Recent Breast Cancer Treatment Drug Enhertu Indicates Expanding Options for Most Aggressive Form of HER2-positive Breast Cancer

According to data published last month in the New England Journal of Medicine and presented in June 2022 at the annual meeting of the American Society of Clinical Oncology (ASCO), 55% of patients with advanced breast cancer could be candidates for treatment with Enhertu.

Enhertu is the first HER2-targeted therapy to demonstrate a survival benefit in the HER2-low breast cancer population. Enhertu’s promise has gained since May of 2021 when the FDA approved the drug Enhertu for adult patients with metastatic HER2-positive breast cancer. The “indication for treatment” designation was a step forward in providing better, proven therapy to mostly women who develop the aggressive HER2-positive forms of cancer. Such patients account for about 15-20% of all breast cancer diagnosis

A recent promising trial finding resulted from a global study of Enhertu. The study compared the effectiveness of the drug to treatment with physicians’ choice of chemotherapy in at least one-two lines of chemotherapy. Enhertu demonstrated a 49% reduction in the risk of disease progression or death versus physician’s choice of chemotherapy in patients with HER2-low metastatic breast cancer with HR-positive disease.

Based on the results of this trial, the FDA granted Enhertu a Breakthrough Therapy Designation in April for the treatment of adult patients with metastatic HER2-low breast cancer who have received a prior systemic therapy.

The safety profile of Enhertu was consistent with past trials; however, there are risks. There is a “significant” safety issue of interstitial lung disease or pneumonitis seen in Enhertu patients. The condition was identified in 12.1% of patients who received the drug in the study, which is similar to prior clinical trial incidence at 15.5% and 3 patients treated with Enhertu died from pneumonitis in this study. This safety concern is a limiting factor in the use of Enhertu.

Enhertu is the first HER2-targeted therapy to demonstrate a survival benefit in the HER2-low breast cancer population. As a result of the DESTINY-Breast04 study approximately 55% of patients with advanced breast cancer could be candidates for treatment with Enhertu. Enhertu costs approximately $14,000 per month. Given the potential wide treatment impact and increased utilization of Enhertu as compared to other therapies, an overall increase in drug treatment costs is likely in this disease state.

To learn more about Enhertu, click here.