Rusfertide (PTG-300)

Rusfertide is an exciting new therapy aimed at patients with phlebotomy-dependent Polycythemia Vera. It is made by Protagonist Therapeutics and also goes by its inside name PTG-300. Rusfertide functions as a hepcidin mimetic, which means it mimics the function of the hormone Hepcidin. Hepcidin helps to control the levels of usable iron in the blood by regulating iron metabolism, storage, and absorption. This is important because many patients with Polycythemia vera have a secondary iron-deficiency as a result of increased erythropoiesis. Iron is being constantly used up to create Red Blood Cells in PV patients, leaving them with a deficiency in iron as a result. 

Blood donation, or in the case of case of PV patients, therapeutic phlebotomy, can worsen iron deficiency. Rusfertide can potentially eliminate the need for regular therapeutic phlebotomy and has been shown to help keep PV patient's hematocrits at or below 45%. This is due to Rusfertide's Hepcidin function, inhibiting the abundance of available iron, thus preventing the overproduction of Red Blood Cells since iron is required for Red Blood Cells production. 

Eliminating the overproduction of Red Blood Cells and the need for regular therapeutic phlebotomies should also allow PV patients to recover (to some level) from the iron deficiency seen in the disease. 

Rusfertide is still in clinical trial phase, with Phase 3 (NCT05210790) expected to have its study completed by 2025.