Evaluating the utilization of fosaprepitant for the treatment of breakthrough chemotherapy-induced vomiting: a retrospective analysis

Introduction: Emend¨, aprepitant and prodrug fosaprepitant, prevents emesis by inhibiting substance P/neurokinin 1 (NK1) receptors. NK-1 inhibitors are commonly used in combination to prevent nausea/vomiting from moderately- and highly-emetogenic chemotherapy. While effective in acute prevention, efficacy wanes in delayed (25-120 hours). No studies have been performed determining the effectiveness of Emend in breakthrough CINV, despite use in practice. Objectives: The primary objective is evaluation of utilization of fosaprepitant in breakthrough CINV. Secondary objectives include evaluation of episodes of N/V prior to and after fosaprepitant administration, assessment of days of N/V before Emend administered, subjective rating N/V after administration. Study Design: Retrospective chart review of electronic medical records from WVUMedicine of admitted patients from 1/1/2015 to 12/31/15 receiving fosaprepitant not apart of CINV protocol. Patient data will be de-identified and stored in a secure, confidential location. Patients will not be contacted in relation to study. Methods: Evaluation for effectiveness based on subjective notes in physicianÕs daily report, documented PO intake and episodes of N/V prior to and after Emend administration, and analysis of additional CINV medication given. Inclusion criteria include admitted patients >18 years receiving Emend after start of chemotherapy. Exclusion criteria include use for preventative CINV or non-chemotherapy-related N/V and outpatient administration of Emend. Results: 34 patients in 41 hospital admissions met the inclusion/exclusion criteria. 29 of the 34 patients had hematologic malignancy with conditioning for hematopoietic stem cell transplantation the most common chemotherapy cycle (11 of 29). Patients on average had 3 days of N/V before Emend was administered (1-10 days). 25 admissions had Emend given during or the day after chemotherapy. Analysis is ongoing. Conclusions: Emend is primarily being used as breakthrough therapy in patients in hematologic malignancies. Preliminary findings have demonstrated Emend does improve N/V in the breakthrough setting. Further studies, including prospective studies are needed.