Expert Insights

Part 4: Real-World Data Concerning Elevated Blood Counts

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Dr Shammo: Polycythemia vera is a hematological malignancy that may become advanced in a subset of patients despite treatment with hydroxyurea and phlebotomy, resulting in ineffective disease control.

Narrator: Clinical characteristics of advanced PV may include hematocrit greater than or equal to 45% plus one additional risk factor despite treatment with hydroxyurea and phlebotomy.

Specifically, clinical characteristics of advanced PV may include hematocrit greater than or equal to 45% plus: elevated white blood cell count greater than 11x109 per liter or burdensome disease-related symptoms (such as fatigue, early satiety, inactivity, concentration problems, and itching).

A retrospective chart review of 1309 patients with PV was conducted in the US between April 2014 and July 2014 by Incyte Corporation. The purpose was to investigate the treatment patterns among US patients with PV in a real-world setting. Hematocrit greater than or equal to 45%, white blood cell counts greater than 10 × 109 per liter, and platelet counts greater than 400 x 109 per liter were considered elevated values.

Dr Shammo: And it was shown that about a third of patients attain complete hematological response and that is typically defined as hematocrit below 45%, white cell count below 10,000, and a platelet count less than 400,000.

It was also shown in that study that more than a third of patients continue to have elevated blood elements in 2 or 3 different lines while on the cytoreductive therapy.

A lot of patients who have polycythemia will present with thrombocytosis. This is not necessarily been associated with an increased propensity for clots. On the other hand, it could certainly lead to bleeding events.

The study's important because it's drawn from real-life PV patients that are being treated with hydroxyurea and because of the sheer number of patients that were enrolled.

Narrator: Actively monitor for hematocrit plus in your patients with polycythemia vera.

Image of Jamile M Shammo, MD, FASCP, FACP
Jamile M Shammo, MD, FASCP, FACP Associate Professor Rush University Medical Center | Chicago, IL
As principal investigator of clinical trials in her area of expertise, Dr Shammo is heavily involved in education, research, and administrative activities in the Division of Hematology/Oncology. She is recognized nationally for her expertise in bone marrow failure syndromes/paroxysmal nocturnal hemoglobinuria (PNH) and was chosen to serve as a national coordinator for the US PNH registry.