The KEYNOTE-522 study is a practice-changing phase III randomized study that demonstrated that the addition of pembrolizumab to polychemotherapy improves outcomes in patients with high-risk early-stage triple-negative breast cancer (TNBC). This regimen is highly efficacious with unprecedented pathologic complete response (pCR) rates, and clinically meaningful improvements in event-free survival (EFS). However, the combination is also associated with significant high-grade treatment-related toxicity. The backbone regimen deviated from common practice, including the addition of carboplatin, lack of dose dense anthracyclines, and adjuvant capecitabine for residual disease, thus brining important questions regarding real-world translation of these results. This brief report practically addresses some of the most relevant questions physicians and patients face in optimizing care using the best available evidence.
Submitted April 11, 2022; accepted for publication April 29, 2022.
Disclosures: Dr. Santa-Maria has disclosed receiving grant/research support from AstraZeneca plc, Bristol-Myers Squibb Company, Pfizer Inc., and Tesaro Inc./GlaxoSmithKline plc; and serving on scientific advisory boards for Athenex, Inc., Bristol-Myers Squibb Company, Genomic Health, and Seattle Genetics, Inc. Dr. Stearns has disclosed receiving grant/research support from AbbVie, Biocept, Pfizer, Novartis, and Puma Biotechnology; and serving as a scientific advisor AstraZeneca and Novartis. The remaining authors no financial interests, arrangements, affiliations, or commercial interests with the manufacturers of any products discussed in this article or their competitors.