Cheung CCL, Seah YHJ, Fang J, Orpilla NHC, Lau MC, Lim CJ, Lim X, Lee JNLW, Lim JCT, Lim S, Cheng Q, Toh HC, Choo SP, Lee SY, Lee JJX, Liu J, Lim TKH, Tai D, and Yeong J
Introduction: Immune checkpoint blockade (ICB) is a systemic therapeutic option for advanced hepatocellular carcinoma (HCC). However, low patient response rates necessitate the development of robust predictive biomarkers that identify individuals who will benefit from ICB. A 4-gene inflammatory signature, comprising CD8 , PD-L1 , LAG-3 , and STAT1 , was recently shown to be associated with a better overall response to ICB in various cancer types. Here, we examined whether tissue protein expression of CD8, PD-L1, LAG-3, and STAT1 predicts response to ICB in HCC., Methods: HCC samples from 191 Asian patients, comprising resection specimens from 124 patients (ICB-naïve) and pre-treatment specimens from 67 advanced HCC patients treated with ICB (ICB-treated), were analyzed for CD8, PD-L1, LAG-3, and STAT1 tissue expression using multiplex immunohistochemistry followed by statistical and survival analyses., Results: Immunohistochemical and survival analyses of ICB-naïve samples showed that high LAG-3 expression was associated with shorter median progression-free survival (mPFS) and overall survival (mOS). Analysis of ICB-treated samples revealed that high proportions of LAG-3 + and LAG-3 + CD8 + cells pre-treatment were most closely associated with longer mPFS and mOS. Using a log-likelihood model, adding the total LAG-3 + cell proportion to the total CD8 + cell proportion significantly increased the predictive values for mPFS and mOS, compared with the total CD8 + cell proportion alone. Moreover, levels of CD8 and STAT1, but not PD-L1, were significantly correlated with better responses to ICB. After analyzing viral-related and non-viral HCC samples separately, only the LAG3 + CD8 + cell proportion was significantly associated with responses to ICB regardless of viral status., Conclusion: Immunohistochemical scoring of pre-treatment levels of LAG-3 and CD8 in the tumor microenvironment may help predict ICB benefits in HCC patients. Furthermore, immunohistochemistry-based techniques offer the advantage of being readily translatable in the clinical setting., Competing Interests: DT is in the advisory board in Novartis, Celgene, Sirtex, MSD, BMS, Eisai, Ipsen, and Bayer; and as research support in Novartis, Sirtex, and BMS. JJL received research funding from Bayer, has participated in the advisory boards for Eisai, Ipsen, and Bayer, and Taiho; and received honorarium from Ipsen and BMS. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be constructed as a potential conflict of interest., (Copyright © 2023 Cheung, Seah, Fang, Orpilla, Lau, Lim, Lim, Lee, Lim, Lim, Cheng, Toh, Choo, Lee, Lee, Liu, Lim, Tai and Yeong.)