A canine melanoma vaccine has received a full license from the US Department of Agriculture, the first therapeutic cancer vaccine approved for human or animal use. The San Diego–based Vical sees the approval of its DNA vaccine Oncept as an indicator of potential success for its human therapeutic vaccine currently in development for metastatic melanoma. Others are more cautious. “[It] is quite an achievement, but I don't believe that Oncept's approval has brought us any closer to a human therapeutic cancer vaccine, as researchers have seen cures in animal models of melanoma for quite some time,” says Martin Bachmann, of Cytos, a company in Schlieren, Switzerland. Oncept contains a gene encoding human tyrosinase, an enzyme associated with skin pigmentation, which stimulates an immune response against canine tyrosinase in melanoma cells. “Canine melanoma is similar in disease course and spread to human melanoma, so the results could be relevant for predicting response in humans for a similar DNA vaccine. However, the study was not randomized, and it's hard to forecast how the human immune system will respond,” says Christian Ottensmeier, a Cancer Research UK investigator at Southampton University. Oncept will be commercialized by Vical's licensee, Merial, the animal health subsidiary of Paris-based Sanofi-aventis.