| Item 7.01 | Regulation FD Disclosure. |
On October 2, 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 (the “Corporate Presentation”). A copy of the Corporate Presentation is furnished herewith as Exhibit 99.1 to this Current Report on Form 8-K.
On October 2, 2023, the Company issued a Press Release announcing that the Company’s third 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 systemic sclerosis (“SSc”) (the “Press Release”). A copy of the Press Release is attached hereto as Exhibit 99.2 to this Current Report on Form 8-K.
The information contained in Item 7.01 of this Current Report on Form 8-K, including Exhibits 99.1 and 99.2 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.
On October 2, 2023, the Company issued the Press Release announcing that the Company’s third IND application for CABA-201, a 4-1BB-containing fully human CD19-CAR T cell investigational therapy, has been allowed to proceed by the FDA for a Phase 1/2 study in patients with SSc. The Company plans to initiate a Phase 1/2 clinical trial of CABA-201 across two parallel SSc cohorts – one cohort of six patients with severe skin manifestations and a separate cohort of six patients with severe organ involvement associated with systemic sclerosis. Consistent with the previously announced CABA-201 IND clearances for lupus and myositis, the starting dose for the trial, 1 x 106 cells/kg, was informed by the high degree of similarity between CABA-201 and the CD19-CAR T construct administered to a patient with severe, diffuse SSc in the recent Annals of Rheumatic Diseases publication.
SSc is a rare and potentially fatal chronic autoimmune disease characterized by progressive skin and internal organ fibrosis that can be life-threatening, including interstitial lung disease, pulmonary hypertension, and scleroderma renal crisis. Although the etiology of SSc is not well understood, the pathogenic role of autoantibodies and B cells in SSc provides a rationale for studying CAR T therapy in this population. SSc affects approximately 88,000 patients in the U.S., and typically affects middle-aged individuals, particularly women. Standard treatment options, which have modest effects, include generalized immunosuppressive agents or drugs targeted to specific symptomatic manifestations. Autologous hematopoietic stem cell transplant may provide some benefits in organ involvement, but carries significant risks, including mortality, infertility, and secondary autoimmune disease, limiting its potential to be applied broadly. Due to the lack of adequate treatments, the risk of mortality in systemic sclerosis remains high, with an average survival of approximately 12 years following diagnosis.
The Phase 1/2 clinical trial will be an open-label study of CABA-201 in subjects with SSc across two parallel cohorts. The severe skin cohort will include six patients with severe skin involvement, and the organ cohort will include six patients who meet the pulmonary, cardiac, or renal involvement criteria regardless of skin involvement. Subjects will receive a one-time infusion of CABA-201, using the same dose being used in the lupus and myositis clinical trials of CABA-201, 1 x 106 cells/kg, preceded by a standard preconditioning regimen of fludarabine and cyclophosphamide. Key inclusion criteria include patients between ages 18 and 70 (inclusive), evidence of significant skin, pulmonary, renal, or cardiac involvement, and significant organ involvement despite use of immunosuppressants. Key exclusion criteria include a primary diagnosis of another rheumatic autoimmune disease, treatment with a B cell depleting agent within six months or treatment with a biologic agent within three months. As the third trial within Cabaletta’s CARTA (Chimeric Antigen Receptor T cells for Autoimmunity) strategy, this study is intended to evaluate the potential ability of CABA-201 to transiently, but completely, eliminate B cells throughout the body, potentially enabling an immune system reset associated with a slowing or halting of active inflammatory disease progression in patients with SSc.
