Guidelines for physicians with patients on IFN beta-1b

The production of neutralizing antibodies (NAB) may be associated with a reduction in clinical effectiveness of interferon beta 1b (IFN beta-1b). However, there are some NAB-positive patients who continue to do well, so the relationship between the clinical state and the NAB state is not constant. Approximately 90% of NAB-positive patients become so between six and 18 months of therapy. In the IFN beta-1b clinical trial, the data indicate that the relapse rate in NAB-positive patients after 18 months of high dose IFN beta-1b reverted to a level similar to placebo treated patients. NAB-negative patients on high dose IFN beta-1b continued to show progress, with a relapse rate of one half of both the NAB-positive patients and the placebo patients. In order to help in clinical decision-making, a test for the detection …