Sanofi provides update on phase-III study evaluating Rilzabrutinib to treat pemphigus

The phase-III Pegasus trial evaluating Rilzabrutinib to treat pemphigus, a rare autoimmune skin condition, did not meet its primary or key secondary endpoints. Rilzabrutinib’s safety profile remained consistent with previous results and no new safety signals were identified, informed Sanofi in a statement.

The statement said that the phase-III study, which is the first placebo-controlled trial of a BTK inhibitor in pemphigus, enrolled adult patients with moderate-to-severe pemphigus vulgaris or pemphigus foliaceus. The primary endpoint was complete remission from weeks 29 to 37 with minimal doses of corticosteroids (≤10 mg/day). Complete remission was defined as the absence of new and established skin lesions. Results show the proportion of patients meeting the primary endpoint on Rilzabrutinib was not significantly different from placebo.

Sanofi is continuing to evaluate the data and plans to share detailed findings at a future medical meeting, added the statement.

Speaking in this regard, Naimish Patel, Head, Global Development, Immunology and Inflammation, Sanofi, said, “While these results are disappointing, we believe the Rilzabrutinib clinical programme holds great potential to address the unmet treatment needs of people living with immune-mediated diseases. Our mission is to improve outcomes by exploring new scientific approaches and novel therapies to advance the standard of care. We are committed to investigating Rilzabrutinib further and progressing our clinical programmes forward to deliver new treatment options for patients.”

The statement also mentioned that pemphigus is a group of potentially life-threatening disorders characterised by blisters and ulceration affecting the skin and mucous membranes. Currently, options for the treatment of pemphigus (including pemphigus vulgaris and pemphigus foliaceus) are limited and systemic corticosteroid treatment remains the standard of care.

Further, according to the statement, Rilzabrutinib is a potential first-in-class, oral Bruton’s Tyrosine Kinase (BTK) inhibitor in development for immune-mediated diseases. The BTK enzyme plays a key role in a number of immune processes including B cell expansion, production of immunoglobulins, and activation of innate cells such as mast cells, eosinophils and basophils. Positive clinical trial data from placebo-controlled studies of BTK inhibitors have revealed the potential role for BTK in rheumatoid arthritis and in chronic spontaneous urticaria. Thus, the function of BTK is biologically diverse and supports continued investigation in a range of diseases with significant unmet need where BTK is implicated.