Oral teriflunomide for patients with a first clinical episode suggestive of multiple sclerosis (TOPIC): a randomised, double-blind, placebo-controlled, phase 3 trial

Background Teriflunomide is a once-daily oral immunomodulator approved for the treatment of relapsing-remitting multiple sclerosis. We aimed to assess the efficacy and safety of teriflunomide in patients with a first clinical episode suggestive of multiple sclerosis. Methods In this randomised, double-blind, placebo-controlled, parallel-group study, we enrolled patients aged 18-55 years with clinically isolated syndrome (defined as a neurological event consistent with demyelination, starting within 90 days of randomisation, and two or more T2-weighted MRI lesions >= 3 mm in diameter) from 112 centres (mostly hospitals) in 20 countries. Participants were randomly assigned (1:1:1) in a double-blind manner (by an interactive voice response system) to once-daily oral teriflunomide 14 mg, teriflunomide 7 mg, or placebo, for up to 108 weeks. Patients, staff administering the interventions, and outcome assessors were masked to treatment assignment. The primary endpoint was time to relapse (a new neurological abnormality separated by >= 30 days from a preceding clinical event, present for >= 24 h in the absence of fever or known infection), which defined conversion to clinically definite multiple sclerosis. The key secondary endpoint was time to relapse or new gadolinium-enhancing or T2 lesions on MM, whichever occurred first. The primary outcome was analysed for the modified intention-to-treat population; safety analyses included all randomised patients who were exposed to the study drug, as treated. This trial is registered with ClinicalTrials.gov, number NCT00622700. Findings Between Feb 13,2008, and Aug 22,2012,618 patients were enrolled and randomly assigned to teriflunomide 14 mg (n=216), teriflunomide 7 mg (n=205), or placebo (n=197). Two patients in each of the teriflunomide groups did not receive the study drug, so the modified intention-to-treat population comprised 214 patients in the teriflunomide 14 mg group, 203 in the teriflunomide 7 mg group, and 197 in the placebo group. Compared with placebo, teriflunomide significantly reduced the risk of relapse defining clinically definite multiple sclerosis at the 14 mg dose (hazard ratio [HR] 0.574 [95% CI 0.379-0.869]; p=0.0087) and at the 7 mg dose (0.628 [0.416-0.949]; p=0.0271). Teriflunomide reduced the risk of relapse or a new MRI lesion compared with placebo at the 14 mg dose (HR 0.651 [95% CI 0.515-0.822]; p=0.0003) and at the 7 mg dose (0.686 [0.540-0.871]; p=0.0020). During the study, six patients who were randomly assigned to placebo accidently also received terifiunomide at some point: four received 7 mg and two received 14 mg. Therefore, the safety population comprised 216 patients on teriflunomide 14 mg, 207 on teriflunomide 7 mg, and 191 on placebo. Adverse events that occurred in at least 10% of patients in either teriflunomide group and with an incidence that was at least 2% higher than that with placebo were increased alanine aminotransferase (40 [19%] of 216 patients in the 14 mg group, 36 [17%] of 207 in the 7 mg group vs 27 [14%] of 191 in the placebo group), hair thinning (25 [12%] and 12 [6%] vs 15 [8%]), diarrhoea (23 [11%] and 28 [14%] vs 12 [6%]), paraesthesia (22 [10%] and 11 [5%] vs 10 [5%]), and upper respiratory tract infection (20 [9%] and 23 [11%] vs 14 [7%]). The most common serious adverse event was an increase in alanine aminotransferase (four [2%] and five [2%] vs three [2%]). Interpretation TOPIC is to our knowledge the first study to report benefits of an available oral disease-modifying therapy in patients with early multiple sclerosis. These results extend the stages of multiple sclerosis in which teriflunomide shows a beneficial effect.