 Patients receive anti-cytotoxic T-lymphocyte-associated antigen-4 monoclonal antibody MDX-010 IV over 90 minutes on days 0, 21, 42, and 63. Treatment repeats every 84 days for up to 2 courses in the absence of disease progression or unacceptable toxicity. Patients with disease progression after achieving a partial response or complete response receive 2 additional courses of therapy. 