MUNICH - A 6-month course of adjuvant trastuzumab appeared more cost-effective than standard 12-month treatment for women with HER2-positive early-stage breast cancer, according to study results presented at European Society for Medical Oncology Congress.
Trastuzumab (Herceptin, Genentech) is an FDA-approved monoclonal antibody that targets HER2.
"Adjuvant trastuzumab has improved outcomes for HER2-positive early-stage breast cancer using the 12-month duration empirically adopted from pivotal registration trials," Peter Hall, PhD, academic medical oncologist at Cancer Research UK Edinburgh Center, said during a presentation.
However, the annual cost per patient is more than 30,000 British pounds - equivalent to 35,000 euros, or $39,000 - so a shorter treatment duration could increase cost-effectiveness provided efficacy is maintained, according to study background.
Hall and colleagues conducted a cost-effectiveness analysis based on data from the PERSEPHONE trial. The randomized phase 3 noninferiority trial compared 6 months and 12 months of adjuvant trastuzumab for early-stage HER2-positive breast cancer.
A landmark analysis compared costs and quality of life throughout follow-up, which ranged from 6 months to 24 months after treatment initiation.
The analysis included 3,759 patients who were disease-free at 6 months. Among them were 1,868 patients treated with 6 months of adjuvant trastuzumab and 1,891 patients from the 12-month treatment group.
Average costs per patient were 2,538.64 pounds (95% CI, 2,383.38-2,700.72) for the 6-month group and 12,333.83 pounds (95% CI, 12,098.58-12,562.27) in the 12-month group.
This equated to an average cost savings of 9,793.25 pounds (95% CI, 9,515.86-10,071.64) per patient with the shorter regimen. Trastuzumab treatment and administration accounted for most (9,699.58 pounds; 95% CI, 9,436.20-9,954.67) of the cost savings, with cardiac assessment, other treatment costs and inpatient days accounting for the remainder.
The average quality-adjusted life-years were 0.764 (95% CI, 0.754-0.774) in the 6-month group and 0.752 (95% CI, 0.742-0.763) in the 12-month group, equating to an average difference of 0.012 (95% CI, 0.002-0.026).
Researchers determined a 94.78% probability that the 6-month regimen would be cost-effective.
Hall and colleagues plan to conduct further study, including creating a lifetime model that will identify a clinical risk cut-point for the cost-effectiveness of 12 months over 6 months trastuzumab, Hall said. They also intend to perform a perspective analysis that will assess out-of-pocket costs and productivity losses.
"The results, alongside the clinical effectiveness results demonstrating noninferiority, are the first steps in the safe reduction of treatment for many women with HER2-positive breast cancer," study author Claire Hulme, PhD, MA, BSc, professor of health economics at the Academic Unit of Health Economics at University of Leeds in the United Kingdom, said in a press release. "They present an opportunity for significant cost savings for health service providers."
Nadia Harbeck, MD, PhD, head of the breast center at University of Munich, called the findings "an important contribution for global access to treatment."
However, the study could not exclude a benefit of the 1-year regimen in clinically relevant subgroups.
"So 1 year remains the standard," Harbeck, who was not involved with the study, said in a press release. "And now we have biosimilars, which could also help to increase access to treatment in countries where there is no general access." - by Jennifer Southall
Hall P, et al. Abstract LBA12_PR. Presented at: European Society for Medical Oncology Congress; Oct. 19-23, 2018; Munich.
Disclosures: The authors report no relevant financial disclosures.