Intranodal Administration of Peptide-Pulsed Mature Dendritic Cell Vaccines Results in Superior CD8+T-Cell Function in Melanoma Patients

PURPOSE: We evaluated the feasibility, safety, and immunogenicity of mature, peptide-pulsed dendritic cell (DC) vaccines administered by different routes. PATIENTS AND METHODS: We performed a randomized, phase I, dose-escalation study in 27 patients with metastatic melanoma receiving four autologous peptide-pulsed DC vaccinations. Patients were randomly assigned to an intravenous (IV), intranodal (IN), or intradermal (ID) route of administration (ROA). For each route, primary end points were dose-limiting toxicity, maximum-tolerated dose, and T-cell sensitization. Sensitization was evaluated through tetramer staining, in vitro peptide recognition assays, and delayed-type hypersensitivity (DTH) responses. RESULTS: Twenty-two (81.5%) of 27 patients completed all four vaccinations. Vaccinations were well tolerated; a few patients exhibited grade 1 to 2 toxicities including rash, fever, and injection site reaction. All routes of administration induced comparable increases in tetramer-staining CD8+ T cells (five of seven IV, four of seven IN, and four of six ID patients). However, the IN route induced significantly higher rates for de novo development of CD8+ T cells that respond by cytokine secretion to peptide-pulsed targets (six 85.7% of seven IN patients v two 33% of six ID patients v none 0% of six IV patients; P =.005) and de novo DTH (seven 87.5% of eight IN patients v two 33.3% of six ID patients v one 14.3% of seven IV patients; P =.01) compared with other routes. CONCLUSION: Administration of this peptide-pulsed mature DC vaccine by IN, IV, or ID routes is feasible and safe. IN administration seems to result in superior T-cell sensitization as measured by de novo target-cell recognition and DTH priming, indicating that IN may be the preferred ROA for mature DC vaccines.