Trastuzumab Deruxtecan Receives Priority Review in China for Second-Line Treatment of HER2-Positive Metastatic Breast Cancer

On May 6, Trastuzumab deruxtecan (T-DXd, also known as DS-8201), an antibody-drug conjugate jointly developed and promoted by Daiichi Sankyo and AstraZeneca, was granted priority review by the Center for Drug Evaluation (CDE) of China's National Medical Products Administration (NMPA). It is intended for the treatment of adult patients with unresectable or metastatic HER2-positive breast cancer who have previously received one or more anti-HER2 therapies. This follows the Breakthrough Therapy Designation (BTD) granted by the CDE on April 12, 2022. The CDE’s Breakthrough Therapy Designation (BTD) aims to expedite the development of potential new drugs that address serious conditions and significant unmet medical needs, provided they demonstrate promising preliminary clinical results and offer substantial clinical advantages over existing treatments.

T-DXd is a novel anti-HER2 targeted antibody-drug conjugate (ADC) jointly developed by Daiichi Sankyo and AstraZeneca. It consists of a humanized anti-HER2 lgG1 antibody, a cleavable tetrapeptide linker, and a topoisomerase I inhibitor (DXd, a camptothecin derivative), offering the dual advantages of precise targeting and high efficacy with low toxicity. The marketing application submitted by Daiichi Sankyo (China) was accepted by the Center for Drug Evaluation (CDE) of the National Medical Products Administration (NMPA) of China on March 18, 2022. This application is based on pivotal data from the large-scale Phase III clinical study DESTINY-Breast03, which was presented at the 2021 European Society for Medical Oncology (ESMO) Congress. The data were also published in the New England Journal of Medicine (NEJM) in March 2022, marking the fifth time that research findings related to T-DXd have been featured in the New England Journal of Medicine.

Dr. Tsunehisa Ogata, General Manager of Daiichi Sankyo (China) Development Headquarters, stated: "Breast cancer is the most prevalent malignant tumor among Chinese women. T-DXd fulfills an unmet treatment need for HER2-positive advanced breast cancer, ushering in a new era of treatment for HER2-positive breast cancer patients in China. Leveraging the proprietary DXd technology developed by Daiichi Sankyo, the innovative linker technology delivers targeted drug payloads precisely to cancerous tissues, providing patients with more stable, effective, and safer treatment options. The priority review granted to T-DXd this time is expected to allow breast cancer patients in China to benefit from cutting-edge international innovative drugs simultaneously with the rest of the world."

Principal investigator of the DESTINY-Breast03 clinical trial in China, Chief Physician at the Cancer Hospital of the Chinese Academy of Medical Sciences, Academician Xu Binghe, stated: "The DESTINY-Breast03 study is the first Phase III study among numerous global clinical trials of HER2 ADC drugs to conduct a head-to-head comparison with the standard treatment T-DM1. With its outstanding clinical benefits, it has become the new global standard for second-line treatment. T-DXd utilizes a cleavable tetrapeptide linker and a more potent novel topoisomerase I inhibitor, DXd, balancing stability in the bloodstream with efficient payload release, demonstrating favorable safety. We look forward to the early introduction of T-DXd in China, providing patients with a new treatment option."

It is worth mentioning that T-DXd officially landed in the Boao Lecheng International Medical Tourism Pilot Zone in Hainan on February 28, 2022, for the treatment of HER2-positive unresectable or recurrent breast cancer after previous chemotherapy (only for patients who are resistant to or intolerant of standard treatment); and HER2-positive advanced unresectable or recurrent gastric cancer with disease progression after previous chemotherapy.

Regarding the Collaboration between Daiichi Sankyo Company Limited and AstraZeneca

Daiichi Sankyo Company Limited (hereinafter referred to as Daiichi Sankyo) and AstraZeneca reached global collaborations respectively in March 2019 and July 2020 to jointly develop and commercialize trastuzumab deruxtecan and datopotamab deruxtecan (Dato-DXd) in markets outside Japan (Daiichi Sankyo holds the exclusive rights for ADC products in Japan). Daiichi Sankyo is responsible for the production and supply of ENHERTU and datopotamab deruxtecan.

About Daiichi Sankyo Company Limited

Daiichi Sankyo is committed to leveraging our world-class scientific technologies to create new modalities and innovative drugs, with the goal of "contributing to the improvement of quality of life for people around the world." In addition to our current portfolio of oncology and cardiovascular disease drugs, Daiichi Sankyo is also focused on developing new therapies for cancer patients and those with unmet medical needs in other diseases. With over 100 years of scientific expertise and operations spanning more than 20 countries, Daiichi Sankyo and its global workforce of 16,000 employees will continue to uphold the company's deep-rooted tradition of innovation as we work towards our 2030 vision of becoming "an innovative global healthcare company contributing to sustainable societal development." For more information, please visit: www.daiichisankyo.com.