In early August, the U.S. Food and Drug Administration approved of a new treatment option called Enhertu for unresectable or metastatic HER2-low breast cancer. This is the first targeted therapy approved for HER2-low subtype.


Dr. Heather Han, director of research in the Department of Breast Oncology at Moffitt Cancer Center.

In the Tampa Bay Area, Moffitt Cancer Center was selected as one of the sites to participate in the three-year clinical trial of Enhertu, which is given as an IV infusion to patients. Dr. Heather Han, director of research in the Department of Breast Oncology at Moffitt Cancer Center, had the opportunity to work with the drug during its clinical trial.

“Studies show that this new therapy can improve progression-free and overall survival of patients with HER2-low advanced breast cancer,” Dr. Han said. “Patients can have a better disease control compared to chemotherapy treatments that was approved prior. When you take this drug, that’s an additional option that wasn’t available for this patient population.”

Dr. Han explained that Enhertu is classified as an antibody-drug conjugate — meaning an antibody is chemically linked to the medication to help its delivery. She added that the antibody binds to tumor cells expressing HER2 protein, bringing chemotherapy directly to the cancer cells. The drug was initially approved by the FDA to target HER2-positive, and studies found that this medication could also target HER2-low subtype.

Patients in a metastatic setting can be on this medication for longer time, resulting as a major benefit for about half of breast cancer patients who can get this treatment.

“Enhertu is the first approved therapy for this new subtype of breast cancer, HER2-low, and led to the major improvement of outcomes for patients compared to existing chemotherapies, which is a major advancement,” Dr. Han said.

According to Moffitt Cancer Center, 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.