Comparison of SP263 and 22C3 immunohistochemistry PD-L1 assays for clinical efficacy of adjuvant atezolizumab in non-small cell lung cancer: results from the randomized phase III IMpower010 trial

• DOI: 10.1136/jitc-2023-007047
• Publication Date: 2023-10-30T17:38:20Z
• Authors: Caicun Zhou; Minu K Srivastava; Hao Xu; Enriqueta Felip; Heather Wakelee; Nasser Altorki; Martin Reck; Rüdiger Liersch; Anna Kryzhanivska; Satoshi Oizumi; Hiroshi Tanaka; John Hamm; Steven L McCune; Elizabeth Bennett; Barbara Gitlitz; Virginia McNally; Marcus Ballinger; Mark McCleland; Wei Zou; Meghna Das Thakur; Silvia Novello
• Keywords: Atezolizumab; Concordance

Background Tumor samples from the phase III IMpower010 study were used to compare two programmed death-ligand 1 (PD-L1) immunohistochemistry assays (VENTANA SP263 and Dako 22C3) for identification of PD-L1 patient subgroups (negative, positive, low, high expression) their predictive value adjuvant atezolizumab compared with best supportive care (BSC) in resectable early-stage non-small cell lung cancer (NSCLC). Methods expression was assessed by assay, which measured percentage tumor cells any membranous staining, 22C3 scored viable showing partial or complete staining. Results When examining concordance at PD-L1-positive threshold (SP263: (TC)≥1%; 22C3: proportion score (TPS)≥1%), results concordant between 83% samples. Similarly, PD-L1–high cut-off TC≥50%; TPS≥50%), 92% The disease-free survival benefit over BSC comparable (TC≥1% SP263: HR, 0.58 (95% CI: 0.40 0.85) vs TPS≥1% 0.65 0.45 0.95)) PD-L1-high (TC≥50% 0.27 0.14 0.53) TPS≥50% 0.31 0.16 0.60)) subgroups. Conclusions showed a clinical validated thresholds, suggesting that both can identify patients NSCLC most likely experience atezolizumab. Trial registration number NCT02486718 .