Company: PRTA
Filing Date: 2025-11-06
Form Type: DEFA14A
Source: 0001193125-25-269620
Chunk: 6

Company: PROTHENA CORP PUBLIC LTD CO
Filing Date: 2025-11-06
Form: DEFA14A
Chunk 6
---
5, Prothena had $331.7 million in
cash, cash equivalents and restricted cash, and no debt.

As of October 31, 2025, Prothena had approximately 53.8 million ordinary shares
outstanding.

2025 Financial Guidance

The Company continues to expect its full year net cash used in operating and investing activities to be $170 to $178 million and to end the year with
approximately $298 million (midpoint) in cash, cash equivalents, and restricted cash. The estimated full year 2025 net cash used from operating and investing activities is primarily driven by an estimated net loss of $240 to $248 million,
which includes an estimated $36 million of non-cash share-based compensation expense and a $44.9 million non-cash income tax expense to book a full valuation
allowance against its federal deferred tax assets.

Share Redemption Program

Prothena will convene an Extraordinary General Meeting (“EGM”) of shareholders on November 19, 2025 to vote on a proposal to approve a
reduction in Prothena’s share capital to create distributable reserves, subject to confirmation by the Irish High Court, to support a potential share redemption program. The Board of Directors is seeking shareholder approval of such a proposal
to create flexibility to potentially return capital to shareholders via a share redemption program through open market purchases or other permissible means in 2026. Any such program would be subject to the discretion of the Board of Directors and
Prothena’s then-current financial condition.

About Prothena

Prothena Corporation plc is a late-stage clinical biotechnology company with expertise in protein dysregulation and a pipeline of investigational therapeutics
with the potential to change the course of devastating neurodegenerative and rare peripheral amyloid diseases. Fueled by its deep scientific expertise built over decades of research, Prothena is advancing a pipeline of therapeutic candidates for a
number of indications and novel targets for which its ability to integrate scientific insights around neurological dysfunction and the biology of misfolded proteins can be leveraged. Prothena’s pipeline includes both wholly-owned and partnered
programs being developed for the potential treatment of diseases including ATTR amyloidosis with cardiomyopathy, Alzheimer’s disease, Parkinson’s disease and a number of other neurodegenerative diseases. For more information, please
visit the Company’s website at www.prothena.com and follow the Company on X (formerly Twitter) @ProthenaCorp.

Forward-Looking Statements