Relationship between tumor infiltrating lymphocytes (TILs) and response to pembrolizumab (pembro)+chemotherapy (CT) as neoadjuvant treatment (NAT) for triple-negative breast cancer (TNBC): Phase Ib KEYNOTE-173 trial
S Loi; P Schmid; G Aktan; V Karantza; R Salgado
Annals of Oncology, Volume 30, Issue Supplement_3, May 2019, mdz095.003, https://doi.org/10.1093/annonc/mdz095.003
Extract
Background: Higher stromal TILs (sTILs) are associated with higher pathologic complete response (pCR) rates with CT in early-stage TNBC. We evaluated the association between sTILs and PD-L1 expression with response to pembro+CT as NAT for TNBC in KEYNOTE-173 (NCT02622074).

Methods: sTILs were quantified pretreatment (PT) and on-treatment (OT; during first 3 weeks of pembro monotherapy). PT PD-L1 expression was reported as combined positive score (CPS). Endpoints were pCR rate (ypT0 ypN0; ypT0/Tis ypN0) and objective response rate (ORR) after the first 4 cycles of NAT (taxane±carboplatin+pembro). Correlation between PD-L1 and sTILs was assessed by Spearman’s rank correlation coefficient.