Dr. Tolaney: So, at ESMO, we saw results of TROPiCS-02. This was a randomized phase III study that had looked at sacituzumab govitecan, which is an antibody-drug conjugate targeting Trop-2, that has a topoisomerase payload. And it was compared to chemotherapy of physician's choice in patients with metastatic hormone-receptor-positive, HER2-negative breast cancer among patients who had had two to four prior lines of chemotherapy for their metastatic disease.
And we had originally seen data come out at ASCO looking at progression-free survival where we did see that sacituzumab was associated with a statistically significant improvement in progression-free survival with a difference between the two arms of about 1.5 months. At that point in time, the study had not yet met significance for overall survival at that interim analysis.
Significant improvement in overall survival with sacituzumab govitecan
However, at a second interim analysis for survival, which became the final OS analysis in TROPiCS-02, there was a statistically significant improvement in overall survival, with a difference between the two arms that was a little over 3 months. And so, we now have data to suggest that sacituzumab not only improves progression-free survival but also improves overall survival when compared to standard chemotherapy in pretreated metastatic hormone-receptor-positive breast cancer patients.