Multicenter retrospective study of adverse events with neoadjuvant pembrolizumab plus chemotherapy for triple-negative breast cancer

The standard neoadjuvant treatment for early-stage or locally advanced TNBC is pembrolizumab plus chemotherapy, resulting in a pCR rate of 64.8% in KEYNOTE-522. A retrospective study at 7 academic centers in the USA evaluated this regime in the real world. The pCR rate was 52%. AEs were seen in 88%, grade ≥ 3 AEs in 38%, early discontinuation of pembrolizumab due to AEs in 31%, and hospitalization in 26%. The authors conclude that the pCR rate in this study was lower than in KEYNOTE-522, potentially due to high rates of pembrolizumab and chemotherapy discontinuation.