Researchers from the National Institutes of Health

reported that results from two studies show that treatment with Roche's Rituxan/MabThera (rituximab) provided comparable benefits to the current standard therapy, cyclophosphamide,

at inducing remission from antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis and was more effective at inducing remission in patients whose disease has relapsed.

 

 "This trial has demonstrated for the first time there is an effective alternative to cyclophosphamide for remission induction, and there are a variety of results that make us think that rituximab should be the treatment of choice for remission induction," commented John Stone, author of one of the studies appearing in Thursday's NEJM.

In the first study, researchers randomised 197 patients with ANCA-positive vasculitis with either Wegener's granulomatosis or microscopic polyangiitis to receive either rituximab or cyclophosphamide, both in combination with glucocorticoids.

 

 After six months, 64 percent of patients given rituximab were in remission and no longer required steroids, compared to 53 percent in the cyclophosphamide arm.

Among patients who relapsed, 67 percent receiving rituximab were in remission, compared to 42 percent of patients given cyclophosphamide.

In a second study, researchers randomised 44 patients with newly diagnosed ANCA-associated vasculitis and renal complications to a standard glucocorticoid regimen plus rituximab or cyclophosphamide. Sustained remission rates were similar in both the rituximab and cyclophosphamide groups, at 76 percent and 82 percent, respectively, but a high rate of side effects was also observed among the groups, at 42 percent and 36 percent, respectively.

In addition, 18 percent of patients in each treatment arm died.

In an accompanying editorial, Ronald Falk said "I think these are two very important pivotal studies that bring hope to patients with ANCA vasculitis," adding that "despite the fact that they are relatively small studies, they are proof of principle that this medicine has the ability to get rid of the group of cells that produce the [antibody]," attacking the cause of the disease as opposed to addressing disease symptoms.

 

 However, he warned that "both studies had greater side effects than previously anticipated with rituximab.

 We would have hoped for far less deaths, so we need to proceed with caution."