<SEC-DOCUMENT>0001104659-21-033076-index.html : 20210308
<SEC-HEADER>0001104659-21-033076.hdr.sgml : 20210308
<ACCEPTANCE-DATETIME>20210308110401
ACCESSION NUMBER:		0001104659-21-033076
CONFORMED SUBMISSION TYPE:	SC 13G/A
PUBLIC DOCUMENT COUNT:		1
FILED AS OF DATE:		20210308
DATE AS OF CHANGE:		20210308

SUBJECT COMPANY:	

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			RHYTHM PHARMACEUTICALS, INC.
		CENTRAL INDEX KEY:			0001649904
		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
		IRS NUMBER:				462159271
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		SC 13G/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	005-90134
		FILM NUMBER:		21720991

	BUSINESS ADDRESS:	
		STREET 1:		222 BERKELEY STREET
		STREET 2:		12TH FLOOR
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02116
		BUSINESS PHONE:		857-264-4280

	MAIL ADDRESS:	
		STREET 1:		222 BERKELEY STREET
		STREET 2:		12TH FLOOR
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02116

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	RHYTHM METABOLIC, INC.
		DATE OF NAME CHANGE:	20150803

FILED BY:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			PRIMECAP MANAGEMENT CO/CA/
		CENTRAL INDEX KEY:			0000763212
		IRS NUMBER:				953868081

	FILING VALUES:
		FORM TYPE:		SC 13G/A

	BUSINESS ADDRESS:	
		STREET 1:		177 EAST COLORADO BLVD.
		STREET 2:		11TH FLOOR
		CITY:			PASADENA
		STATE:			CA
		ZIP:			91105
		BUSINESS PHONE:		6263049222

	MAIL ADDRESS:	
		STREET 1:		177 EAST COLORADO BLVD.
		STREET 2:		11TH FLOOR
		CITY:			PASADENA
		STATE:			CA
		ZIP:			91105
</SEC-HEADER>
<DOCUMENT>
<TYPE>SC 13G/A
<SEQUENCE>1
<FILENAME>tm218676d3_sc13ga.htm
<DESCRIPTION>SCHEDULE 13G/A
<TEXT>
Document 1 - file: tm218676d3_sc13ga.htm

</DOCUMENT>
</SEC-DOCUMENT>