Do Interferons Reduce MS-Related Mortality?

Between 1988 and 1990, the pivotal trial that led to the approval of interferon beta-1b (IFNβ-1b) recruited 372 participants (mean age, 31) from 11 U.S. sites (Neurology 1993; 43:655). Participants were randomized to placebo, 50 μg of IFN, or 250 μg of IFN (the approved dose) every other day. Now, researchers report follow-up findings on mortality 21 years after the original study randomization; the original and follow-up studies were manufacturer-sponsored. After 1993, treatment was at the discretion of the treating physician.

This follow-up study included 366 of the 372 original patients (98.4%). Of 81 participants (22.1%) who had died, 37 had originally received placebo, 22 had received IFN 250 μg, and 22 had received IFN 50 μg. The rate …