Severe Skin Disease Drug Gets FDA Breakthrough Therapy Designation

The US Food and Drug Administration (FDA) Thursday granted Breakthrough Therapy Designation status to rituximab (Rituxan/Genentech) for the treatment of pemphigus vulgaris (PV) — a painful, disfiguring and potentially fatal autoimmune disease associated with progressive skin blisters and/or mucous membranes.

The standard of care currently used involves high doses of corticosteroids administered for several weeks and corticosteroids combined with the off-label use of corticosteroid-sparing immunosuppressive drugs for many months, which can cause significant, long-term side effects.

According to Victoria P. Werth, MD, Professor of Dermatology and Medicine at the University of Pennsylvania, this approval can provide an alternative regimen potentially sparing patients from severe, long-term adverse events.

Officials reported that the Breakthrough Therapy Designation status was awarded following data from a phase 2 study of 90 patients comparing Rituxan plus oral corticosteroid (CS) treatment to CS as a first-line treatment in patients with moderate to severe PV.

Results showed that Rituxan could provide substantial improvement in the pemphigus vulgaris remission rates as well as successful tapering (or cessation) of CS therapy.

The most commonly reported adverse events were diabetes, endocrine disorder, myopathy, and bone disorders.

Sandra Horning, MD, chief medical officer and head of Global Product Development, said in a news release, “We are committed to developing therapies that target B cells in areas of unmet need across a range of immune and malignant diseases, including new antibody constructs that enhance efficacy, safety or both.”

The FDA had already granted Orphan Drug Designation to Rituxan to treat PV in 2015.

Genentech has continued the patients enrolled for phase 3 study randomized, double-blind, double-dummy, active-comparator, parallel-arm multicenter study (PEMPHIX, NCT02383589) to evaluate the efficacy and safety of Rituxan compared with mycophenolate mofetil (MMF) in patients with moderate to severe active pemphigus vulgaris.