Dato-DXd demonstrated a statistically significant and clinically meaningful improvement for the primary endpoint of progression-free survival compared to the investigator's choice of chemotherapy. 

Datopotamab deruxtecan's safety profile aligned with previous breast cancer clinical trials, noting no fresh safety signals. All-grade interstitial lung disease rates remained low. 

While the overall survival (OS) data is yet to mature, the trial will persist in assessing this metric.

Breast cancer remains a global concern, with over two million diagnoses annually. Among these, HR-positive, HER2 low, or negative breast cancer is prevalent, making up more than 65% of cases. 

Susan Galbraith, Executive Vice President, Oncology R&D, at AstraZeneca, added, "Today's TROPION-Breast01 news is a significant development for patients whose tumors have become insensitive to endocrine therapy."

The company's shares fell after the data due to the lack of numerical detail, despite being statistically significant— a minimum 2-3 month benefit was targeted.

Price Action: AZN shares are up 2.66% at $68.80 during the premarket session on the last check Friday.