Association between high TIL levels and pCR in patients receiving neoadjuvant K522 chemoimmunotherapy for early-stage TNBC

Based on results of the phase 3 KEYNOTE-522 study, the standard of care for patients with early-stage triple-negative breast cancer (TNBC)is neoadjuvant K522 chemoimmunotherapy (chemotherapy plus pembrolizumab). A retrospective study at Emory University (Atlanta, GA) evaluated factors predicting pathological complete response (pCR) to neoadjuvant K522 among real-world early-stage TNBC patients. The study found that high tumor infiltrating lymphocytes (TILs) were predictive of pCR in univariate and multivariate analysis. Other variables including age, race, nuclear grade, Nottingham grade, Ki-67, lymphovascular invasion, BMI, pre-treatment tumor size, and lymph node status were not associated with pCR (p>0.1). The authors conclude that among real-world early-stage TNBC patients high TILs levels are significantly associated with pCR rate to K522 and may potentially serve as a biomarker to select optimal treatment.