Rusfertide Cuts Phlebotomy Need in Polycythemia Vera: Andrew Kuykendall, MD

With an expected completion date sometime in June, the phase 3 VERIFY trial (NCT05210790) will soon conclude its investigation of rusfertide (Takeda) as add-on therapy to a patient’s current course of treatment for their polycythemia vera. The investigative agent has already received breakthrough therapy, orphan drug, and fast track designations from the FDA.

In this fourth part of a discussion with The American Journal of Managed Care®, Andrew Kuykendall, MD, clinical researcher at Moffitt Cancer Center and VERIFY investigator, speaks to the impressive patient-reported outcomes seen thus far.

This transcript has been lightly edited for clarity; captions were auto-generated.

Transcript

Can you summarize the key findings seen so far in the phase 3 VERIFY study?

Super exciting results that we saw. The study design, a lot of this was really built on a phase 2 study that was published in The New England Journal of Medicine that took patients with polycythemia vera who were requiring phlebotomies on a regular basis. That study basically put everyone on rusfertide and assessed over time their need for phlebotomy. There are a couple of different nuances to that study, but I would say the take home point of what we saw is that rusfertide very effectively eliminated the need for these patients that were regularly needing phlebotomies to need any phlebotomies at all—really rapidly reduced that and so certainly paved the way for designing a phase 3 clinical trial that could show that in comparison to standard therapy.

This trial took patients that had polycythemia vera that were requiring regular phlebotomy—so at least 3 over the preceding 28 weeks or 5 over the course of the prior year—and it randomized them to either stay on their standard therapy and add rusfertide or stay on their standard therapy and add a placebo. Everyone was treated in kind of the standard way, even if you were randomized to the “placebo arm”; that was just the standard therapy. If you were on cytoreductive therapy like hydroxyurea or interferon or ruxolitinib—these are agents we use to treat the disease as well—you stayed on those agents and you continued to get phlebotomies, as you would if you if you were kind of in routine clinical care. Then the other group did the same thing, but they added on rusfertide as a weekly subcutaneous injection. For 20 weeks, there was a a dose-finding period where rusfertide, the doses were increased based on hematocrit level and various different control of the disease.

The primary end point, at least in the US, was looking at the number of patients that were “phlebotomy eligible,” meaning that they needed a phlebotomy to control their disease—and that was being looked at between weeks 20 and 32. What we found is significantly more patients in the placebo group, so in the patients that were not receiving rusfertide, were “phlebotomy eligible” during that period of time. Another way to say that is, more patients in the rusfertide group did not need a phlebotomy during that that critical time period. Just another way of showing the control that rusfertide has, and that was the primary end point. Based on the phase 2 data, we certainly were optimistic that this was going to be reached.

We know that this is an agent that was quite adept at controlling the need for phlebotomy. But there was other key secondary end points; one of those was the primary end point for the European Union, which was looking at average phlebotomies over the whole time point, week 0 to 32, and consistent control of hematocrit over this period of time as well.

I think for me, what was quite impressive was looking at symptoms, patient-reported outcomes. I mentioned that our goal of this is to not only decrease risk for thrombosis, which we do from controlling hematocrit, but also we care about quality of life for patients. This is something that on the day to day, patient might not say, “Well, I feel so much better because my hematocrit’s 43 vs 45,” but they might say, “I'm suffering from fatigue. I can't work. I'm having to take time off,” and so I was very encouraged by the fact that this study also met these other key secondary end points, looking at patient-reported outcomes, specifically this PROMIS fatigue scale, as well as what we call MFSAF, or the myelofibrosis symptom assessment for total symptom score. Two different ways to look at patient symptoms, but both of these showed that rusfertide did a better job than placebo at improving these patient-reported outcomes.