Aggregated alpha-synuclein (α-syn), a major constituent of Lewy bodies, is thought to play a central role in the progression of PD. Cinpanemab (BIIB054), a monoclonal antibody that preferentially binds to aggregated forms of α-syn, is in development as a potential treatment for PD.

Baseline characteristics of participants enrolled in the SPARK trial, an ongoing phase 2, randomized, double-blind, placebo-controlled, adaptively designed, parallel group study to evaluate safety of Cinpanemab for PD, were analyzed. The study enrolled untreated participants aged 40–80 years, diagnosed with PD within 3 years and who had SPECT imaging with DaTscan^TM showing evidence of striatal dopaminergic deficit. Participants were randomized to treatment with Cinpanemab or placebo, administered intravenously every 4 weeks.

Enrollment began in January 2018, at 85 sites in 9 countries, and has been completed. Baseline data were summarized for 357 participants (mean [SD] age, 60.1 [9.02] years). The majority of participants are male (70.0%), and most are Caucasian (90.8%). Median time since disease onset at enrollment was 1.4 years, and median time since diagnosis was 0.5 years. Baseline mean (SD) Movement Disorder Society Unified PD Rating Scale (MDS-UPDRS) total score was 32.2 (12.61). Additional baseline characteristics including Modified Schwab and England ADL scale, Physical Activity Scale for the Elderly (PASE), and cognitive function, as measured by the Montreal Cognitive Assessment (MoCA), will be presented.

The SPARK trial participants exhibit disease characteristics at baseline typical for early PD and provide contemporaneous information on early PD clinical trial recruitment. Trial recruitment was completed ahead of projected timelines, confirming the feasibility of rapid enrollment of de novo patients with PD.