Essential 3 - Decentralized, Phase 3 Study Evaluating the Safety and Efficacy of Ulixacaltamide in Essential Tremor (ET)

Inclusion Criteria: Has a body mass index (BMI) at Screening between 18 and 40 kg/m2, inclusive. Has a clinical diagnosis of ET prior to screening as characterized by postural and action tremor If currently receiving medication prescribed for ET, must be on ≤1 medications, on stable dose(s) for at least 1 month prior to Screening, and willing to maintain stable dose(s) throughout the study. As needed (PRN) use of prescribed ET medicines is not allowed. Primidone use is not allowed within 2 weeks prior to screening and throughout duration of study. Women of childbearing potential must undertake pregnancy tests, with a documented negative serum pregnancy test at Screening on Day -28, negative urine pregnancy tests Baseline (Day 1) prior to administration of study drug, throughout the intervention periods (as outlined in the SoA) and at the SFU or ED Visit, as appropriate. Is willing and able to use contraception as defined in the protocol and ICF. Has been assessed as an appropriate and suitable candidate by investigator and has a neurological exam and medical record(s) consistent with ET diagnosis, as confirmed by the ERC central reviewer. Confirm key inclusion criteria at Baseline Exclusion Criteria: Neuropathy, muscle weakness, arthropathy or other musculoskeletal diagnosis of the upper extremity that impairs dexterity or function. Has a known hypersensitivity to any component of the formulation of ulixacaltamide. Is unwilling or unable to refrain from episodic use of medication(s)/substance(s) that might interfere with the evaluation of tremor during the study. Is sporadically using a benzodiazepine, sleep medication or anxiolytic (as further defined in the protocol), that in the judgement of the investigator or sponsor would confound the assessment of tremor. Has trauma to the nervous system within 3 months preceding the onset of tremor. Has a history of unilateral tremor or clinical evidence of another medical, neurological, or psychiatric condition that may explain or cause tremor, including but not limited to Parkinson's disease, Huntington's disease, Alzheimer's disease, stroke with neurologic sequelae, intention tremor (IT) caused by etiology other than ET, cerebellar disease (including spinocerebellar ataxias), primary dystonia, Fragile X Tremor/Ataxia syndrome or family history of Fragile X syndrome, traumatic brain injury, psychogenic tremor, alcohol or benzodiazepine abuse or withdrawal, multiple sclerosis, polyneuropathy (diabetic neuropathy allowed if disease does not affect gait or balance and does not involve upper extremity), and endocrine states such as uncontrolled or inadequately treated hypothyroidism, food, or supplement induced movement disorders (e.g., tremor related to beta agonists or caffeine), or other medical, neurological, or psychiatric conditions that may explain or cause tremor. Has had prior magnetic resonance-guided focused ultrasound or surgical intervention for ET such as a deep brain stimulator (DBS) or lesion therapy such as thalamotomy. Has had botulinum toxin injection for ET in the 6 months prior to Screening or throughout the study. Is using the Cala kIQ™ health device for ET in 14 days prior to Screening or throughout the study. Is unwilling or unable to refrain from drinking alcohol 24 hours before and during clinical study assessments, or regular use of alcohol that would preclude abstinence from alcohol for this time period around visits. Has a history of substance use disorder consistent with Diagnostic and Statistical Manual of Mental Disorders Fifth Edition Text Revision (DSM-5-TR) criteria. Participants with a previous diagnosis of substance use disorder who have been in remission for at least 2 years can participate in the study. Is currently taking a prescription or non-prescription product(s) and food known to be moderate or strong inhibitors or strong inducers (moderate inducers are not prohibited) of cytochrome P450 (CYP3A4), which cannot be discontinued at least 5 half-lives or 14 days prior (whichever is the longer period of time) to Baseline and withheld throughout the clinical study. Prior participation in an ulixacaltamide clinical study, with the exception of participants that are currently enrolled in and complete the EOT visit in PRAX-944-222 extension period.