Proof of concept for the clinical effects of oral rilzabrutinib, the first Bruton tyrosine kinase inhibitor for pemphigus vulgaris: the phase II BELIEVE study*

Abstract

Background: Bruton tyrosine kinase (BTK) inhibition targets B-cell and other non-T-cell immune cells implicated in the pathophysiology of pemphigus, an autoimmune disease driven by anti-desmoglein autoantibodies. Rilzabrutinib is a new reversible, covalent BTK inhibitor demonstrating preclinical efficacy as monotherapy in canine pemphigus foliaceus. Objectives: To evaluate the efficacy and safety of oral rilzabrutinib in patients with pemphigus vulgaris in a multicentre, proof-of-concept, phase II trial. Methods: Patients with Pemphigus Disease Area Index severity scores 8–45 received 12 weeks of oral rilzabrutinib 400–600 mg twice daily and 12 weeks of follow-up. Patients initially received..