A Study to Assess Single and Multiple Doses of IkT-148009 in Healthy Elderly Participants and Parkinson's Patients

This is a randomized, Phase 1 study in older adult or elderly healthy volunteer subjects with subsequent extension into Parkinson patients to identify the safety, tolerability, maximum tolerated dose (MTD) and the pharmacokinetic (PK) profile of IkT-148009 capsules given as single or multiple doses. In Part A (SAD) cohorts will consist of eight (8) subjects, six (6) of whom will receive treatment with IkT-148009 and two (2) with matching placebo. Sentinel dosing will be employed on the first day of each cohort, with one subject randomized to receive IkT-148009 and the other placebo. These two subjects in each cohort will be monitored for 48 hours after dosing before deciding to dose the remainder of the cohort. The other six subjects in the first cohort will be dosed approximately 48 hours later. Each cohort will be monitored for at least 48 hours before deciding whether to administer drug to the sentinel pair for the next cohort. Each cohort will be dosed at approximately weekly intervals to allow adequate time for collection and review of safety and PK data. A Safety Review Committee (SRC) will evaluate all available safety, tolerability, and PK data for each cohort. Escalation to a next dose will be undertaken only after these data have been reviewed by the SRC and agreement reached that it is safe to increase the dose. The SRC will not receive any unblinded PK data unless they agree to unblind a subject and/or cohort based on the completed safety review. In Part B (MAD) cohorts will consist of eight (8) subjects, six (6) of whom will receive treatment with IkT-148009 and two (2) with matching placebo daily for up to seven consecutive days. Subjects in each cohort will be observed for 48 hours after their last dose before deciding to initiate the next (higher dose) cohort. Each cohort will be dosed at approximately weekly intervals in order to allow adequate time for collection and review of safety and PK data. At the discretion of the SRC, MAD cohorts may be added consisting of eligible participants with Parkinson's Disease (Part C). In Part C (MAD with Parkinson\'s Disease) eligible PD participants will arrive the evening before initiation of study drug dosing. No Parkinsonism medications will be given after midnight, the following morning potential participants will be clinically assessed in the practically-defined OFF state using MDS-UPDRS Part III. Cohorts will consist of eight (8) subjects, six (6) of whom will receive treatment with IkT-148009 and two (2) with matching placebo daily for up to seven consecutive days. Subjects in each cohort will be observed for 48 hours after their last dose before deciding to initiate the next (higher dose) cohort. Each cohort will be dosed at approximately weekly intervals in order to allow adequate time for collection and review of safety and PK data.