We found low-level evidence for the use of teriflunomide as a disease-modifying therapy for MS, due to the limited quality of the available RCTs. We did not conduct meta-analysis because of the clinical and methodological diversity of the included studies. Short-term teriflunomide, 7 or 14 mg alone or with add-on IFN-β, was safe for patients with relapsing MS. Both teriflunomide 7 and 14 mg alone had potential benefits for patients with relapsing forms of MS. We are waiting for the publication of ongoing trials. RCTs with high methodological quality and longer periods of observation are needed to assess safety, disability progression, neuroprotection and quality of life.
Teriflunomide added to interferon-β in relapsing multiple sclerosis: a randomized phase II trial.
To evaluate teriflunomide as add-on therapy to ongoing stable-dosed interferon-β (IFNβ) in patients with relapsing forms of multiple sclerosis (RMS).
                A total of 118 patients with RMS were randomly assigned 1:1:1 to receive oral placebo or teriflunomide, 7 or 14 mg, once daily for 24 weeks; 86 patients entered the 24-week extension. The primary objective was to evaluate safety; secondary objectives were to evaluate the effects of treatment on disease activity assessed by MRI and relapse rate.
                Teriflunomide was well tolerated with a low and similar incidence of treatment-emergent adverse events (TEAEs) across the 3 groups; TEAEs led to treatment discontinuation of 4.9%, 8.1%, and 7.9% of patients in the placebo, 7-mg, and 14-mg groups, respectively. The number of gadolinium-enhancing T1 (T1-Gd) lesions was reduced in both teriflunomide groups, with relative risk reductions (RRRs) of 84.6% (p = 0.0005) and 82.8% (p < 0.0001) for 7 and 14 mg, respectively, compared with IFNβ alone at 48 weeks. T1-Gd lesion volume was also reduced in the 7-mg group (RRR 72.1%, p = 0.1104) and 14-mg group (RRR 70.6%, p = 0.0154). A trend toward dose-dependent reduction in annualized relapse rate was also noted (RRRs 32.6% [p = 0.4355] and 57.9% [p = 0.1005] for 7 and 14 mg, respectively).
                Teriflunomide as add-on therapy to IFNβ had acceptable safety and tolerability and reduced MRI disease activity compared with IFNβ alone. Classification of evidence: This study provides Class II evidence that teriflunomide, 7 and 14 mg, added to IFNβ, is safe. The T1-Gd lesion burden was significantly reduced with both teriflunomide doses.