Preventing Thrombosis in Patients with Polycythemia Vera

Srdan Verstovsek, MD, PhD, a professor of Medicine and a hematologic oncologist at the University of Texas MD Anderson Cancer Center, discusses some of the best practices to try and prevent thrombosis in patients with polycythemia vera (PV).

Patients with PV can get thrombosis because the disease causes the patient’s bone marrow to make too many red blood cells. This then puts patients at risk for blood clots, which can cause other serious problems such as pulmonary embolisms.

Verstovsek highlights how clinicians need to watch patients’ hematocrit levels throughout their treatment and how the use of ruxolitinib (Jakafi) can potentially benefit these patients.

Transcription:

0:07 | You want to, in either case, minimize the time the patients spend at about 45% hematocrit, because that increases the risk of blood clotting and the risk of dying. In the low-risk patients this is done by frequent phlebotomist, which means bloodletting. So low risk patients you phlebotomize and the patients and with that you would decrease the hematocrit. With phlebotomies, you also make people iron deficient. Iron is simply food for the red blood cells, and as more phlebotomies happen more iron deficiency happens, and that would decrease the rate of the phlebotomy. [However], there are patients that still require too many phlebotomies, maybe 3, 4, 5, or 6 [times] a year, so the bottom line is there are several patients that still spend a significant amount of time above 45% in their life. This is unnecessary.

1:00 | In the high-risk group, we give patients, on top of phlebotomy, medications to eliminate the need for phlebotomy, because they're at higher risk for blood clotting. So we give them hydroxyurea 9 out of 10 times, which is a chemotherapy by mouth, [we also] sometimes give interferon injections, or we can even give them ruxolitinib, that would be a JAK2 inhibitor that is approved as a second line therapy. The goal here is to smooth that hematocrit percent below 45% all the time and eliminate a need for phlebotomy. That is not the case in every practice, there are many retrospective chart review studies that show that this is not achievable. And this is critical to maintain the patients below 45% all the time, particularly in the high-risk group. With the inability to control it we need new agents that would help maintain the hematocrit below 45% in high-risk group all the time. So, the need is there, either in the low risk group or in the high risk group to help achieve the goal of the therapy.