SCHEDULE 13G/A

PROTHENA CORP PLC

Ordinary Shares, par value $0.01 per share · CUSIP: G72800108

Event date: 2025-09-30

Reporting persons may disclose overlapping interests. Their amounts are shown individually and are not added into a filing total.

Filing-level shares

Unavailable

Percent of class

Unavailable

• ADAR1 Capital Management, LLC

  Shares: 1,469,098.00 · Class: 2.7%

• ADAR1 Capital Management GP, LLC

  Shares: 1,189,587.00 · Class: 2.2%

• Daniel Schneeberger

  Shares: 1,469,098.00 · Class: 2.7%

Amounts are as disclosed in this filing. Schedule type alone does not establish investment intent.