All subjects who were previously randomized in the Phase 2b studies SGN113399 or SGN113404 and received GSK2248761 will be targeted for enrollment in the study. Study SGN11339 had 20 subjects randomized to receive GSK2248761 and was conducted at 12 sites in the United States and one site in Romania. Study SGN113404 was conducted at three sites in France and three sites in Germany, with 15 subjects randomized to receive GSK2248761. Therefore, the study population for the current study will consist of 35 subjects originating from sites located in the United States, Romania, France, and Germany.