NEW YORK – The US Food and Drug Administration granted accelerated approval on Friday to trastuzumab deruxtecan (Daiichi Sankyo's Enhertu, DS-8201) for the treatment of unresectable or metastatic HER2-positive breast cancer that had been previously treated with anti-HER2 regimens.
Prior to its FDA approval, DS-8201 was granted Fast Track Designation and Breakthrough Therapy Designation by the agency. "There have been many advances in the development of drugs for HER2-positive breast cancer since the introduction of Herceptin (trastuzumab) in 1998," Richard Pazdur, director of FDA's Oncology Center of Excellence, said in a statement. "The approval of Enhertu represents the newest treatment option for patients who have progressed on available HER2-directed therapies."
HER2-positive breast cancers have a protein called human epidermal growth factor receptor 2 — HER2 — which promotes the growth of cancer cells. The drug DS-8201 comprises a HER2-directed antibody and topoisomerase inhibitor, which can target the changes in HER2 on a cancer cell and kill it.
The approval follows the results of a Phase II single-arm DESTINY-Breast01 trial of 184 patients, announced earlier this month at the San Antonio Breast Cancer Symposium.
In the trial, 60 percent of patients saw their tumors shrink. The median duration of response was 14.8 months. Adverse events were mostly in grade 1 or 2, similar to the safety profile observed in the Phase I trial for the drug. The drug label includes a boxed warning regarding the risk of interstitial lung disease and embryo fetal toxicity. Some patients on the drug have developed interstitial lung disease and pneumonitis, and died.