Characterization of Risk Factors for Calciphylaxis in Hemodialysis Patients in the Fraser Health Renal Program - A Matched Case-Control Retrospective Review.

Introduction: Calciphylaxis is a lethal and rare disease characterized by ischemic and necrotic skin lesions caused by vascular calcification of adipose tissue. There have been many risk factors analyzed in the literature; however, the pathogenesis of calciphylaxis is still not well understood and treatment options are limited due to the lack of interventional studies. Our objectives were to describe risk factors, prevalence, incidence, and outcomes for calciphylaxis in hemodialysis patients within the Fraser Health Renal Program. Methods: This was a retrospective matched case-control study of hemodialysis patients within the Fraser Health Renal Program. Hemodialysis patients with calciphylaxis were matched to hemodialysis patients without calciphylaxis in a 1:2 ratio for age and sex from September 2, 2017 to July 3, 2020. Findings: There was a total of 40 calciphylaxis cases matched to 80 controls. In the univariate analysis, peritoneal dialysis, higher body mass index, lower serum iron, lower transferrin saturation, sevelamer, cinacalcet, warfarin, iron (PO), and insulin were associated with increased risk of calciphylaxis. In the multivariate analysis, only peritoneal dialysis, serum iron, sevelamer, and warfarin were identified as significant and strong risk factors associated with calciphylaxis. A low prevalence of 1.9% and high mortality rate of 57.5% at 12 months was found for calciphylaxis cases. Discussion: Significant risk factors associated with calciphylaxis were peritoneal dialysis, serum iron, sevelamer, and warfarin. Future studies should further investigate the impact of minimizing exposure to these risk factors to reduce calciphylaxis development.

A real-world data approach to determine the optimal dosing strategy for pembrolizumab.

INTRODUCTION: Cancer drug therapy costs continue to rise and threaten the sustainability of Canada's public healthcare system. Previous studies have calculated potential savings utilizing different dosing regimens of cancer treatments. Our objectives were to determine the financial impact of drug wastage and to explore cost-effective dosing regimens for pembrolizumab. METHODS: This was a retrospective study reviewing data for non-small cell lung cancer and melanoma patients at all six BC Cancer Regional Centres during fiscal years 2017 and 2018. Pembrolizumab waste amounts recorded in pharmacy wastage logs were totalled. Estimates of the number of vials used were compared between vial sharing and non-vial sharing practices to determine the cost differences. Costs for dosing regimens used during fiscal years 2017 and 2018 were compared to 2 mg/kg weight-based dosing (to a maximum of 200 mg), 2 mg/kg dosing rounding down within 5% and 10%, and flat dosing of 200 mg. RESULTS: There were a total of 202 non-small cell lung cancer and 182 melanoma patients with 2948 doses dispensed. Documented wastage was valued at $1,829,047.44 (8.65%) and across all six centres, vial sharing could reduce costs by $3,207,600.00 using the 100 mg vials. Compared to fiscal years 2017 and 2018, 2 mg/kg dosing (to a maximum of 200 mg) was the most cost-effective, decreasing costs by $222,719.20; flat dosing of 200 mg was the most expensive, increasing costs by $6,625,260.40. CONCLUSIONS: Having smaller vial sizes, practicing vial sharing, and using weight-based dosing all improve cost savings. Further investigations on the allocation of resources to optimize drug use and minimize wastage are needed.