Active immunotherapy for cancer patients using tumor lysate pulsed dendritic cell vaccine: a safety study

Cancer vaccine therapy represents a promising therapeutical option. Consistently, with these new treatment strategies, the use of dendritic cell vaccines is becoming increasingly widespread and currently in the forefront for cancer treatment. The purpose of this study was to evaluate the feasibility and safety of tumor lysate-pulsed dendritic cell (DC) vaccine in patients with advanced cancers. For this purpose, eighteen patients with relapsed or refractory cancer were vaccinated with peripheral monocyte-derived DCs generated with GM-CSF and IL-4, and pulsed consequently with 100 microg/ml of tumor lysate before maturation in culture in the presence of IL-1beta, PGE2 and TNF alpha for two days. The first two vaccinations were given intradermally every two weeks while further injections were given monthly. Tumor lysate-pulsed dendritic cell injections were well-tolerated in all patients with no more than grade 1 injection-related toxicity. Local inflammatory response was mainly erythematous which subsided in 48 hrs time. No end organ toxicity or autoimmune toxicity was identified. Clinical responses observed in our study were satisfactory for a phase I clinical study. We observed 4 (22%) objective clinical responses. These responses are significantly correlated with delayed type hypersensitivity testing (DTH) (p < 0.01). The results showed that this active immunotherapy is feasible, safe, and may be capable of eliciting immune responses against cancer.