Drug Utilization Patterns and Cost Considerations for Erythropoiesis Stimulating Agents in Cancer Chemotherapy Patients in a Managed Care Setting.

Objective and Purpose: To understand current utilization patterns, this study examined real-world dosing and drug costs for erythropoiesis-stimulating agents (ESAs), epoetin alfa (EPO) and darbepoetin alfa (DARB) in cancer patients receiving chemotherapy.

Methods: An analysis of ESA utilization in chemotherapy patients using adjudicated medical claims between 2004 and 2006 from seven health plans was conducted. Patients with ≥1 ESA claim, receiving concurrent chemotherapy identified through alphanumeric HCPCS codes, and newly initiated on EPO or DARB (no ESA administration within 90 days prior to initiation), and receiving chemotherapy were included. Those patients who received both EPO and DARB or who had myelodysplastic syndromes or end-stage renal disease were excluded. Treatment duration was defined as time from first to last ESA administration. Mean cumulative ESA dose was used to calculate drug cost (based on 1/2007 wholesale acquisition cost: EPO $12.52/1000 Units; DARB: $4.576/mcg) and dose ratio (Units EPO: mcg DARB).

Results: 1,446 EPO and 2,729 DARB patients were included. Mean treatment duration was longer in the DARB-treated group by three days (EPO:49 days; DARB:52 days; p= 0.037). The EPO-treated group reported 5.8 administrations with a mean administered dose of 42,603 Units (median 40,000, interquartile range 40,000–45,714) corresponding to a mean cumulative dose of 247,097 Units. The DARB-treated group reported 5.0 administrations with mean administered dose of 262 mcg (median 250, interquartile range 200–300) corresponding to a mean cumulative dose of 1,310 mcg. Drug costs were $2,901 lower in the EPO group compared to the DARB group (EPO $3,094; DARB $5,995) and utilization reflected a dose ratio of 189:1 (Units EPO: mcg DARB).

Conclusions: This observational study of over 4,100 cancer patients receiving chemotherapy found 48% lower drug cost in the EPO group compared to the DARB group. These findings provide greater understanding of current real-world ESA utilization and are consistent with other studies in the cancer chemotherapy population.