For the treatment of advanced HER2-positive breast cancer, the use of trastuzumab emtansine (T-DM1) is not cost-effective when compared with lapatinib plus capecitabine from both a societal and a payer’s perspective, according to an analysis conducted at Western University of Health Sciences College of Pharmacy in Pomona, CA.
From a societal perspective only, T-DM1 may be cost-effective compared with capecitabine monotherapy at the willingness-to-pay threshold of $150,000 per quality-adjusted life-year (QALY), Quang A. Le, PharmD, PhD, and Yuna Bae, PharmD, also reported in a poster.
In the EMILIA trial, T-DM1 significantly increased both median progression-free survival (PFS) and overall survival (OS), relative to lapatinib plus capecitabine, in patients with HER2-positive advanced breast cancer previously treated with trastuzumab and a taxane. Using data from this trial and the EGF100151 trial of capecitabine, the investigators performed an economic analysis of T-DM1 compared with lapatinib/capecitabine (LC) and with monotherapy with capecitabine from both the US payer’s perspective and a societal perspective.
The model assumed a median PFS of 9.6 months with T-DM1, 6.4 months with LC, and 4.3 months with capecitabine; median OS of 30.9 months, 25.1 months, and 15.3 months; overall response rates of 43.6%, 30.8%, and 13.9%; and duration of response of 12.6 months, 6.5 months, and 7.1 months, respectively.
Le and Bae examined outcomes with 4 possible Markov models for advanced breast cancer, comparing the projected lifetime costs and outcomes with the 3 regimens as applied to a typical 53-year-old patient (Table). From the US payer’s perspective, at the willingness-to-pay threshold of $150,000 per QALY, the analysis found a 14.1% probability that T-DM1 was cost-effective versus LC, and a 22.9% probability it was cost-effective against capecitabine. From a society perspective, these probabilities were 29.2% and 88.4%, respectively, the researchers reported.
