Company: PRTA
Filing Date: 2025-05-08
Form Type: 10-Q
Source: 0001559053-25-000023
Chunk: 30

Company: PROTHENA CORP PUBLIC LTD CO
Filing Date: 2025-05-08
Form: 10-Q
Item: Part I, Item 2
Chunk 30
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.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, in addition to a potential biological effect of prasinezumab on MRI biomarkers. Prasinezumab continues to be well tolerated and no new safety signals were observed in the study.

Prasinezumab is the first anti-alpha synuclein antibody to advance into late-stage development. In March 2022, results from the analysis of part 2 of the Phase 2 PASADENA trial of prasinezumab were presented in an oral presentation by Roche at the International Conference on Alzheimer’s and Parkinson’s Diseases (“ AD/PD 2022”). Results showed that participants with Parkinson’s disease who were treated with prasinezumab for two years (early-start group) showed slower decline of MDS-UPDRS Part III scores relative to participants treated with placebo in the first year and prasinezumab in the second year (delayed-start group), further supporting a potential effect on delaying motor progression in patients. In October 2024, Roche published results inNature Medicine from the long term open-label extension of the PASADENA trial, which compared the prasinezumab population with a propensity score-balanced cohort of real-world data (“ RWD”) Parkinson’s Progression Markers Initiative (“ PPMI”). The data suggests that prasinezumab continued to show reduced motor and functional progression in prazinezumab-treated individuals with early-stage Parkinson’s disease compared to a real-world data arm on MDS-UPDRS Part III score (clinician rated motor examination) OFF and ON symptomatic medication state and