Cabaletta Bio, Inc., a clinical-stage biotechnology company, focuses on the discovery and development of engineered T cell therapies for patients with autoimmune diseases. The company's lead product candidate is resecabtagene autoleucel, a 4-1BB co-stimulatory domain-containing fully human CD19-CAR T, which is in Phase 1/2 clinical trials for the treatment of dermatomyositis, anti-synthetase syndrome, immune-mediated necrotizing myopathy, juvenile myositis, lupus nephritis, systemic lupus erythematosus, relapsing and progressive multiple sclerosis, mucocutaneous and mucosal pemphigus vulgaris (PV), systemic sclerosis, and generalized myasthenia gravis. It also develops DSG3-CAART, a CAAR T cell therapy that is in Phase 1 clinical trial for the treatment of mucosal PV; and MuSK-CAART, an investigational cell therapy in Phase 1 trial for treating patients with anti-muscle-specific kinase (MuSK) antibody positive myasthenia gravis. It has collaborations with the University of Pennsylvania and the Children's Hospital of Philadelphia; Nanjing IASO Biotherapeutics Co., Ltd; Oxford Biomedica; Autolus Holdings (UK) Limited; and WuXi Advanced Therapies, Inc. The company was formerly known as Tycho Therapeutics, Inc. and changed its name to Cabaletta Bio, Inc. in August 2018. Cabaletta Bio, Inc. was incorporated in 2017 and is headquartered in Philadelphia, Pennsylvania.