Abstract 2526: Exploratory study of predicting systemic therapy response by IGRA in advanced stage NSCLC patients

Abstract Purpose: In this study, we aim to prospectively evaluate how patients’ pretreatment PSIG correlated with chemotherapy, immune checkpoint inhibitors (ICI) and epidermal growth factor receptor (EGFR) Tyrosine Kinasae Inhibior (TKI). Also, to assess the change of PSIG during anti-cancer treatment and the relation with clinical condition. Materials and Methods: Newly diagnosed advanced stage non-small cell lung cancer patients were enrolled. The inclusion criteria included pathology or cytology-proved stage IV and non-operable stage III non-small cell lung cancer, treatment-naïve, and planned to receive chemotherapy, EGFR-TKI therapy. Or, planned to receive any line of singe agent immunotherapy. We planned to enroll 30 patients in each treatment group (chemotherapy, immunotherapy, EGFR TKI therapy) with and additional control group of stage I NSCLC.Blood sample from each enrolled patient was obtained for INF-γ release assay (IGRA) within 3 days before the initiation of systemic therapy and 8-12 weeks after treatment. The IGRA was performed with QuantiFERON-TB In-Tube (QFT-GIT; Qiagen, Germany) according to the manufacture’s instruction. The amount of INF-γ produced in response to PHA is determined by the INF-γ level in the PHA-coated tube minus saline-coated tube, and is termed PHA-stimulated INF-γ (PSIG) level. Patients with PSIG level above 7.06IU were defined had high PSIG level according to our previous study. we also performed our in house INF-γ level by ELISA. Tumor response was assessed mainly by chest CT and brain MRI (if available) according to Response Evaluation Criteria in Solid Tumors (RECST). Results: Total 116 patients were enrolled. Demographic distribution was summarized in Table 1. Thirty-five of 116 (30.2%) patients had latent TB infection, while 12 patients (10.3%) had indeterminate OFT test, all due to low mitogen-stimulated INF-γ level. 84 patients had been obtained post-treatment blood test, and the box-plot of in-house INF-γ level were shown in Figure1. For stage I control group, INF-γ level seemed higher after surgery; for chemotherapy and immunotherapy, the INF-γ level also seemed increase among responders (who achieved disease control after treatment). There were no statistically difference of disease control rate between patients with high PSIG level and low PSIG level. Overall survival also showed no statistically difference between 2 PSIV level patient group among advanced stage NSCLC patients. Conclusions:There were no statistically different of disease control rate in PSIG high and low group. The increased trend of INF-γ level after surgery, immunotherapy and chemotherapy may suggested improving immune function after treatment even in the very early disease stage. Citation Format: Hsu Ching Huang, Chi-Lu Chiang, Yung-Hung Luo, Yuh-Min Chen, Chao-Hua Chiu. Exploratory study of predicting systemic therapy response by IGRA in advanced stage NSCLC patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2526.