Roche group Genentech has received US approval for Rituxan to treat moderate to severe pemphigus vulgaris (PV), giving patients access to the first new therapy for the condition in more than 60 years.

PV is a rare, serious, potentially life-threatening condition characterised by progressive painful blistering of the skin and mucous membranes.

The condition accounts for up to 80 percent of cases of pemphigus, a group of autoimmune disorders affecting 30,000 to 40,000 people in the US.

Rituxan (rituximab) is the first biologic therapy approved by the FDA for the condition.

Clearance was based on data showing that 90 percent of PV patients treated with rituximab plus corticosteroids met the primary endpoint - complete remission at month 24 without the use of steroids for two or more months - compared to 28 percent those given corticosteroids alone.

The drug, which is sold as MabThera in Europe, is now approved to treat four autoimmune diseases, the others being rheumatoid arthritis, granulomatosis withpPolyangiitis (GPA; Wegener’s Granulomatosis) and microscopic polyangiitis (MPA).