Disease Management Decisions in Patients With Low-Risk Polycythemia Vera

Patients with polycythemia vera (PV) fall on a spectrum of risk for thrombotic events, which can be one of the factors that comes into play when choosing therapy, explained Jennifer Vaughn, MD, hematologist-oncologist and assistant professor in the Division of Hematology at The Ohio State University Comprehensive Cancer Center – James Cancer Hospital and Solove Research Institute. However, management is less clear when the patient is considered low risk.

Vaughn recently spoke about the topic at The American Journal of Managed Care®’s Cleveland Regional Institute for Value-Based Care® (IVBM) meeting.

This transcript has been lightly edited for clarity.

Transcript

At the Cleveland IVBM, you discussed treatment options for polycythemia

vera and how a patient might choose between them. Can you discuss that decision making process and what they're weighing?

First and foremost, anytime you're meeting a patient with PV, you want to decide where they fall on the spectrum of risk for developing thrombotic events. We know that patients who fit into the high-risk category for PV—whether that be because they're over age 60 or because they've had a prior thrombotic event—they are recommended to receive some sort of cytoreductive therapy in addition to phlebotomy and aspirin and possibly even anticoagulation, if they've ever had a venous thrombotic event in the past. That's kind of the easy portion of that question, because we know that those patients are just a general higher risk, probably due to sort of the aging process, other comorbidities, etc, that warrants additional treatment.

However, what's really an evolving science is, how do we manage patients who've been into the low-risk category? Traditionally, those patients have been younger. They've never had a thrombotic event, and we have focused on treating them with phlebotomy and aspirin exactly as you said, because it's felt to be less invasive—I guess that's the wrong word—less expensive, for sure, and perhaps easier on the patient, but really, the goals of phlebotomy are to reduce the red blood cell count and help the blood to flow better, so that their risk of blood clotting is reduced. What we do with phlebotomy is we introduce a little bit of iron deficiency in those patients, so that you're basically depriving the bone marrow of the building blocks it needs to be able to make red blood cells.

That's all well and good if you can do that, it just in just the right way. But eventually patients will become symptomatic from having iron deficiency, and more and more attention is being given to the time that patients are required to spend seeking out therapeutic phlebotomy as a routine part of their treatment. If you're a younger patient, and you are working, you have children you have to take care of, just general things in life that you have to balance, then taking time to go to the clinic to receive phlebotomy is actually a detriment in many ways. I've actually had patients who have inquired about cytoreductive therapy because they felt like it was too burdensome for them to be able to take the time they needed to be able to get the routine phlebotomies and maintain that hematocrit below the goal level of 45%.

There's also a new and involving literature that early treatment with certain drugs, perhaps interferon therapies, could potentially lead to a reduction in the detectable JAK2 [Janus kinase 2] allele burden. And while we don't have really rigorous data to confirm this, the hope is that by reducing the detectable JAK2 allele burden—meaning we're reducing the detectable number of mutated cells in the blood—perhaps we are, in the long term, going to reduce that patient's risk of developing progression to a more serious hematologic illness in the future. I say that very, very cautiously, because it's really mostly an active area of research right now, because patients do live a really long time and take a long time to progress with polycythemia vera, if they progress at all. It's really hard to get that concrete data to sort of guide our management that way.