Adding pertuzumab to standard combination therapy with docetaxel plus trastuzumab is not cost-effective in patients with metastatic HER2-positive breast cancer, according to a report published online Sept. 8 in Journal of Clinical Oncology.
Adding pertuzumab in this setting is highly effective at extending survival, although patients usually succumb to their disease eventually. And this approach is recommended as the first-line treatment of choice by the National Comprehensive Cancer Network. But its cost-effectiveness has never been studied in the United States until now, said Dr. Ben Y. Durkee of the department of radiation oncology at Stanford (Calif.) University.
Dr. Durkee and his associates assessed the cost-effectiveness of adding pertuzumab to standard treatment by incorporating into their statistical model such existing data as the annual incidence of metastatic HER2-positive breast cancer (17,450 patients per year), the direct and indirect costs of standard combination therapy alone ($347,627 per patient per year), and the direct and indirect costs of adding pertuzumab therapy ($805,449 per patient per year) until disease progressed or toxic effects became unmanageable. The model assigned hypothetical patients to four possible health states based on data in the literature – stable disease, progressing disease, hospice, and dead – and tracked each one weekly for their remaining lifetimes.
This model produced outcomes consistent with those reported in the literature regarding overall survival, progression-free survival, major toxicities, and time spent in each health state. Median overall survival was 39.4 months for standard treatment and 56.9 months with the addition of pertuzumab.
In this statistical model, adding pertuzumab yielded an extra 1.82 life-years per patient and 0.64 QALYs at a per-patient cost of $457,821. “Taken together, the addition of pertuzumab to combined docetaxel plus trastuzumab cost $713,219 per QALY gained,” which is “well above any commonly used threshold and well above the de facto threshold of cost-effectiveness for interventions already in practice,” Dr. Durkee and his associates noted (J Clin Oncol. 2015 Sep 8. doi:10.1200/JCO.2015.62.9105).
Willingness-to-pay thresholds in most analyses of medical treatments range from $50,000 to $160,000 per QALY. A sensitivity analysis of the data demonstrated a 0% chance of cost-effectiveness at a willingness-to-pay level of $100,000 per QALY gained. Even when the willingness-to-pay level rose to $500,000 per QALY, this analysis showed a 0% chance of cost-effectiveness, the researchers noted.
“This analysis highlights the economic challenges of extending life for patients with noncurable disease. It also typifies the broader observation that half of our health care dollars are spent on 5% of the population,” the investigators said.
The Henry S. Kaplan Research Fund, the department of radiation oncology at Stanford University, and the National Institute on Aging supported the study. Dr. Durkee reported having no conflicts of interest. An associate reported stock or other ownership with ViewRay.