TOWER
Teriflunomide
TOWER independently confirmed the relapse efficacy of teriflunomide and showed reduced sustained disability accumulation with 14 mg.
- Phase
- Phase III
- Population
- Relapsing multiple sclerosis (RMS)
- Controlled period
- Aug 2008 — Apr 2012
What was compared
Teriflunomide 14 mg
Orally once daily
n=372Placebo
Matching oral tablet once daily
n=389Additional randomized arm
Teriflunomide 7 mg
Orally once dailyn=408Primary endpoint
Annualized relapse rate
Variable-duration treatment period
Primary endpoint results
Annualized relapse rate
Relapses per participant-year
36.3% lower with 14 mg (P=0.0001); the 7 mg reduction was smaller.
Selected secondary outcomes
Risk was reduced 31.5% with 14 mg versus placebo (P=0.0442).
The 14 mg dose reduced several prespecified measures of severe relapse burden.
Study population
- Randomized
- 1,169 randomized
- Age
- Mean 37.9 years; eligible 18–55
- Sex
- 831 women (71%)
- Disability
- Ambulatory relapsing MS
- Disease definition
- Relapsing MS with one relapse in 1 year or two in 2 years
Who entered the trial
Key inclusion criteria
- Relapsing multiple sclerosis
- At least one relapse in the prior year or two in the prior 2 years
- Age 18–55 years
Key exclusion criteria
- Major cardiovascular, hepatic, neurologic, endocrine, or systemic disease
- Significant anemia, leukopenia, thrombocytopenia, or bone-marrow impairment
- Pregnancy, breastfeeding, or prior specified immunosuppressant use
Safety signal
- Hair thinning and liver-enzyme elevation were among the characteristic teriflunomide-associated events.
- Serious adverse events were broadly similar across groups in the primary report.
Why it mattered
Together with TEMSO, TOWER provided replicated evidence for the approved 14 mg dose across relapse and disability outcomes.
Important limitation
Treatment duration varied because the study ended 48 weeks after the last participant enrolled, complicating simple cross-trial comparisons based on a fixed timepoint.