The Spanish company is focused in the development of CAR T therapies for the treatment of oncological diseases, with the lead prodcut being a novel and selective CAR T therapy against CD1a (OC-1) for the treatment of refractory/relapsed patients with cortical T-cell acute lymphoblastic leukemia/lymphoblastic lymphoma (co T-ALL). OC-1 has been granted Orphan Drug Designation for ALL by the EMA and the FDA.

OneChain was founded by the Josep Carreras Leukemia Research Institute and ICREA in June 2020.