PROTHENA CORP PUBLIC LTD CO — Director's Dealing 2013

Jan 31, 2013

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: Prothena Corp plc (PRTA)
CIK: 0001559053
Period of Report: 2013-01-29

Reporting Person: Kinney Gene G. (CSO & Head of R&D)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2013-01-30	Ordinary Shares, par value $0.01 per share	J	25	—	Acquired	293	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2013-01-29	Stock Option (right to buy)	$6.41	A	200000	Acquired	2023-01-29	Ordinary Shares (200000)	Direct

Footnotes

F1: Represents an additional number of Issuer's ordinary shares held by Reporting Person after giving effect to the distribution of Issuer's ordinary shares in connection with the spin-off of the Issuer from Elan Pharmaceuticals, Inc. ("Elan") completed on December 20, 2012. Reporting Person received one Issuer ordinary share for each 41 Elan ordinary shares or Elan American Depository Shares held by Reporting Person as of December 14, 2012, the record date for the spin off. Such shares had not been received at the time of, and therefore were not included with, the original allocation reported previously on Reporting Person's Form 3, Initial Statement of Beneficial Ownership.

F2: Exercise price is equal to the average per share closing price of the Issuer's ordinary shares for the first 25 trading days commencing on December 21, 2012.

F3: 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 January 29, 2014 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.