New clinical trial of DNA-based vaccines for patients with non-small cell lung cancer.

Abstract

e13034 Background: We report a new immunotherapeutic trial for patients with non-small cell lung cancer (NSCLC). The trial to be conducted at the University of Pittsburgh Cancer Institute is a two-stage uncontrolled non-randomized Phase IB study designed to evaluate the safety, immunogenicity and feasibility of a new vaccine, consisting of human allogeneic fibroblasts transfected with DNA derived from the patient’s own tumor. The vaccine is prepared by transfer of genomic DNA-fragments (25 kb) from the patient’s tumor into MRC-5 cells, a human embryonic fibroblast cell line. The rationale is that numerous mutant and dysregulated genes in the tumor specifying an array of patient-specific tumor antigens are expressed in a highly immunogenic form by the DNA-transfected cells. A large body of preclinical studies in tumor-bearing mice supports this approach. An IND has been issued. Cohort 1 is underway without DLT. Methods: We plan to use a two-stage trial design. Initially, 15 early-stage patients with NSCLC will be enrolled. If there is no evidence of toxicity, and >3 of the initial patients show an immunologic response, the second stage of the study will be opened for the accrual of 22 additional patients. A portion of the primary tumor removed at surgery will be obtained to serve as a source of tumor-DNA. Each vaccine will contain 1 X 10E7 DNA-transfected fibroblasts. The vaccine will be lethally irradiated before it is administered. It will be injected intradermally in the Outpatient Clinic. Immunologic responses to the vaccine and to the autologous tumor will be evaluated by IFN-g secretion in ELISPOT assays prior to and after vaccination for the frequency of T-cells responsive to the autologous tumor. Additional assays will include lymphocyte proliferation determinations in response anti CD3 and anti CD28 monoclonal antibodies and the effect of the immunizations on the proportion of myeloid-derived suppressor T cells in the patient’s peripheral blood. The patients will also be evaluated before and after immunization for the capacity of their T cells to respond to activating signals delivered via the T cell receptor (TcR). Results: Vaccines have been prepared. First patient has been enrolled. Conclusions: No data to report in this early trial.