The goal of this clinical trial is to assess long-term safety and efficacy of rusfertide in subjects with polycythemia vera. Subjects who complete dosing with rusfertide until the end-of-treatment visit of a Phase 2 rusfertide study and meet the inclusion/exclusion criteria for this study, are eligible to participate in this open-label study and continue treatment with rusfertide.

This is an open-label study designed to assess the long-term safety and efficacy of rusfertide. This study aims to provide long-term rusfertide treatment to subjects who complete dosing until the end-of-treatment of a previous Phase 2 rusfertide study and are likely to continue benefiting from treatment with rusfertide based on their improved control of hematocrit levels <45% and reduced need for therapeutic phlebotomies. This study will provide long-term rusfertide treatment to these subjects and obtain data on safety and efficacy of long-term treatment with rusfertide.

Inclusion Criteria:

• Subject who has completed at least 12 months of dosing with rusfertide and successfully completed the end of treatment visit of a previous Phase 2 study of rusfertide.
• Subject understands the study procedures, is willing and able to adhere to study requirements and agrees to participate in the study by giving written informed consent.

Key Exclusion Criteria:

• Subject who, in the opinion of the investigator, should not participate in the study.
• Subject who discontinue early from a previous rusfertide study for reasons other than enrolling in this study.
• Pregnant or lactating females.
• Women of childbearing potential (WOCBP) who do not agree to use medically acceptable contraception (<1% annual failure rate) during the study and for 30 days after the last dose of study drug.
• Men with partners of childbearing potential who do not agree to use medically acceptable contraception (<1% annual failure rate) during the study and for 90 days after the last dose of study drug.
• Men who do not agree to use a condom during the study and for 90 days after the last dose of study drug regardless of the partner's childbearing potential.
• A female subject intends to donate eggs (ova, oocytes) for the purposes of assisted reproduction during the study and for a period of 30 days after receiving the last dose of study drug.
• A male subject intends to donate sperm for the purpose of reproduction during the study and for a minimum of 90 days after receiving the last dose of study drug.
• Plan to use investigational treatment other than rusfertide during the course of the study or within 28 days after last rusfertide dose.
• Subject with hypersensitivity to rusfertide or to any of the excipients.
• In the investigator's opinion the subject has progressive disease that cannot be managed by adjusting concurrent cytoreductive therapy.