How Do We Monitor Hemoglobin S in Patients Who Undergo Red Blood Cell Exchange and Take Voxelotor?

Voxelotor has recently been approved by the U.S. Food and Drug Administration (FDA) for the treatment of sickle cell disease (SCD). Voxelotor has been reported to interfere with hemoglobin quantification methodologies that are in common use for evaluating patients with hemoglobinopathies. There is still a general lack of awareness of potential voxelotor interference in assays for quantitative analysis of hemoglobin variants. In this How Do I article, the authors call attention to the effects of voxelotor on the daily practices of Apheresis and Transfusion Medicine specialists. The article emphasizes that apheresis/transfusion medicine physicians and the laboratory should work together to develop a communication process in order to notify the laboratory when patients are receiving voxelotor. The article briefly reviews published studies on interference mitigation approaches and describes how our institution developed a communication process to inform the laboratory when analyzing specimens from patients receiving voxelotor.