the ongoing Phase 3 clinical study LUNA 3, initiated in April 2021, the company said.

David Kuter, M.D. Director of clinical hematology at Massachusetts General Hospital and professor of medicine at Harvard Medical School, lead author of the study said: “Currently, there are no standard treatment recommendations for ITP patients with multiple relapses. Despite advances in treatment options over the years, some patients remain refractory to existing therapies and durable remission remains elusive. The Bruton’s tyrosine kinase is a critical signaling molecule in the immune system that is involved in certain immune-mediated diseases, and our research suggests that targeting BTK may represent a promising approach to addressing the underlying cause of ITP.”

ITP is an acquired autoimmune blood disorder characterized by low platelet count (thrombocytopenia) resulting from immune-mediated platelet destruction and impairment of platelet production. A decrease in platelet counts – whether temporary or persistent – can predispose a person to a higher risk of bleeding, hospitalization, fatigue, impaired quality of life, and even death. The incidence of ITP increases with age and is more common over the age of 60.

Dietmar Berger, M.D., Ph.D. Global Head of Clinical Development and Chief Medical Officer, Sanofi commented: “We are pleased to share these encouraging early clinical results through this publication. These findings demonstrate a clinically meaningful response in difficult-to-treat ITP patients who received a median of four prior ITP therapies. Moreover, the overall study population, which also included less refractory patients, showed a numerically higher response. Rilzabrutinib could become a first-in-class BTK inhibitor therapy with the potential to increase platelet counts quickly and durably for people with ITP.”

Rilzabrutinib was granted Fast Track Designation by the U.S. Food and Drug Administration (FDA) for treatment of ITP in November of 2020 and was previously granted orphan drug designation. Rilzabrutinib is being investigated in multiple clinical trials across a range of diseases including immunological and inflammatory diseases.