NEW YORK – Japan-based Daiichi Sankyo today announced that it had submitted a supplemental new drug application to Japan's Ministry of Health, Labor, and Welfare for its HER2-directed antibody drug conjugate, trastuzumab deruxtecan (Enhertu), for the treatment of patients with HER2-positive metastatic gastric cancer.
Trastuzumab deruxtecan has already received accelerated approval in the US and in Japan for patients with previously treated, metastatic HER2-positive breast cancer. The antibody drug works by delivering cytotoxic chemotherapy to HER2-expressing cancer cells by way of a HER2 monoclonal antibody attached to a tetrapeptide-based linker.
Daiichi Sankyo said in a statement that the gastric cancer indication has received "sakigake" designation, which puts it on a six-month expedited review clock. A positive decision would provide a new treatment option for a patient population with significant unmet need.
About one in five gastric cancers are HER2 positive, and patients whose disease progresses after the recommended first-line treatment of chemotherapy plus trastuzumab (Genentech's Herceptin) lack additional approved HER2-targeting treatment options.
The supplemental new drug application includes data from the Phase II DESTINY-Gastric01 trial, as well as the Phase I trial published last spring in the Lancet Oncology. The full results of the Phase II trial, which compared objective response rates and overall survival with trastuzumab deruxtecan with investigator's choice chemotherapy, will be presented during the 2020 American Society of Clinical Oncology Annual Meeting later this month. In the study, according to Daiichi Sankyo, patients treated with its drug experienced clinically meaningful improvements in tumor shrinkage and survival compared to the chemotherapy-only arm.
"Today's submission by Daiichi Sankyo brings us closer to bringing trastuzumab deruxtecan to a population of patients with unmet medical need in Japan," Wataru Takasaki, Daiichi Sankyo's head of research and development, said in a statement. "If approved, trastuzumab deruxtecan has the potential to meaningfully advance the treatment of patients with HER2-positive metastatic gastric cancer as the first ever antibody-drug conjugate approved to treat this type of cancer."
While Daiichi Sankyo maintains exclusive rights to trastuzumab deruxtecan in Japan, the company has collaborated with AstraZeneca for joint development and commercialization in the rest of the world.