Clinical efficacy of teriflunomide over a fixed 2-year duration in the TOWER study.

Patients enrolled in the phase 3 TOWER study (NCT00751881) of teriflunomide had variable treatment durations (48-173 weeks). This has led to challenges when interpreting results in the context of other phase 3 trials of disease-modifying therapies for multiple sclerosis, which typically have a fixed 2-year duration. This communication reports clinical outcomes in TOWER over a fixed 2-year period. Reductions in annualised relapse rates and 12-week confirmed disability worsening associated with teriflunomide were comparable between overall intent-to-treat and fixed 2-year study populations in TOWER. Consistency in outcomes supports the inclusion of TOWER data in comparative analyses with other disease-modifying therapies. ClinicalTrials.gov: NCT00751881.