Abstract | BACKGROUND: METHODS: Samples from 614 patients (68.1% of intention-to-treat population) were centrally evaluated by immunohistochemistry for PD-L1 status on IC (VENTANA SP142, SP263, Dako 22C3) or as a combined positive score (CPS; 22C3). RESULTS: Using SP142, SP263, and 22C3 assays, PD-L1 IC ≥1% prevalence was 46.4% (95% confidence interval [CI] = 42.5% to 50.4%), 74.9% (95% CI = 71.5% to 78.3%), and 73.1% (95% CI = 69.6% to 76.6%), respectively; 80.9% were 22C3 CPS ≥1. At IC ≥1% (+), the analytical concordance between SP142 and SP263 and 22C3 was 69.2% and 68.7%, respectively. Almost all SP142+ cases were captured by other assays (double positive), but several SP263+ (29.6%) or 22C3+ (29.0%) cases were SP142- (single positive). A+nP clinical activity vs placebo+nP in SP263+ and 22C3+ patients (progression-free survival [PFS] hazard ratios [HRs] = 0.64 to 0.68; overall survival [OS] HRs = 0.75 to 0.79) was driven by double-positive cases (PFS HRs = 0.60 to 0.61; OS HRs = 0.71 to 0.75) rather than single-positive cases (PFS HRs = 0.68 to 0.81; OS HRs = 0.87 to 0.95). Concordance for harmonized cutoffs for SP263 (IC ≥4%) and 22C3 (CPS ≥10) to SP142 (IC ≥1%) was subpar (approximately 75%). CONCLUSIONS: 22C3 and SP263 assays identified more patients as PD-L1+ (IC ≥1%) than SP142. No inter-assay analytical equivalency was observed. Consistent improved A+nP efficacy was captured by the SP142 PD-L1 IC ≥1% subgroup nested within 22C3 and SP263 PD-L1+ (IC ≥1%) populations.
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Authors | Hope S Rugo, Sherene Loi, Sylvia Adams, Peter Schmid, Andreas Schneeweiss, Carlos H Barrios, Hiroji Iwata, Véronique Diéras, Eric P Winer, Mark M Kockx, Dieter Peeters, Stephen Y Chui, Jennifer C Lin, Anh Nguyen-Duc, Giuseppe Viale, Luciana Molinero, Leisha A Emens |
Journal | Journal of the National Cancer Institute
(J Natl Cancer Inst)
Vol. 113
Issue 12
Pg. 1733-1743
(11 29 2021)
ISSN: 1460-2105 [Electronic] United States |
PMID | 34097070
(Publication Type: Clinical Trial, Phase III, Journal Article, Research Support, Non-U.S. Gov't)
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Copyright | © The Author(s) 2021. Published by Oxford University Press. |
Chemical References |
- 130-nm albumin-bound paclitaxel
- atezolizumab
- B7-H1 Antigen
- Biomarkers, Tumor
- CD274 protein, human
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Topics |
- Humans
- B7-H1 Antigen
- Biomarkers, Tumor
- Immunohistochemistry
- Triple Negative Breast Neoplasms
(drug therapy)
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