High-dose Chemotherapy and Adoptive Immunotherapy in the Treatment of Recurrent Pediatric Brain Tumors

Pediatric patients with recurrent brain tumors have a poor prognosis and limited therapeutic options. We investigated the use of high-dose chemotherapy with adoptive immunotherapy for recurrent brain tumors. Three pediatric patients with recurrent brain tumors received high-dose chemotherapy. This was followed by adoptive transfer of ex-vivo expanded T-cells. The T-cells were generated from peripheral blood after immunization with autologous cancer cells. The objectives of this study included (1) establishing the safety and feasibility of this potential treatment, (2) measuring changes in immune response after high-dose chemotherapy and adoptive immunotherapy, and (3) determining whether adoptive immunotherapy would be able to translate into a clinical response. Immune function was tested in all patients at the time of enrollment into the study. Humoral responses to recall antigens delayed-type hypersensitivity (DTH) were intact in all patients. After immunizing patients with autologous cancer cells, peripheral blood lymphocytes were harvested and activated with anti-CD3, expanded in-vitro, and infused post-autologous transplant. Patients received at least three doses of the vaccine, each consisting of an intradermal administration near a draining lymph node at biweekly intervals. Toxicity was limited and well tolerated in all patients. All three patients showed a tumor-specific immune response by serial imaging. Responses were durable at 16, 23, and 48 months, respectively.