Adoptive chemoimmunotherapy for the treatment of relapsed and refractory solid tumors using Ex vivo activated memory T cells (autolymphocyte therapy) and cyclophosphamide

Autolymphocytes (ALT cells) are ex vivo activated peripheral blood lymphocytes (PBL) from tumor-bearing hosts (TBH) that consist primarily of tumor specific CD45RO⁺(memory) T cells. These ALT cells combined with cimetidine as autolymphocyte therapy (ALT) have previously been demonstrated to be a safe and active form of outpatient adoptive immunotherapy (AIT) in human TBH with metastatic renal cell cancer (RCC). To determine activity of ALT in human TBH with therapy-resistant solid tumors other than RCC and whether it was feasible to combine ALT with chemotherapy, we studied 21 patients with relapsed or primary refractory solid tumors following a study protocol of adoptive chemoimmunotherapy (ACIT) using ALT and cyclophosphamide. Twenty patients were evaluable. Five responses were seen, including two complete responses (CRs) and three partial responses (PRs). ACIT activity was noted in relapsed TBH who had responded to their previous chemotherapy and/or radiation therapy. The toxic effects of this ACIT study were minimal with no treatment-related morbidity or mortality. It appears that in some relapsed but not primary refractory solid tumors, ACIT using ALT (CD45RO⁺T cells and cimetidine) together with cyclophosphamide has definite antitumor activity associated with little or no toxic effects. Further studies of ACIT in solid tumors other than RCC are justified.