a phase 2 study of cx-8998 in adults with tremor associated with parkinson's disease

Conditions: Parkinson's Disease; Tremor

Summary: this is a phase 2, multicenter, double-blind, placebo-controlled, parallel-group study consisting of a screening period of up to 4 weeks, a 4 week randomized double-blind, dose-titration treatment period, followed by a 1 week safety follow-up period after the last dose of study medication, and a scheduled follow-up safety telephone call one week later.

this is a phase 2, multicenter, double-blind, placebo-controlled, parallel-group study consisting of a screening period of up to 4 weeks, a 4 week randomized double-blind, dose-titration treatment period, followed by a 1 week safety follow-up period after the last dose of study medication, and a scheduled follow-up safety telephone call one week later. subjects will be randomized 1:1 to one of two treatment groups. group a will receive titrating doses of cx-8998 up to 10 mg bid and group b will receive placebo. subjects will participate for a total of up to 12 weeks, including screening, the 4-week treatment period and follow-up.

Eligibility criteria:
inclusion criteria: * men or non-pregnant, non-breastfeeding women 40 to 80 years-of-age who are able to read and understand english. * mini mental state exam (mmse) score ≥ 24. * clinical diagnosis of idiopathic parkinson's disease and presence of at least 2 out of 3 cardinal characteristics (tremor, rigidity, and/or bradykinesia). * hoehn \& yahr stage i iii (inclusive) if not experiencing motor fluctuations. if experiencing motor fluctuations, must be hoehn \& yahr stage i iv (inclusive) when off or i-iii (inclusive) when on. * an mds-updrs tremor score (sum of items 2.10, 3.15, 3.16, 3.17, 3.18) of a least 10 (during on for subjects experiencing fluctuations) (centrally rated) (forjaz et al., 2015). a limited number of subjects with an mds-updrs of 8 or 9 may be included with sponsor approval. * treated with a stable regimen of anti-parkinsonian and/or anti-tremor medication (with the exception of primidone) for at least 2 weeks prior to screening. changes to anti-parkinsonian or anti-tremor medications after screening is not permitted. exclusion criteria: * current diagnosis of: a. essential tremor / b. cerebellar disease * presence or known history of: a. significant visual hallucinations (in the opinion of the investigator and/or study safety representative) / b. significant impulse control disorder (icd) (in the opinion of the investigator and/or study safety representative). * history or clinical features consistent with an atypical parkinsonian syndrome. * dyskinesia or dystonia that would, in the opinion of the investigator, central rater, or sponsor, interfere with the assessment of tremor. * exposure to tremorigenic drugs or drug withdrawal states within the 30 days prior to the first planned dose of study drug. * direct or indirect trauma to the nervous system within 3 months preceding the onset of tremor. * history or clinical evidence of psychogenic tremor origin. known history of other medical or neurological conditions that may cause or explain subject's tremor. * prior mr-guided focused ultrasound or surgical intervention (e.g., deep brain stimulation, ablative thalamotomy or gamma knife thalamotomy) for treatment of tremor or parkinson's disease. * use of medication(s) in the past month that might produce tremor or interfere with the evaluation of tremor. * inability to refrain from use of medication/substance(s) that might produce tremor or interfere with the evaluation of tremor on study visit days. * positive urine drug screen for drugs of abuse, except if this is explained by use of an allowed prescription medicine. * regular use of more than two units of alcohol per day. * use of prescription or non-prescription drugs or other products (i.e. grapefruit juice) known to be strong inhibitors or inducers of cyp3a4 which cannot be discontinued 2 weeks prior to day 1 of dosing and withheld throughout the study. * concurrent illnesses that would be a contraindication to trial participation. * psychological, social, familial, or geographical reasons that would hinder or prevent compliance with the requirements of the protocol or compromise the informed consent process. * any other condition and/or situation that causes the investigator or study safety representative to deem a subject unsuitable for the study (e.g., due to expected study medication non-compliance, inability to medically tolerate the study procedures, or a subject's unwillingness to comply with study-related procedures). * treatment with an investigational agent within 30 days prior to the first dose of cx-8998 or planning to receive an investigational agent during the study.