In both cohorts, patients are evaluated 3-4 weeks after the fourth immunization. Patients achieving stable disease or a partial response receive retreatment according to their assigned cohort. Patients with progressive disease who are eligible for interleukin-2 (IL-2) receive retreatment according to their assigned cohort AND high-dose IL-2 IV over 15 minutes 3 times daily on days 2-5, 23-26, 44-47, and 65-68 (1 course). Patients receive up to 3 retreatment courses. Patients achieving a complete response (CR) receive 1 retreatment course beyond CR. Patients with progressive disease who are ineligible for IL-2 administration are removed from the study.