Cabaletta Bio is a late clinical-stage biotech developing CAR T cell therapies for autoimmune diseases. Cabaletta's only clinical asset is resecabtagene autoleucel (rese-cel), a CD19-targeting CAR T cell therapy designed to treat B cell-driven autoimmune diseases. The core idea: B cells drive many autoimmune diseases by producing autoantibodies that attack healthy tissue. Rese-cel is a one-time infusion of engineered T cells that depletes B cells, after which healthy B cells repopulate — potentially "resetting" the immune system and eliminating the need for chronic immunosuppression. Cabaletta is evaluating rese-cel across five autoimmune indications: myositis, systemic lupus erythematosus and lupus nephritis, systemic sclerosis, generalized myasthenia gravis, and pemphigus vulgaris. Cabaletta is furthest along in myositis, where a registrational trial is underway and a BLA submission is planned for 2027. Rese-cel holds RMAT designation for myositis, SLE/LN, and SSc, which provides early FDA interaction and eligibility for accelerated approval. Cabaletta is pre-revenue and funds operations through equity financing. Once approved, rese-cel would be sold as a one-time autologous CAR T therapy at a high per-patient price. Cabaletta outsources manufacturing entirely to CDMOs, avoiding large capital expenditure, and is partnering with Cellares and its automated platform to scale production for the larger patient volumes typical of autoimmune indications.