AbbVie announced positive topline results from its Phase 2 ELATE trial evaluating onabotulinumtoxinA (BOTOX) for treating upper limb essential tremor, marking a potential breakthrough in a therapeutic area that has seen no new approved treatments for more than three decades.
The multicenter, randomized, double-blind, placebo-controlled study met its primary endpoint, demonstrating statistically significant improvements in the Tremor Disability Scale-Revised (TREDS-R) total unilateral score compared to placebo at week 18. Specifically, patients receiving onabotulinumtoxinA showed a greater reduction in TREDS-R scores of -2.61 versus -1.61 in the placebo group (p=0.029).
Trial Design and Outcomes
The ELATE trial evaluated the safety and efficacy of onabotulinumtoxinA in adults with upper limb essential tremor through a parallel-group design. The primary efficacy measure assessed changes in TREDS-R total scores across seven unilateral items from baseline across weeks 15, 18, and 21. Secondary outcome measures included activity of daily living assessments, various tremor assessment scales, and global impression of severity scores.
Beyond meeting the primary endpoint, the study achieved all six secondary endpoints, though specific details of these measures were not disclosed in the announcement.
Safety Profile
Safety results aligned with the well-established profile of onabotulinumtoxinA across its approved indications. Muscular weakness emerged as the most common adverse event, affecting 24.5% of patients in the treatment group compared to 2.3% in the placebo group. These instances were characterized as localized and transient, with most classified as mild or moderate in severity.
Clinical Significance
"Essential tremor is a progressive neurological condition that affects millions worldwide and often results in unsatisfactory outcomes with current treatments," said Daniel Mikol, M.D., Ph.D., vice president of neuroscience development at AbbVie. "No new pharmacological treatments have been approved in the U.S. for essential tremor for more than 30 years. These results represent a significant advance and demonstrate further proof of mechanism for a neurotoxin as a potential treatment option."
Essential tremor represents the most common movement disorder globally, impacting approximately 25-60 million individuals worldwide. The condition complicates physical activities through uncontrollable and involuntary action tremors, often resulting in depression, anxiety, and social embarrassment that significantly affect quality of life. Current treatment options remain limited in both efficacy and tolerability, frequently leaving patients with few viable therapeutic alternatives.
Regulatory Status and Next Steps
The use of BOTOX for essential tremor is not currently approved by the U.S. Food and Drug Administration or any other global regulatory authority. The safety and efficacy for this indication have not been evaluated by regulatory authorities.
Results from the ELATE study were presented at the International Congress of Parkinson's Disease and Movement Disorders on October 8, 2025, providing the scientific community with detailed data from this potentially practice-changing trial.
BOTOX was first approved by the FDA in 1989 for two rare eye muscle disorders and has since expanded to multiple therapeutic indications, including chronic migraine, overactive bladder, cervical dystonia, adult and pediatric spasticity, and severe underarm sweating.
