Study of BOTOX Injections to Assess Change in Disease Symptoms in Adult Participants With Upper Limb Essential Tremor

A Phase 2 Multicenter, Randomized, Double-blind, Placebo-controlled Study of BOTOX® (Botulinum Toxin Type A) Purified Neurotoxin Complex for the Treatment of Upper Limb Essential Tremor

Upper limb essential tremor (UL ET) is a movement disorder characterized by postural and/or kinetic tremor. It can cause difficulty with everyday tasks such as writing, pouring, and eating, and patients also experience associated social embarrassment. This study will assess how safe and effective BOTOX is in treating UL ET. Adverse events and change in disease activity will be evaluated.

BOTOX is an investigational drug being developed for the treatment of UL ET. Participants are randomly assigned to 1 of the 4 groups, called treatment arms. Each group receives different treatment. There is 1 in 2 chance that participants will be assigned to placebo. Around 174 participants, aged 18 to 80 years with UL ET will be enrolled in approximately 40 sites in North America.

Participants will receive BOTOX or placebo injections in Cycle 1 and Cycle 2. In Cycle 3, participants will receive unilateral or bilateral BOTOX injections. Each cycle is 12 weeks.

There may be higher treatment burden for participants in this trial compared to their standard of care. Participants will attend regular visits during the study at a hospital or clinic. The effect of the treatment will be checked by medical assessments, blood tests, checking for side effects and completing questionnaires.

Inclusion Criteria:

• Diagnosis of essential tremor in accordance with modified Tremor Investigation Group (TRIG) criteria as described in the protocol.

• TREDS-Revised Scale (1-4 scale, whole numbers) unilateral score of >= 3 for the Tremor Disability Scale (TREDS) on any of the 7 unilateral items; no more than a single item score of 1 among the 7 unilateral items in the dominant limb.

• TETRAS activities of daily living (ADL) (recorded on a 0-4 scale, whole numbers) minimum score of >= 3 on any of the 5 unilateral items; no more than a single item score of <=1 among the 5 unilateral items in the dominant limb.

• At least one of the following criteria must also be met:

  • TETRAS UL score (0-4 scale, with 0.5 increments) of > 2 in the dominant limb on at least one of the 3 maneuvers OR
  • TETRAS Archimedes spiral task score (0-4 scale, with 0.5 increments) of > 2 in the dominant limb

Exclusion Criteria:

• Any uncontrolled clinically significant medical condition other than the one under study.
• Any medical condition that may put the participant at increased risk with exposure to BOTOX Purified Neurotoxin Complex.