Andrew T. Kuykendall, MD, VERIFY Lead Investigator and Associate Member in the Department of Hematology at Moffitt Cancer Center, discusses 52-week results from the VERIFY clinical trial testing rusfertide in patients with polycythemia vera (PV).
PV is a condition characterized by an increased number of red blood cells. Affected people may also have excess white blood cells and platelets. The excess cell levels leads to thicker blood and increased risk for blood clots. PV occurs more frequently in men than it does in women. The condition has been associated with genetic changes in the JAK2 and TET2 genes.
At the 2025 American Society of Hematology (ASH) meeting, 52-week results from the phase 3 VERIFY (NCT05210790) clinical trial evaluating rusfertide in patients with PV were presented. The study was designed to evaluate the safety and efficacy of rusfertide in patients with uncontrolled hematocrit who are phlebotomy-dependent despite current standard of care.
During Part 1a of the study, 293 patients were randomized to receive either rusfertide or placebo, as an add-on to their current treatment. During Part 1b, all participants were eligible to receive open-label rusfertide to evaluate the durability of the treatment response. 274 patients continued into Part 1b, and 267 patients remained in the study through week 52, with 254 continuing to receive rusfertide in part 2.
Phlebotomy Eligibility
At week 52, 61.9% of patients treated with rusfertide plus standard of care throughout parts 1a and 1b experienced a durable clinical response, defined as absence of phlebotomy eligibility. Additionally, 84.1% of patients treated with rusfertide who experienced a clinical response in the part 1a assessment window maintained their response and 77.9% of patients who crossed over from placebo to rusfertide at week 32 for part 1b experienced a clinical response during the part 1b assessment window. Median time to first phlebotomy was 16 weeks in the placebo group but was not reached in the rusfertide group in part 1a or 1b, or the placebo to rusfertide crossover group in part 1b.
HCT Control
Mean hematocrit remained less than 43% through week 52 in patients treated with rusfertide throughout Part 1a and Part 1b and those who switched from placebo to rusfertide for Part 1b. Median time to first hematocrit 45% or greater was 8.3 weeks in the placebo group in part 1a, but was not reached in the rusfertide group during parts 1a or 1b.
Quality of Life Endpoints
Patients treated with rusfertide in parts 1a and 1b maintained improvements in patient reported outcomes as measured by PROMIS Fatigue SF-8a and MFSAF TSS7.
Safety and Tolerability
Rusfertide was generally well tolerated through 52 weeks of treatment with the most common treatment-emergent adverse events including injection site reactions, anemia, and fatigue, all of which were primarily grade 1 or 2. Serious adverse events occurred in 8.1% of patients treated with rusfertide.
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To learn more about PV and other rare hematologic conditions, visit https://checkrare.com/diseases/hematologic-disorders/