Extended Tumor Control after Dendritic Cell Vaccination with Low-Dose Cyclophosphamide as Adjuvant Treatment in Patients with Malignant Pleural Mesothelioma

Rationale: We demonstrated previously that autologous tumor lysate–pulsed dendritic cell–based immunotherapy in patients with malignant pleural mesothelioma is feasible, well-tolerated, and capable of inducing immunologic responses against tumor cells. In our murine model, we found that reduction of regulatory T cells with metronomic cyclophosphamide increased the efficacy of immunotherapy.Objectives: To assess the decrease in number of peripheral blood regulatory T cells during combination therapy of low-dose cyclophosphamide and dendritic cell immunotherapy and determine the induction of immunologic responses with this treatment in patients with mesothelioma.Methods: Ten patients with malignant pleural mesothelioma received metronomic cyclophosphamide and dendritic cell–based immunotherapy. During the treatment, peripheral blood mononuclear cells were analyzed for regulatory T cells and immunologic responses.Measurements and Main Results: Administration of dendritic cells pulsed with autologous tumor ly...