Could Reference Rituximab's New EU Indication Help It Stave Off Biosimilars?

The European Commission has approved Roche’s innovator rituximab, sold in Europe as MabThera, for the treatment of pemphigus vulgaris (PV), a rare autoimmune disorder. The approval marks the first biologic approval for PV in the European Union, and the first major new therapeutic option in 60 years.

PV is a blistering disease that occurs within the epidermis, affecting the skin and the mucous membranes. The condition is progressive, and can lead to life-threatening fluid loss, infection, and death.

“We’re pleased to bring the first biologic medicine to the more than 50,000 people in Europe suffering from pemphigus vulgaris,” says Sandra Horning, MD, Roche’s chief medical officer and head of global product development, in a statement. “This MabThera approval provides a much-needed new treatment that has been shown to provide higher remission rates than corticosteroids alone, which can cause debilitating side effects.”

The approval was based on phase 3 data from the Ritux 3 trial, which evaluated rituximab plus a tapering regimen of corticosteroids versus a standard dose of steroids alone as first-line treatment in 90 new patients with PV. In total, 89.5% of patients treated with rituximab plus steroids achieved complete steroid-free remission for 2 months or more, while only 27.8% of patients receiving steroids alone did so.

Currently, the phase 3, multicenter, randomized, double-blind PEMPHIX study is evaluating the safety and efficacy of rituximab versus the immunosuppressant mycophenolate mofetil.

The approval is not only positive news for European patients but also for Roche; according to Roche’s 2018 finance report, sales of MabThera have been declining since the advent of biosimilar rituximab in 2017. In Europe, sales dropped by 47% in 2018 versus 2017 as the branded drug fought for market share with 2 biosimilars.

In the United States, the FDA approved rituximab for the treatment of PV in 2018. The drug, sold in the United States as Rituxan, does not yet face a marketed biosimilar challenger, and the sole FDA-approved rituximab biosimilar, Truxima, sought only indications in oncology due to patent expiry considerations.