Rituxan's challenge in RA
Anti-TNF drugs, particularly Enbrel etanercept from Amgen Inc. and Wyeth, have been the new stars in rheumatoid arthritis (RA) treatment. But they could be in danger of being displaced by another biologic, Rituxan rituximab, the CD20 anti-B cell antibody from Idec Pharmaceuticals Corp., Genentech Inc. and Roche.
Results of a Phase II study announced on Saturday at the American College of Rheumatology meeting showed 24-week ACR scores for Rituxan are equal to and possibly better than those seen with the anti-TNF drugs. If the results carry forward to the market, Rituxan could inject a more convenient and potentially significantly lower cost competitor into the mix.
Indeed, if the right variables fall into place, Rituxan could cost less than half as much as current biologic therapies. In addition, a more convenient dosing regimen might drive both patients and physicians toward Rituxan as the biologic of choice.
This outcome is not a foregone conclusion, however, as immunosuppression caused by B cell depletion is a concern for physicians. Thus even though Rituxan already is marketed to treat non-Hodgkin's lymphoma (NHL), past experience with immune cell depleting therapies will give rheumatologists pause until the safety is proven in