<SEC-DOCUMENT>0000080255-18-002727-index.html : 20180510
<SEC-HEADER>0000080255-18-002727.hdr.sgml : 20180510
<ACCEPTANCE-DATETIME>20180510090222
ACCESSION NUMBER:		0000080255-18-002727
CONFORMED SUBMISSION TYPE:	SC 13G/A
CONFIRMING COPY:	
PUBLIC DOCUMENT COUNT:		1
FILED AS OF DATE:		20180510
DATE AS OF CHANGE:		20180510

SUBJECT COMPANY:	

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Prothena Corp plc
		CENTRAL INDEX KEY:			0001559053
		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
		IRS NUMBER:				000000000
		STATE OF INCORPORATION:			L2
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		SC 13G/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	005-87112

	BUSINESS ADDRESS:	
		STREET 1:		ADELPHI PLAZA
		STREET 2:		UPPER GEORGE'S STREET
		CITY:			DUN LAOGHAIRE, CO. DUBLIN
		STATE:			L2
		ZIP:			A96 T927
		BUSINESS PHONE:		011-353-1-236-2500

	MAIL ADDRESS:	
		STREET 1:		ADELPHI PLAZA
		STREET 2:		UPPER GEORGE'S STREET
		CITY:			DUN LAOGHAIRE, CO. DUBLIN
		STATE:			L2
		ZIP:			A96 T927

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	Neotope Corp Ltd
		DATE OF NAME CHANGE:	20120926

FILED BY:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			PRICE T ROWE ASSOCIATES INC /MD/
		CENTRAL INDEX KEY:			0000080255
		STANDARD INDUSTRIAL CLASSIFICATION:	SECURITY & COMMODITY BROKERS, DEALERS, EXCHANGES & SERVICES [6200]
		IRS NUMBER:				520556948
		STATE OF INCORPORATION:			MD
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		SC 13G/A

	BUSINESS ADDRESS:	
		STREET 1:		100 EAST PRATT ST
		CITY:			BALTIMORE
		STATE:			MD
		ZIP:			21202
		BUSINESS PHONE:		(410)345-6603

	MAIL ADDRESS:	
		STREET 1:		P.O. BOX 89000
		CITY:			BALTIMORE
		STATE:			MD
		ZIP:			21289
</SEC-HEADER>
<DOCUMENT>
<TYPE>SC 13G/A
<SEQUENCE>1
<FILENAME>prta13gaapr18.txt
<TEXT>
Document 1 - file: prta13gaapr18.txt

</DOCUMENT>
</SEC-DOCUMENT>