Impact of Crizanlizumab on Acute Medical Care Utilization in the Height of the COVID-19 Pandemic

Background Sickle cell disease (SCD) is a hemoglobinopathy which manifests clinically as hemolytic anemia and recurrent episodes of pain caused by vaso-occlusion, among other symptoms. Vaso-occlusive crises (VOCs) account for an overwhelming majority of visits to the emergency room (ER) and hospitalizations for patients with SCD (Shah et al. PLoS One 2019). Upregulation of P-selectin, a cellular adhesion protein expressed on activated platelets and endothelial cells, contributes to the pathophysiology of VOCs. Crizanlizumab is a monoclonal antibody administered intravenously that inhibits the interaction of P-selectin with its ligand; it was approved by the Food and Drug Administration (FDA) as a treatment for SCD patients in 2019. In the Phase II SUSTAIN trial, crizanlizumab therapy resulted in a significantly lower rate of sickle cell-related pain crises than placebo (Ataga et al. N Engl J Med 2017). Due to their high-risk status for COVID-19, the pandemic has posed significant challenges for SCD patients to readily access healthcare, including novel therapies such as crizanlizumab. This study aimed to investigate the utility of telemedicine in facilitating access to crizanlizumab as well as compare acute medical care utilization for patients on crizanlizumab six months before initiating therapy and up to six months after their final dose in 2020. Methods All patients (≥18 years of age as of January 1, 2020) with SCD who received crizanlizumab between January 1, 2020 and December 31, 2020 at Rush University Medical Center (RUMC) were included in the final analysis. Demographic features as well as the type of visit when the patient and healthcare provider discussed crizanlizumab treatment was documented. Paired t-tests and Wilcoxon matched-pairs signed rank tests were utilized to compare acute medical care utilization - defined by the number of ER visits, urgent care visits, and hospitalizations - six months prior to initiating therapy and six months after completing the specified therapy regimen for 2020. Simple linear regression models and multiple regression models were conducted to control for sex, BMI, age, insurance, duration of treatment, and type of visit. Results A total of ten patients were included in the final analysis. Five (50%) patients first agreed to proceed with crizanlizumab therapy during a telehealth video visit with their provider, one (10%) made the decision during a telehealth phone visit, and the other four (40%) did so during a t