 DUBLIN, Ireland, March 24, 2021 GLOBE NEWSWIRE -- Prothena Corporation plc NASDAQ:PRTA, a late-stage clinical company with expertise in protein dysregulation and a pipeline of investigational therapeutics for rare peripheral amyloid and neurodegenerative diseases, today announced that it priced an underwritten public offering of 3,500,000 of its ordinary shares at a price to the public of 20.75 per ordinary share, before the underwriting discount and estimated offering expenses. All of the ordinary shares in the offering were sold by Prothena. In addition, Prothena has granted the underwriters a 30-day option to purchase up to an additional 525,000 of its ordinary shares. 