A Study of Suvecaltamide in Adults With Moderate to Severe Residual Tremor in Parkinson's Disease

KEY Inclusion Criteria:

• Diagnosis of clinically probable or clinically established Parkinson's disease (PD)meeting the Movement Disorder Society (MDS) 2015 criteria.

• Participants must be individually optimized on PD medications for the treatment ofother cardinal signs of PD (bradykinesia, rigidity) per the judgment of theinvestigator.

• Participants must be on a stable dosing regimen of their permitted PD and/or othertremor (eg, propranolol) medications for the treatment of motor symptoms for atleast 6 weeks prior to screening and do not anticipate the need to make any changesfor the duration of the study. A lack of use of medications used to treat motorsymptoms also must be stable for 6 weeks prior to screening and remain stable forthe duration of the study.

• Participants have moderate to severe impairment associated with tremor at both thescreening and baseline visits, as determined by all the following:

1. A score of > 21 on the TETRAS-ADL subscale; and

2. CGI-S rating of tremor severity of > 2 (at least moderate for participantsability to function).

KEY Exclusion Criteria:

Medical Conditions

• Female participants who are pregnant, nursing, or lactating or plan to becomepregnant during the study or within 90 days of study completion.

• Known history or current evidence of other medical or neurological conditions thatmay cause or explain the participant's tremor, in the opinion of the investigator,including, but not limited to: psychogenic tremor; myoclonus or ataxia; cerebellardisease; traumatic brain injury; alcohol abuse or withdrawal; mercury poisoning;hyperthyroidism; pheochromocytoma; multiple sclerosis; clinically significantpolyneuropathy in the opinion of the investigator; or family history or diagnosis ofFragile X syndrome. Note: Participants with a history of essential tremor areeligible.

• Hoehn & Yahr stage 5 (confinement to bed or wheelchair unless aided).

• Participants who only experience tremor during their "OFF" periods.

• Severity of motor fluctuations or medication-induced dyskinesia that would interferewith the assessment of tremor and/or "ON"/"OFF" periods that are unpredictable perthe opinion of the investigator.

• Clinically significant symptomatic orthostatic hypotension in the opinion of theinvestigator.

• Has evidence at screening of cognitive impairment as defined by a Montreal CognitiveAssessment (MoCA) score < 22 or has a cognitive impairment that, in theinvestigator's opinion, would prevent completion of study procedures or the abilityto provide informed consent.

• History or presence of gastrointestinal disease (including prior bariatric bypasssurgery), hepatic (including ALT or AST ≥ 2 × ULN or total bilirubin ≥ 1.5 ULN), orsevere renal impairment or end-stage renal disease, or any other condition that, inthe opinion of the investigator, may interfere with the absorption, distribution,metabolism, or excretion of suvecaltamide.

• Presence of significant cardiovascular disease at Screening

• History or presence of bipolar and related mood disorders, schizophrenia,schizophrenia spectrum disorders, or other psychotic disorders according toDiagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5)criteria.

Prior/Concomitant Therapy

• Treatment-naïve patients (ie, those who have never tried PD medication) are excludedfrom participating in the study.

• Use of PRN medication/substance(s) that might produce or interfere with theevaluation of tremor on study visit days prior to discharge

• Prior or planned surgical intervention to treat PD, including but not limited tomagnetic resonance-guided focused ultrasound thalamotomy, deep brain stimulation,ablative thalamotomy, and gamma knife thalamotomy.

• Use of PRN medications to treat tremor or continuous infusion of PD medications.Note: Use of dopaminergic rescue medications (eg, PRN use of carbidopa/levodopa,including levodopa inhalation powder) for non-tremor PD symptoms (eg, rigidity orbradykinesia) is permitted.

• Botulinum toxin injection for the treatment of tremor in the 6 months beforescreening or planned use at any time during the study. Note: Use of botulinum toxinfor other reasons (eg, cosmetic, excessive salivation, dystonia) is permitted aslong as the location of use is anatomically distinct from the region with tremor.

• Use of prescription or nonprescription drugs or other products (eg, St. John's Wort)known to be inducers of cytochrome 3A4 (CYP3A4) (cause > 30% reduction of sensitivesubstrates area under the plasma concentration-time curve [AUC]), which cannot bediscontinued at least 4 weeks before baseline, or planned use at any time during thestudy.

• Use of prescription or nonprescription drugs or other products (eg, grapefruit)known to be strong or moderate inhibitors of CYP3A4, which cannot be discontinued 2weeks or 5 half-lives, whichever is longer, before baseline, or planned use at anytime during the study.

• Use of proton pump inhibitors, which cannot be discontinued at least 2 weeks beforebaseline, or planned use at any time during the study. (Occasional use of antacidsor histamine receptor type 2 [H2] receptor antagonists will be permitted, butantacids should be taken at least 4 hours apart from study intervention; H2 receptorantagonists should be taken at least 4 hours after and/or 12 hours before studyintervention).

Diagnostic Assessments

• Known use of recreational drugs, inclusive of the following: phencyclidine, cocaine,opioids, barbiturates, amphetamines, or 3,4-methylenedioxymethamphetamine [ecstasy].

• Opioid use at stable doses, either regularly or PRN, for pain management, asprescribed, is permitted. Use of cannabinoids (including cannabidiol) is permittedif there is no impact on tremor symptoms per the judgment of the investigator.

Other protocol-defined inclusion and exclusion criteria may apply.