Dr Sara Tolaney speaks to ecancer about an exploratory biomarker analyses from the phase 3 ASCENT-04/KEYNOTE-D19 study evaluating sacituzumab govitecan in combination with pembrolizumab as first-line treatment for patients with PD-L1–positive metastatic triple-negative breast cancer.

The discussion highlights how this combination improves progression-free survival compared with chemotherapy plus pembrolizumab across a range of biomarker-defined subgroups.

The data show that patients derive benefit regardless of Trop-2 expression level, tumour BRCA mutation status, or HER2 expression, with particularly notable improvements seen in those with higher Trop-2 expression.

Efficacy is observed in both BRCA wild-type and mutated populations, as well as in HER2-low and HER2-zero disease, supporting the broad activity of this regimen.

Overall, the findings reinforce the clinical value of sacituzumab govitecan plus pembrolizumab as a first-line treatment option in metastatic triple-negative breast cancer, demonstrating meaningful improvements in progression-free survival with a safety profile consistent with prior experience.