Efficacy and predictive biomarkers of immunotherapy in Epstein-Barr virus-associated gastric cancer

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BACKGROUND: Epstein-Barr virus (EBV)-associated gastric cancer (GC) (EBVaGC) is a distinct molecular subtype of GC with a favorable prognosis. However, the exact effects and potential mechanisms of EBV infection on immune checkpoint blockade (ICB) efficacy in GC remain to be clarified. Additionally, EBV-encoded RNA (EBER) in situ hybridization (ISH), the traditional method to detect EBV, could cause false-positive/false-negative results and not allow for characterizing other molecular biomarkers recommended by standard treatment guidelines for GC. Herein, we sought to investigate the efficacy and potential biomarkers of ICB in EBVaGC identified by next-generation sequencing (NGS).

DESIGN: An NGS-based algorithm for detecting EBV was established and validated using two independent GC cohorts (124 in the training cohort and 76 in the validation cohort). The value of EBV infection for predicting ICB efficacy was evaluated among 95 patients with advanced or metastatic GC receiving ICB. The molecular predictive biomarkers for ICB efficacy were identified to improve the prediction accuracy of ICB efficacy in 22 patients with EBVaGC.

RESULTS: Compared with orthogonal assay (EBER-ISH) results, the NGS-based algorithm achieved high performance with a sensitivity of 95.7% (22/23) and a specificity of 100% (53/53). EBV status was identified as an independent predictive factor for overall survival and progression-free survival in patients with DNA mismatch repair proficient (pMMR) GC following ICB. Moreover, the patients with EBV+/pMMR and EBV-/MMR deficient (dMMR) had comparable and favorable survival following ICB. Twenty-two patients with EBV+/pMMR achieved an objective response rate of 54.5% (12/22) on immunotherapy. Patients with EBVaGC with a high cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) level were less responsive to anti-programmed death-1/ligand 1 (PD-1/L1) monotherapy, and the combination of anti-CTLA-4 plus anti-PD-1/L1 checkpoint blockade benefited patients with EBVaGC more than anti-PD-1/L1 monotherapy with a trend close to significance (p=0.074). There were nearly significant differences in tumor mutational burden (TMB) level and SMARCA4 mutation frequency between the ICB response and non-response group.

CONCLUSIONS: We developed an efficient NGS-based EBV detection strategy, and this strategy-identified EBV infection was as effective as dMMR in predicting ICB efficacy in GC. Additionally, we identified CTLA-4, TMB, and SMARCA4 mutation as potential predictive biomarkers of ICB efficacy in EBVaGC, which might better inform ICB treatment for EBVaGC.

Medienart:

E-Artikel

Erscheinungsjahr:

2022

Erschienen:

2022

Enthalten in:

Zur Gesamtaufnahme - volume:10

Enthalten in:

Journal for immunotherapy of cancer - 10(2022), 3 vom: 20. März

Sprache:

Englisch

Beteiligte Personen:

Bai, Yuezong [VerfasserIn]
Xie, Tong [VerfasserIn]
Wang, Zhenghang [VerfasserIn]
Tong, Shuang [VerfasserIn]
Zhao, Xiaochen [VerfasserIn]
Zhao, Feilong [VerfasserIn]
Cai, Jinping [VerfasserIn]
Wei, Xiaofan [VerfasserIn]
Peng, Zhi [VerfasserIn]
Shen, Lin [VerfasserIn]

Links:

Volltext

Themen:

Biomarkers, Tumor
CTLA-4 Antigen
DNA Helicases
EC 3.6.1.-
EC 3.6.4.-
Gastrointestinal neoplasms
Immune Checkpoint Inhibitors
Immunotherapy
Journal Article
Nuclear Proteins
Research Support, Non-U.S. Gov't
SMARCA4 protein, human
Transcription Factors

Anmerkungen:

Date Completed 10.05.2022

Date Revised 10.05.2022

published: Print

Citation Status MEDLINE

doi:

10.1136/jitc-2021-004080

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM337727015