Abstract 5100: Analysis of genetic alterations related to hyper-progressive disease after immunotherapy in patients with non-small cell lung cancer

Abstract

Abstract Background Hyper-progressive disease (HPD) is an unexpected response pattern observed in immune checkpoint therapy, such patients experience a very rapid disease progression (usually progressed seriously in three months). Predictors of HPD are one of the keys to the management of patients receiving immune checkpoint inhibitors. Some factors, such as MDM2/4 amplification, EGFR mutations and old age may be risk factors for HPD, but the results of different studies are inconsistent. Herein, we evaluated the characteristics of MDM2/4 alterations in Chinese patients with NSCLC. Methods The formalin-fixed paraffin-embedded specimens of cancer patients who have underwent next-generation sequencing (NGS) in 3D Medicines, a laboratory accredited by CAP and Clinical Laboratory Improvement Amendments (CLIA) from May 2017 to May 2020, were included in this study. NGS was performed to detect gene mutation, and tumor mutational burden (TMB) measured by a 733 gene panel. PD-L1 expression detected by using Dako PD-L1 IHC 22C3 pharmDx. Results The proportion of MDM2/4 amplification in Chinese NSCLC patients is 0.86%, the proportion of MDM2 and MDM4 amplification in Chinese NSCLC patients were 0.74% and 0.12%. respectively. Further analysis found lower TMB level in patients with MDM2/4 amplification than patients without MDM2/4 amplification (p<0.001). The median TMB level was also found lower in patients with MDM2/4 amplification than without, and higher ratio of patients with TMB-high (defined as TMB≥10mutant/Mb) was displayed in group with MDM2/4 amplification. Conversely, patients with TMB-high showed lower copy number gain in MDM2/4. However, no difference was found in level of PD-L1 expression between patients with and without MDM2/4 amplification. Conclusion HPD happened during ICI treatment in solid tumor with MDM2/4 amplification may associated with lower TMB level, and PD-L1 expression level has limit effect on MDM2/4 alteration related HPD. Citation Format: Xudong Xiang, Hushan Zhang, Deguang Wang, Heng Li, Qing Lei, Qianli Ma. Analysis of genetic alterations related to hyper-progressive disease after immunotherapy in patients with non-small cell lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5100.