Michael Gerard - 02 Mar 2026 Form 4 Insider Report for Cabaletta Bio, Inc. (CABA)

Role: General Counsel
Signature: By: /s/ Michael Gerard, as Attorney-in-Fact
Issuer symbol: CABA
Transactions as of: 02 Mar 2026
Net transactions value: $0
Form type: 4
Filing time: 02 Mar 2026, 19:27:54 UTC
Previous filing: 21 Jan 2026
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
Gerard Michael	General Counsel	C/O CABALETTA BIO, INC., 2929 ARCH STREET, SUITE 600, PHILADELPHIA	By: /s/ Michael Gerard, as Attorney-in-Fact	02 Mar 2026	0001881529

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Underlying Class	Amount	Exercise Price	Ownership	Footnotes
transaction	CABA	Stock Option (Right to Buy)	Award	$0	+175,000		$0.000000	175,000	02 Mar 2026	Common Stock	175,000	$3.30	Direct	F1

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	25% of the shares underlying this option shall vest and become exercisable on March 1, 2027, with the remainder vesting in twelve substantially equal quarterly installments thereafter, subject to the reporting person's continued service on each such vesting date.