Utilization Patterns of Erythropoiesis Stimulating Agents Prescribed for Chemotherapy-Induced Anemia, and the Impact of the Outpatient Regimen on Subsequent Inpatient Use: A Pilot Study. John Reitan, PharmD; 1 Arletta van Breda, RN; 1 Patricia Corey-Lisle, PhD, RN; 2 Ze Cong, PhD; 2 Sanatan Shreay, PhD 2. 1 RJM Group, LLC ; 2 Amgen Inc. BACKGROUND METHODS OBJECTIVES RESULTS CONCLUSIONS DISCLOSURES Supportive therapy to treat anemia due to concomitantly administered myelosuppressive chemotherapy (CIA) with erythropoiesis stimulating agents (ESAs) involves considerable resource utilization. ESA regimens that decrease the number of interventions needed to maintain adequate hemoglobin may be beneficial for clinicians and patients. The primary objective is to characterize ESA usage in institutional outpatient oncology centers that have included every week (QW) and every-three-weeks (Q3W) ESA dosing in their outpatient ESA guidelines, and to describe the frequency of ESA doses, and hemoglobin determinations during courses of ESA therapy. A secondary objective is to compare rates at which inpatient ESA doses are administered to patients receiving ESAs on QW versus Q3W schedules. Study Description: Retrospective observational record review. Conducted in 2 outpatient cancer clinics in the Mid- Atlantic and Southeast United States. Selection of Participants: Eligible sites are those using ESAs on both QW and Q3W schedules. Eligible patients are those >18 years of age, receiving chemotherapy for a solid tumor, who initiated an ESA regimen between August 1, 2007 and June 30, Data Collection Follow-up continued as long as the patient was maintained on his/her original ESA regimen, or until death, change to an alternative ESA schedule, or termination of the ESA course (i.e., 42 days elapsed since the last ESA dose). All inpatient admissions were noted, and inpatient ESA dosing, hemoglobin and transfusion administration were recorded from the inpatient record. Statistical Analysis: Baseline characteristics were compared using using Students t-test, Chi Squared, or Wilcoxon rank sum test, as appropriate. Differences in rates of utilization between QW and Q3W groups were assessed using Students t-test or Chi Squared, as appropriate. RESULTS A total of 312 patients were eligible for inclusion (219: Q3W, 93: QW). Age and duration of follow-up were similar for the Q3W and QW groups. The mean number of outpatient ESA doses per patient was lower among patients on the Q3W schedule (4.4 versus 8.3, p<0.01). The number of hemoglobin determinations were also lower among patients on the Q3W schedule (12.3 versus 14.6, p=0.03). There was no difference in mean pre-ESA hemoglobin (9.9g/dl for both groups). Patients receiving ESAs on a QW schedule twice as likely to receive at least one inpatient ESA dose (15% versus 7%, p=0.05). The number of inpatient ESA doses was 27 per 100 patients receiving the QW regimen versus 8 per 100 patients receiving the Q3W regimen (p=0.04). In this pilot study of outpatient ESA use, it appears that the use of longer-acting ESAs (Q3W) may be associated with reduced frequencies of 1) hemoglobin determinations and 2) ESA doses required. Q3W dosing may reduce inpatient utilization of ESAs, by reducing the number of ESA doses required for previously maintained outpatients. As this was a pilot investigation, further scrutiny of these findings, with a larger study is warranted. Authors of this presentation have the following to disclose concerning possible financial or personal relationships with commercial entities that may have a direct or indirect interest in the subject matter of this presentation: John Reitan: Nothing to disclose Arletta van Breda: Nothing to disclose Patricia Corey-Lisle: Employee and stockholder Amgen, Inc. Ze Cong: Employee and stockholder Amgen, Inc. Sanatan Shreay: Employee and stockholder Amgen, Inc.