Amendment: Cabaletta Bio Inc. filed SEC Form 8-K: Regulation FD Disclosure

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K/A

(Amendment No. 1)

CURRENT REPORT

Pursuant to Section 13 or 15(d)

of The Securities Exchange Act of 1934

February 18, 2025

Date of Report (Date of earliest event reported)

CABALETTA BIO, INC.

(Exact name of Registrant as Specified in its Charter)

(267) 759-3100

(Registrant’s telephone number, including area code)

Not Applicable

(Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

Securities registered pursuant to Section 12(b) of the Act:

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Explanatory Note

Cabaletta Bio, Inc. (the “Company” or “Cabaletta”) filed a Current Report on Form 8-K on February 18, 2025 in connection with a press release announcing new and updated clinical data from the first 10 patients dosed with resecabtagene autoleucel (rese-cel, formerly referred to as CABA-201) across the RESET clinical development program (the “Original 8-K”). This Amendment No. 1 (“Amendment No. 1”) to the Original 8-K is being filed to clarify that as of the data cut-off date of January 8, 2025, in the RESET-Myositis trial, the first adult dermatomyositis patient was off all immunosuppressants and tapering steroids, to revise other similar statements, and to note that a revised copy of the corporate presentation has been posted to the Company’s website and a copy of the revised press release has been furnished herewith to reflect the same, and no changes to the other information filed with the Original Form 8-K have been made.

On February 18, 2025, the Company filed Amendment No. 1. A revised copy of the corporate presentation has been posted to the Company’s website and a copy of the revised press release is attached hereto as Exhibit 99.1, and no changes to the other information filed with the Original Form 8-K have been made.

The information contained in Item 7.01 of this Current Report on Form 8-K, including Exhibit 99.1 attached hereto, is being furnished and shall not be deemed to be “filed” for the purposes of Section 18 of the Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section and shall not be incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such filing.

On February 18, 2025, the Company issued a revised press release to clarify that as of the data cut-off date of January 8, 2025, in the RESET-Myositis trial, the first adult dermatomyositis patient was off all immunosuppressants and tapering steroids.

(d) Exhibits

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, as amended, the registrant has duly caused this report to be signed on its behalf by the undersigned, hereunto duly authorized.