Ultrasound TVR > 50% at Week 6 Pinpoints 94% of pCRs on Keynote-522 in Early TNBC

In the prospective ARTEMIS study (NCT02276443), 150 patients with stage I–III triple-negative breast cancer received the KN-522 regimen, which includes paclitaxel (a taxane), carboplatin (a platinum-based chemotherapy), and pembrolizumab (a PD-1 inhibitor). Breast ultrasound performed after six weeks showed that each 10% increment in tumor volume reduction (TVR) nearly doubled the odds of achieving a pathologic complete response (pCR). The area under the receiver operating characteristic curve (AUC-ROC) for TVR was 0.74. A TVR threshold of greater than 50% identified pCR with 94% sensitivity, 73% positive predictive value, and 79% negative predictive value. In contrast, clinicopathologic factors lacked predictive power. The overall pCR rate was 63%.