X0206 3 2022-01-05 0 0001759138 Cabaletta Bio, Inc. CABA 0001903997 Das Arun CABALETTA BIO, INC. 2929 ARCH STREET, SUITE 600 PHILADELPHIA PA 19104 0 1 0 0 Chief Business Officer Stock Option (Right to Buy) 1.01 2028-11-15 Common Stock 29168 D Stock Option (Right to Buy) 11.00 2029-10-23 Common Stock 18416 D Stock Option (Right to Buy) 11.47 2031-02-28 Common Stock 35000 D 21,529 shares underlying this option have vested and the remainder shall vest in substantially equal monthly installments from January 16, 2022 to November 16, 2022, subject to the reporting person's continued service on each such vesting date. 25% of the shares underlying this option vested and became exercisable on October 24, 2020, with the remainder vesting in twelve substantially equal quarterly installments thereafter, subject to the reporting person's continued service on each such vesting date. 25% of the shares underlying this option shall vest and become exercisable on March 1, 2022, with the remainder vesting in twelve substantially equal quarterly installments thereafter, subject to the reporting person's continued service on each such vesting date. Exhibit 24 - Power of Attorney /s/ Arun Das 2022-01-13