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.
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.