Form 4 Filing for William P. Scully

This filing details transactions made by William P. Scully, a 10% owner of PROTHENA CORP PUBLIC LTD CO. On October 7, 2026, Mr. Scully acquired 125,000 ordinary shares at a weighted average price of $8.4012 per share. On October 8, 2026, he acquired an additional 90,000 ordinary shares at a weighted average price of $8.5656 per share. Following these transactions, his direct ownership stands at 927,000 shares. Additionally, he has indirect ownership of 187,000 shares through Manatee Equity Fund LLC. The transactions were executed via a Power of Attorney from William P. Scully by Reid E. Buchanan.