| Item 7.01 | Regulation FD Disclosure. |
On May 16, 2023, Cabaletta Bio, Inc. (the “Company” or “Cabaletta”) posted to the “Investors & Media” section of the Company’s website at www.cabalettabio.com an updated corporate presentation providing a corporate overview and updated development plan (the “Corporate Presentation”). A copy of the Corporate Presentation is attached hereto as Exhibit 99.1 and is incorporated by reference into this Item 7.01 of this Current Report on Form 8-K.
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 Securities 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.
Myositis Press Release
On May 16, 2023, the Company issued a press release announcing that the Company’s second Investigational New Drug (“IND”) application for CABA-201, a 4-1BB-containing fully human CD19-CAR T cell investigational therapy, has been cleared by the U.S. Food and Drug Administration (the “FDA”) for a Phase 1/2 study in patients with active idiopathic inflammatory myopathy (“IIM” or “myositis”). The Company plans to initiate a Phase 1/2 clinical trial of CABA-201 for the treatment of six patients with dermatomyositis (“DM”), six patients with anti-synthetase syndrome (“ASyS”), and six patients with immune-mediated necrotizing myopathy (“IMNM”), all in separate parallel cohorts. The initial dose for the trial, 1 x 106 cells/kg, was informed by preclinical data evaluating the binder in CABA-201 and the binder used in the CD19-CAR T construct administered to a patient with myositis in the recent Lancet Rheumatology publication.
Myositis refers to a group of autoimmune diseases characterized by inflammation and muscle weakness. In some cases, myositis may also affect other organs and systems in the body, such as the lungs, heart, or skin. Myositis is classified into several subtypes based on the underlying immune mechanisms and clinical characteristics. Although the pathogenesis of myositis is not well understood, there are several subtypes thought to be driven by B cells, including DM, ASyS and IMNM. These three subtypes impact approximately 66,000 patients in the US alone, and typically affect middle-aged individuals, particularly women. All three subtypes can lead to severe functional impairment and may be life-threatening. Current treatment typically involves medications to suppress the immune system and/or chronic intensive therapies such as intravenous immunoglobulin, or IVIg. Despite these therapies, a significant portion of myositis patients have disease that remains refractory to existing medications.
The Phase 1/2 clinical trial will be an open-label study of CABA-201 in subjects with active myositis, including the subtypes of DM, ASyS and IMNM. Subjects will receive a one-time infusion of CABA-201 at a dose of 1.0 x 106 cells/kg, preceded by a standard preconditioning regimen of fludarabine and cyclophosphamide. Key inclusion criteria include patients between ages 18 to 65 (inclusive), evidence of active disease and disease activity despite prior or current treatment with standard of care treatments. Key exclusion criteria include cancer-associated myositis, significant lung or cardiac impairment, treatment with a B cell depleting agent within approximately six months or treatment with a biologic agent within approximately three months.
Corporate Presentation
On May 16, 2023, the Company posted the Corporate Presentation to the “Investors & Media” section of the Company’s website at www.cabalettabio.com, which included the following updates: (i) a modest increase in persistence was observed in the first two patients in the combination sub-study, incorporating a pre-treatment combination regimen with intravenous immunoglobulin (“IVIg”) and cyclophosphamide (“Cy”) in the DesCAARTes™ trial; (ii) the Company is planning to initiate a cohort of incorporating a pre-treatment combination regimen with fludarabine, IVIg and Cy in the DesCAARTes™ trial following completion of the dose-limiting toxicity window for the IVIg and Cy combination cohort; and (iii) the previously announced MusCAARTes™ study timelines are being evaluated based on emerging data from the DesCAARTes™ study.
