Roche backs Rituxan with further data in rare skin disease PV

Roche’s Rituxan (rituximab) has been on the market for years as a blood cancer drug, and is finally succumbing to pressure from cut-price biosimilars.

But the company’s Genentech unit has new data that could encourage doctors to use it in its recently approved indication of pemphigus vulgaris (PV), a rare and potentially life-threatening autoimmune condition causing blistered skin and mucous membranes.

The FDA approved Rituxan in this indication only last year, the first advancement in treatment of the disease in 60 years, and the firm now has further positive findings from a year-long study to demonstrate its safety and effectiveness on top of the data already shared with the regulator.

The phase 3 PEMPHIX study met its primary endpoint at week 52 and demonstrated that Rituxan is superior to mycophenolate mofetil (MMF), with 40.3% of patients treated with Rituxan achieving sustained complete remission (CR) without the use of steroids for 16 consecutive weeks or more, compared to 9.5% in the MMF arm.

All secondary endpoints were statistically significant in favour of Rituxan: lower cumulative oral corticosteroid dose, a greater likelihood of sustained CR and a greater improvement in quality of life compared with patients in an arm treated with MMF.

MMF is an unapproved, commonly used treatment for PV that is recommended in published treatment guidelines.

The study is ongoing, with patients participating in a 48-week safety follow-up period after treatment completion or discontinuation.

Rituxan, also branded as MabThera in Europe works by targeting a protein called CD20, which is found on precursor or mature B lymphocytes.

This means the drug can be used to target rogue B-cells found in diseases such as non-Hodgkin lymphoma.

But the mechanism of action means it can also be used to treat autoimmune diseases such as PV that are caused by overactive B-cells.

Results were presented at a late-breaking oral presentation at the Congress of the European Academy of Dermatology and Venereology in Madrid, last week.