Cost-effectiveness analysis of eribulin (E) versus treatment of physician’s choice (TPC) in patients (pts) with pretreated metastatic breast cancer (MBC).

Abstract

e16525 Background: Eribulin was FDA approved in 2010 for pts previously receiving >2 prior chemotherapeutic regimens for MBC. This approval was based on the phase 3 trial (EMBRACE) which demonstrated that E significantly improved median overall survival (OS) relative to different TPC by 2.5 months [HR 0.81; p=0.041]. Methods: The aim of this study was to assess the cost-effectiveness of E versus the 3 most commonly selected TPC in EMBRACE. We also evaluated the cost effectiveness of E compared to other approved drugs for MBC. We created a decision-analytical model using clinical data from the EMBRACE trial. Health utilities were derived from the published literature. Costs for drug acquisition, physician visits, and laboratory tests were obtained from Medicare Services Drug Payment Table and Physician Fee Schedule and are represented in 2011 USD. Life-years saved (LY), Quality-adjusted life years (QALY), and Incremental Cost Effectiveness Ratio (ICER) were calculated using the EMBRACE median OS data. TPC cost was calculated with 3 most commonly used drugs: vinorelbine (V), gemcitabine (G), and capecitabine (X), comprising 60% of pts in the TPC arm. Other drugs analyzed included liposomal doxorubicin (D), nab-paclitaxel (A), and ixabepilone (I). Greater GCSF use with E vs. TPF was also accounted for in our model. Results: E added 0.208 LY and 0.119 QALY with an incremental cost over TPC of $24,035; and therefore a cost of $115,369/LY and an ICER of $201,790/QALY. The main drivers of the model were drug acquisition cost, OS, and health utility values. The results of the model were robust in sensitivity analyses. Because of the very low cost of V and G, we looked at the cost-effectiveness of E relative to several other drugs commonly used in this setting, but used in fewer pts in the pivotal trial. Relative to ixabepilone, liposomal doxorubicin, nab-paclitaxel, and capecitabine the ICER for E was $85,130, $98,538, $119,029, and $154,591, respectively. Conclusions: Using commonly accepted willingness-to-pay thresholds, E appears to be cost effective in the treatment of MBC relative to D, A, X, and I; with marginal cost effectiveness for less expensive drugs such as V and G.