Company: PRTA
Filing Date: 2025-11-06
Form Type: 10-Q
Source: 0001559053-25-000044
Chunk: 29

Company: PROTHENA CORP PUBLIC LTD CO
Filing Date: 2025-11-06
Form: 10-Q
Item: Part I, Item 2
Chunk 29
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 treatment in early-stage Parkinson’s disease.

Phase 3 PARAISO Clinical Trial

PARAISO is a Phase 3, randomized, double-blind, placebo-controlled, multicenter clinical trial to evaluate the efficacy and safety of prasinezumab in approximately 900 participants with early-stage Parkinson's disease on stable symptomatic monotherapy with levodopa. Primary endpoint of the trial is time to confirmed motor progression event on Movement Disorder Society - Unified Parkinson’s Disease Rating Scale (“ MDS-UPDRS”) Part III score with a timeframe of at least 104 weeks.

Phase 2b PADOVA Clinical Trial

In December 2024, topline results were announced from the Phase 2b clinical trial (PADOVA) conducted by partner Roche investigating prasinezumab in 586 people with early-stage Parkinson’s disease, treated for a minimum of 18 months while on stable symptomatic treatment. In April 2025, results from the Phase 2b PADOVA trial were presented for the first time in an oral presentation by Roche at the International Conference on Alzheimer’s and Parkinson’s Diseases (“ AD/PD 2025”). Prasinezumab showed potential clinical effect in the primary endpoint of time to confirmed motor progression, as assessed by ≥5 point increase in MDS-UPDRS Part III score from baseline, with a HR=0.84 [0.69-1.01] and p=0.0657. The effect of prasinezumab was more pronounced in a pre-specified analysis in the population treated with levodopa (75% of participants), HR=0.79 [0.63-0.99] and nominal p=0.0431. Pre-specified supplementary covariate-adjusted analyses of these endpoints demonstrated nominally significant effects on the primary endpoint (HR=0.81 [0.67-0.98]; nominal p=0.0334) and in the levodopa subgroup (HR=0.76 [0.61-0.95]; nominal p=0.0175). Covariates used for adjustment: medication at baseline, H& Y stage, DaT-SPECT, age, sex, baseline dependent parameter. Consistent positive trends across multiple secondary and exploratory clinical endpoints were also observed. Positive trends towards reduced motor progression at 104 weeks (two years) were observed, showing 30-40% relative reduction versus placebo across the overall and levodopa-treated populations. The PADO