ABSTRACT
Introduction In sickle cell disease (SCD), the polymerization of deoxygenated HbS fundamentally alters the structure of the erythrocyte, producing the sickle cell that is characteristic of the disease. Clinical manifestations often perceived in patients suffering from SCD include vaso-occlusion, anemia, and hemolysis. Due to these sequelae, patients frequent the emergency room (ER), urgent care clinic, and hospital. Voxelotor, an oral medication approved by the Food and Drug Administration (FDA) in 2019 for the treatment of SCD, directly targets the pathophysiology of SCD by inhibiting deoxygenated HbS polymerization. Results of the Phase III HOPE trial indicate that the drug can increase hemoglobin levels and reduce markers of hemolysis as well as the incidence of worsening anemia in patients with SCD (Vichinsky et al. N Engl J Med 2019). The COVID-19 pandemic has posed several challenges for patients with SCD in 2020. Amid the pandemic, patients continued to seek out acute medical care, including care in the ER, urgent care clinics, and hospital. The aim of this study was to determine whether utilization of acute medical care differed for patients who received voxelotor before and after therapy in 2020. We also evaluated the utilization of healthcare through telemedicine platforms to facilitate access to novel therapies such as voxelotor for patients with SCD. Methods 13 patients (≥18 years of age as of January 1, 2020) with SCD who had begun treatment with voxelotor between January 1, 2020 and December 31, 2020 were included in the initial analysis. Six patients were excluded from final analysis: three discontinued treatment due to side effects, one was noncompliant with treatment, and two were lost to follow-up. Acute care utilization, measured by the number of times each patient visited the ER, urgent care clinic, and hospital was compared for each patient in the period six months prior to their first dose of voxelotor and in the period six months after their last dose of the drug in 2020 using paired t-tests and Wilcoxon matched-pairs signed rank tests. Demographic information and the type of visit at which patients agreed to proceed with voxeletor was recorded for each patient. Simple linear regressions and multiple regressions controlled for covariates, defined as sex, BMI, age, type of insurance coverage, and duration of treatment. Results All seven (100%) patients discussed voxelotor treatment with their provider during a telehealth video visit. In the period before initiating treatment, patients frequented the ER an average of 2.71 (SD=6.75) times. In the six months after their last dose, patients visited the ER less than they had in the period prior to treatment, on average 0.57 (SD=0.79) times. This difference did not achieve statistical significance (p>0.9999). The mean number of visits to the urgent care clinic in the six months before treatment was 2.71 (SD=6.75) compared to 2 (SD=4) in the period after patients' last dose in 2020. This finding was not statistically significant (p>0.9999). Hospitalizations, on average, decreased significantly from 5.14 (SD=2.34) in the six months before starting treatment to 1.57 (SD=0.98) after ending therapy for 2020 (p=0.0015). Covariates did not have an effect on the differences in acute care utilization before treatment and after last treatment in 2020. Conclusions The findings of this study imply that treatment with voxelotor was associated with a decrease in the frequency of hospitalizations for the seven patients analyzed. This finding can potentially be attributed to the efficacy of voxelotor in improving anemia and reducing complications associated with SCD. While the difference between ER visits and urgent care visits before treatment and after the last dose in 2020 did not achieve statistical significance, likely due to small sample size, the data does suggest a reduction in both outcomes. In addition, the observation that all visits in which patient and provider discussed and initiated treatment were virtual support the use of telemedicine technology o improve access to multidisciplinary care and novel therapies for SCD patients. The impact of voxelotor treatment will continue to be assessed in SCD patients at our institution, and more data from clinical encounters will lead to a greater understanding of the efficacy of voxelotor. [Formula presented] Disclosures: Jain: GBT: Speakers Bureau;Novartis: Speakers Bureau;Sanofi: Other: advisory board;Argenx: Other: advisory board;DOVA: Other: advisory board.
ABSTRACT
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 traditional office visit. 9 (90%) patients were still on crizanlizumab after June 1, 2020, the date that RUMC urgent care started seeing patients with SCD. The mean number of visits to the ER in the period before initiating therapy was 2.8 (SD=4.26) compared to 2.5 (SD=2.76) after last dose in 2020, however this finding did not achieve statistical significance (p>0.9999). Visits to the urgent care clinic, on average, increased significantly from 1.7 (SD=2.87) in the six months before initiating therapy to 8.2 (SD=11.02) in the six months after ending therapy for 2020 (p=0.0234). The mean number of hospitalizations in the period before initiating therapy was 6.6 (SD=5.19) compared to 4.6 (SD=3.44) in the period after last dose in 2020, however this was also not statistically significant (p=0.2309). None of the covariates had a significant effect on differences in acute care utilization in the period before and after therapy in 2020. Conclusion This study suggests that administration of crizanlizumab therapy did reduce hospitalization and ED visits, but the results could not achieve statistical significance due to our small sample size and short study duration. The number of urgent care visits for these patients, however, did differ significantly from the period before initiating therapy to the six months after the last dose in 2020. This finding can be attributed to the fact that due to the COVID-19 pandemic, urgent care services were made increasingly available to SCD patients beginning on June 1, 2020 to avoid admissions to the ER and hospital. Additionally, our study suggests that during the COVID-19 pandemic, telemedicine played an important role in providing health services to patients with SCD, and it could continue to improve care accessibility for SCD patients after the pandemic. Continued collection and analysis of real-world data is needed to further understand the effect of crizanlizumab therapy on utilization of acute medical care. [Formula presented] Disclosures: Jain: DOVA: Other: advisory board;Sanofi: Other: advisory board;Argenx: Other: advisory board;Novartis: Speakers Bureau;GBT: Speakers Bureau.