2314 - TP53 and ATM Co-mutation Predicts Response to Immune Checkpoint Inhibitors in Non-Small Cell Lung Cancer

Background

Immune checkpoint inhibitors (ICIs) elicits durable responses in non–small cell lung cancer (NSCLC), but only a fraction of patients responded. TP53 and ATM co-mutation may lead to genomic instability and hypermutation. However, the prevalence and utility of a TP53/ATM co-mutation as a biomarker to ICIs are not fully understood.

Methods

This was a multiple cohort pooled study, 2020 NSCLC samples from Geneplus Institute, 1031 samples from TCGA, 1567 samples from MSKCC, 853 samples from POLAR/OAK databases were statically analyzed. Next-generation sequencing assays were performed in the Geneplus Institute. Genomic, transcriptomic and clinical data were obtained from the TCGA, MSKCC, POLAR/OAK databases. Comprehensive profiling was performed to determine the prevalence of TP53/ATM co-mutation and correlation with the prognosis and the response to ICIs.

Results

TP53/ATM co-mutation sites were found to be scattered throughout the genes and we did not observe any significant difference in TP53/ATM co-mutated frequency within the histologic subtypes and driver genes. In five independent NSCLC cohorts, TP53/ATM co-mutation contributed to significantly higher tumor mutation burden (TMB) compared to both the sole mutation and both wild type groups. Furthermore, in the MSKCC-IO cohort, a TP53/ATM co-mutation was associated with better OS than sole mutation and both wild type groups, especially in pan-cancer (P=.241, NSCLC and P<.0001, Pan-cancer). Similar results were shown in the POLAR/OAK cohort, the disease control benefit rate, and progression free survival (PFS) and OS were all greater in patients with the TP53/ATM co-mutation compared with the other three groups. GSEA showed that IFN-α response, IFN-γ response, IL6/JAK/STAT3 signaling, and TNF-α signaling pathways had higher levels of activation and there was greater PD-L1 expression in the co-mutated group, compared with solely mutated and both wild type group.

Conclusions

Our findings suggest that patients with TP53/ATM co-mutation comprise a special subgroup of NSCLC patients and correlate with increasing TMB and responses to ICIs. It may have implications for potential predictive biomarker in guiding ICIs immunotherapy.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

Jian Ji Pan.

Funding

National Natural Science Foundation of China (Grant No. U1705282).

Disclosure

All authors have declared no conflicts of interest.