Cost-effectiveness Analysis of Pertuzumab With Trastuzumab in Patients With Metastatic Breast Cancer

IMPORTANCE The initial assessment of pertuzumab use for treatment of metastatic breast cancer by health technology assessment agencies suggested that pertuzumab was not cost-effective. In Ontario, Canada, pertuzumab became funded in November 2013 based on the substantial clinical benefit. To date, there is a paucity of analysis of pertuzumab using real-world data for cost-effectiveness. OBJECTIVE To assess the cost-effectiveness of pertuzumab, trastuzumab, and chemotherapy vs trastuzumab and chemotherapy for patients with metastatic breast cancer. DESIGN, SETTING, AND PARTICIPANTS A population-based retrospective economic evaluation was conducted in Ontario, Canada. Patients who received first-line treatments formetastatic breast cancer from January 1, 2008, to March 31, 2018, were identified. Patients were followed up from the start of treatment up to 5 years, with maximum follow-up to March 31, 2019. Patients were identified from the Ontario Cancer Registry and linked to the New Drug Funding Program database to identify receipt of first-line treatment (N = 1158). INTERVENTIONS Treatment with pertuzumab, trastuzumab, and chemotherapy after public funding (November 25, 2013) compared with treatment with trastuzumab and chemotherapy before funding. MAIN OUTCOMES AND MEASURES Cost-effectiveness, from a public payer perspective, was estimated from administrative data with a 5-year time horizon, adjusted for censoring, and discounted (1.5%). Incremental cost-effectiveness ratios for life-years gained and quality-adjusted life year (QALY) with bootstrapped 95% CIs were calculated. Sensitivity analysis with price reduction of pertuzumab alone or in combination with trastuzumab was conducted. RESULTS A total of 579 pairs of matched patients receiving pertuzumab and controls were included. The mean (SD) age of the matched study cohort was 58 (12.97) years; 1151 were women (99.4%). Pertuzumab resulted in 0.61 life-years gained and 0.44 QALYs gained at an incremental cost of $192 139 (all costs measured in Canadian dollar values, CAD) with an incremental cost-effectiveness ratio of $316 203 per life-year gained and $436 679 per QALY. The main factors associated with cost included the cost of pertuzumab (60%), outpatient cancer treatment delivery (24%), and trastuzumab (15%). With 100% price reduction of pertuzumab, the incremental cost-effectiveness ratio was $174 027 per QALY. When the price of pertuzumab and trastuzumab were both reduced by more than 71%, the incremental cost-effectiveness ratio decreased below $100 000 per QALY. CONCLUSIONS AND RELEVANCE The findings of this population-based study suggest that pertuzumab may increase survival for patients with metastatic breast cancer but would not be considered cost-effective, even after 100% price reduction, under conventional thresholds.