Study of AGN-151607-DP to Assess Adverse Events and Change in Disease Activity in Adult Participants With 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. This study will assess if AGN-151607-DP is safe and effective by assessing adverse events and change in disease activity in adult participants with UL ET. AGN-151607-DP is an investigational drug being developed to treat UL ET. Participants will be randomly placed in treatment groups to receive either AGN151607-DP or matching placebo. Approximately 94 adult participants with upper limb essential tremor will be enrolled in approximately 40 sites in the United States/Canada. Participants will receive intramuscular injections of AGN-151607-DP or matching placebo. Duration of the study is approximately 72 weeks. The effect of the treatment will be checked by completion of questionnaires and side effects will be monitored by medical assessments.

Inclusion Criteria: * Minimum body weight of 50 kg (110 pounds) at Screening. * Diagnosis of essential tremor (ET) in accordance with the modified Tremor Research Investigation Group (TRIG) criteria, as follows: * Bilateral postural tremor with or without kinetic tremor, involving hands and forearms * Tremor of other body parts may or may not be present in addition to upper limb (UL) tremor * Bilateral tremor may or may not be asymmetric * Tremor that is reported by the participant to be persistent, although the amplitude may fluctuate. Exclusion Criteria: * History of any medical condition that may put the participant at increased risk with exposure to purified botulinum toxin type A complex, including diagnosed muscular dystrophy (e.g., Duchenne's muscular dystrophy), myasthenia gravis, Eaton-Lambert syndrome, amyotrophic lateral sclerosis, mitochondrial disease, or any other significant disease that might interfere with neuromuscular junctional disorders. * History of an allergic reaction to or significant sensitivity to AGN-151607-DP or its excipients and/or other botulinum toxins.