8555 Background: Patient-specific vaccines utilizing proliferating tumor cells, or tumor stem cells, may be the ideal products for active specific immunotherapy. Methods: Eligible patients had recurrent or metastatic melanoma from which a cell line was established, expanded to 200 million cells, incubated with interferon-gamma, irradiated and cryopreserved. Autologous dendritic cells (DC) were derived from peripheral blood mononuclear cells cultured in IL-4 and GM-CSF. DC were incubated with the irradiated tumor cells, then cryopreserved in 20- million-cell aliquots, which were thawed, washed and suspended in 500 micrograms of GM-CSF for injection. Treatment consisted of s.c. injections weekly × 3, then monthly × 5 in a 2-stage phase II trial with two stratifications. Patients were characterized as having objectively measurable disease (OMD) or non-measurable disease (NMD). Plans were to enroll 30 to 80 patients: 15 to 40 with OMD, 15 to 40 with MD. Objectives were to determine safety, frequency of conversion of delayed type hypersensitivity (DTH) reactions to irradiated autologous tumor cells, objective response rate (ORR) using RECIST criteria, progression-free survival (PFS), overall survival (OS), and comparison to a historical control group. Results: Between January 2001 and April 2006, 55 patients were enrolled; 53 were eligible and evaluable. The 30 men and 23 women had a median age of 50 years; 15 had OMD and 38 NMD. Patients received an average of 7.4 vaccinations out of a possible 8. Treatment was well- tolerated. 25% had a positive tumor DTH test: 1 at baseline, 7 after 3 injections, 5 after 8 injections. ORR was 0/15. Follow up for the 39 surviving patients ranges from 7 to 67 months with a median of 30 months. Median PFS is 7.1 months with 24 patients remaining progression-free. Only 14 patients have died; median OS has not been reached. 5-year projected survival is 70%; 20 patients are alive 2.5 to 5.5 years from start of vaccine. OS is better than observed for 48 comparable patients that we treated previously in a trial with irradiated tumor cells without DC (p=0.016). Conclusion: This patient-specific vaccine approach is feasible, safe, associated with encouraging survival, and warrants further investigation. No significant financial relationships to disclose.
Phase III randomized, double-blinded, placebo-controlled multicenter trial of melapuldencil-t: autologous dendritic cells loaded with irradiated autologous tumor cells (dc-tc) in gm-csf in patients with metastatic melanoma
