Safety, Tolerability, and Pharmacokinetics of Exidavnemab in Patients With Parkinson's Disease and Patients With Multiple System Atrophy

Inclusion criteria

• ✓. Male and female participants 40 to 85 years of age.
• ✓. Body weight more than or equal to 50 kg and less than or equal to 120 kg.
• ✓. Have idiopathic PD (i.e., not induced by drugs or other diseases) as defined by bradykinesia combined with at least 1 of resting tremor and rigidity, as per the Movement Disorder Society Criteria for PD (Postuma, et al. 2015).
• ✓. Classified as Stage 1 to 2.5 on the modified Hoehn and Yahr scale for the staging of PD severity.
• ✓. Participants must have cognition inconsistent with dementia as confirmed by a score of more than or equal to 22 on the MoCA.
• ✓. Stable and optimized symptomatic PD medication, defined as the same list of medications for at least 3 months prior to the Screening Visit with no change in the dose for at least 1 month prior to the Baseline Visit, and no planned changes in dose-regimen during trial participation.
• ✓. Prior (any time; i.e., no time limit) or current DaT-SPECT or DaT-PET consistent with dopamine transporter deficit, as per the Movement Disorder Society Criteria for PD(Postuma, et al. 2015). For participants who have not undergone DaT-SPECT or DaT-PET prior to Screening, or who have previously undergone DaT-SPECT or DaT-PET scan(s) but without results consistent with dopamine transporter deficit, DaT-SPECT or DaT-PET should be performed and read locally as part of the Screening procedures.
• ✓. Positive smell test showing hyposmia, as defined by UPSIT scores of around or below the 15% percentile for their relevant sex and age group. Cut-off scores are provided below for reference (Table 5.1; based on Brumm, et al. 2023) Ability to use a tablet device to measure cognitive function, as per Investigator judgment.

Exclusion criteria