Preclinical safety and biodistribution of adenovirus-based cancer vaccines after intradermal delivery.

The recombinant adenoviral (Ad) vector is being considered as a cancer vaccine platform because it efficiently induces immune responses to tumor antigens by intradermal immunization. The aims of this study were to evaluate the potential toxicities and biodistribution after a single dose or six weekly intradermal doses of Ad2/gp100v2 and Ad2/MART-1v2, which encode tumor-associated antigens gp100 and MelanA/MART-1, respectively. The only dose-related toxicities associated with intradermal administration of these Ad vectors were inflammatory cell infiltrates in the draining lymph nodes and injection sites that persisted 83 days after administration.

Enhanced efficacy of melanoma vaccines in the absence of B lymphocytes.

Provoking a specific cellular immune response against tumor-associated antigens is a promising therapeutic strategy to treat cancers with defined antigens such as melanoma. In recent clinical trials, however, immune responses against melanoma antigens have been elicited without consistent clinical responses, suggesting the need for approaches that potentiate the specific cellular immune response. Since B lymphocytes have been reported to exert a negative effect on the cellular arm of the immune response in certain model systems, the authors compared the protective immunity elicited by melanoma antigens in B cell-deficient microMT mice to that obtained in fully immunocompetent C57BL/6 mice.