Objectives TOWER (NCT00751881), a phase 3 study in patients with relapsing forms of MS (RMS), was conducted in 26 countries, including 32 sites in China. In the overall population, teriflunomide 14 mg significantly reduced annualised relapse rate (ARR; 36.3%, p=0.0001) and risk of disability worsening confirmed for ≥12 weeks (12 w-CDW) by 31.5% vs placebo (p=0.0442). The objective of this analysis was to report efficacy and safety outcomes in Chinese patients enrolled in TOWER.

Methods Patients with RMS were randomised 1:1:1 to placebo, teriflunomide 7 mg or 14 mg for ≥48 weeks. The primary and key secondary endpoints were ARR and 12 w-CDW, respectively. Incidence of adverse events (AEs) was monitored throughout the study.

Results Of 1165 patients randomised and treated in TOWER, 148 (12.7%) were Chinese patients from Chinese sites. Demographic and baseline disease characteristics of this population were comparable to the overall TOWER population, with the exception that Chinese patients had a shorter time since first symptoms of MS (mean (SD): 5.02 (5.25) years vs overall, 8.0 (6.72) years), and a smaller proportion had received another disease-modifying therapy within the last 2 years (2.0% vs 32.8% overall). Within the Chinese population, teriflunomide 14 mg reduced ARR and risk of 12 w-CDW by 71.2% (p=0.0012) and 68.1% (p=0.1194) vs placebo, respectively. Incidence of AEs was consistent with the overall population. Two deaths (placebo, respiratory infection; 14 mg, suicide) were not considered related to study treatment.

Conclusions In Chinese patients enrolled in TOWER, teriflunomide 14 mg reduced ARR and risk of 12 w-CDW vs placebo; the small number of patients in this subgroup may have contributed to the lack of statistical significance observed for 12 w-CDW. However, there was a consistency of outcomes between the Chinese subpopulation and the overall TOWER population in terms of efficacy and safety. Study supported by Sanofi Genzyme.