The purpose of this study is to determine whether the study drug, Rusfertide, is safe and effective for treating Polycythemia Vera for those that require routine phlebotomies (removal of red blood cells) to control their disease.
Participants in this study should have previously participated in a study in which Rusfertide (also known as PTG-300) was being studied. Participants will continue to receive Rusfertide in this study.