Company: PRTA
Filing Date: 2025-10-07
Form Type: DEF 14A
Source: 0001140361-25-037500
Chunk: 9

Company: PROTHENA CORP PUBLIC LTD CO
Filing Date: 2025-10-07
Form: DEF 14A
Chunk 9
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 AND ANSWERS ABOUT THESE PROXY MATERIALS AND VOTING |

| 13. |     | What is the quorum requirement? |

A quorum of shareholders is necessary to hold a valid meeting. A quorum will be present if the holders of not less than one-half of the ordinary shares issued and outstanding and entitled to vote are present in person or represented by proxy at the EGM. On the Record Date, there were 53,829,928 ordinary shares issued and outstanding and entitled to vote. Accordingly, 26,914,965 ordinary shares must be represented in person or by proxy at the EGM to have a quorum. Your shares will be counted towards the quorum if you submit a valid proxy vote or vote at the EGM. Abstentions will also be counted towards the quorum requirement. If there is no quorum, either the chairperson of the EGM or a majority in voting power of the shareholders entitled to vote at the EGM, present in person or represented by proxy, may adjourn the EGM to another time or place.

| 14. |     | How can I find out the results of the voting at the EGM? |

Voting results will be announced by the filing with the SEC of a Current Report on Form 8-K within four business days after the EGM.

| 15. |     | Where can I find directions to the EGM? |

To obtain directions to the EGM, which will be held at the offices of the Company’s legal counsel, A&L Goodbody LLP, 25 North Wall Quay, Dublin 1, D01 H104, Ireland, you may send a request to our Company Secretary at Prothena Corporation plc, 77 Sir John Rogerson’s Quay, Block C, Grand Canal Docklands, Dublin 2, D02 VK60, Ireland.

| 16. |     | When are shareholder proposals and nominations due for next year’s annual general meeting? |

In accordance with Rule 14a-8 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), shareholders may submit to us proposals on matters appropriate for shareholder action at meetings of our shareholders. In order to be considered for inclusion in next year’s proxy materials, your proposal must comply with the requirements of Rule 14a-8 of the Exchange Act and other SEC rules and be submitted in writing no later than November 28, 2025, to our Company Secretary at Prothena Corporation