PV is a myeloproliferative disorder characterised by the overproduction of red blood cells.
The Phase II clinical proof-of-concept study is expected to enrol about 30 patients. It will monitor the safety profile and obtain preliminary evidence of efficacy in patients requiring phlebotomy.
It comprises a 16-week open-label dose-escalation stage every four weeks from 10mg to 80mg and a 12-week maintenance period at doses that generate desired hematocrit levels followed by a randomised and blinded withdrawal stage for 12 weeks.
The PTG-300 study also has an open-label extension for up to one year to monitor the drug’s long-term safety and benefits.
The study’s endpoints include the measurement of blood parameters, including hematocrit and haemoglobin levels, reductions or delay in phlebotomy requirements, and improvements in quality-of-life symptoms.
Protagonist Therapeutics president and CEO Dinesh Patel said: “In addition to our ongoing study of PTG-300 in patients with beta-thalassemia, we are excited to expand its clinical development with the initiation of this proof-of-concept study in polycythemia vera.
“An important aspect of the mechanism of action of the hepcidin mimetic PTG-300 is to reduce iron availability, which is required to support the excessive erythropoiesis which occurs in PV, thereby potentially enabling PTG-300 to manage this excessive erythropoiesis and ultimately reduce the phlebotomy burden in these patients.”
The injectable hepcidin mimetic PTG-300 has secured Orphan Drug designation in the US and EU.
The US Food and Drug Administration also granted fast-track designation for development in the potential treatment of beta-thalassemia.
In January this year, Protagonist dosed the first patient in a Phase II trial of PTG-300 for the treatment of patients with beta-thalassemia.