A Clinical Trial of PRAX-944 in Participants With Essential Tremor

A Phase 2 Clinical Trial Evaluating the Efficacy, Safety, Tolerability, and Pharmacokinetics of PRAX-944 in Adults With Essential Tremor

This is a 2-part clinical trial to evaluate the efficacy, safety, and tolerability of 40 and 120 mg oral PRAX-944 compared to placebo in the treatment of adults with essential tremor. Part A is designed to study the dose titration from 20 to 40 mg every morning (QAM) (ie, 2 weeks with 7 days at each dose level). Part B is designed to study the dose titration from 20 to up to 120 mg QAM with at least 14 days of dosing at the highest tolerated dose for each participant. Blood levels of PRAX-944 will also be measured throughout the trial and pharmacokinetics will be evaluated.

Inclusion Criteria:

1. Clinical diagnosis of ET consistent with Movement Disorders Society Criteria, a duration of ET of at least 3 years and with onset before the age of 65
2. TETRAS upper limb score (ie, sum of bilateral upper limb items 4a, 4b, and 4c) of ≥10 as rated by the Investigator at Screening and Baseline OR A score of ≥2 on 2 or more of the following TETRAS activities of daily living (ADL) subscale items: (2) Feeding with a spoon, (3) Drinking from a glass, (5) Dressing, (6) Pouring, (9) Writing OR A score of ≥2 on 1 of the following TETRAS ADL subscale items: (2) Feeding with a spoon, (3) Drinking from a glass, (5) Dressing, (6) Pouring, or (9) Writing AND a score of ≥2 on both of the following TETRAS ADL subscale items: (10) Working and (12) Social Impact
3. If currently receiving any medication for ET, is on a stable dose of any of these medications for ET for 28 days prior to Screening and is willing to maintain stable doses throughout the trial. If receiving primidone for ET, is willing and able to discontinue 14 days prior to Day 1.
4. Body mass index (BMI) between 18 and 40 kg/m2 (inclusive).

Exclusion Criteria:

1. Sporadically using a benzodiazepine, sleep medication, or anxiolytic that would confound the assessment of tremor.
2. Trauma to the nervous system within 3 months preceding the onset of tremor.
3. History of other medical, neurological or psychiatric condition that may explain or cause tremor, including but not limited to Parkinson's disease, dystonia, cerebellar disease, family history of Fragile X syndrome, traumatic brain injury, alcohol abuse or withdrawal, benzodiazepine abuse or withdrawal, multiple sclerosis, polyneuropathy, and endocrine states such as hyperthyroidism.
4. Prior magnetic resonance-guided focused ultrasound or surgical intervention for ET such as deep brain stimulation or thalamotomy.
5. Botulinum toxin injection for ET in the 6 months prior to Screening.
6. Unwilling or unable to refrain from alcohol 24 hours before and during clinical trial visits.
7. History of substance use disorder