Accelerated Approval Granted by FDA for [Fam]-Trastuzumab Deruxtecan-nxki in HER2-Positive Breast Cancer
Posted: Thursday, January 2, 2020
On December 20, the U.S. Food and Drug Administration (FDA) granted accelerated approval to [fam]-trastuzumab deruxtecan-nxki (Enhertu) for the treatment of adults with unresectable or metastatic HER2-positive breast cancer who have received two or more prior anti–HER2-based regimens in the metastatic setting.
Approval was based on the results of a clinical trial that enrolled 184 female patients with HER2-positive, unresectable and/or metastatic breast cancer who had received two or more prior anti-HER2 therapies in the metastatic setting. These patients were heavily pretreated in the metastatic setting, receiving between 2 and 17 therapies prior to receiving [fam]-trastuzumab deruxtecan-nxki. Patients in the clinical trial received this treatment every 3 weeks, and tumor imaging was obtained every 6 weeks. The overall response rate was 60.3%, which reflects the percentage of patients who had a certain amount of tumor shrinkage, with a median duration of response of 14.8 months.
The prescribing information for [fam]-trastuzumab deruxtecan-nxki includes a boxed warning to advise health-care professionals and patients about the risk of interstitial lung disease and embryofetal toxicity. Interstitial lung disease and pneumonitis, including cases resulting in death, have been reported with this agent. Health-care professionals should monitor for and promptly investigate signs and symptoms including cough, dyspnea, fever, and other new or worsening respiratory symptoms.
The most common side effects for patients taking [fam]-trastuzumab deruxtecan-nxki were nausea, fatigue, vomiting, alopecia, constipation, decreased appetite, anemia, decreased neutrophil count, diarrhea, leukopenia, cough, and decreased platelet count. In addition, patients treated with [fam]-trastuzumab deruxtecan-nxki may be at increased risk of developing left ventricular dysfunction, as this has been seen with other HER2-directed therapies for breast cancer.
