Combined Modality Treatment for Patients With Stage IV Melanoma

A novel dendritic cell vaccine is being developed at the Baylor Institute for Immunology Research. Pre-clinical studies have found that this dendritic cell vaccine is more efficient in inducing a tumor specific immunity than other dendritic cell vaccines. Further studies in BIIR have been done with dendritic cells that were loaded with killed melanoma cells from a melanoma cell line treated with heat before loading. Both studies have shown that DCs manufactured in this novel way were more efficient in priming the melanoma specific CD8+ cells. Our previous studies indicate that a portion of patients with stage IV melanoma cannot mount an immune response to tumor antigens presented on dendritic cells. Also, regulatory/suppressor T cells can be identified in the blood of these patients, which may account for the lack of induction of T cell immunity to dendritic cell vaccines. Cyclophosphamide treatments have improved antitumor immunity in humans with melanoma and a clear relationship between cyclophosphamide dosage and suppressor cell activity has been documented. Therefore, this trial will test a combined modality treatment, using dendritic cell based vaccines in patients who have been treated with cyclophosphamide. This clinical trial will evaluate the cyclophosphamide/dendritic cell vaccine in patients with Stage IV melanoma. The trial will accrue a total of 33 subjects. The primary goal of this trial will be to test the safety/tolerability/feasibility of the combined modality and the rate of objective clinical response.However if feasibility data in the first 10 subjects demonstrate the need to adjust the dose of CPA, the new dose will be tested in the next 10 subjects thereby extending the accrual to 43 subjects. A 15% objective response rate will be accepted in patients with stage IV Melanoma. Patients will receive cyclophosphamide 300 mg/m2, administered 24 hours prior to DC vaccinations # 1, 3, 5, 6 and 7. Each subject will initially receive 7 doses of vaccination with each individual dose being administered at weeks 0, 2, 4, 6, 10, 14 and 18. A clinical evaluation of the patients will be done at weeks 10 \& 20. Patients with progressive disease will be taken off of the study. Patients with SD, PR or CD (according to RECIST criteria) may receive 4 more vaccinations. Scans and re-staging tests will be performed at scheduled intervals throughout the study.