| Item 7.01 | Regulation FD Disclosure. |
On November 6, 2023, Cabaletta Bio, Inc. (the “Company” or “Cabaletta”) issued a press release announcing that the Company’s fourth 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 generalized myasthenia gravis (the “Press Release”). A copy of the Press Release is attached hereto as Exhibit 99.1 to 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.
On November 6, 2023, the Company issued the Press Release announcing that the Company’s fourth 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 generalized myasthenia gravis (“gMG”). The Company plans to initiate a Phase 1/2 clinical trial of CABA-201 across two parallel gMG cohorts based on autoantibody status – one cohort of six patients with acetylcholine receptor (“AChR”) antibody-positive gMG and a second cohort of six patients with AChR antibody-negative gMG. Consistent with the previously announced CABA-201 IND application clearances for lupus, myositis and systemic sclerosis, the starting dose for the Phase 1/2 trial evaluating CABA-201 in gMG will be 1 x 106 cells/kg.
Myasthenia gravis (“MG”) is a rare autoimmune disease characterized by autoantibodies that interfere with signaling at the neuromuscular junction (“NMJ”), leading to potentially life-threatening muscle weakness. The majority of patients with MG have autoantibodies known to be pathogenic based on their interference with proteins in the NMJ, of which the majority target AChR. gMG affects approximately 85% of the between 50,000 and 80,000 estimated MG patients in the United States. Symptoms of gMG include profound muscle weakness throughout the body, disabling fatigue, shortness of breath due to respiratory muscle weakness and risk for episodes of respiratory failure. Standard of care therapies include cholinesterase inhibitors, steroids, immunomodulators, and biologics, which often provide modest clinical effect and require chronic administration, increasing the risk of serious long-term side effects.
The Phase 1/2 clinical trial will be an open-label study of CABA-201 in subjects with gMG across two parallel cohorts. The first cohort will include six patients with AChR antibody-positive gMG, and the second will include six patients with AChR antibody-negative gMG. Participants will receive a one-time infusion of CABA-201, using the same dose being used in the lupus, myositis and systemic sclerosis 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), a diagnosis of gMG, and disease activity despite standard of care therapies. Key exclusion criteria include MG with only ocular manifestations, an active or untreated thymoma, and treatment with a B cell depleting agent within six months. As the fourth 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.
