Karin L. Walker - 03 Mar 2026 Form 4 Insider Report for PROTHENA CORP PUBLIC LTD CO (PRTA)

Role: Chief Accounting Officer
Signature: /s/ Michael J. Malecek, as Attorney-in-Fact for Karin L. Walker
Issuer symbol: PRTA
Transactions as of: 03 Mar 2026
Net transactions value: $0
Form type: 4
Filing time: 05 Mar 2026, 16:51:02 UTC
Previous filing: 30 Jul 2025
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
Walker Karin L	Chief Accounting Officer	C/O PROTHENA BIOSCIENCES INC, 1800 SIERRA POINT PARKWAY, BRISBANE	/s/ Michael J. Malecek, as Attorney-in-Fact for Karin L. Walker	05 Mar 2026	0001559422

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Underlying Class	Amount	Exercise Price	Ownership	Footnotes
transaction	PRTA	Stock Option (Right to Buy)	Award		+150,000		$0.000000^*	150,000	03 Mar 2026	Ordinary Shares	150,000	$9.36	Direct	F1

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	The shares subject to the option will vest and become exercisable as to 25% of the total number of shares subject to the option on March 3, 2027, and with respect to 1/48th of the total number of shares subject to the option in successive, equal monthly installments on each monthly anniversary thereafter, subject to the Reporting Person's continued employment with the Issuer on each such vesting date.

Content

The shares subject to the option will vest and become exercisable as to 25% of the total number of shares subject to the option on March 3, 2027, and with respect to 1/48th of the total number of shares subject to the option in successive, equal monthly installments on each monthly anniversary thereafter, subject to the Reporting Person's continued employment with the Issuer on each such vesting date.