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 of other cardinal signs of PD (bradykinesia, rigidity) per the judgment of the investigator.
• Participants must be on a stable dosing regimen of their permitted PD and/or other tremor (eg, propranolol) medications for the treatment of motor symptoms for at least 6 weeks prior to screening and do not anticipate the need to make any changes for the duration of the study. A lack of use of medications used to treat motor symptoms also must be stable for 6 weeks prior to screening and remain stable for the duration of the study.
• Participants have moderate to severe impairment associated with tremor at both the screening and baseline visits, as determined by all the following:
• A score of > 21 on the TETRAS-ADL subscale; and
• CGI-S rating of tremor severity of > 2 (at least moderate for participants ability to function).

KEY Exclusion Criteria

Medical Conditions

• Female participants who are pregnant, nursing, or lactating or plan to become pregnant during the study or within 90 days of study completion.
• Known history or current evidence of other medical or neurological conditions that may cause or explain the participant's tremor, in the opinion of the investigator, including, but not limited to: psychogenic tremor; myoclonus or ataxia; cerebellar disease; traumatic brain injury; alcohol abuse or withdrawal; mercury poisoning; hyperthyroidism; pheochromocytoma; multiple sclerosis; clinically significant polyneuropathy in the opinion of the investigator; or family history or diagnosis of Fragile X syndrome. Note: Participants with a history of essential tremor are eligible.
• 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 interfere with the assessment of tremor and/or "ON"/"OFF" periods that are unpredictable per the opinion of the investigator.
• Clinically significant symptomatic orthostatic hypotension in the opinion of the investigator.
• Has evidence at screening of cognitive impairment as defined by a Montreal Cognitive Assessment (MoCA) score 30% reduction of sensitive substrates area under the plasma concentration-time curve [AUC]), which cannot be discontinued at least 4 weeks before baseline, or planned use at any time during the study.
• Use of prescription or nonprescription drugs or other products (eg, grapefruit) known to be strong or moderate inhibitors of CYP3A4, which cannot be discontinued 2 weeks or 5 half-lives, whichever is longer, before baseline, or planned use at any time during the study.
• Use of proton pump inhibitors, which cannot be discontinued at least 2 weeks before baseline, or planned use at any time during the study. (Occasional use of antacids or histamine receptor type 2 [H2] receptor antagonists will be permitted, but antacids should be taken at least 4 hours apart from study intervention; H2 receptor antagonists should be taken at least 4 hours after and/or 12 hours before study intervention).

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, as prescribed, is permitted. Use of cannabinoids (including cannabidiol) is permitted if there is no impact on tremor symptoms per the judgment of the investigator.

Other protocol-defined inclusion and exclusion criteria may apply.