Roche Holding AG’s top-selling drug Rituxan effectively cured most cases of a rare and deadly skin disease in a patient study that suggests the medicine may replace steroids as the standard treatment.
In a trial among 22 people with severe pemphigus, a disorder marked by blisters on the skin and in the mouth and genitals, 59 percent were symptom-free more than six years after treatment with a single dose of Rituxan, researchers at France’s National Institute of Health and Medical Research in Rouen wrote in the journal Science Translational Medicine today.
Pemphigus is usually treated with steroids, though relapses are common, requiring long-term treatment that can cause complications including diabetes, osteoporosis and severe infections. While the study tested Rituxan in patients already treated with steroids, the researchers expect results in about a year from a larger trial that compares the drug with steroids as a frontline therapy, said Philippe Musette, a professor of dermatology who led the research.
“In an autoimmune disease it’s really difficult to have complete remission,” Musette said in a telephone interview. “With one shot of rituximab we have a long-term result,” he said, using Rituxan’s generic name.
Rituxan, approved as a treatment for lymphoma, leukemia and rheumatoid arthritis, had sales of 6.7 billion Swiss francs ($7.1 billion) last year, making it Basel, Switzerland-based Roche’s biggest-selling product. The drug is sold as MabThera outside the U.S.
Roche has no plans to seek regulatory approval of Rituxan for the treatment of pemphigus, Daniel Grotzky, a company spokesman, said in an e-mail. The drugmaker is aware that some doctors prescribe the medicine for pemphigus, but doesn’t promote the so-called off-label use of any of its products, Grotzky said. Doctors in some countries, including the U.S., are allowed to prescribe drugs that are approved for one disease for any other disease.
In the trial, a single dose of Rituxan cleared the lesions caused by pemphigus in all but one of the patients in an average of 3 months. Seventeen patients relapsed, of whom nine received a second dose, with seven achieving complete remission -- meaning they had no symptoms and required no further treatment. Two patients died of heart disease, who were also considered to be in complete remission.
Pemphigus is a so-called autoimmune disease in which the immune system attacks proteins needed to glue cells together. It strikes as many as seven people per million each year, mostly in middle-age or older.
Before it was treated with steroids, about 70 percent of people with the disease would die within a year, according to the Sacramento, California-based International Pemphigus and Pemphigoid Foundation.