PRIMARY PROPHYLAXIS WITH PEGFILGRASTIM IS COST-SAVING COMPARED WITH FILGRASTIM FOR BREAST CANCER IN SPAIN

OBJECTIVES: Primary (first-cycle) prophylaxis with filgrastim or second generation pegfilgrastim has been recommended in the 2006 ASCO and EORTC clinical guidelines when the risk of febrile neutropenia (FN) is >20%. Recent studies reported significantly greater reduction of FN with pegfilgrastim than with filgrastim, yet no study has compared their cost-effectiveness. The study purpose was to evaluate the cost-effectiveness of primary prophylaxis with pegfilgrastim versus 11-day use of filgrastim (as recommended) in women with stage I-III breast cancer receiving chemotherapy with moderate to high risk of FN in Spain. METHODS: We constructed a decision-analytic model from a health care payer's perspective. Costs included costs for drugs, drug administration, FN-related hospitalizations and subsequent care, and were based on ex-factory price listing and literature. Effectiveness was measured as FN avoided and life-years-gained (LYG). FN risk (varied by days of filgrastim), FN case-fatality, relative dose intensity (RDI), and the impact of RDI on survival were based on a comprehensive literature review and expert panel validation. Breast cancer mortality and all-cause mortality were from national cancer registries and vital statistics report. Sensitivity analyses were conducted on key variables. RESULTS: In addition to being more effective, pegfilgrastim primary prophylaxis produced an average cost-savings of €32 per patient (€4,243 pegfilgrastim versus €4275 filgrastim). Pegfilgrastim reduced the absolute risk of FN by 5.5% (12.5% versus 7%) and had a LYG of 0.06 (16.48 versus 16.42 years). Age of diagnosis and cancer stage had minimal impact on the results. Key influencing factors included drug costs, relative risk of FN, and drug administration cost. CONCLUSION: Primary prophylaxis with pegfilgrastim in Spain appeared not only to be more effective but also cost-saving compared with filgrastim used for 11 days per cycle.