The efficacy of
cytoreductive surgery for metastatic
melanoma depends in part on the patient's immune response, which can be modulated by post-operative active immunotherapy with
Canvaxin therapeutic polyvalent
cancer vaccine (
CancerVax Corp., Carlsbad, CA).
Canvaxin vaccine induces polyvalent humoral and cell-mediated immune responses to a wide variety of
protein and
ganglioside melanoma antigens; these responses correlate with subsequent prognosis in immunized patients. Matched-pair analyses of data from extensive phase II trials have demonstrated a consistent overall survival (OS) benefit for
Canvaxin therapy in stage IV
melanoma (five-year OS of 39% for 107
vaccine patients versus 20% for 107 non-
vaccine patients; P = .0009) and stage III
melanoma (five-year OS of 49% for 739
vaccine patients versus 37% for 739 non-
vaccine patients; P = .0001).
Vaccine-induced immune responses have been correlated with survival after resection of local, regional, and distant
melanoma. In 77 patients who received
Canvaxin vaccine after resection of stage IV
melanoma, five-year OS rate was 75% for patients with an elevated level of
IgM antibodies against a 90-kD
glycoprotein antigen (TA90) expressed by the
vaccine, and a strong delayed-type
hypersensitivity (DTH) response to the
vaccine; by contrast, survival was 36% for patients who had either an elevated
IgM response or a strong DTH response, and only 8% if neither response was strong (P < .001). In 59 patients with resected stage III
melanoma, both cellular (DTH) and humoral (anti-TA90
IgG and
IgM antibodies) immune responses impacted survival (P = 0.046, 0.0005, and 0.0053, respectively). In stage II
melanoma, five-year OS and disease-free survival rates were 94% and 89%, respectively, when maximal anti-TA90
IgM titre was at least 1:800, compared to only 52% and 17%, respectively, for lower titres (P = .0001). Cumulatively, these data represent the largest phase II experience for any
cancer vaccine and indicate the clinical efficacy of stimulating a patient's endogenous immune response to
melanoma.