March 3, 2025
− Study met the primary endpoint, with a significantly higher proportion of clinical responders on rusfertide compared to placebo
− All four key secondary endpoints were met, including EU primary endpoint and patient-reported outcomes
− Rusfertide was generally well tolerated; no new safety findings were observed in the study
NEWARK, Calif. & OSAKA, Japan & CAMBRIDGE, Mass.–(BUSINESS WIRE)–Protagonist Therapeutics, Inc. (“Protagonist”) (NASDAQ:PTGX) and Takeda (TSE:4502/NYSE:TAK) today announced positive topline results for the Phase 3 VERIFY study, in which phlebotomy-dependent patients with polycythemia vera (PV) were randomized to treatment with either rusfertide or placebo, as an add-on to standard of care treatment. The study met its primary endpoint and all four key secondary endpoints. Rusfertide is a first-in-class investigational hepcidin mimetic peptide therapeutic, which has received Orphan Drug designation and Fast Track designation from the U.S. Food & Drug Administration (FDA).
Key findings from the study include:
- The primary endpoint of the study was met, with a significantly higher proportion of clinical responders1 among rusfertide-treated patients with PV (77%) compared to those who received placebo (33%) during weeks 20-32; p<0.0001. The primary endpoint of the study was the proportion of patients achieving a response, which was defined as the absence of phlebotomy eligibility.
- The first key secondary endpoint, which is the pre-specified primary endpoint for European Union (EU) regulators, was also met, with a mean of 0.5 phlebotomies per patient in the rusfertide arm compared to 1.8 phlebotomies per patient in the placebo arm during weeks 0-32; p<0.0001.
- The other three pre-specified key secondary endpoints, namely hematocrit control2 and patient-reported outcomes using PROMIS Fatigue SF-8a3 and MFSAF TSS-74, were also achieved with statistical significance.
- Rusfertide was generally well tolerated in the Phase 3 VERIFY trial, and safety was in line with previous rusfertide clinical studies. No new safety findings were observed in the study. The majority of adverse events were grade 1-2 injection site reactions and all serious adverse events reported were deemed to be not drug related. There was no evidence of an increased risk of cancer in rusfertide-treated patients compared to those on placebo.
“The positive results of the Phase 3 VERIFY study across the primary and all key secondary endpoints provide compelling evidence of the potential for rusfertide as a first-in-class erythrocytosis-specific agent to address unmet medical needs in patients with PV who are unable to achieve adequate hematocrit control despite standard of care treatments,” said Arturo Molina, M.D., M.S., Chief Medical Officer of Protagonist. “We plan to submit additional details of these promising results for presentation at upcoming medical conferences in 2025. We are immensely grateful to the patients, study staff and principal investigators who made the VERIFY study possible.”