On August 11, 2022, the FDA accelerated the approval of fam-trastuzumab deruxtecan-nxki (Enhertu; Daiichi Sankyo), an HER2-directed antibody and topoisomerase inhibitor conjugate, for the treatment of unresectable or metastatic non–small-cell lung cancer (NSCLC) in adults with HER2 mutations, as detected by an FDA-approved test, who have received systemic therapy. Fam-trastuzumab deruxtecan received a breakthrough therapy designation for this indication.
The FDA concomitantly approved the Oncomine Dx Target Test for tissue and the Guardant360 CDx plasma test as companion diagnostics for fam-trastuzumab deruxtecan: the tumor tissue test should be used if no mutation is detected with the plasma test.
Fam-trastuzumab deruxtecan was previously approved for several solid tumors involving the HER2 biomarker.
“After 2 decades of research into the role of targeting HER2 in lung cancer, the approval of the first HER2-directed treatment option validates HER2 as an actionable target in lung cancer,” said Bob T. Li, MD, PhD, MPH, Memorial Sloan Kettering Cancer Center.
This approval was based on the results of the multicenter, multicohort, randomized, blinded, dose-optimization DESTINY-Lung02 clinical trial of 52 patients with unresectable or metastatic HER2-positive nonsquamous NSCLC whose disease progressed after systemic therapy.
Patients received 5.4 mg of fam-trastuzumab deruxtecan intravenously every 3 weeks until unacceptable adverse events or disease progression. The objective response rate was 58% (95% confidence interval [CI], 43%-71%), and the duration of response was 8.7 months (95% CI, 7.1-not estimable).
The most common (≥20%) adverse events were nausea, decreased white blood cell count, decreased hemoglobin, decreased neutrophil count, decreased lymphocyte count, decreased platelet count, decreased albumin, increased aspartate aminotransferase, increased alanine aminotransferase, fatigue, constipation, decreased appetite, vomiting, increased alkaline phosphatase, and alopecia.