• Prothena 10% owner William P. Scully bought 50,000 ordinary shares at a weighted average price of $9.31.
• His directly held stake rose to 936,000 ordinary shares.
• He also reported indirect holdings of 80,000 shares via Manatee Equity Fund LLC, plus 52,000 shares held by his spouse.

Disclaimer: This news brief was created by Public Technologies (PUBT) using generative artificial intelligence. While PUBT strives to provide accurate and timely information, this AI-generated content is for informational purposes only and should not be interpreted as financial, investment, or legal advice. Prothena Corporation plc published the original content used to generate this news brief via EDGAR, the Electronic Data Gathering, Analysis, and Retrieval system operated by the U.S. Securities and Exchange Commission (Ref. ID: 0001045463-26-000006), on June 05, 2026, and is solely responsible for the information contained therein.