AstraZeneca says Dato-DXd showed significant improvement for primary endpoint

First Phase III results in breast cancer for AstraZeneca (AZN) and Daiichi Sankyo’s (DSNKY) datopotamab deruxtecan, Dato-DXd, have been announced. Positive high-level results from the TROPION-Breast01 Phase III trial showed datopotamab deruxtecan demonstrated a statistically significant and clinically meaningful improvement for the primary endpoint of progression-free survival compared to investigator’s choice of chemotherapy in patients with inoperable or metastatic hormone receptor-positive, HER2-low or negative breast cancer previously treated with endocrine-based therapy and at least one systemic therapy. A trend in improvement for the dual primary endpoint of overall survival was observed for datopotamab deruxtecan versus chemotherapy. Data for OS were not mature at this interim analysis and the trial will continue as planned to assess OS. The safety profile of datopotamab deruxtecan was consistent with previous clinical trials in breast cancer with no new safety signals identified. All grade interstitial lung disease rates were low. Susan Galbraith, Executive Vice President, Oncology R&D, AstraZeneca, said: “Today’s TROPION-Breast01 news is a significant development for patients with HR-positive, HER2-low or negative metastatic breast cancer whose tumors have become insensitive to endocrine therapy and who currently face poor outcomes. We are encouraged by these positive results.”