The present disclosure relates in some aspects to methods, compositions and uses involving immunotherapies, such as adoptive cell therapy, e.g., T cell therapy, and an immunomodulatory compound, such as a structural or functional analog or derivative of thalidomide and/or an inhibitor of E3-ubiquitin ligase. The provided methods, compositions and uses include those for combination therapies involving the administration or use of one or more immunomodulatory compounds in conjunction with a T cell therapy, such as a genetically engineered T cell therapy involving cells engineered with a recombinant receptor, such as chimeric antigen receptor (CAR)-expressing T cells. Also provided are compositions, methods of administration to subjects, articles of manufacture and kits for use in the methods. In some aspects, features of the methods and cells provide for increased or improved activity, efficacy, persistence, expansion and/or proliferation of T cells for adoptive cell therapy or endogenous T cells recruited by immunotherapeutic agents.