The U.S. Food and Drug Administration has granted Priority Review to a new application submitted by AstraZeneca and Daiichi Sankyo seeking expand the use of the cancer therapy Enhertu (trastuzumab deruxtecan) to treat people with HER2-positive early breast cancer who have residual invasive disease after receiving targeted therapy before surgery.
The regulatory submission is based on results from the Phase 3 DESTINY-Breast05 trial, which evaluated Enhertu in patients whose cancer remained after neoadjuvant therapy. In the study, the therapy significantly reduced the risk of invasive disease recurrence or death by 53% compared with trastuzumab emtansine (T-DM1), the current standard treatment in this setting.
The trial, which included 1,635 patients across Asia, Europe, North America, Oceania and South America, also found that Enhertu reduced the risk of distant disease recurrence by 51% and lowered the risk of brain metastases by 36% compared with T-DM1.
“While there has been significant progress in treating HER2-positive early breast cancer, managing patients at a higher risk of recurrence remains challenging,” Susan Galbraith, Executive Vice President, Oncology Haematology R&D, AstraZeneca said in a statement. “With this Priority Review, we move closer to bringing Enhertu to the post-neoadjuvant setting, offering more patients the opportunity for sustained long-term outcomes and a potential path to cure.”
Priority Review is granted to medicines that could offer meaningful improvements in treatment, and it shortens the FDA’s review timeline.
Many people with HER2-positive early breast cancer receive drug treatment before surgery to shrink the tumor. When no cancer is found in the tissue removed during surgery, it’s known as a pathologic complete response and is linked to better long-term outcomes. However, about half of patients still have some cancer remaining after this initial treatment, which increases the risk that the disease could return.
Even with additional therapy after surgery, some patients eventually experience recurrence or disease progression. Once breast cancer spreads to other parts of the body, five-year survival drops from nearly 90% to about 30%.
Learn more about breast cancer prognosis
Enhertu is a HER2-targeted antibody-drug conjugate designed to deliver chemotherapy directly to cancer cells that carry the HER2 protein. The medicine combines a HER2-targeting antibody with a chemotherapy payload linked together so the treatment can more precisely attack cancer cells.
Enhertu is already approved in the United States and other countries for several types of cancer, including certain types of metastatic breast cancer. If approved for this new setting, the therapy could provide another option to help reduce the risk of cancer returning in patients with HER2-positive early breast cancer whose disease remains after initial treatment.
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