Four weekly infusions of the biologic drug rituximab (Rituxan) work just as well to control a type of vasculitis as the current standard of care that involves 18 months of daily immunospressive pills, according to a study published recently in The New England Journal of Medicine.

“It’s a game changer,” says lead study author Ulrich Specks, MD, chair of the division of pulmonary and critical care medicine at the Mayo Clinic in Rochester, Minn. “If I was a patient, I think it would be very good news that we finally have a good alternative to [the traditional treatment].”

Vasculitis is an autoimmune disease in which the body mistakenly sees blood vessels as a foreign invader and attacks them, causing inflammation and leading to a narrowing of the vessels. In severe cases, patients can experience organ damage or death. There are many types of vasculitis, but the one examined in the study is called antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis, or AAV for short. Patients in this study had two subtypes of AAV: either granulomatosis with polyangiitis (formerly known as Wegener's granulomatosis) or microscopic polyangiitis.

Sometimes vasculitis can be treated successfully, but it recurs; other times, the condition never really goes away and requires ongoing, long-term treatment. The traditional treatment for AAV involves oral cyclophosphamide (Endoxan, Cytoxan) for three to six months followed by maintenance therapy of oral azathioprine (Imuran, Azasan) for an additional 12 to 15 months.

Rituximab – a biologic drug that works by depleting a type of white blood cell (called B-cells) involved in the immune response – is used for rheumatoid arthritis, certain blood cancers and other conditions. In 2011 the U.S. Food and Drug Administration (FDA) approved rituximab as the first new treatment for AAV in 40 years based on a six-month study of nearly 200 patients with severe AAV from these same researchers.

This latest study is a continuation of the initial research and looks at results after 12 and 18 months. It found the two treatments are equally effective: 39 percent of patients on rituximab stayed in remission for 18 months, compared with 33 percent on cyclophosphamide and azathioprine.

Those taking rituximab had fewer cases of pneumonia and leukopenia (low white blood cell count), but the overall risk of infections was the same between the two groups. Dr. Specks says the two treatment groups also had the same relapse rate, the same time to the first relapse, the same severity of relapses and the same average improvement in kidney function. “No matter which efficacy marker you looked at, the results were the same,” he explains. This makes the rituximab treatment “noninferior” to the traditional treatment.

Rituximab also has a few advantages. In addition to shorter treatment duration, the infusions don’t require weekly or biweekly blood tests to monitor infection risk, which is needed with the current standard of care. Dr. Specks says rituximab also doesn’t threaten fertility for younger patients or increase the risk of cancer like cyclophosphamide does (although in this study, there were no unexpected cancers found in either group).