<SEC-DOCUMENT>0001144204-18-009568-index.html : 20180216
<SEC-HEADER>0001144204-18-009568.hdr.sgml : 20180216
<ACCEPTANCE-DATETIME>20180216164224
ACCESSION NUMBER:		0001144204-18-009568
CONFORMED SUBMISSION TYPE:	SC 13D/A
PUBLIC DOCUMENT COUNT:		1
FILED AS OF DATE:		20180216
DATE AS OF CHANGE:		20180216
GROUP MEMBERS:		PETER KOLCHINSKY
GROUP MEMBERS:		RA CAPITAL HEALTHCARE FUND, L.P.

SUBJECT COMPANY:	

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Ra Pharmaceuticals, Inc.
		CENTRAL INDEX KEY:			0001481512
		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
		IRS NUMBER:				262908274
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		SC 13D/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	005-89680
		FILM NUMBER:		18621770

	BUSINESS ADDRESS:	
		STREET 1:		87 CAMBRIDGE PARK DRIVE
		CITY:			CAMBRIDGE
		STATE:			MA
		ZIP:			02140
		BUSINESS PHONE:		(617) 401-4060

	MAIL ADDRESS:	
		STREET 1:		87 CAMBRIDGE PARK DRIVE
		CITY:			CAMBRIDGE
		STATE:			MA
		ZIP:			02140

FILED BY:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			RA CAPITAL MANAGEMENT, LLC
		CENTRAL INDEX KEY:			0001346824
		IRS NUMBER:				830406777
		STATE OF INCORPORATION:			MA
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		SC 13D/A

	BUSINESS ADDRESS:	
		STREET 1:		20 PARK PLAZA, SUITE 1200
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02116
		BUSINESS PHONE:		617-778-2500

	MAIL ADDRESS:	
		STREET 1:		20 PARK PLAZA, SUITE 1200
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02116
</SEC-HEADER>
<DOCUMENT>
<TYPE>SC 13D/A
<SEQUENCE>1
<FILENAME>tv486378_sc13da.htm
<DESCRIPTION>SC 13D/A
<TEXT>
Document 1 - file: tv486378_sc13da.htm

</DOCUMENT>
</SEC-DOCUMENT>