Yelena Ginzburg, MD, on the Phase II PACIFIC Study of Rusfertide in Polycythemia Vera

Yelena Ginzburg, MD, of the Tisch Cancer Institute and the Icahn School of Medicine at Mount Sinai, discusses findings from the phase II PACIFIC study of rusfertide presented at the 65^th American Society of Hematology Annual Meeting and Exposition.

Most patients with polycythemia vera are iron deficient and receive therapeutic phlebotomies, which can exacerbate the deficiency, Dr. Ginzburg explained, noting that “there isn’t really a therapy specifically for iron deficiency in this patient population, and the therapy, in fact, induces iron deficiency.”

The open-label study investigated the efficacy and safety of rusfertide in 20 patients with poor hematocrit control, defined as hematocrit levels above 48%. The study showed that rusfertide “rapidly and robustly” reduced the mean hematocrit, with a sustained hematocrit of less than 45% for the duration of treatment.

The ferritin levels in patients also increased, as 30% of patients had serum below 20 µg/L at baseline, but all sustained ferritin levels above 20 µg/L by week 4 of rusfertide treatment. In patients with evidence of baseline iron deficiency, the treatment with rusfertide normalized and stabilized iron levels in patients with normal iron levels before treatment.

“It’s important to see that the iron deficiency in these patients appears to be normalized and it also shows that in the patients who are most iron deficient at baseline at the start of the trial, you get the most benefit in terms of their hematopoiesis,” Dr. Ginzburg said. “The hematopoietic iron status is improved most robustly in the patients who were the most iron deficient at the beginning.”

Dr. Ginzburg explained what she sees as the next steps with the line of research, noting that she thinks there is a possibility that rusfertide could be used in patients with lower-risk polycythemia vera. Further research could also build upon the understanding of “how iron metabolism is dysregulated in this population,” she said.