Tumor stem cell antigens as consolidative active specific immunotherapy: a randomized phase II trial of dendritic cells versus tumor cells in patients with metastatic melanoma.

Only 10% of metastatic melanoma patients survive 5 years, even though many can achieve substantial tumor reduction by surgical resection and/or radiation therapy and/or systemic therapy. An effective, nontoxic, consolidation immunotherapy could benefit such patients. We initiated a randomized trial to compare 2 promising patient-specific immunotherapy cell products. Patients had to have a diagnosis of metastatic melanoma and availability of an autologous melanoma cell line. Patients were stratified by whether their most advanced stage had been regional or distant metastases, and by whether they had measurable disease at the time of treatment, then they were randomized to receive irradiated autologous proliferating tumor cells or autologous dendritic cells (DC) loaded with antigens from such cells. Both products were injected subcutaneously in 500 µg of granulocyte-macrophage colony stimulating factor, weekly for 3 weeks and then monthly for 5 months. Patients in the 2 arms did not differ in baseline characteristics. All patients received prescribed therapy. Treatment was well tolerated. At the time of initial analysis, with no patients lost to follow-up, 50% of patients deceased, and all surviving patients followed for at least 6 months after randomization, survival is superior in the DC arm (hazard ratio, 0.27; 95% confidence interval, 0.098-0.729) with median survival not reached versus 15.9 months, and 2-year survival rates of 72% versus 31% (P=0.007). This trial provides evidence that a DC vaccine is associated with longer survival compared with a tumor cell vaccine, and is consistent with previous data suggesting a survival benefit from this patient-specific immunotherapy.

Phase II trial of dendritic cells loaded with antigens from self-renewing, proliferating autologous tumor cells as patient-specific antitumor vaccines in patients with metastatic melanoma: final report.

UNLABELLED: Between January 2001 and September 2007, we treated 54 metastatic melanoma patients with patient-specific tumor cell vaccines consisting of dendritic cells (DCS), derived from their peripheral blood cells that were cultured in interleukin (IL)-4 and granulocyte macrophage colony-stimulating factor (GM-CSF), which had phagocytosed irradiated autologous tumor cells from a continuously proliferating, self-renewing, autologus tumor cell (TC) culture. The loaded DCs were injected subcutaneously in 500 microg of GM-CSF weekly x three, and then monthly for 5 months, for a total of up to 8 injections. The 34 men and 20 women had a median age of 50.5 years; 32 had M1c (visceral metastases and/or elevated lactate dehydrogenase) as their most advanced disease stage. Overall, 83% had received other systemic therapies, including interferon-alpha (n = 20), biochemotherapy (n = 19), GM-CSF (n = 19), chemotherapy (n = 16), IL-2 (n = 13), and other investigational vaccines (n = 7). Patients received an average of 7.4 vaccinations. Treatment was well-tolerated, with most patients experiencing only mild local pruritus and/or erythema. A positive delayed-type hypersensitivity reaction to purified autologous tumor cells was observed at baseline in only 1 of 54 patients, compared to 12 of 54 following vaccination (p = 0.001). The projected 5-year survival rate is an impressive 54% at a median follow-up of 4.5 years (range, 2.4-7.4) for the 30 surviving patients. This survival was superior to that observed following vaccination with irradiated TC in 48 melanoma patients in a previous trial (64 versus 31 months, p = 0.016). This patient-specific vaccine warrants further investigation, based on its safety and encouraging survival rates. ( CLINICAL TRIAL NUMBER: NCI-V01-1646).