Pegasus Study

Pemphigus (Pemphigus Vulgaris and Pemphigus Foliaceus) is an immune-mediated blistering skin disorder that has few treatment options.

We have an ongoing Phase 3 clinical trial of rilzabrutinib (formerly known as PRN1008), a novel investigational drug to treat pemphigus. The PEGASUS study is a global, randomized, double-blind, placebo-controlled, pivotal, Phase 3 clinical trial designed to evaluate rilzabrutinib versus placebo. All patients may use a background treatment of tapering doses of corticosteroids, the current standard of care in this disease.

The trial entry criteria include patients with moderate to severe pemphigus who are either newly diagnosed or relapsing with chronic disease. This demographic will potentially represent three-quarters of the pemphigus patient population. The primary efficacy endpoint is the ability of rilzabrutinib to achieve durable complete remission on a very low dose of corticosteroids after 36 weeks of treatment. Rilzabrutinib has been granted orphan drug designation by the U.S. Food and Drug Administration for the treatment of patients with pemphigus vulgaris and by the European Commission for treatment of patients with pemphigus.

Clinical trial information can be found on, and information related to the disease can be found on Phase 2 clinical trial information can also be found on

Dealing with Pemphigus?

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