The agent had already been approved for several cancer types, including certain patients with unresectable or metastatic HER2-positive breast cancer as well as adults with locally advanced or metastatic HER2-positive gastric or gastroesophageal junction adenocarcinoma who had received a prior trastuzumab-based regimen.
The current accelerated approval is the first tumor-agnostic approval of a HER2-directed therapy and antibody drug conjugate.
“Until approval of trastuzumab deruxtecan, patients with metastatic HER2-positive tumors have had limited treatment options,” Funda Meric-Bernstam, MD, chair of investigational cancer therapeutics at the University of Texas MD Anderson Cancer Center, Houston, said in an AstraZeneca press statement. “Based on the clinically meaningful response rates across clinical trials, this tumor-agnostic approval means that patients may now be treated with a HER2-directed medicine.”
Approval was based on findings in 192 patients enrolled in either the DESTINY-PanTumor02 trial, the DESTINY-Lung01 trial, or the DESTINY-CRC02 trial. Patients in the multicenter trials underwent treatment until disease progression, death, withdrawal of consent or unacceptable toxicity.
Confirmed objective response rates were 51.4%, 52.9%, and 46.9% in the three studies, respectively. Median duration of response was 19.4, 6.9, and 5.5 months, respectively.
The most common adverse reactions occurring in at least 20% of patients included decreased white blood cell count, hemoglobin, lymphocyte count, and neutrophil count, as well as nausea, fatigue, platelet count, vomiting, alopecia, diarrhea, stomatitis, and upper respiratory tract infection.
Full prescribing information includes a boxed warning about the risk for interstitial lung disease and embryo-fetal toxicity.
The recommended dosage is 5.4 mg/kg given as an intravenous infusion one every 3 weeks until disease progression or unacceptable toxicity.
A version of this article appeared on Medscape.com.