PROTHENA CORP PUBLIC LTD CO — Director's Dealing 2017

Mar 3, 2017

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: Prothena Corp plc (PRTA)
CIK: 0001559053
Period of Report: 2017-03-01

Reporting Person: HOMAN ARTHUR W (Chief Legal Officer)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2017-03-01	Ordinary Shares, par value $0.01 per share	M	3125	$22.14	Acquired	3125	Direct
2017-03-01	Ordinary Shares, par value $0.01 per share	S	3125	$59.2824	Disposed	0	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2017-03-01	Stock Option (right to buy)	$22.14	M	3125	Disposed	2024-05-01	Ordinary Shares (3125)	Direct

Holdings (Non-Derivative)

Security	Shares	Ownership
Ordinary Shares, par value $0.01 per share	2000	Indirect

Footnotes

F1: The sale reported in the Form 4 was effected pursuant to a Rule 10b5 1 trading plan adopted by the Reporting Person.

F2: The transaction was executed in multiple trades in prices ranging from $58.86 to $59.785, inclusive. The price reported in Column 4 above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the Issuer, or a stockholder of the Issuer, information regarding the number of shares and prices at which the transaction was effected.

F3: The shares are held by the Homan Family Trust, dated 9/21/2001, of which the Reporting Person is a trustee.

F4: 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 April 30, 2015 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 or service relationship with the Issuer on each such vesting date.