<SEC-DOCUMENT>0000950170-25-084019-index.html : 20250609
<SEC-HEADER>0000950170-25-084019.hdr.sgml : 20250609
<ACCEPTANCE-DATETIME>20250609202215
ACCESSION NUMBER:		0000950170-25-084019
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20250609
FILED AS OF DATE:		20250609
DATE AS OF CHANGE:		20250609

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Brun Scott C.
		CENTRAL INDEX KEY:			0001863614
		ORGANIZATION NAME:           	

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-39103
		FILM NUMBER:		251035703

	MAIL ADDRESS:	
		STREET 1:		C/O CABALETTA BIO, INC.
		STREET 2:		2929 ARCH STREET, SUITE 600
		CITY:			PHILADELPHIA
		STATE:			PA
		ZIP:			19104

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Cabaletta Bio, Inc.
		CENTRAL INDEX KEY:			0001759138
		STANDARD INDUSTRIAL CLASSIFICATION:	BIOLOGICAL PRODUCTS (NO DIAGNOSTIC SUBSTANCES) [2836]
		ORGANIZATION NAME:           	03 Life Sciences
		EIN:				000000000
		STATE OF INCORPORATION:			AZ
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		2929 ARCH STREET
		STREET 2:		SUITE 600
		CITY:			PHILADELPHIA
		STATE:			PA
		ZIP:			19104
		BUSINESS PHONE:		(267) 759-3100

	MAIL ADDRESS:	
		STREET 1:		2929 ARCH STREET
		STREET 2:		SUITE 600
		CITY:			PHILADELPHIA
		STATE:			PA
		ZIP:			19104
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>ownership.xml
<DESCRIPTION>4
<TEXT>
Document 1 - file: ownership.html

Document 1 - RAW XML: ownership.xml

</DOCUMENT>
</SEC-DOCUMENT>