NEW YORK – The US Food and Drug Administration on Friday granted accelerated approval to AstraZeneca and Daiichi Sankyo's antibody-drug conjugate Enhertu (trastuzumab deruxtecan) as a treatment for patients with unresectable or metastatic HER2-positive solid tumors who have failed prior therapy and have no remaining treatment options.
Patients must have HER2-overexpressing refractory solid tumors with immunohistochemistry scores of 3+ to be eligible for Enhertu in a tissue-agnostic fashion.
The agency's decision was based on results from three Phase II trials — DESTINY-PanTumor02, DESTINY-Lung01, and DESTINY-CRC02. In those trials, researchers assessed the safety and efficacy of Enhertu in nearly 200 patients. The overall response rates were 51.4 percent in DESTINY-PanTumor02, 52.9 percent in DESTINY-Lung01, and 46.9 percent in DESTINY-CRC02.Patients in DESTINY-PanTumor02 had a 19.4-month median duration of response to Enhertu. In DESTINY-Lung01, the median duration of response was 6.9 months, and in DESTINY-CRC02 it was 5.5 months. Patients with a history of interstitial lung disease or pneumonitis requiring steroids, clinically significant heart disease, or active brain metastases were excluded from these trials.
Since the FDA has granted accelerated approval, long term availability of Enhertu in this indication will require confirmation of its safety and efficacy. Enhertu is already approved in the US for HER2-positive and HER2-low metastatic breast, HER2-positive gastric, and HER2-mutant non-small cell lung cancer.
In gaining tissue-agnostic approval, Enhertu joins a growing list of therapies the FDA has approved based on a biomarker that is common across histologies. Other tissue-agnostic indications approved by the agency, all in the refractory setting, include Merck's Keytruda (pembrolizumab) in microsatellite instability-high or mismatch repair-deficient tumors and in tumor mutational burden high cancers; Bayer's Vitrakvi (Larotrectinib) and Genentech's Rozlytrek (entrectinib) in tumors with NTRK fusions; GlaxoSmithKline's Jemperli (dostralimab) in mismatch repair-deficient tumors; Eli Lilly's Retevmo (selpercatinib) for tumors with RET fusions; and the combination of Novartis' Tafinlar and Mekinist (dabrafinibi/tramatenib) in BRAF V600E-mutated cancers.