Company: PRTA
Filing Date: 2025-03-28
Form Type: DEF 14A
Source: 0001559053-25-000017
Chunk: 44

Company: PROTHENA CORP PUBLIC LTD CO
Filing Date: 2025-03-28
Form: DEF 14A
Chunk 44
---
.

| Why You Should Vote FOR the Amendment to the 2018 LTIP |

In its determination to approve the Amendment, our Board considered an analysis prepared by the compensation consultant engaged by the Compensation Committee, which included an analysis of our historical share usage, certain burn rate metrics, and the costs of the 2018 LTIP. Specifically, our Board considered the following:

• We need the additional 2,000,000 ordinary shares requested in the Amendment to retain and hire the talent deemed necessary to execute on our research and development objectives and long-term strategy. We expect that share authorization, used in conjunction with our 2020 EIIP where appropriate, to provide us with enough shares for

| 26 |     | 2025 PROXY STATEMENT |

TABLE OF CONTENTS

| PROPOSAL NO. 4 – APPROVAL OF AN AMENDMENT |

awards for at least one year (until the annual meeting of our shareholders in 2026).

• In determining the reasonableness of the Amendment, our Board considered our historical equity "burn rate." Equity burn rate is calculated by dividing the number of shares subject to equity awards granted during the fiscal year (without adjusting for forfeitures) by the weighted average ordinary shares outstanding during the fiscal year.

◦ In 2024, 2023, and 2022, we awarded options and restricted share units representing a total of 2,288,450 ordinary shares, 1,802,621 ordinary shares, and 2,343,936 ordinary shares, respectively, under the 2018 LTIP and the 2020 EIIP. This level of option awards represents a three-year average burn rate of approximately 4.20% of weighted average ordinary shares outstanding.

• We do not have an evergreen provision in our 2018 LTIP.

• Our Compensation Committee considers equity awards to be a particularly effective incentive and retention tool because they motivate our employees to increase shareholder value and remain with the Company. Equity awards link compensation directly to increases in the price of our ordinary shares, which directly reflects increased shareholder value; and our equity awards have generally required continued employment for four years in order to

fully vest. All of the companies in the peer group used by the Compensation Committee used option awards for at least a portion of equity compensation.

• Our use of equity awards is broad-based across our organization. All of our employees participate in the 2018 LTIP and/or the 2020 EIIP and we currently expect to continue this approach.

In light