There are few treatment options for children with multiple sclerosis and most therapies for the disease have not been tested in children. Researchers conducted a phase 3 clinical trial to examine safety and efficacy in children of teriflunomide, an oral immunomodulatory drug approved in more than 80 countries for the treatment of adults with relapsing forms of MS. Based on the trial’s results, teriflunomide was recently approved by the European Commission for children aged 10-17 years with a diagnosis of relapsing remitting MS.

In the trial, conducted by an international team of investigators, including researchers at Massachusetts General Hospital, 109 children were randomized to receive teriflunomide and 57 were randomized to receive placebo for up to 96 weeks (nearly two years). Early entry in an open-label extension phase (where patients were guaranteed to receive teriflunomide) was possible before the end of the double-blind period for patients who experienced a relapse or demonstrated high disease activity on MRI imaging tests. Importantly, more patients in the placebo group entered the open-label extension phase (because of high MRI activity) than anticipated, with 26 percent of patients switching from placebo to teriflunomide before 96 weeks.

After 96 weeks, there was no difference in time to first clinical relapse of MS with teriflunomide compared with placebo. Teriflunomide was well tolerated — serious adverse events occurred in 11 percent of patients in the teriflunomide group and 11 percent of patients in the placebo group. Nasal inflammation, upper-respiratory-tract infection, hair loss, tingling sensations, abdominal pain, and increased blood creatine phosphokinase (a marker of muscle damage) were more frequent with teriflunomide than with placebo.

Researchers said the trial did not meet its primary endpoint — delaying time to the next clinical relapse — possibly because of more frequent switches to the open-label arm due to high MRI activity. However, the study did meet several key secondary endpoints related to teriflunomide’s ability to reduce the number of new or enlarged lesions that are detected through MRI, suggesting that the medication might have beneficial effects in children with relapsing forms of MS. Researchers note that an ongoing open-label treatment extension study is continuing to evaluate the long-term effects of teriflunomide in young patients.

This work was supported by Sanofi.

The results were published in the journal Lancet Neurology.