Company: PRTA
Filing Date: 2025-03-28
Form Type: DEF 14A
Source: 0001559053-25-000017
Chunk: 103

Company: PROTHENA CORP PUBLIC LTD CO
Filing Date: 2025-03-28
Form: DEF 14A
Chunk 103
---
 upon written or oral request to the address or telephone number above, a separate copy of the Notice of Internet Availability of Proxy Materials or other Annual Meeting materials to a shareholder at a shared address to which a single copy of the documents was delivered.

### ANNUAL REPORT
Our Annual Report on Form 10-K for fiscal year 2024 is being mailed with this Proxy Statement to those shareholders that receive this Proxy Statement in the mail. Shareholders that receive the Notice of Internet Availability of Proxy Materials can access our Annual Report on Form 10-K for 2024 at www.proxyvote.com (which does not have "cookies" that identify visitors to the site).

Our Annual Report on Form 10-K for our fiscal year 2024 has also been filed with the SEC. It is available free of charge at the SEC's website at www.sec.gov . Upon written request by a shareholder, we will mail without charge a copy of our Annual Report on Form 10-K, including the financial statements and financial statement schedules, but excluding exhibits. Exhibits to our Annual Report on Form 10-K are available upon payment of a reasonable fee, which is limited to our expenses in furnishing the requested exhibit. All requests should be directed to our Company Secretary at Prothena Corporation plc, 77 Sir John Rogerson’s Quay, Block C, Grand Canal Docklands, Dublin 2, D02 VK60, Ireland.

| By Order of the Board of Directors |
| Yvonne M. Tchrakian                |
| Company Secretary                  |
| Dublin, Ireland                    |
| March 28, 2025                     |

| 2025 PROXY STATEMENT |     | 63 |

#### TABLE OF CONTENTS

### APPENDIX A

### AMENDMENT TO

#### THE PROTHENA CORPORATION PLC 2018

### LONG TERM INCENTIVE PLAN
Section 2.28 of the Prothena Corporation plc 2018 Long Term Incentive Plan is proposed to be amended as indicated below:

2.28 " Overall Share Limit " means the sum of (i) 13,100,000 11,100,000 Shares; (ii) the aggregate number of Shares that remain available for future awards under the Prior Plan as of immediately prior to the Effective Date; and (iii) any Shares that are subject to Prior Plan Awards that become available for issuance under the Plan pursuant to Article V.

| 2025 PROXY STATEMENT |     | A-1 |

#### TABLE OF CONTENTS