Abstract: In accordance with the present invention, there are provided fully human monoclonal antibodies against human cytotoxic T-lymphocyte antigen 4 (CTLA-4). Nucelotide sequences encoding and amino acid sequences comprising heavy and light chain immunoglobulin molecules, particularly contiguous heavy and light chain sequences spanning the complementarity determining regions (CDRs), specifically from within FR1 and/or CDR1 through CDR3 and/or within FR4, are provided. Further provided are antibodies having similar binding properties and antibodies (or other antagonists) having similar functionality as antibodies disclosed herein.

Abstract: The invention relates to treatment of cancer in a mammal who has undergone stem cell transplantation by administering an effective amount of a human anti-CTLA-4 antibody to the mammal. Stem cell transplantation may be allogeneic or autologous stem cell transplantation and may be preceded by a preparatory treatment such as chemotherapy. The methods of the invention may be combined with additional cancer treatments. Further, the invention relates to treatment of cancer using at least 10 mg/kg of a human anti-CTLA-4 antibody, and, more preferably, about 15-20 mg/kg of antibody.