Implementation of Outpatient High-Dose Cytarabine (HiDAC) for AML: Evaluation of the Impact of Transitioned Outpatient Chemotherapy in an Oncology Care Model Setting

Background: Patients with acute myeloid leukemia (AML) who achieve complete remission with induction therapy require consolidation therapy. The standard of care consolidation is HiDAC based on age and risk stratification. Consolidation therapy has historically been administered in the inpatient setting. The rising cost of inpatient care, alternative payment model implementation and patient preference has prompted institutions to consider shifting therapy to the outpatient setting. However, the safety and feasibility of outpatient high dose Cytarabine (HiDAC) consolidation therapy is not well established. The University of Arizona Cancer Center developed an Outpatient Program (OP) to facilitate administration of hematologic chemotherapy regimens in the outpatient setting. We hypothesized that OP administration of HiDAC consolidation therapy would be safe and efficacious and have large cost-savings implications under alternative payment model pilots, such as the oncology care model.

Methods: We conducted a retrospective chart review on high-risk MDS/AML patients who were 18 years or older and received HiDAC consolidation therapy at UACC following induction therapy from November 1st 2013 to June 1^st 2019. Interim data collection included age, risk stratification, treatment history, clinic visits, number of cycles received in the OP versus inpatient setting, supportive care, hospitalizations, and chemotherapy related adverse events. Our Outpatient HiDAC protocol consisted of a one-hour infusion for all cytarabine doses administered at 7:30am and 4:00pm, with neurologic checks prior to each dose. Growth factor support, if required was administered on the same day as the last dose of cytarabine

Results: We evaluated 19 patients at our cancer center who received 52 total cycles of HiDAC consolidation therapy. The median patient age was 49.6 yrs with 21.1 % being over the age of 60. Thirty-three cycles were administered in the outpatient setting, with 19 cycles being administered inpatient. None of the patients who were administered HiDAC in either the IP or OP setting had reported clinically significant neurotoxicity (≥ grade III). Nine patients receive all of their cycles in the outpatient setting. 57.9% of our patients developed febrile neutropenia, with 47.4% of the patients requiring hospitalization for neutropenic fever. The average inpatient HiDAC length of stay was 6 days. Transitioning HiDAC to the outpatient setting led to a savings of 198 hospital days, with a corresponding cost reduction to our healthcare system of $529,650. Transitioning HiDAC to the outpatient setting also improved patient satisfaction.

Conclusion: Outpatient administration of HiDAC consolidation therapy for AML patients is a safe and effective treatment option. In addition, transitioning HiDAC to the outpatient setting led to a reduced overall cost of care for AML treatment , under an OCM based practice model. Utilization of outpatient HiDAC for the outpatient setting provides a unique opportunity for select patients.