A Phase 2b, multicenter, randomized, double-blind, placebo-controlled study to evaluate the efficacy and safety of intravenous prasinezumab in early-stage Parkinson's disease (PADOVA): Rationale, design, and baseline data

Abstract

Introduction: Prasinezumab was shown to potentially delay motor progression in individuals with early-stage Parkinson's disease (PD) who were either treatment-naïve or on monoamine oxidase type B inhibitor (MAO-Bi) therapy in the PASADENA study. We report the rationale, design, and baseline patient characteristics of the PADOVA study, designed to evaluate prasinezumab in an early-stage PD population receiving standard-of-care (SOC) symptomatic medications.

Methods: PADOVA (NCT04777331) is a Phase 2b, multicenter, randomized, double-blind, placebo-controlled, parallel-group study, in which individuals with early-stage PD on SOC stable symptomatic monotherapy (levodopa or MAO-Bi) receive intravenous prasinezumab 1500 mg every 4 weeks. The primary endpoint is time to confirmed motor progression, defined as ≥5 points increase from baseline on the Movement Disorder Society-sponsored revision of the Unified Parkinson's Disease Rating Scale (MDS-UPDRS) Part III in practically defined OFF-medication state.

Results: 586 participants were enrolled between May 5th, 2021 and March 22nd, 2023. At baseline, 74.2 % and 25.8 % of participants were receiving levodopa and MAO-Bi, respectively. Mean age was 64.2 years and 63.5 % were male. Mean time from diagnosis was 18.6 months, 85 % of participants were in Hoehn & Yahr (H&Y) Stage 2, and mean MDS-UPDRS Part III score was 24.5. Compared with the PASADENA population, PADOVA participants were older (∼5 years), with longer disease duration (∼8 months), and slightly more advanced based on H&Y stage (10 % more in Stage 2) and MDS-UPDRS Part III (∼3 points more).

Conclusions: PADOVA has successfully recruited an early-stage PD population to test the effect of prasinezumab when added to background SOC.

Keywords: Alpha-synuclein; Clinical trial; Levodopa; Monoamine oxidase; Monoclonal antibodies; Parkinson's disease.