The FDA announced today that it approved Enhertu, an IV infusion for the treatment of patients with unresectable or metastatic HER2-low breast cancer.
Enhertu (fam-trastuzumab-deruxtecan-nxki) IV infusion is now the first approved therapy targeted to patients with the HER2-low breast cancer subtype, which is a newly defined subset of HER2-negative breast cancer.
The therapy received priority review and breakthrough therapy designations for this indication. The FDA granted the approval of Enhertu to Japanese pharmaceutical outfit Daiichi Sankyo four months ahead of the Prescription Drug User Fee Act (PDUFA) deadline, according to an FDA news release.
FDA said that an estimated 287,850 new cases of female breast cancer will be diagnosed in 2022 in the U.S., with approximately 80-85% of those new cases previously considered to be HER2-negative subtype (including hormone receptor positive and triple negative breast cancer).
HER2 cancer means the tumors do not overexpress or make too many copies of the HER2 protein. Out of that proportion of breast cancer diagnoses, FDA estimates that about 60% of patients previously classified as having HER2-negative subtype can now be considered as HER2-low. HER2-low patients previously received endocrine therapy or chemotherapy.
“Today’s approval highlights the FDA’s commitment to be at the forefront of scientific advances, making targeted cancer treatment options available for more patients,” said Dr. Richard Pazdur, director of the FDA’s Oncology Center of Excellence and acting director of the Office of Oncologic Diseases in the FDA’s Center for Drug Evaluation and Research. “Having therapies that are specially tailored to each patient’s cancer subtype is a priority to ensure access to safe and innovative treatments.”
Patients with HER2-low breast cancer are eligible for Enhertu if they have received a prior chemotherapy in the metastatic setting, or their cancer returned during, or within 6 months of completing, adjuvant chemotherapy.
The Destiny-Breast04 randomized, multicenter, open-label clinical trial of 557 adults with unresectable or metastatic HER2-low breast cancer provided Enhertu treatment to 373 patients through intravenous infusion every three weeks, while the remaining 184 received physicians’ choice of chemotherapy (eribulin, capecitabine, gemcitabine, nab paclitaxel or paclitaxel).
Results showed improvement in both progression-free survival and overall survival in people with unresectable or metastatic HER2-low breast cancer with Enhertu. The most common adverse reactions in those patients are nausea, fatigue, alopecia, vomiting, constipation, decreased appetite, musculoskeletal pain and diarrhea.
The FDA review was conducted under the FDA Oncology Center of Excellence’s Project Orbis initiative for providing a framework for concurrent submission and review of oncology drugs among international partners. The FDA collaborated with the Australian Therapeutic Goods Administration, Health Canada, and Switzerland’s Swissmedic for the review.
Additionally, the agency said that the approval falls in line with the Cancer Moonshot initiative from the Biden administration to reduce the rate of cancer deaths and improve the lives of cancer patients and their families through advancements in cancer research and technology, as well as the development of new programs.
“Enhertu’s approval further illustrates how the FDA’s efforts align with the Cancer Moonshot goals of targeting the right treatments to the right patients, speeding progress against the most deadly and rare cancers and learning from the experience of all patients,” the FDA said.