AstraZeneca and Daiichi Sankyo's Datroway (datopotamab deruxtecan, Dato-DXd) has secured its first global approvals for the treatment of advanced breast cancer. Japan's Ministry of Health, Labour and Welfare (MHLW) granted approval for patients with previously treated, unresectable, or recurrent hormone receptor (HR)-positive, HER2-negative breast cancer. Subsequently, the U.S. Food and Drug Administration (FDA) and the European Medicines Agency (EMA) have also endorsed the drug, marking significant milestones in its global rollout. This approval marks a pivotal advancement, offering a novel therapeutic option for patients who have exhausted conventional treatments. Datroway is the first TROP2-directed drug to reach the market in Japan for this type of cancer. It is also the second in the class after Gilead Sciences' ADC Trodelvy (sacituzumab govitecan).
Clinical Efficacy and Safety
The approvals are based on the TROPION-Breast01 trial, which demonstrated a statistically significant improvement in progression-free survival (PFS) compared to standard chemotherapy. Patients treated with Datroway experienced a median PFS of 6.9 months, compared to 4.9 months in the chemotherapy arm, representing a 37% improvement. While overall survival (OS) data were not significantly improved, the PFS benefit underscores the clinical relevance of Datroway in this patient population. The Japanese label includes a warning for interstitial lung disease (ILD), observed in approximately 3% of patients in the TROPION-Breast01 study. However, emerging data suggest that the risk of ILD can be mitigated through careful patient selection and monitoring.
Mechanism of Action
Datroway is an antibody-drug conjugate (ADC) that targets the TROP2 protein, which is frequently overexpressed in breast cancer cells. By selectively delivering a cytotoxic payload to TROP2-expressing cells, Datroway minimizes off-target effects and enhances antitumor activity. This targeted approach offers a potential advantage over traditional chemotherapy, which can indiscriminately damage both cancerous and healthy cells.
Market Impact and Future Prospects
Breast cancer is the most common cancer in women in Japan, with approximately 92,000 cases diagnosed annually, and around 70% of cases fall into the HR+/HER2- category. AstraZeneca projects that peak annual sales could exceed $5 billion, making Datroway a cornerstone of its broader oncology ambitions to reach $80 billion by 2030. While the path to market for non-small cell lung cancer (NSCLC) has been less straightforward, AstraZeneca and Daiichi Sankyo remain optimistic about the potential of Datroway in treating various cancers. The drug is also being investigated in combination with Merck & Co’s PD-1 inhibitor Keytruda (pembrolizumab) as a first-line therapy for patients with advanced NSCLC.
