X0609 4 2026-06-02 0 0001559053 PROTHENA CORP PUBLIC LTD CO PRTA 0001045463 SCULLY WILLIAM P false 771 MANATEE COVE VERO BEACH FL 32963 0 0 1 0 0 Ordinary Shares, par value $0.01 per share 2026-06-02 4 P 0 50000 9.426 A 886000 D Ordinary Shares, par value $0.01 per share 80000 I By Manatee Equity Fund LLC Ordinary Shares, par value $0.01 per share 52000 I By Spouse The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $9.2323 to $9.4892, inclusive. The reporting person undertakes to provide to Prothena Corp Public Ltd Co, any security holder of Prothena Corp Public Ltd Co, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in footnote (1) to this Form 4. The reporting person disclaims beneficial ownership of these securities except to the extent of his pecuniary interest therein. Reid E. Buchanan by POA from William P. Scully 2026-06-03