Provided are methods of treatment involving immunotherapy, such as T cell therapy, and administration of a tryptophan metabolism and/or kynurenine pathway modulator. In some embodiments, the method includes a combination therapy that involves administration of engineered T cells, such as chimeric antigen receptor (CAR)-expressing cells, and a tryptophan metabolism and/or kynurenine pathway modulator, such as an inhibitor of an enzyme. Also provided are engineered cells in which the expression of a molecule involved in the kynurenine pathway is modified. Also provided are methods of manufacturing engineered cells, cells, compositions, methods of administration to subjects, nucleic acids and kits for use in the methods. In some aspects, features of the methods and cells provide for increased or improved activity, activity, outcome, function, response, persistence, expansion and/or proliferation of cells for adoptive cell therapy.
