This is a Phase 2 study with an open-label dose escalation phase followed by a blinded withdrawal phase and an open label extension. The study is designed to monitor the PTG-300 safety profile and to obtain preliminary evidence of efficacy of PTG-300 for the treatment of phlebotomy-requiring polycythemia vera.



Eligible Ages
Over 18 Years
Eligible Genders
Accepts Healthy Volunteers

Inclusion Criteria

All subjects must meet ALL of the following inclusion criteria to be enrolled. 1. Male and female subjects aged 18 years or older. 2. Meet revised 2016 World Health Organization (WHO) criteria for the diagnosis of polycythemia vera. 3. Records of all phlebotomies performed for at least 24 weeks (preferably up to 52 weeks) before screening are available. 4. Subjects who are not receiving cytoreductive therapy must have been discontinued from any prior cytoreductive therapy for at least 24 weeks before screening and have recovered from any adverse events due to cytoreductive therapy. 5. Subjects receiving cytoreductive therapy with hydroxyurea, interferon, or ruxolitinib must be on a stable dose for at least 24 weeks and be on a stable dose for at least 8 weeks before screening and with no planned change in dose. Main

Exclusion Criteria

Subjects must meet NONE of the following exclusion criteria to be enrolled: 1. Active or chronic bleeding within 4 weeks of screening. 2. Meets the criteria for post-PCV myelofibrosis as defined by the International Working Group-Myeloproliferative Neoplasms Research and Treatment (IWG-MRT). 3. Known primary or secondary immunodeficiency. 4. Any surgical procedure requiring general anesthesia within 1 month prior to screening or planned elective surgery during the study.

Study Design

Phase 2
Study Type
Intervention Model
Sequential Assignment
Intervention Model Description
Part 1: 28 week open-label dose escalation phase in which each subject's dose of PTG-300 is increased at 4-week intervals until the subject reaches the maximum planned dose or has a pre-specified decrease in hematocrit from baseline. After a potentially clinically active dose is found, subject will be maintained at that dose until Week 29. Part 2: 12-week blinded randomized withdrawal phase. Subjects are randomized 1:1 to continue PTG-300 or to receive placebo. Part 3: 1 year open label extension.
Primary Purpose
Double (Participant, Investigator)
Masking Description
Part 1 open label, Part 2 blinded, Part 3 open label

Arm Groups

ArmDescriptionAssigned Intervention
Experimental Dose Escalation (Part 1)
PTG-300 Subcutaneous (SC) weekly. Each subject's PTG-300 dose is increased at 4 week intervals until the subject reaches the maximum planned dose or has a prespecified decrease in hematocrit from baseline.
  • Drug: PTG-300
Blinded Withdrawal (Part 2) PTG-300 or placebo
PTG-300 or placebo Subcutaneous (SC) weekly.
  • Drug: PTG-300
  • Drug: Placebo
Experimental Open label extension (Part 3) PTG-300
PTG-300 Subcutaneous (SC) weekly
  • Drug: PTG-300

Recruiting Locations

University of Kansas
Westwood, Kansas 66205

More Details

Protagonist Therapeutics, Inc.

Study Contact

Study Director

Detailed Description

Phase 2 study in approximately thirty subjects previously diagnosed with Polycythemia Vera who require phlebotomy on a routine basis. There is a 16 week dose finding phase followed by a dose stabilization phase. Subjects who successfully complete dose stabilization will be entered into a 12 week randomized withdrawal phase to confirm the response. Subsequently patients will enter into a 1 year open label extension to investigate long term safety.


Study information shown on this site is derived from ClinicalTrials.gov (a public registry operated by the National Institutes of Health). The listing of studies provided is not certain to be all studies for which you might be eligible. Furthermore, study eligibility requirements can be difficult to understand and may change over time, so it is wise to speak with your medical care provider and individual research study teams when making decisions related to participation.