CABA

SEC source: 0001193125-26-266220 · ownership.xml · derivative · entry 1

Brun Scott C. · CIK 0001863614 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 22,000

Underlying: Common Stock · 22,000 shares

Expires 2036-06-08

F1 · derivative.exercise_date: This option shall vest in full upon the earlier of (i) June 9, 2027 or (ii) the date of the next annual meeting of the Corporation's stockholders.

SEC source: 0001193125-26-266229 · ownership.xml · derivative · entry 1

HENRIQUES RICHARD C JR · CIK 0001181178 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 22,000

Underlying: Common Stock · 22,000 shares

Expires 2036-06-08

F1 · derivative.exercise_date: This option shall vest in full upon the earlier of (i) June 9, 2027 or (ii) the date of the next annual meeting of the Corporation's stockholders.

SEC source: 0001193125-26-266232 · ownership.xml · derivative · entry 1

Simon Mark · CIK 0001400717 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 22,000

Underlying: Common Stock · 22,000 shares

Expires 2036-06-08

F1 · derivative.exercise_date: This option shall vest in full upon the earlier of (i) June 9, 2027 or (ii) the date of the next annual meeting of the Corporation's stockholders.

SEC source: 0001193125-26-266239 · ownership.xml · derivative · entry 1

Tomasello Shawn · CIK 0001617239 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 22,000

Underlying: Common Stock · 22,000 shares

Expires 2036-06-08

F1 · derivative.exercise_date: This option shall vest in full upon the earlier of (i) June 9, 2027 or (ii) the date of the next annual meeting of the Corporation's stockholders.

SEC source: 0001193125-26-266224 · ownership.xml · derivative · entry 1

Bollard Catherine · CIK 0001790411 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 22,000

Underlying: Common Stock · 22,000 shares

Expires 2036-06-08

F1 · derivative.exercise_date: This option shall vest in full upon the earlier of (i) June 9, 2027 or (ii) the date of the next annual meeting of the Corporation's stockholders.

SEC source: 0001193125-26-086143 · ownership.xml · derivative · entry 1

Gerard Michael · CIK 0001881529 · General Counsel

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 175,000

Underlying: Common Stock · 175,000 shares

Expires 2036-03-01

F1 · derivative.exercise_date: 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.

SEC source: 0001193125-26-086145 · ownership.xml · derivative · entry 1

Das Arun · CIK 0001903997 · Chief Business Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 175,000

Underlying: Common Stock · 175,000 shares

Expires 2036-03-01

F1 · derivative.exercise_date: 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.

SEC source: 0001193125-26-086135 · ownership.xml · derivative · entry 1

Binder Gwendolyn · CIK 0001791742 · President, Science & Tech.

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 225,000

Underlying: Common Stock · 225,000 shares

Expires 2036-03-01

F1 · derivative.exercise_date: 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.

SEC source: 0001193125-26-086129 · ownership.xml · derivative · entry 1

Chang David J. · CIK 0001790552 · Chief Medical Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 225,000

Underlying: Common Stock · 225,000 shares

Expires 2036-03-01

F1 · derivative.exercise_date: 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.

SEC source: 0001193125-26-086123 · ownership.xml · derivative · entry 1

Nichtberger Steven · CIK 0001487989 · Director · President & CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 674,000

Underlying: Common Stock · 674,000 shares

Expires 2036-03-01

F1 · derivative.exercise_date: 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.

SEC source: 0001193125-26-086118 · ownership.xml · derivative · entry 1

Marda Anup · CIK 0001790410 · Chief Financial Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 225,000

Underlying: Common Stock · 225,000 shares

Expires 2036-03-01

F1 · derivative.exercise_date: 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.

SEC source: 0001193125-26-018323 · ownership.xml · nonDerivative · entry 1

Gavel Steve · CIK 0002090785 · Chief Commercial Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 22,170

F1 · price: The price reported in Column 4 is a weighted average price. These shares were purchased at prices ranging from $2.26 to $2.27, inclusive. The reporting person has provided to the Issuer, and undertakes to provide any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range set forth in this footnote.

SEC source: 0001193125-26-018316 · ownership.xml · nonDerivative · entry 1

Gerard Michael · CIK 0001881529 · General Counsel

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 6,600

F1 · price: The price reported in Column 4 is a weighted average price. These shares were purchased at prices ranging from $2.269 to $2.2699, inclusive. The reporting person has provided to the Issuer, and undertakes to provide any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range set forth in this footnote.

SEC source: 0001193125-26-018327 · ownership.xml · nonDerivative · entry 1

Chang David J. · CIK 0001790552 · Chief Medical Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 8,800

SEC source: 0001193125-26-018325 · ownership.xml · nonDerivative · entry 1

Binder Gwendolyn · CIK 0001791742 · President, Science & Tech.

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 31,312

SEC source: 0001193125-26-018324 · ownership.xml · nonDerivative · entry 1

Tomasello Shawn · CIK 0001617239 · Director

10b5-1 filing: No plan indicated

Ownership: Indirect · By Shawn Tomasello Consulting LLC

Disclosed balance after: 22,725

SEC source: 0001193125-26-018319 · ownership.xml · nonDerivative · entry 1

Bollard Catherine · CIK 0001790411 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 5,405

SEC source: 0001193125-26-018318 · ownership.xml · nonDerivative · entry 1

Nichtberger Steven · CIK 0001487989 · Director · President & CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 1,031,483

F1 · price: The price reported in Column 4 is a weighted average price. These shares were purchased at prices ranging from $2.1985 to $2.26, inclusive. The reporting person has provided to the Issuer, and undertakes to provide any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range set forth in this footnote.

SEC source: 0001193125-26-018317 · ownership.xml · nonDerivative · entry 1

Simon Mark · CIK 0001400717 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 147,205

F1 · price: The price reported in Column 4 is a weighted average price. These shares were purchased at prices ranging from $2.245 to $2.32, inclusive. The reporting person has provided to the Issuer, and undertakes to provide any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range set forth in this footnote.

SEC source: 0001193125-25-240356 · ownership.xml · derivative · entry 1

Gavel Steve · CIK 0002090785 · CHIEF COMMERCIAL OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 275,000

Underlying: Common Stock · 275,000 shares

Expires 2035-10-12

F1 · shares: The stock option has been granted pursuant to the Cabaletta Bio, Inc. 2025 Inducement Plan as a material inducement to the Reporting Person's acceptance of employment with the Issuer in accordance with NASDAQ Listing Rule 5635(c)(4).

F2 · derivative.exercise_date: 25% of the shares underlying this option shall vest and become exercisable on October 13, 2026, with the remainder vesting in twelve substantially equal quarterly installments thereafter, subject to the Reporting Person's continued service on each such vesting date.

SEC source: 0000950170-25-084019 · ownership.xml · derivative · entry 1

Brun Scott C. · CIK 0001863614 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 22,000

Underlying: Common Stock · 22,000 shares

Expires 2035-06-08

F1 · derivative.exercise_date: This option shall vest in full upon the earlier of (i) June 9, 2026 or (ii) the date of the next annual meeting of the Corporation's stockholders.

SEC source: 0000950170-25-084014 · ownership.xml · derivative · entry 1

HENRIQUES RICHARD C JR · CIK 0001181178 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 22,000

Underlying: Common Stock · 22,000 shares

Expires 2035-06-08

F1 · derivative.exercise_date: This option shall vest in full upon the earlier of (i) June 9, 2026 or (ii) the date of the next annual meeting of the Corporation's stockholders.

SEC source: 0000950170-25-084017 · ownership.xml · derivative · entry 1

Bollard Catherine · CIK 0001790411 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 22,000

Underlying: Common Stock · 22,000 shares

Expires 2035-06-08

F1 · derivative.exercise_date: This option shall vest in full upon the earlier of (i) June 9, 2026 or (ii) the date of the next annual meeting of the Corporation's stockholders.

SEC source: 0000950170-25-084022 · ownership.xml · derivative · entry 1

Simon Mark · CIK 0001400717 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 22,000

Underlying: Common Stock · 22,000 shares

Expires 2035-06-08

F1 · derivative.exercise_date: This option shall vest in full upon the earlier of (i) June 9, 2026 or (ii) the date of the next annual meeting of the Corporation's stockholders.

SEC source: 0000950170-25-084015 · ownership.xml · derivative · entry 1

Tomasello Shawn · CIK 0001617239 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 22,000

Underlying: Common Stock · 22,000 shares

Expires 2035-06-08

F1 · derivative.exercise_date: This option shall vest in full upon the earlier of (i) June 9, 2026 or (ii) the date of the next annual meeting of the Corporation's stockholders.

SEC source: 0000950170-25-074825 · ownership.xml · derivative · entry 8

Gerard Michael · CIK 0001881529 · General Counsel

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 100,000

Underlying: Common Stock · 100,000 shares

Expires 2034-02-28

F3 · derivative.exercise_price: The exercise price of the option is $1.92 per share, representing the fair market value per share of the Issuer's Common Stock on the Repricing Date. Under the terms of the stock option award repricing, a repriced stock option award will revert to its original exercise price if exercised during the Retention Period. The "Retention Period", through which the Reporting Person must remain in service to the Issuer, commenced on the Repricing Date and ends upon the earliest of (i) the one-year anniversary of the Repricing Date, (ii) a Sale Event (as defined in the 2018 Plan and 2019 Plan, as applicable) and (iii) the termination of the Reporting Person's Service Relationship (as defined in the 2018 Plan and 2019 Plan, as applicable) due to the Reporting Person's death or disability.

F1 · kind: On May 15, 2025, the Issuer's board of directors approved an option repricing (the "Repricing"), to be effective May 19, 2025 (the "Repricing Date"). All of the other terms of the options remain unchanged. Such transactions were exempt pursuant to Rule 16b-6(d) and Rule 16b-3 of the Exchange Act, as applicable.

F2 · derivative.exercise_date: This stock option award was issued pursuant to the Cabaletta Bio, Inc. 2018 Stock Option and Incentive Plan, as amended (the "2018 Plan") or the Cabaletta Bio, Inc. 2019 Stock Option and Incentive Plan, as amended (the "2019 Plan"), as applicable, and becomes exercisable in accordance with the vesting schedule specified in the award agreement and as previously reported on applicable Form 4, subject to the Reporting Person's continued service with the Issuer as of the applicable vesting date.

SEC source: 0000950170-25-074825 · ownership.xml · derivative · entry 7

Gerard Michael · CIK 0001881529 · General Counsel

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 100,000 shares

Expires 2034-02-28

F1 · kind: On May 15, 2025, the Issuer's board of directors approved an option repricing (the "Repricing"), to be effective May 19, 2025 (the "Repricing Date"). All of the other terms of the options remain unchanged. Such transactions were exempt pursuant to Rule 16b-6(d) and Rule 16b-3 of the Exchange Act, as applicable.

F2 · derivative.exercise_date: This stock option award was issued pursuant to the Cabaletta Bio, Inc. 2018 Stock Option and Incentive Plan, as amended (the "2018 Plan") or the Cabaletta Bio, Inc. 2019 Stock Option and Incentive Plan, as amended (the "2019 Plan"), as applicable, and becomes exercisable in accordance with the vesting schedule specified in the award agreement and as previously reported on applicable Form 4, subject to the Reporting Person's continued service with the Issuer as of the applicable vesting date.

SEC source: 0000950170-25-074825 · ownership.xml · derivative · entry 6

Gerard Michael · CIK 0001881529 · General Counsel

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 112,500

Underlying: Common Stock · 112,500 shares

Expires 2033-01-17

F3 · derivative.exercise_price: The exercise price of the option is $1.92 per share, representing the fair market value per share of the Issuer's Common Stock on the Repricing Date. Under the terms of the stock option award repricing, a repriced stock option award will revert to its original exercise price if exercised during the Retention Period. The "Retention Period", through which the Reporting Person must remain in service to the Issuer, commenced on the Repricing Date and ends upon the earliest of (i) the one-year anniversary of the Repricing Date, (ii) a Sale Event (as defined in the 2018 Plan and 2019 Plan, as applicable) and (iii) the termination of the Reporting Person's Service Relationship (as defined in the 2018 Plan and 2019 Plan, as applicable) due to the Reporting Person's death or disability.

F1 · kind: On May 15, 2025, the Issuer's board of directors approved an option repricing (the "Repricing"), to be effective May 19, 2025 (the "Repricing Date"). All of the other terms of the options remain unchanged. Such transactions were exempt pursuant to Rule 16b-6(d) and Rule 16b-3 of the Exchange Act, as applicable.

F2 · derivative.exercise_date: This stock option award was issued pursuant to the Cabaletta Bio, Inc. 2018 Stock Option and Incentive Plan, as amended (the "2018 Plan") or the Cabaletta Bio, Inc. 2019 Stock Option and Incentive Plan, as amended (the "2019 Plan"), as applicable, and becomes exercisable in accordance with the vesting schedule specified in the award agreement and as previously reported on applicable Form 4, subject to the Reporting Person's continued service with the Issuer as of the applicable vesting date.

SEC source: 0000950170-25-074825 · ownership.xml · derivative · entry 5

Gerard Michael · CIK 0001881529 · General Counsel

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 112,500 shares

Expires 2033-01-17

F1 · kind: On May 15, 2025, the Issuer's board of directors approved an option repricing (the "Repricing"), to be effective May 19, 2025 (the "Repricing Date"). All of the other terms of the options remain unchanged. Such transactions were exempt pursuant to Rule 16b-6(d) and Rule 16b-3 of the Exchange Act, as applicable.

F2 · derivative.exercise_date: This stock option award was issued pursuant to the Cabaletta Bio, Inc. 2018 Stock Option and Incentive Plan, as amended (the "2018 Plan") or the Cabaletta Bio, Inc. 2019 Stock Option and Incentive Plan, as amended (the "2019 Plan"), as applicable, and becomes exercisable in accordance with the vesting schedule specified in the award agreement and as previously reported on applicable Form 4, subject to the Reporting Person's continued service with the Issuer as of the applicable vesting date.

SEC source: 0000950170-25-074825 · ownership.xml · derivative · entry 4

Gerard Michael · CIK 0001881529 · General Counsel

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 75,000

Underlying: Common Stock · 75,000 shares

Expires 2032-01-17

F3 · derivative.exercise_price: The exercise price of the option is $1.92 per share, representing the fair market value per share of the Issuer's Common Stock on the Repricing Date. Under the terms of the stock option award repricing, a repriced stock option award will revert to its original exercise price if exercised during the Retention Period. The "Retention Period", through which the Reporting Person must remain in service to the Issuer, commenced on the Repricing Date and ends upon the earliest of (i) the one-year anniversary of the Repricing Date, (ii) a Sale Event (as defined in the 2018 Plan and 2019 Plan, as applicable) and (iii) the termination of the Reporting Person's Service Relationship (as defined in the 2018 Plan and 2019 Plan, as applicable) due to the Reporting Person's death or disability.

F1 · kind: On May 15, 2025, the Issuer's board of directors approved an option repricing (the "Repricing"), to be effective May 19, 2025 (the "Repricing Date"). All of the other terms of the options remain unchanged. Such transactions were exempt pursuant to Rule 16b-6(d) and Rule 16b-3 of the Exchange Act, as applicable.

F2 · derivative.exercise_date: This stock option award was issued pursuant to the Cabaletta Bio, Inc. 2018 Stock Option and Incentive Plan, as amended (the "2018 Plan") or the Cabaletta Bio, Inc. 2019 Stock Option and Incentive Plan, as amended (the "2019 Plan"), as applicable, and becomes exercisable in accordance with the vesting schedule specified in the award agreement and as previously reported on applicable Form 4, subject to the Reporting Person's continued service with the Issuer as of the applicable vesting date.

SEC source: 0000950170-25-074825 · ownership.xml · derivative · entry 3

Gerard Michael · CIK 0001881529 · General Counsel

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 75,000 shares

Expires 2032-01-17

F1 · kind: On May 15, 2025, the Issuer's board of directors approved an option repricing (the "Repricing"), to be effective May 19, 2025 (the "Repricing Date"). All of the other terms of the options remain unchanged. Such transactions were exempt pursuant to Rule 16b-6(d) and Rule 16b-3 of the Exchange Act, as applicable.

F2 · derivative.exercise_date: This stock option award was issued pursuant to the Cabaletta Bio, Inc. 2018 Stock Option and Incentive Plan, as amended (the "2018 Plan") or the Cabaletta Bio, Inc. 2019 Stock Option and Incentive Plan, as amended (the "2019 Plan"), as applicable, and becomes exercisable in accordance with the vesting schedule specified in the award agreement and as previously reported on applicable Form 4, subject to the Reporting Person's continued service with the Issuer as of the applicable vesting date.

SEC source: 0000950170-25-074825 · ownership.xml · derivative · entry 2

Gerard Michael · CIK 0001881529 · General Counsel

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 100,000

Underlying: Common Stock · 100,000 shares

Expires 2031-08-31

F3 · derivative.exercise_price: The exercise price of the option is $1.92 per share, representing the fair market value per share of the Issuer's Common Stock on the Repricing Date. Under the terms of the stock option award repricing, a repriced stock option award will revert to its original exercise price if exercised during the Retention Period. The "Retention Period", through which the Reporting Person must remain in service to the Issuer, commenced on the Repricing Date and ends upon the earliest of (i) the one-year anniversary of the Repricing Date, (ii) a Sale Event (as defined in the 2018 Plan and 2019 Plan, as applicable) and (iii) the termination of the Reporting Person's Service Relationship (as defined in the 2018 Plan and 2019 Plan, as applicable) due to the Reporting Person's death or disability.

F1 · kind: On May 15, 2025, the Issuer's board of directors approved an option repricing (the "Repricing"), to be effective May 19, 2025 (the "Repricing Date"). All of the other terms of the options remain unchanged. Such transactions were exempt pursuant to Rule 16b-6(d) and Rule 16b-3 of the Exchange Act, as applicable.

F2 · derivative.exercise_date: This stock option award was issued pursuant to the Cabaletta Bio, Inc. 2018 Stock Option and Incentive Plan, as amended (the "2018 Plan") or the Cabaletta Bio, Inc. 2019 Stock Option and Incentive Plan, as amended (the "2019 Plan"), as applicable, and becomes exercisable in accordance with the vesting schedule specified in the award agreement and as previously reported on applicable Form 4, subject to the Reporting Person's continued service with the Issuer as of the applicable vesting date.

SEC source: 0000950170-25-074825 · ownership.xml · derivative · entry 1

Gerard Michael · CIK 0001881529 · General Counsel

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 100,000 shares

Expires 2031-08-31

F1 · kind: On May 15, 2025, the Issuer's board of directors approved an option repricing (the "Repricing"), to be effective May 19, 2025 (the "Repricing Date"). All of the other terms of the options remain unchanged. Such transactions were exempt pursuant to Rule 16b-6(d) and Rule 16b-3 of the Exchange Act, as applicable.

F2 · derivative.exercise_date: This stock option award was issued pursuant to the Cabaletta Bio, Inc. 2018 Stock Option and Incentive Plan, as amended (the "2018 Plan") or the Cabaletta Bio, Inc. 2019 Stock Option and Incentive Plan, as amended (the "2019 Plan"), as applicable, and becomes exercisable in accordance with the vesting schedule specified in the award agreement and as previously reported on applicable Form 4, subject to the Reporting Person's continued service with the Issuer as of the applicable vesting date.

SEC source: 0000950170-25-074832 · ownership.xml · derivative · entry 6

Brun Scott C. · CIK 0001863614 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 22,000

Underlying: Common Stock · 22,000 shares

Expires 2034-06-02

F3 · derivative.exercise_price: The exercise price of the option is $1.92 per share, representing the fair market value per share of the Issuer's Common Stock on the Repricing Date. Under the terms of the stock option award repricing, a repriced stock option award will revert to its original exercise price if exercised during the Retention Period. The "Retention Period", through which the Reporting Person must remain in service to the Issuer, commenced on the Repricing Date and ends upon the earliest of (i) the one-year anniversary of the Repricing Date, (ii) a Sale Event (as defined in the 2018 Plan and 2019 Plan, as applicable) and (iii) the termination of the Reporting Person's Service Relationship (as defined in the 2018 Plan and 2019 Plan, as applicable) due to the Reporting Person's death or disability.

F1 · kind: On May 15, 2025, the Issuer's board of directors approved an option repricing (the "Repricing"), to be effective May 19, 2025 (the "Repricing Date"). All of the other terms of the options remain unchanged. Such transactions were exempt pursuant to Rule 16b-6(d) and Rule 16b-3 of the Exchange Act, as applicable.

F2 · derivative.exercise_date: This stock option award was issued pursuant to the Cabaletta Bio, Inc. 2018 Stock Option and Incentive Plan, as amended (the "2018 Plan") or the Cabaletta Bio, Inc. 2019 Stock Option and Incentive Plan, as amended (the "2019 Plan"), as applicable, and becomes exercisable in accordance with the vesting schedule specified in the award agreement and as previously reported on applicable Form 4, subject to the Reporting Person's continued service with the Issuer as of the applicable vesting date.

SEC source: 0000950170-25-074832 · ownership.xml · derivative · entry 5

Brun Scott C. · CIK 0001863614 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 22,000 shares

Expires 2034-06-02

F1 · kind: On May 15, 2025, the Issuer's board of directors approved an option repricing (the "Repricing"), to be effective May 19, 2025 (the "Repricing Date"). All of the other terms of the options remain unchanged. Such transactions were exempt pursuant to Rule 16b-6(d) and Rule 16b-3 of the Exchange Act, as applicable.

F2 · derivative.exercise_date: This stock option award was issued pursuant to the Cabaletta Bio, Inc. 2018 Stock Option and Incentive Plan, as amended (the "2018 Plan") or the Cabaletta Bio, Inc. 2019 Stock Option and Incentive Plan, as amended (the "2019 Plan"), as applicable, and becomes exercisable in accordance with the vesting schedule specified in the award agreement and as previously reported on applicable Form 4, subject to the Reporting Person's continued service with the Issuer as of the applicable vesting date.

SEC source: 0000950170-25-074832 · ownership.xml · derivative · entry 4

Brun Scott C. · CIK 0001863614 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 22,000

Underlying: Common Stock · 22,000 shares

Expires 2033-05-31

F3 · derivative.exercise_price: The exercise price of the option is $1.92 per share, representing the fair market value per share of the Issuer's Common Stock on the Repricing Date. Under the terms of the stock option award repricing, a repriced stock option award will revert to its original exercise price if exercised during the Retention Period. The "Retention Period", through which the Reporting Person must remain in service to the Issuer, commenced on the Repricing Date and ends upon the earliest of (i) the one-year anniversary of the Repricing Date, (ii) a Sale Event (as defined in the 2018 Plan and 2019 Plan, as applicable) and (iii) the termination of the Reporting Person's Service Relationship (as defined in the 2018 Plan and 2019 Plan, as applicable) due to the Reporting Person's death or disability.

F1 · kind: On May 15, 2025, the Issuer's board of directors approved an option repricing (the "Repricing"), to be effective May 19, 2025 (the "Repricing Date"). All of the other terms of the options remain unchanged. Such transactions were exempt pursuant to Rule 16b-6(d) and Rule 16b-3 of the Exchange Act, as applicable.

F2 · derivative.exercise_date: This stock option award was issued pursuant to the Cabaletta Bio, Inc. 2018 Stock Option and Incentive Plan, as amended (the "2018 Plan") or the Cabaletta Bio, Inc. 2019 Stock Option and Incentive Plan, as amended (the "2019 Plan"), as applicable, and becomes exercisable in accordance with the vesting schedule specified in the award agreement and as previously reported on applicable Form 4, subject to the Reporting Person's continued service with the Issuer as of the applicable vesting date.

SEC source: 0000950170-25-074832 · ownership.xml · derivative · entry 3

Brun Scott C. · CIK 0001863614 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 22,000 shares

Expires 2033-05-31

F1 · kind: On May 15, 2025, the Issuer's board of directors approved an option repricing (the "Repricing"), to be effective May 19, 2025 (the "Repricing Date"). All of the other terms of the options remain unchanged. Such transactions were exempt pursuant to Rule 16b-6(d) and Rule 16b-3 of the Exchange Act, as applicable.

F2 · derivative.exercise_date: This stock option award was issued pursuant to the Cabaletta Bio, Inc. 2018 Stock Option and Incentive Plan, as amended (the "2018 Plan") or the Cabaletta Bio, Inc. 2019 Stock Option and Incentive Plan, as amended (the "2019 Plan"), as applicable, and becomes exercisable in accordance with the vesting schedule specified in the award agreement and as previously reported on applicable Form 4, subject to the Reporting Person's continued service with the Issuer as of the applicable vesting date.

SEC source: 0000950170-25-074832 · ownership.xml · derivative · entry 2

Brun Scott C. · CIK 0001863614 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 44,000

Underlying: Common Stock · 44,000 shares

Expires 2031-06-23

F3 · derivative.exercise_price: The exercise price of the option is $1.92 per share, representing the fair market value per share of the Issuer's Common Stock on the Repricing Date. Under the terms of the stock option award repricing, a repriced stock option award will revert to its original exercise price if exercised during the Retention Period. The "Retention Period", through which the Reporting Person must remain in service to the Issuer, commenced on the Repricing Date and ends upon the earliest of (i) the one-year anniversary of the Repricing Date, (ii) a Sale Event (as defined in the 2018 Plan and 2019 Plan, as applicable) and (iii) the termination of the Reporting Person's Service Relationship (as defined in the 2018 Plan and 2019 Plan, as applicable) due to the Reporting Person's death or disability.

F1 · kind: On May 15, 2025, the Issuer's board of directors approved an option repricing (the "Repricing"), to be effective May 19, 2025 (the "Repricing Date"). All of the other terms of the options remain unchanged. Such transactions were exempt pursuant to Rule 16b-6(d) and Rule 16b-3 of the Exchange Act, as applicable.

F2 · derivative.exercise_date: This stock option award was issued pursuant to the Cabaletta Bio, Inc. 2018 Stock Option and Incentive Plan, as amended (the "2018 Plan") or the Cabaletta Bio, Inc. 2019 Stock Option and Incentive Plan, as amended (the "2019 Plan"), as applicable, and becomes exercisable in accordance with the vesting schedule specified in the award agreement and as previously reported on applicable Form 4, subject to the Reporting Person's continued service with the Issuer as of the applicable vesting date.

SEC source: 0000950170-25-074832 · ownership.xml · derivative · entry 1

Brun Scott C. · CIK 0001863614 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 44,000 shares

Expires 2031-06-23

F1 · kind: On May 15, 2025, the Issuer's board of directors approved an option repricing (the "Repricing"), to be effective May 19, 2025 (the "Repricing Date"). All of the other terms of the options remain unchanged. Such transactions were exempt pursuant to Rule 16b-6(d) and Rule 16b-3 of the Exchange Act, as applicable.

F2 · derivative.exercise_date: This stock option award was issued pursuant to the Cabaletta Bio, Inc. 2018 Stock Option and Incentive Plan, as amended (the "2018 Plan") or the Cabaletta Bio, Inc. 2019 Stock Option and Incentive Plan, as amended (the "2019 Plan"), as applicable, and becomes exercisable in accordance with the vesting schedule specified in the award agreement and as previously reported on applicable Form 4, subject to the Reporting Person's continued service with the Issuer as of the applicable vesting date.

SEC source: 0000950170-25-074824 · ownership.xml · derivative · entry 8

HENRIQUES RICHARD C JR · CIK 0001181178 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 22,000

Underlying: Common Stock · 22,000 shares

Expires 2034-06-02

F3 · derivative.exercise_price: The exercise price of the option is $1.92 per share, representing the fair market value per share of the Issuer's Common Stock on the Repricing Date. Under the terms of the stock option award repricing, a repriced stock option award will revert to its original exercise price if exercised during the Retention Period. The "Retention Period", through which the Reporting Person must remain in service to the Issuer, commenced on the Repricing Date and ends upon the earliest of (i) the one-year anniversary of the Repricing Date, (ii) a Sale Event (as defined in the 2018 Plan and 2019 Plan, as applicable) and (iii) the termination of the Reporting Person's Service Relationship (as defined in the 2018 Plan and 2019 Plan, as applicable) due to the Reporting Person's death or disability.

F1 · kind: On May 15, 2025, the Issuer's board of directors approved an option repricing (the "Repricing"), to be effective May 19, 2025 (the "Repricing Date"). All of the other terms of the options remain unchanged. Such transactions were exempt pursuant to Rule 16b-6(d) and Rule 16b-3 of the Exchange Act, as applicable.

F2 · derivative.exercise_date: This stock option award was issued pursuant to the Cabaletta Bio, Inc. 2018 Stock Option and Incentive Plan, as amended (the "2018 Plan") or the Cabaletta Bio, Inc. 2019 Stock Option and Incentive Plan, as amended (the "2019 Plan"), as applicable, and becomes exercisable in accordance with the vesting schedule specified in the award agreement and as previously reported on applicable Form 4, subject to the Reporting Person's continued service with the Issuer as of the applicable vesting date.

SEC source: 0000950170-25-074824 · ownership.xml · derivative · entry 7

HENRIQUES RICHARD C JR · CIK 0001181178 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 22,000 shares

Expires 2034-06-02

F1 · kind: On May 15, 2025, the Issuer's board of directors approved an option repricing (the "Repricing"), to be effective May 19, 2025 (the "Repricing Date"). All of the other terms of the options remain unchanged. Such transactions were exempt pursuant to Rule 16b-6(d) and Rule 16b-3 of the Exchange Act, as applicable.

F2 · derivative.exercise_date: This stock option award was issued pursuant to the Cabaletta Bio, Inc. 2018 Stock Option and Incentive Plan, as amended (the "2018 Plan") or the Cabaletta Bio, Inc. 2019 Stock Option and Incentive Plan, as amended (the "2019 Plan"), as applicable, and becomes exercisable in accordance with the vesting schedule specified in the award agreement and as previously reported on applicable Form 4, subject to the Reporting Person's continued service with the Issuer as of the applicable vesting date.

SEC source: 0000950170-25-074824 · ownership.xml · derivative · entry 6

HENRIQUES RICHARD C JR · CIK 0001181178 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 22,000

Underlying: Common Stock · 22,000 shares

Expires 2033-05-31

F3 · derivative.exercise_price: The exercise price of the option is $1.92 per share, representing the fair market value per share of the Issuer's Common Stock on the Repricing Date. Under the terms of the stock option award repricing, a repriced stock option award will revert to its original exercise price if exercised during the Retention Period. The "Retention Period", through which the Reporting Person must remain in service to the Issuer, commenced on the Repricing Date and ends upon the earliest of (i) the one-year anniversary of the Repricing Date, (ii) a Sale Event (as defined in the 2018 Plan and 2019 Plan, as applicable) and (iii) the termination of the Reporting Person's Service Relationship (as defined in the 2018 Plan and 2019 Plan, as applicable) due to the Reporting Person's death or disability.

F1 · kind: On May 15, 2025, the Issuer's board of directors approved an option repricing (the "Repricing"), to be effective May 19, 2025 (the "Repricing Date"). All of the other terms of the options remain unchanged. Such transactions were exempt pursuant to Rule 16b-6(d) and Rule 16b-3 of the Exchange Act, as applicable.

F2 · derivative.exercise_date: This stock option award was issued pursuant to the Cabaletta Bio, Inc. 2018 Stock Option and Incentive Plan, as amended (the "2018 Plan") or the Cabaletta Bio, Inc. 2019 Stock Option and Incentive Plan, as amended (the "2019 Plan"), as applicable, and becomes exercisable in accordance with the vesting schedule specified in the award agreement and as previously reported on applicable Form 4, subject to the Reporting Person's continued service with the Issuer as of the applicable vesting date.

SEC source: 0000950170-25-074824 · ownership.xml · derivative · entry 5

HENRIQUES RICHARD C JR · CIK 0001181178 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 22,000 shares

Expires 2033-05-31

F1 · kind: On May 15, 2025, the Issuer's board of directors approved an option repricing (the "Repricing"), to be effective May 19, 2025 (the "Repricing Date"). All of the other terms of the options remain unchanged. Such transactions were exempt pursuant to Rule 16b-6(d) and Rule 16b-3 of the Exchange Act, as applicable.

F2 · derivative.exercise_date: This stock option award was issued pursuant to the Cabaletta Bio, Inc. 2018 Stock Option and Incentive Plan, as amended (the "2018 Plan") or the Cabaletta Bio, Inc. 2019 Stock Option and Incentive Plan, as amended (the "2019 Plan"), as applicable, and becomes exercisable in accordance with the vesting schedule specified in the award agreement and as previously reported on applicable Form 4, subject to the Reporting Person's continued service with the Issuer as of the applicable vesting date.

SEC source: 0000950170-25-074824 · ownership.xml · derivative · entry 4

HENRIQUES RICHARD C JR · CIK 0001181178 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 22,000

Underlying: Common Stock · 22,000 shares

Expires 2031-05-31

F3 · derivative.exercise_price: The exercise price of the option is $1.92 per share, representing the fair market value per share of the Issuer's Common Stock on the Repricing Date. Under the terms of the stock option award repricing, a repriced stock option award will revert to its original exercise price if exercised during the Retention Period. The "Retention Period", through which the Reporting Person must remain in service to the Issuer, commenced on the Repricing Date and ends upon the earliest of (i) the one-year anniversary of the Repricing Date, (ii) a Sale Event (as defined in the 2018 Plan and 2019 Plan, as applicable) and (iii) the termination of the Reporting Person's Service Relationship (as defined in the 2018 Plan and 2019 Plan, as applicable) due to the Reporting Person's death or disability.

F1 · kind: On May 15, 2025, the Issuer's board of directors approved an option repricing (the "Repricing"), to be effective May 19, 2025 (the "Repricing Date"). All of the other terms of the options remain unchanged. Such transactions were exempt pursuant to Rule 16b-6(d) and Rule 16b-3 of the Exchange Act, as applicable.

F2 · derivative.exercise_date: This stock option award was issued pursuant to the Cabaletta Bio, Inc. 2018 Stock Option and Incentive Plan, as amended (the "2018 Plan") or the Cabaletta Bio, Inc. 2019 Stock Option and Incentive Plan, as amended (the "2019 Plan"), as applicable, and becomes exercisable in accordance with the vesting schedule specified in the award agreement and as previously reported on applicable Form 4, subject to the Reporting Person's continued service with the Issuer as of the applicable vesting date.

SEC source: 0000950170-25-074824 · ownership.xml · derivative · entry 3

HENRIQUES RICHARD C JR · CIK 0001181178 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 22,000 shares

Expires 2031-05-31

F1 · kind: On May 15, 2025, the Issuer's board of directors approved an option repricing (the "Repricing"), to be effective May 19, 2025 (the "Repricing Date"). All of the other terms of the options remain unchanged. Such transactions were exempt pursuant to Rule 16b-6(d) and Rule 16b-3 of the Exchange Act, as applicable.

F2 · derivative.exercise_date: This stock option award was issued pursuant to the Cabaletta Bio, Inc. 2018 Stock Option and Incentive Plan, as amended (the "2018 Plan") or the Cabaletta Bio, Inc. 2019 Stock Option and Incentive Plan, as amended (the "2019 Plan"), as applicable, and becomes exercisable in accordance with the vesting schedule specified in the award agreement and as previously reported on applicable Form 4, subject to the Reporting Person's continued service with the Issuer as of the applicable vesting date.

SEC source: 0000950170-25-074824 · ownership.xml · derivative · entry 2

HENRIQUES RICHARD C JR · CIK 0001181178 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 46,428

Underlying: Common Stock · 46,428 shares

Expires 2029-02-18

F3 · derivative.exercise_price: The exercise price of the option is $1.92 per share, representing the fair market value per share of the Issuer's Common Stock on the Repricing Date. Under the terms of the stock option award repricing, a repriced stock option award will revert to its original exercise price if exercised during the Retention Period. The "Retention Period", through which the Reporting Person must remain in service to the Issuer, commenced on the Repricing Date and ends upon the earliest of (i) the one-year anniversary of the Repricing Date, (ii) a Sale Event (as defined in the 2018 Plan and 2019 Plan, as applicable) and (iii) the termination of the Reporting Person's Service Relationship (as defined in the 2018 Plan and 2019 Plan, as applicable) due to the Reporting Person's death or disability.

F1 · kind: On May 15, 2025, the Issuer's board of directors approved an option repricing (the "Repricing"), to be effective May 19, 2025 (the "Repricing Date"). All of the other terms of the options remain unchanged. Such transactions were exempt pursuant to Rule 16b-6(d) and Rule 16b-3 of the Exchange Act, as applicable.

F2 · derivative.exercise_date: This stock option award was issued pursuant to the Cabaletta Bio, Inc. 2018 Stock Option and Incentive Plan, as amended (the "2018 Plan") or the Cabaletta Bio, Inc. 2019 Stock Option and Incentive Plan, as amended (the "2019 Plan"), as applicable, and becomes exercisable in accordance with the vesting schedule specified in the award agreement and as previously reported on applicable Form 4, subject to the Reporting Person's continued service with the Issuer as of the applicable vesting date.

SEC source: 0000950170-25-074824 · ownership.xml · derivative · entry 1

HENRIQUES RICHARD C JR · CIK 0001181178 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 46,428 shares

Expires 2029-02-18

F1 · kind: On May 15, 2025, the Issuer's board of directors approved an option repricing (the "Repricing"), to be effective May 19, 2025 (the "Repricing Date"). All of the other terms of the options remain unchanged. Such transactions were exempt pursuant to Rule 16b-6(d) and Rule 16b-3 of the Exchange Act, as applicable.

F2 · derivative.exercise_date: This stock option award was issued pursuant to the Cabaletta Bio, Inc. 2018 Stock Option and Incentive Plan, as amended (the "2018 Plan") or the Cabaletta Bio, Inc. 2019 Stock Option and Incentive Plan, as amended (the "2019 Plan"), as applicable, and becomes exercisable in accordance with the vesting schedule specified in the award agreement and as previously reported on applicable Form 4, subject to the Reporting Person's continued service with the Issuer as of the applicable vesting date.

SEC source: 0000950170-25-074826 · ownership.xml · derivative · entry 12

Nichtberger Steven · CIK 0001487989 · Director · President & CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 353,000

Underlying: Common Stock · 353,000 shares

Expires 2034-02-28

F3 · derivative.exercise_price: The exercise price of the option is $1.92 per share, representing the fair market value per share of the Issuer's Common Stock on the Repricing Date. Under the terms of the stock option award repricing, a repriced stock option award will revert to its original exercise price if exercised during the Retention Period. The "Retention Period", through which the option holder must remain in service to the Issuer, commenced on the Repricing Date and ends upon the earliest of (i) the one-year anniversary of the Repricing Date, (ii) a Sale Event (as defined in the 2018 Plan and 2019 Plan, as applicable) and (iii) the termination of the Reporting Person's Service Relationship (as defined in the 2018 Plan and 2019 Plan, as applicable) due to the Reporting Person's death or disability.

F1 · kind: On May 15, 2025, the Issuer's board of directors approved an option repricing (the "Repricing"), to be effective May 19, 2025 (the "Repricing Date"). All of the other terms of the options remain unchanged. The transactions were exempt pursuant to Rule 16b-6(d) and Rule 16b-3 of the Exchange Act of 1934, as amended, as applicable.

F2 · derivative.exercise_date: This stock option award was issued pursuant to the Cabaletta Bio, Inc. 2018 Stock Option and Incentive Plan, as amended (the "2018 Plan") or the Cabaletta Bio, Inc. 2019 Stock Option and Incentive Plan, as amended (the "2019 Plan"), as applicable, and becomes exercisable in accordance with the vesting schedule specified in the award agreement and as previously reported on applicable Form 4, subject to the Reporting Person's continued service with the Issuer as of the applicable vesting date.

SEC source: 0000950170-25-074826 · ownership.xml · derivative · entry 11

Nichtberger Steven · CIK 0001487989 · Director · President & CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 353,000 shares

Expires 2034-02-28

F1 · kind: On May 15, 2025, the Issuer's board of directors approved an option repricing (the "Repricing"), to be effective May 19, 2025 (the "Repricing Date"). All of the other terms of the options remain unchanged. The transactions were exempt pursuant to Rule 16b-6(d) and Rule 16b-3 of the Exchange Act of 1934, as amended, as applicable.

F2 · derivative.exercise_date: This stock option award was issued pursuant to the Cabaletta Bio, Inc. 2018 Stock Option and Incentive Plan, as amended (the "2018 Plan") or the Cabaletta Bio, Inc. 2019 Stock Option and Incentive Plan, as amended (the "2019 Plan"), as applicable, and becomes exercisable in accordance with the vesting schedule specified in the award agreement and as previously reported on applicable Form 4, subject to the Reporting Person's continued service with the Issuer as of the applicable vesting date.

SEC source: 0000950170-25-074826 · ownership.xml · derivative · entry 10

Nichtberger Steven · CIK 0001487989 · Director · President & CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 411,600

Underlying: Common Stock · 411,600 shares

Expires 2033-01-17

F3 · derivative.exercise_price: The exercise price of the option is $1.92 per share, representing the fair market value per share of the Issuer's Common Stock on the Repricing Date. Under the terms of the stock option award repricing, a repriced stock option award will revert to its original exercise price if exercised during the Retention Period. The "Retention Period", through which the option holder must remain in service to the Issuer, commenced on the Repricing Date and ends upon the earliest of (i) the one-year anniversary of the Repricing Date, (ii) a Sale Event (as defined in the 2018 Plan and 2019 Plan, as applicable) and (iii) the termination of the Reporting Person's Service Relationship (as defined in the 2018 Plan and 2019 Plan, as applicable) due to the Reporting Person's death or disability.

F1 · kind: On May 15, 2025, the Issuer's board of directors approved an option repricing (the "Repricing"), to be effective May 19, 2025 (the "Repricing Date"). All of the other terms of the options remain unchanged. The transactions were exempt pursuant to Rule 16b-6(d) and Rule 16b-3 of the Exchange Act of 1934, as amended, as applicable.

F2 · derivative.exercise_date: This stock option award was issued pursuant to the Cabaletta Bio, Inc. 2018 Stock Option and Incentive Plan, as amended (the "2018 Plan") or the Cabaletta Bio, Inc. 2019 Stock Option and Incentive Plan, as amended (the "2019 Plan"), as applicable, and becomes exercisable in accordance with the vesting schedule specified in the award agreement and as previously reported on applicable Form 4, subject to the Reporting Person's continued service with the Issuer as of the applicable vesting date.