Prothena to Present Clinical Results From Its Phase 1 Single Ascending Dose Study of PRX002 at 19th International Congress of Parkinson's Disease and Movement Disorders

Prothena Corporation plc PRTA, a late-stage clinical biotechnology company focused on the discovery, development and commercialization of novel protein immunotherapy programs, today announced that Gene Kinney, PhD, Chief Scientific Officer and Head of Research and Development of Prothena, will highlight clinical results from a Phase 1 single ascending dose study of PRX002, as part of the late breaker abstract track, during a poster presentation at the 19th International Congress of Parkinson's Disease and Movement Disorders to be held June 14 – 18, 2015 in San Diego, CA. PRX002 is a monoclonal antibody for the potential treatment of Parkinson's disease and other related synucleinopathies, and the focus of a worldwide collaboration between Prothena and Roche. Clinical data on PRX002 will be presented in the following session: (Abstract #LBA 19) Results from a Randomized, Double-Blind, Placebo-Controlled, Single Ascending-Dose Study in Healthy Subjects with PRX002, an Anti-Alpha-Synuclein Monoclonal Antibody Presenter: Gene Kinney, PhD, Prothena Corporation plc Session: Late Breaking Abstract Poster Presentation Date and Time: Wednesday, June 17, 2015, 3:00 p.m. – 4:30 p.m. EDT Location: Harbor Foyer Conference Call and Webcast Details Prothena management will discuss the clinical trial results from the Phase 1 single ascending dose study of PRX002 during a live audio webcast and conference call on Wednesday, June 17, 2015 at 5:30 p.m. EDT. The webcast and slide presentation will be made available on the company's website at www.prothena.com under the Investors tab in the Events and Presentations section. Following the live audio webcast, a replay of the webcast will be available on the Company's website for 90 days. To access the conference call via dial-in, please dial (877) 887-5215 (U.S. toll free) or (315) 625-3069 (international) five minutes prior to the start time and refer to conference ID number 54868803. A replay of the call will be available until June 24, 2015 via dial-in at (855) 859-2056 (U.S. toll free) or (404) 537-3406 (international), Conference ID Number 54868803.