Cost-effectiveness of lapatinib plus capecitabine (LAP+C) versus capecitabine alone (C-only) or trastuzumab plus capecitabine (TZ+C) in women with HER2-positive metastatic breast cancer (MBC) who have received prior therapy with trastuzumab (TZ) from the U.K. National Health Service (NHS) perspective.

Abstract

6037 Background: In a phase III trial of women with HER2-positive MBC previously treated with TZ, an anthracycline, and taxanes (EGF100151), LAP+C improved time to progression (TTP) vs. C-only. In a trial of less heavily pretreated patients that was stopped early due to slow accrual (GBG 26/BIG 03-05), continued TZ+C also improved TTP vs C-only. Methods: An economic model and patient-level data from EGF100151 and published results of GBG 26/BIG 03-05 as well as the literature were used to evaluate the cost effectiveness (incremental cost per quality-adjusted life year [QALY]) gained with LAP+C vs. C-only and TZ+C in women with HER2-positive MBC previously treated with TZ from the UK NHS perspective. Results: Expected total costs are £29,037 with LAP+C, £14,206 with C-only, and £29,483 with TZ+C. Corresponding QALYs are 0.927, 0.737 and 0.896. Cost per QALY gained is £77,996 with LAP+C vs. C-only. LAP+C provides more QALYs at a lower cost than TZ+C. The cost per QALY gained with LAP+C was £59,734 vs. C-only when a utility weight equal to that of a healthy woman of the same age (0.85) was assigned to gains in life expectancy with combination therapy consistent with NICE advice for evaluation of life-extending end-of-life treatments. Conclusions: When compared with C-only, addition of lapatinib results in a cost effectiveness ratio that exceeds the £30,000/QALY threshold normally used by NICE. When indirectly compared with continued TZ+C (as per GBG 26/BIG 03-05), which is widely used in the UK and other parts of Europe but lacks an approved indication, LAP+C is a dominant treatment strategy (greater effectiveness at lower cost ). Author Disclosure Employment or Leadership Position Consultant or Advisory Role Stock Ownership Honoraria Research Funding Expert Testimony Other Remuneration GlaxoSmithKline GlaxoSmithKline GlaxoSmithKline GlaxoSmithKline GlaxoSmithKline, Roche