Sanofi’s (NASDAQ:SNY) multiple sclerosis drug Lemtrada showed strong results in the first year of an extended phase 3 study, reducing relapse rates in treated patients and improved disability outcomes, the company said this week.

The study results [file opens in PDF], released by Sanofi and subsidiary Genzyme, came as the European Medicines Agency and the FDA review Lemtrada for regulatory decisions expected later in 2013.

Sixty-seven percent of patients new to treatment and 55% of patients who had relapsed on prior therapy remained relapse-free a year into the extended study. More than 70% of each patient group showed improved or stable disability, while more than 80% of patients didn’t require a third round of treatment during the trial.

Lemtrada’s safety profile remained steady as no new risks emerged for patients on the drug; infections were the most common adverse events over the course of the extended study’s first year.