ECLIPSE PV Trial Begins Ropeginterferon Alfa-2b Dosing in Polycythemia Vera

The first patients have been dosed in the phase 3b ECLIPSE PV trial, which is evaluating an accelerated dosing schedule of ropeginterferon alfa-2b-njft for the treatment of patients with polycythemia vera.

John Mascarenhas, MD

John Mascarenhas, MD

The first patients have been dosed in the phase 3b ECLIPSE PV trial (NCT05481151), which is evaluating an accelerated dosing schedule of ropeginterferon alfa-2b-njft (Besremi) using a prefilled syringe for the treatment of patients with polycythemia vera (PV).1

“This therapy represents an important addition to the treatment arsenal for PV in the U.S., and clinical data support its use across a broad range of patients regardless of their treatment history,” John Mascarenhas, MD, professor of medicine, hematology, and medical oncology at the Icahn School of Medicine at Mount Sinai in New York, stated in a news release. “This new study is addressing an important therapeutic and clinical question regarding whether treatment utilizing accelerated dosing leads to a more rapid hematologic and molecular response, indicating potential disease modifying activity and long-term disease control.”

In November 2021, the FDA approved ropeginterferon alfa-2b for the treatment of patients with PV.2 The agent is a novel monopegylated, long-acting interferon that can be administered once every 2 weeks, or every 4 weeks with hematological stability, for at least 1 year. The agent has the potential to produce durable activity through its pegylation technology.1

The phase 3b study will evaluate an accelerated dosing schedule for ropeginterferon alfa-2b compared with the current labeled dosing.3 The primary end point of the study is the proportion of patients achieving a complete hematologic response at 24 weeks of treatment, defined as hematocrit below 45% for at least 3 months since last phlebotomy, platelets not exceeding 400 x 109/L, and leukocytes of 10 x 109/L or below.

The study, which will enroll approximately 100 patients with PV in the United States and Canada, will randomly assign patients to receive either the accelerated dosing or the current labeled dosing of 50 µg or 100 µg with 50 mcg titration every 2 weeks. Patients assigned to the accelerated dosing arm will receive a starting dose of 250 µg, then 350 µg at week 2, with a target optimal dose of 500 µg at week 4. Subsequent dosing will remain fixed at the highest tolerated dose for the rest of treatment.

The study will run for 48 weeks and will be followed by a 28-day period of safety follow-up. Patients who respond to treatment will be eligible to participate in a long-term extension phase of the study.

Topline data from the trial are expected by 2024.

“Our goal with this study is to deliver evidence on the potentially enhanced benefits of treating patients with ropeginterferon alfa-2b through this accelerated dosing schedule and to bring additional confidence to clinicians and patients in the utility of the treatment to manage this chronic cancer,” Raymond Urbanski, MD, PhD, U.S. head of Clinical Development and Medical Affairs, said in a news release. “We believe this study will deliver further insight into the potential of ropeginterferon alfa-2b to meet the needs of PV patients.”


  1. PharmaEssentia initiates phase 3b trial of ropeginterferon alfa-2b-njft investigatng new dosing regimen for patients with polycythemia vera (PV). News release. May 3, 2023. Accessed May 15, 2023.
  2. US FDA approves BESREMI (ropeginterferon alfa-2b-njft) as the only interferon for adults with polycythemia vera. News release. PharmaEssentia Corporation. November 12, 2021. Accessed May 15, 2023.
  3. A study to assess efficacy, safety, and tolerability of P1101 in adult patients with PV. Updated March 27, 2023. Accessed May 15, 2023.
Related Videos
Justin M. Watts, MD
Mikkael A. Sekeres, MD, professor, medicine, chief, Division of Hematology, Leukemia Section, the University of Miami Sylvester Comprehensive Cancer Center
Ashwin Kishtagari, MD
Aaron Gerds, MD
Naseema Gangat, MBBS
Ashwin Kishtagari, MD
Somedeb Ball, MBBS
Rebecca Klisovic, MD
Sunil Iyer, MD
Sunil Iyer, MD