A Patient Centric Model for Vaso-Occlusive Crises in Sickle Cell Disease—Outcomes of a Consensus Exercise Conducted Across Patients and Experts

Sickle cell disease (SCD) is a group of inherited disorders caused by a mutation in the beta globin gene that leads to sickling of red blood cells and results in anemia and Vaso-occlusive crises (VOC). VOC are described as an acute worsening of symptoms impacting daily life and often requiring treatment to resolve. A majority of SCD interventional trial endpoints consider VOC that require attendance at a health facility and do not account for VOC managed at home. These studies report lower VOC incidence compared to those that consider VOC managed both in the healthcare setting and at home. This presents challenges to the consistent and accurate assessment of treatment effect in reducing overall VOC count. This paper outlines a USA consensus exercise conducted with patients and a scientific expert review committee to develop a patient-centric VOC model that may apply across incidences, individuals, and treatment settings. The model is supported by a monitoring biomarker specification for the objective identification and classification of VOC taking place in the healthcare setting and at home. We additionally propose hardware, software, diaries, and patient-reported outcomes for an initial instrument design to evaluate the potential of the model in a validation study.