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Clinical Trials

Prothena commences phase 2 trial of Parkinson's disease drug

Published 06 July 2017

Prothena has reported that the first patient has been enrolled in PASADENA, a global Phase 2 study of PRX002/RG7935 in patients with early Parkinson's disease.

PRX002/RG7935 is an anti-alpha-synuclein antibody under investigation as a disease-modifying treatment for Parkinson's disease and is the focus of a worldwide collaboration between Prothena and Roche.

The start of the study triggered a $30 million milestone from Roche to Prothena, which was earned in the second quarter of 2017. Prothena had previously received $45 million in upfront and development milestone payments.

"Building upon the data from two completed Phase 1 studies of PRX002/RG7935, which demonstrated favorable safety, tolerability and pharmacologic properties, the Phase 2 study will evaluate the impact of targeting alpha-synuclein on the slowing of progression of Parkinson's disease in patients," stated Gene Kinney, PhD, President & Chief Executive Officer of Prothena.

"Two dose levels have been selected for the Phase 2 study of PRX002/RG7935 that, based on our preclinical and clinical data, we expect to meaningfully reduce pathogenic alpha-synuclein in the brains of patients with Parkinson's disease."

PASADENA is a two-part Phase 2 clinical study in early Parkinson's disease patients that is being conducted by Roche. Part 1 is a randomized, double-blind, placebo-controlled, three-arm study designed to enroll approximately 300 patients to evaluate the efficacy and safety of PRX002/RG7935 in patients over 52 weeks. In part 1, patients will be randomized on a 1:1:1 basis to receive one of two active doses (1500 mg or 4500 mg) of PRX002/RG7935 or placebo via intravenous infusion once every 4 weeks.

Eligible patients must not be on dopaminergic therapy and must not be expected to require dopaminergic therapy for at least 52 weeks. Part 2 of the study is a 52-week blinded extension phase in which patients from the placebo arm of the study will be re-randomized onto one of two active doses on a 1:1 basis, so that all participants will be on active treatment.

Patients who were originally randomized to an active dose will continue at that dose level for the additional 52 weeks. In part 2, patients will be allowed to use concomitant dopaminergic therapy.

Any patient who medically requires initiation of dopaminergic therapy during part 1 will have their subsequent data censored for the primary endpoint analysis.

The primary endpoint of this study is the comparison of change from baseline in the Movement Disorder Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS) total score (sections 1, 2 and 3) at the completion of part 1 (week 52) in each treatment group vs. the placebo group.

The study is designed with 80 percent power and a one-sided alpha of 0.10 to detect a 37.5 percent relative between group reduction from baseline to week 52. A prespecified exploratory analysis will compare the results of the two pooled treatment arms vs. placebo. Key secondary endpoints include safety, tolerability and DaT-SPECT imaging.

Source: Company Press Release