Brief Summary

This is an multicenter, open-label, rollover, single arm Extension Study to Evaluate the Long-term Safety of Rusfertide (PTG-300) in Subjects with Polycythemia Vera Phase III study.

The purpose of this study is to determine the long-term safety, tolerability, and efficacy of rusfertide in subjects with polycythemia vera (PV).

This is a study:

Subjects who complete dosing with rusfertide until the end-of-treatment (EOT) visit of a Phase 2 or Phase 3 study and meet the inclusion/exclusion criteria for this study, are eligible to participate. Subjects should be provided with a copy of the informed consent form (ICF) and other study-related materials prior to the EOT visit of the subject’s previous study. Subjects must give informed consent before undergoing any study-specific assessments. Assessments performed as part of the previous study’s EOT visit will be used to determine eligibility for the current protocol and are not considered study specific. Upon meeting the inclusion/exclusion criteria for rolling over to this study, dosing will begin on Week 0 Day 1, which should be the same day as the EOT visit from the previous study; any exception to this will require written approval from the medical monitor.

Subjects will continue to receive the dosing regimen from the previous study unless a change is required per the investigator’s evaluation. Subjects previously treated with the rusfertide prefilled syringe (PFS) formulation will be converted to an appropriate dose of the lyophilized formulation.

This study allows the doses of cytoreductive agents to be adjusted as well as initiation of new cytoreductive therapy.

Clinic Visits

For subjects transitioning from the PFS formulation to the lyophilized formulation, clinic visits will be:

 Week 0 Day 1 (1st dose)

 Every 4 weeks for the first 12 weeks

 Every 12 weeks thereafter

End of Study (Safety follow-up): 4 weeks post last dose

Unscheduled visits are allowed between the scheduled clinic visits for safety assessment or to ensure a subject is on an appropriate rusfertide dose. If a subject’s concurrent cytoreductive therapy requires a change or if new cytoreductive therapy needs to be initiated, the investigator should utilize unscheduled visits to monitor the subject.

Subjects who discontinue participation before completing the study should undergo the Early Termination (ET) assessments as soon as possible.

Subjects who complete the study or who terminate early from the study should undergo a follow-up evaluation of safety approximately 4 weeks after the last dose of study drug.

Additionally, approximately 6 months and 12 months after the last dose of study drug administration subjects should be contacted (e.g., phone) to determine if there has been a development of new cancers.