| Item 7.01 | Regulation FD Disclosure. |
On May 2, 2023, Cabaletta Bio, Inc. (the “Company”) issued a Press Release announcing that Samik Basu, M.D., Chief Scientific Officer at the Company, will deliver an invited, oral presentation titled “CD 19 CAR T-cells for SLE” as part of the session titled “Immune Effector Cells: 2023 and Beyond!” on Tuesday, May 16, 2023, at 11:05 a.m. PT at the upcoming American Society of Gene and Cell Therapy (“ASGCT”) 26th Annual Meeting, which is being held at the Los Angeles Convention Center in Los Angeles, CA from May 16-20, 2023 (“ASGCT Annual Meeting”). A copy of the press release 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.
On May 2, 2023, two abstracts providing (i) new preclinical data for CABA-201, a 4-1BB-containing fully human CD19-CAR T cell investigational therapy, and (ii) updated clinical and translational data from the ongoing DesCAARTes™ trial for DSG3-CAART in adults with mucosal-dominant pemphigus vulgaris (mPV) were published at the ASGCT’s website. The abstracts have been selected for poster presentations at the upcoming ASGCT Annual Meeting as further detailed in Item 7.01 of this Current Report on Form 8-K.
The accepted abstracts are as follows:
| | • | | Preclinical Specificity and Activity of CABA-201, a Fully Human 4-1BB Containing CD19 CAR T Therapy for Treatment-Resistant Autoimmune Disease: Over 4% of the world population is estimated to live with autoimmune disease. Treatment typically requires systemic immunosuppressive therapy that have associated toxicities and are not curative. There is increasing evidence that B cells play a central role in disease pathogenesis, based upon responsiveness to B cell depletion by antibody-based therapeutics; however, responses are typically transient due to the incomplete depletion of B cells in secondary lymphoid tissue. Chimeric antigen receptor (CAR) T cells are a novel gene-engineered cellular immunotherapy where a synthetic T cell receptor is expressed to redirect the T cell to a desired target. Several B cell targeted CD19 CAR T cell products have led to durable remissions of B cell leukemias and lymphomas; three have been approved by regulators globally, each of which utilizes the murine derived CD19 scFv binding domain FMC63. Data from numerous studies have established the ability of these products to deeply deplete B cells. An early proof of concept pilot study evaluating the safety and efficacy of an FMC63-41BB-CD3z CAR T cell product, analogous to one of the approved therapies, in 5 patients with treatment refractory systemic lupus erythematosus suggests the potential to achieve rapid, deep and durable drug-free remissions. We designed a new CD19 CAR T product (CABA-201) containing a clinically de-risked (NCT05091541) fully human CD19 binder (IC78), to minimize immune mediated interference with activity. In addition, the construct utilizes the same 41BB costimulatory domain used in the pilot study above, which is reported to have a reduced incidence and severity of cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS) in oncology patients. Preclinical studies were conducted to explore the specificity and activity of CABA-201 compared to the specificity and activity of the FMC63-41BB-CD3z construct using the same cell production method. CABA-201 demonstrated comparable cytotoxic activity to FMC63 CAR T cells against CD19+ Nalm6 cells in vitro, and comparable in vivo potency was observed in a dose ranging study in the NSG-Nalm6 tumor model. No evidence of off-target cytotoxic activity of CABA-201 was identified against a panel of selected primary human cells, and no off-target binding against IC78 was detected in a membrane proteome array, or in clinical studies evaluating IC78 in a tandem CAR formation. CABA-201 generated from primary T cells from multiple autoimmune disease patients showed robust CAR surface expression and effective elimination of target autologous CD19+ B cells in vitro. Together, these data support the safety and activity of CABA-201, and provide a clinically relevant benchmark for dose related potency in clinical studies planned for initiation later this year. |
| | • | | Correlative Findings Following DSG3-CAART Infusion with and without Combination Preconditioning Therapy in Patients with Pemphigus Vulgaris (DesCAARTes™ Study): Mucosal-dominant pemphigus vulgaris (mPV) is a painful autoimmune blistering disease mediated by anti-desmoglein 3 autoantibodies (anti-DSG3 Ab). The current standard of care for mPV includes broadly immunosuppressive therapies that have risks of serious or |
