Antibody-drug conjugate plus a checkpoint inhibitor shows a trend toward improved survival in PD-L1-positive hormone receptor-positive, HER2-negative breast cancer.
This is a randomized phase two trial of Sasa Gove T can with or without Pemba for patients with metastatic hormone receptor positive. Her two negative breast cancer who have received prior endocrine therapy and up to one prior line of chemotherapy in the advanced setting. Uh The primary end point of the study was progression free survival in the intent to treat population. And as key secondary end points, PFS in the subgroup of patients with PDL, one positive tumors defined as a uh by the 22 C three assay and using a combined positive score cut off greater than or equal than one and also overall survival both in the intent to treat and PDL one positive subgroup. Uh This study showed that in patients with hormone receptor positive, her two negative metastatic disease unselected by PDL one status addition of pembrolizumab to Sassou aab govi T can did not result in a significant improvement in median progression free survival. Compared to Sasao map go to T alone. Median PFS with SG plus pembrolizumab was 8.1 months and with SG alone, it was 6.2 months. So 1.9 month numerical difference that was not statistically significant. Now, while overall survival data are not mature and the median follow up at the time of the cut off for this analysis was 12.5 months. OS also did not significantly differ by treatment arms in patients unselected by PDL one status. What we did see is that among the subgroup of patients with PDL one positive tumors, uh which was approximately 39% of the patient population on the trial. There was a nonsignificant 4.4 month increase in median progression free survival. 11.1 months with SG with SG plus pembrolizumab versus 6.7 months with SG alone. But also a six month uh difference in median overall survival, 18.5 months compared to 12.5 months. That was also not statistically significant, favoring the combination of SG plus pembrolizumab. And so, while these results are not statistically significant, we do think that uh given the uh data from, from this trial in the subgroup of patients with PDL one positive tumors that these results do warrant further study of the combination in uh patients with PDL one positive metastatic hormone receptor positive, her two negative breast cancer.
