More than 60% of the people who were treated with SAGE-324 requested a lower dose of the steroid treatment due to tolerability issues, the company said. Nearly 40% of patients discontinued dosing altogether.
Sleepiness or drowsiness was the most often reported side effect, affecting about 68% of patients. The company plans to use the Phase 2b trial to optimize the dose of the treatment.
The drug "achieved its primary endpoint of a statistically significant reduction" of the extent of tremors from a baseline compared with placebo, the company said.
"The strong correlation observed in this study between Tetras performance scale – measuring reduction of upper limb tremor, a disabling symptom experienced by more than 90% of people suffering from essential tremor -- and improvement on the [Activities of Daily Living] score provides suggestive evidence that these findings have the potential to be truly impactful for people with essential tremor," Chief Executive Barry Greene.
Sage Therapeutics shares at last check were down 2.9% to $74.38.
Essential tremor is one of the most common movement disorders in the country, affecting an estimated 6.4 million people, according to Alfred Sandrock Jr., a physician who directs research and development at Biogen (BIIB) - Get Report, which is collaborating with Sage on the treatment.
The only medicine approved to treat the disorder was approved more than 50 years ago.
"We believe the data announced today provide clear support and insights for the continued development of SAGE-324 in an area of significant unmet medical need," Greene said.