X0306 4 2022-09-28 0001559053 PROTHENA CORP PUBLIC LTD CO PRTA 0001110751 COLLIER RICHARD T C/O PROTHENA BIOSCIENCES INC 331 OYSTER POINT BOULEVARD SOUTH SAN FRANCISCO CA 94080 true Ordinary Shares, par value $0.01 per share 2022-09-28 4 M 0 25000 6.41 A 26219 D Ordinary Shares, par value $0.01 per share 2022-09-28 4 S 0 25000 48.09 D 1219 D Stock Option (Right to Buy) 6.41 2022-09-28 4 M 0 25000 0 D 2014-01-29 2023-01-29 Ordinary Shares 25000 20000 D The transactions reported in the Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person. The option was granted on January 29, 2013, and all shares subject to the option were fully vested and exercisable January 29, 2014. The option will expire in approximately four months and be forfeited to the extent it is not exercised on or prior to January 29, 2023. /s/ Michael Malecek, as Attorney in Fact for Richard T. Collier 2022-09-30