NEW ORLEANS (FRONTLINE MEDICAL NEWS) The long-term safety of interferon beta-1b for the treatment of multiple sclerosis is well established, and 11-year outcomes from the randomized, placebo-controlled BENEFIT trial (BENEFIT 11) provide further support for the existing data.

Eleven years after patients with clinically isolated syndrome were randomized to receive 250 mcg every other day or placebo (with an option at 2 years to switch to active treatment), no new safety signals were found, and the safety profile remained favorable, Dr. Mark S. Freedman of the University of Ottawa and his colleagues reported in a poster at the meeting sponsored by the Americas Committee for Treatment and Research in Multiple Sclerosis.

In the 278 of the 468 patients originally enrolled in BENEFIT who were evaluated at 11 years , 107 (38.5%) reported one or more safety events (total, 278). Interferon beta-1b was used continuously during the 2 years prior to the 11-year evaluation in 82 patients (29.5%), and 28 (34.1%) of those reported an adverse event or medical history event (total, 72 events). Of 196 patients not treated continuously with interferon beta-1b in the 2 years prior to BENEFIT 11, 79 (40.3%) reported an adverse event or medical history event (total, 206 events), the investigators said.

The events reported in BENEFIT 11 were consistent with those seen previously in interferon beta-1b–treated patients; back pain was the most commonly reported musculoskeletal/connective tissue adverse event (reported by 2.4% of patients in the continuous treatment group and 2.6% in the remaining patients, and headache was the most common neurologic adverse event (reported by 1.2% and 2.0% of patients in the groups, respectively).

Neoplasms occurred in 3.7% and 3.6%; most were benign.

“Overall, the safety results from BENEFIT 11 supported the already well-established long-term safety profile of interferon beta-1b,” the investigators wrote.

The higher rates of some events in patients without continuous interferon beta-1b treatment may be due to escalation to second-line therapy in some patients who required agents that may be associated with greater frequency of safety events, they explained.

This study was supported by Bayer. Dr. Freedman has received compensation from Actelion, Bayer, Biogen Idec, Chugai, EMD Canada, Genzyme, Merck Serono, Novartis, Roche Canada, Sanofi-Aventis, and Teva Canada Innovation for consulting services. He also participates in a Genzyme-sponsored speakers bureau.