X0306 4/A 2021-07-12 2021-07-12 0001559053 PROTHENA CORP PUBLIC LTD CO PRTA 0001242880 HENNEY CHRISTOPHER S C/O PROTHENA BIOSCIENCES INC 331 OYSTER POINT BOULEVARD SOUTH SAN FRANCISCO CA 94080 true Ordinary Shares, par value $0.01 per share 2021-07-12 4 M 0 17500 9.23 A 17500 D Ordinary Shares, par value $0.01 per share 2021-07-12 4 S 0 6228 53.843 D 11272 D Ordinary Shares, par value $0.01 per share 2021-07-12 4 S 0 5886 54.554 D 5386 D Ordinary Shares, par value $0.01 per share 2021-07-12 4 S 0 2475 55.9499 D 2911 D Ordinary Shares, par value $0.01 per share 2021-07-12 4 S 0 1634 56.8751 D 1277 D Ordinary Shares, par value $0.01 per share 2021-07-12 4 S 0 500 58.212 D 777 D Ordinary Shares, par value $0.01 per share 2021-07-12 4 S 0 600 59.245 D 177 D Ordinary Shares, par value $0.01 per share 2021-07-12 4 S 0 177 61.25 D 0 D Ordinary Shares, par value $0.01 per share 2021-07-12 4 M 0 6392 11.33 A 6392 D Ordinary Shares, par value $0.01 per share 2021-07-12 4 S 0 2315 55.2572 D 4077 D Ordinary Shares, par value $0.01 per share 2021-07-12 4 S 0 2100 56.5557 D 1977 D Ordinary Shares, par value $0.01 per share 2021-07-12 4 S 0 700 57.8543 D 1277 D Ordinary Shares, par value $0.01 per share 2021-07-12 4 S 0 800 58.655 D 477 D Ordinary Shares, par value $0.01 per share 2021-07-12 4 S 0 300 59.4467 D 177 D Ordinary Shares, par value $0.01 per share 2021-07-12 4 S 0 177 61.25 D 0 D Stock Option (Right to Buy) 9.23 2021-07-12 4 M 0 17500 0 A 2029-05-22 Ordinary Shares 17500 0 D Stock Option (Right to Buy) 11.33 2021-07-12 4 M 0 6392 0 A 2030-05-20 Ordinary Shares 6392 11108 D The transaction was executed in multiple trades in prices ranging from $53.31 to $54.30, inclusive. The price reported in Column 4 above reflects the weighted average sale price. The reporting person hereby undertakes to provide to the Securities and Exchange Commission staff, the Issuer, or a security holder of the Issuer, upon request, full information regarding the number of shares sold at each respective price within the range set forth in this footnote. The transaction was executed in multiple trades in prices ranging from $54.31 to $55.21, inclusive. The price reported in Column 4 above reflects the weighted average sale price. The reporting person hereby undertakes to provide to the Securities and Exchange Commission staff, the Issuer, or a security holder of the Issuer, upon request, full information regarding the number of shares sold at each respective price within the range set forth in this footnote. The transaction was executed in multiple trades in prices ranging from $55.50 to $56.41, inclusive. The price reported in Column 4 above reflects the weighted average sale price. The reporting person hereby undertakes to provide to the Securities and Exchange Commission staff, the Issuer, or a security holder of the Issuer, upon request, full information regarding the number of shares sold at each respective price within the range set forth in this footnote. The transaction was executed in multiple trades in prices ranging from $56.53 to $57.41, inclusive. The price reported in Column 4 above reflects the weighted average sale price. The reporting person hereby undertakes to provide to the Securities and Exchange Commission staff, the Issuer, or a security holder of the Issuer, upon request, full information regarding the number of shares sold at each respective price within the range set forth in this footnote. The transaction was executed in multiple trades in prices ranging from $57.93 to $58.36, inclusive. The price reported in Column 4 above reflects the weighted average sale price. The reporting person hereby undertakes to provide to the Securities and Exchange Commission staff, the Issuer, or a security holder of the Issuer, upon request, full information regarding the number of shares sold at each respective price within the range set forth in this footnote. The transaction was executed in multiple trades in prices ranging from $59.12 to $59.44, inclusive. The price reported in Column 4 above reflects the weighted average sale price. The reporting person hereby undertakes to provide to the Securities and Exchange Commission staff, the Issuer, or a security holder of the Issuer, upon request, full information regarding the number of shares sold at each respective price within the range set forth in this footnote. The transaction was executed in multiple trades in prices ranging from $55.00 to $55.83, inclusive. The price reported in Column 4 above reflects the weighted average sale price. The reporting person hereby undertakes to provide to the Securities and Exchange Commission staff, the Issuer, or a security holder of the Issuer, upon request, full information regarding the number of shares sold at each respective price within the range set forth in this footnote. The transaction was executed in multiple trades in prices ranging from $56.00 to $56.99, inclusive. The price reported in Column 4 above reflects the weighted average sale price. The reporting person hereby undertakes to provide to the Securities and Exchange Commission staff, the Issuer, or a security holder of the Issuer, upon request, full information regarding the number of shares sold at each respective price within the range set forth in this footnote. The transaction was executed in multiple trades in prices ranging from $57.34 to $58.21, inclusive. The price reported in Column 4 above reflects the weighted average sale price. The reporting person hereby undertakes to provide to the Securities and Exchange Commission staff, the Issuer, or a security holder of the Issuer, upon request, full information regarding the number of shares sold at each respective price within the range set forth in this footnote. The transaction was executed in multiple trades in prices ranging from $58.34 to $59.18, inclusive. The price reported in Column 4 above reflects the weighted average sale price. The reporting person hereby undertakes to provide to the Securities and Exchange Commission staff, the Issuer, or a security holder of the Issuer, upon request, full information regarding the number of shares sold at each respective price within the range set forth in this footnote. The transaction was executed in multiple trades in prices ranging from $59.39 to $59.54, inclusive. The price reported in Column 4 above reflects the weighted average sale price. The reporting person hereby undertakes to provide to the Securities and Exchange Commission staff, the Issuer, or a security holder of the Issuer, upon request, full information regarding the number of shares sold at each respective price within the range set forth in this footnote. The shares subject to the option were fully vested as of the date of the exercise. The Reporting Person is filing this amendment to indicate that the sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person. This Form 4 amendment is being filed solely to indicate that the reported sales were effected pursuant to a Rule 10b5-1 trading plan. /s/ Karin L. Walker, as Attorney in Fact for Christopher Henney 2021-07-13