OnabotulinumtoxinA Meets Primary End Point in Phase 2 ELATE Trial for Upper Limb Essential Tremor

Late-breaking data from the phase 2 ELATE trial (NCT05216250), presented at the 2025 International Congress of Parkinson’s Disease and Movement Disorders (MDS), held October 5-9, in Honolulu, Hawaii, showed that onabotulinumtoxinA (AbbVie) met the primary end point of reducing tremor-related disability compared with placebo in patients with upper limb essential tremor (ET) over 18 weeks.¹

In the intent-to-treat population, 182 patients with upper limb ET were randomized 1:1 to receive either placebo (n = 87) or onabotulinumtoxinA (n = 95). Presented by lead author Atul Patel, MD, MHSA, physiatrist and vice president at Kansas City Bone & Joint Clinic, topline findings revealed that the least squares mean change from baseline in Tremor Disability Scale-Revised (TREDS-R) total unilateral score at 18 weeks was -1.61 for placebo and -2.61 for onabotulinumtoxinA (least squares mean difference, -1.00 [SE, 0.45]; 95% CI, -1.90 to -0.11; P = .029).

"Essential tremor is a progressive neurological condition that affects millions worldwide and often results in unsatisfactory outcomes with current treatments," Daniel Mikol, MD, PhD, vice president of neuroscience development at AbbVie, said in a statement.¹ "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 to help patients and healthcare providers manage this challenging condition."

ELATE was a multicenter, randomized, double-blind, placebo-controlled, parallel-group phase 2 study assessing the efficacy and safety of onabotulinumtoxinA compared with placebo in adults with upper limb ET. Eligible patients had a diagnosis of ET according to modified Tremor Research Group criteria, aged between 18 to 80 years, and had TREDS-R scores of greater than 3 on any of the 7 unilateral items. Participants also scored at least 3 on any of the 5 unilateral items of the TETRAS Rating Assessment Scale Activities of Daily Living, and had either TETRAS upper limb score of at least 2 or TETRAS Archimedes spiral task score of at least 2 in the dominant limb.³

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Participants in the trial received 2 treatments of onabotulinumtoxinA or placebo unilaterally in the dominant limb at 12-week intervals. Investigators used changes from baseline in the TREDS-R score across 7 unliteral items across weeks 15, 18 and 21 as the primary efficacy end point. The study included several notable secondary end point measures, including activity of daily living assessment, various tremor assessment scales, and global impression of severity scores. Researchers noted that baseline demographics were similar between the 2 treatment groups and that the trial also met all of its secondary end points.

Throughout the study duration, safety monitoring included common and treatment-emergent adverse events (TEAEs). Investigators reported that the placebo and onabotulinumtoxinA TEAE profiles were comparable, apart from muscular weakness, which was more frequent in onabotulinumtoxinA group (24.5%) compared in the placebo group (2.5%); most muscular weakness events were mild or moderate and transient. Researchers noted that none of the TEAEs suggested a distant spread of toxin. Overall, the safety results were consistent with the established safety profile of onabotulinumtoxinA.

ET is the most common movement disorder, characterized by postural and kinetic tremor and affecting an estimated 25 million patients worldwide.⁴ Conventional oral pharmacologic therapies can have limited efficacy and are often associated with tolerability issues, whereas secondary nonpharmacologic interventions may be invasive and carry procedure-related risks.⁵ Local injections of botulinum toxin offer a potential alternative for patients with upper limb ET by reducing muscle contractions at the site of tremor and improving functional outcomes without the limitations associated with existing therapies.

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REFERENCES
1. Patel A, Patterson K, Kholsa D, et al. Results From the ELATE Trial: A Phase 2 Multicenter, Randomized, Double-Blind, Placebo-Controlled Study of OnabotulinumtoxinA for the Treatment of Upper Limb Essential Tremor. Presented at: 2025 MDS Congress; October 5-9; Honolulu, Hawaii. LBA-8.
2. AbbVie Announces Positive Topline Results from Phase 2 ELATE Trial Evaluating OnabotulinumtoxinA (BOTOX®) for the Treatment of Upper Limb Essential Tremor. News release. Ocobter 6, 2025. Accessed October 16, 2025. https://news.abbvie.com/2025-10-06-AbbVie-Announces-Positive-Topline-Results-from-Phase-2-ELATE-Trial-Evaluating-OnabotulinumtoxinA-BOTOX-R-for-the-Treatment-of-Upper-Limb-Essential-Tremor
3. Patterson K, Alibhai N, Khosla D, James L. A Phase 2b Multicenter, Randomized, Double-Blind, Placebo-Controlled Study of OnabotulinumtoxinA for the Treatment of Upper Limb Essential Tremor: ELATE Trial. Presented at: 2024 MDS Congress; September 27-October 1; Philadelphia, PA. ABSTRACT 1551.
4. Welton T, Cardoso F, Carr JA, et al. Essential tremor. Nat Rev Dis Primers. 2021;7(1):83. Published 2021 Nov 11. doi:10.1038/s41572-021-00314-w
5. Alharbi O, Albaibi SA, Almutairi AA, et al. The Pharmacological Management of Essential Tremor and Its Long-Term Effects on Patient Quality of Life: A Systematic Review. Cureus. 2024;16(12):e76016. Published 2024 Dec 19. doi:10.7759/cureus.76016