Study: Rituximab Superior to Mycophenolate Mofetil as Pemphigus Vulgaris Treatment

New phase 3 study results of rituximab (Rituxan, Genentech) underscored the safety and efficacy of rituximab compared with mycophenolate mofetil (MMF) in adults with moderate-to-severe pemphigus vulgaris (PV).

The findings were presented at the 28^th Congress of the European Academy of Dermatology and Venereology in Madrid, Spain, as a late-breaking oral presentation.

PV is a rare autoimmune disease that affects the skin and mucous membranes and can be potentially life-threatening. The disease accounts for up to 80% of causes of pemphigus, a group of autoimmune disorders that affect approximately 30,000 to 40,000 individuals in the United States, according to Genentech.

Currently, MMF is an unapproved but commonly used treatment for PV. Rituximab was approved by the FDA as the first biologic therapy for PV in June 2018.

The phase 3 PEMPHIX study evaluated the efficacy and safety of rituximab compared with MMF in patients with moderate-to-severe active PV requiring 60 to 20 mg per day of oral prednisone or equivalent. Patients received either rituximab plus MMF placebo or rituximab placebo plus MMF over a 52-week treatment period, in combination with 60 or 80 mg oral prednisone with intention to taper by week 24.

Patients received rituximab 1000 mg via intravenous (IV) infusion on days 1 and 15, with a repeat administration on days 168 and 182. MMF was administered at a dose of 2 grams orally daily, starting at 1 g per day on day 1 and titrated to achieve a goal of 2 g per day by week 2.

According to the results, rituximab demonstrated superiority to MMF, with 40.3% of patients treated with rituximab achieving sustained complete remission (CR) without the use of steroids for 16 consecutive weeks or more, compared with 9.6% in the MMF arm. Additionally, all secondary endpoints were in favor of rituximab, including lower cumulative oral corticosteroid dose, fewer flares, a greater likelihood of sustained CR, a lesser likelihood of flare, and a greater improvement in the Dermatology Life Quality Index.

Adverse events were generally consistent with those seen in previous studies in PV and other approved autoimmune conditions.

“The approval of Rituxan for the treatment of pemphigus vulgaris was the first major advancement in the treatment of this rare, serious disease in more than 60 years,” Levi Garraway, MD, PhD, Genentech chief medical officer and head of Global Product Development, said in a statement. “The PEMPHIX study showed that 40% of people in the study could achieve complete remission from painful blistering without the need for corticosteroids for 16 weeks or more and that Rituxan may be a superior treatment option to mycophenolate mofetil.”

Reference

Phase III PEMPHIX Study Shows Genentech’s Rituxan (Rituximab) Superior to Mycophenolate Mofetil in Patients With Pemphigus Vulgaris [news release]. Genentech’s website. https://www.gene.com/media/press-releases/14816/2019-10-13/phase-iii-pemphix-study-shows-genentechs. Accessed October 14, 2019.