Form 4 Filing for Tomasello Shawn - Stock Option Grant

This filing details a Form 4 submission by Tomasello Shawn, a director at Cabaletta Bio, Inc. The report documents the grant of a stock option on June 9, 2026, for 22,000 shares of Common Stock. The option has a purchase price of $0.00 and an exercise price of $3.22. It is set to expire on June 8, 2036. The option will vest in full on the earlier of June 9, 2027, or the date of the corporation's next annual stockholder meeting. This transaction is classified as the acquisition of a derivative security.