Daiichi Sankyo Company, Limited announced that the first patient has been dosed in a global phase 2 study evaluating the safety and efficacy of DS-8201, an investigational HER2-targeting antibody drug conjugate (ADC), in patients with HER2-expressing advanced colorectal cancer who have received at least two prior lines of standard treatment.
An increase in the number of approved targeted therapies for advanced colorectal cancer over the past decade has helped improve outcomes for some patients, however efficacy and tolerability of second and third-line treatments remain limited. Approximately 3 per cent of colorectal cancers overexpress the HER2 protein, which is a well-established therapeutic target in breast and gastric cancer. In addition, research indicates that HER2 amplification may be associated with resistance to anti-epidermal growth factor receptor (EGFR)-targeted therapy and shorter survival. Currently, no approved HER2-targeting therapies exist for patients with colorectal cancer.
“Given the existing unmet medical need for advanced colorectal cancer, we are exploring the smart delivery of chemotherapy with DS-8201 as a potential new type of targeted treatment for patients with HER2-expressing disease who have progressed on or become resistant to standard therapies,” said Antoine Yver, MD, MSc, executive vice president and global head, oncology research and development, Daiichi Sankyo. “Similar to our breast and gastric cancer programs, we are pursuing a development path focused first on patients with HER2-overexpressing tumours followed by potential expansion to include patients with advanced colorectal cancer with lower levels of HER2 expression.”
The global, multi-center, phase 2, open-label, three-cohort study will investigate the safety and efficacy of DS-8201 in patients with HER2-expressing advanced colorectal cancer. The first part of the study will enroll patients with HER2-positive (defined as IHC3+ or IHC2+/ISH+) advanced colorectal cancer. The primary endpoint of the study is overall response rate. Secondary endpoints include progression-free survival, overall survival, duration of response, disease control rate, pharmacokinetics and safety. Exploratory endpoints include time to response and biomarker analysis. This part of the study is expected to enroll approximately 50 patients in North America, Europe and Japan.
Following the outcome of the first part of the study, two additional exploratory cohorts may proceed to enroll patients whose tumours have lower levels of HER2-expression.
DS-8201 is the lead product in the investigational ADC Franchise of the Daiichi Sankyo Cancer Enterprise. ADCs are targeted cancer medicines that deliver cytotoxic chemotherapy (“payload”) to cancer cells via a linker attached to a monoclonal antibody that binds to a specific target expressed on cancer cells. Designed using Daiichi Sankyo’s proprietary ADC technology, DS-8201 is a smart chemotherapy comprised of a humanized HER2 antibody attached to a novel topoisomerase I inhibitor payload by a tetrapeptide-based linker. It is designed to target and deliver chemotherapy inside cancer cells and reduce systemic exposure to the cytotoxic payload (or chemotherapy) compared to the way chemotherapy is commonly delivered.
In addition to the phase 2 study in HER2-expressing advanced colorectal cancer, DS-8201 is currently in pivotal phase 2 clinical development for HER2-positive unresectable and/or metastatic breast cancer resistant or refractory to T-DM1 (DESTINY-Breast01) in North America, Europe and Asia, and pivotal phase 2 development for HER2-positive advanced gastric cancer resistant or refractory to trastuzumab (DESTINY-Gastric01) in Japan and South Korea. DS-8201 is also in phase 1 development for other HER2-expressing advanced/unresectable or metastatic solid tumours.
DS-8201 has been granted Breakthrough Therapy designation for the treatment of patients with HER2-positive, locally advanced or metastatic breast cancer who have been treated with trastuzumab and pertuzumab and have disease progression after ado-trastuzumab emtansine (T-DM1), and Fast Track designation for the treatment of HER2-positive unresectable and/or metastatic breast cancer in patients who have progressed after prior treatment with HER2-targeted therapies including T-DM1 by the US Food and Drug Administration (FDA). DS-8201 is an investigational agent that has not been approved for any indication in any country. Safety and efficacy have not been established.
The mission of Daiichi Sankyo Cancer Enterprise is to leverage our world-class, innovative science and push beyond traditional thinking to create meaningful treatments for patients with cancer. We are dedicated to transforming science into value for patients, and this sense of obligation informs everything we do. Anchored by three pillars including our investigational Antibody Drug Conjugate Franchise, Acute Myeloid Leukemia Franchise and Breakthrough Science Franchise, we aim to deliver seven distinct new molecular entities over eight years during 2018 to 2025. Our powerful research engines include two laboratories for biologic/immuno-oncology and small molecules in Japan, and Plexxikon Inc., our small molecule structure-guided R&D center in Berkeley, CA. Compounds in pivotal stage development include: DS-8201, an antibody drug conjugate (ADC) for HER2-expressing breast, gastric and other cancers; quizartinib, an oral selective FLT3 inhibitor, for newly-diagnosed and relapsed/refractory acute myeloid leukemia (AML) with FLT3-ITD mutations; and pexidartinib, an oral CSF-1R inhibitor, for tenosynovial giant cell tumour (TGCT).