Cabaletta Bio, Inc. 8-K

What Happened
Cabaletta Bio, Inc. (CABA) filed an 8-K on May 4, 2026 announcing it will present new clinical and translational data at the American Society of Gene & Cell Therapy (ASGCT) Annual Meeting on May 14, 2026. The data come from four refractory patients in the RESET-PV® pemphigus vulgaris trial who received the lowest dose of rese-cel without cyclophosphamide or fludarabine preconditioning (data cut-off April 2, 2026; follow-up 24–36 weeks).

Key Details

• Four refractory patients treated at the lowest dose without preconditioning; follow-up ranged from 24 to 36 weeks as of April 2, 2026.
• Clinical activity observed after patients discontinued all immunomodulators; 2 of 4 patients showed compelling clinical activity through 6 months.
• Three of 4 patients remained off all immunomodulators and steroids at data cut-off; complete peripheral B cell elimination observed in 3 of 4 patients.
• Safety: cytokine release syndrome (CRS) occurred in 1 of 4 patients (Grade 1); no immune effector cell-associated neurotoxicity syndrome (ICANS) reported.
• Development updates: additional patients have been enrolled at a higher dose in RESET-PV with durability data expected in the second half of 2026; RESET-SLE initial dose cohort is fully enrolled with initial data anticipated in the first half of 2026.

Why It Matters
This filing highlights early evidence that rese-cel can produce biologic and clinical activity in pemphigus vulgaris without standard chemotherapy-like preconditioning, potentially simplifying treatment. Investors should note the very small sample size (four patients at lowest dose) and early follow-up; the company is escalating dose and expects more durability and SLE cohort data later in 2026, which will be more informative for assessing clinical benefit and safety.