Abstract 7099: Prognostic value of serum proteomic signature in NSCLC patients on immune checkpoint inhibitors: Impact of treatment regimen and PD-L1 levels
Authors: Kim Leeseul , Um Taegyu , Chae Young Kwang , Cho Allen 
Published: March 2024

Background: The VeriStrat test, a blood-based proteomic test utilizing MALDI-ToF mass spectrometry, employs machine learning for prognostic assessment in non-small-cell lung cancer (NSCLC) across various stages, histologies, and treatments. Recently, its prognostic utility has extended to patients undergoing immune checkpoint inhibitor (ICI) treatment. Yet, the influence of treatment regimen and PD-L1 levels on its prognostic power remains less explored.

Methods: In this retrospective study, 174 NSCLC patients receiving ICI monotherapy (ICI mono) or combination with chemotherapy (combination) underwent VeriStrat testing from 2016 to 2023. Blood sample spectra categorized patients into VeriStrat 'Good' (VS-G) or VeriStrat 'Poor' (VS-P) groups. Overall survival (OS) and progression-free survival (PFS) were calculated using the log-rank test for the first ICI-containing regimen post-serum sample draw.

Results: Among 174 patients, 97 received combination therapy, and 77 received ICI alone. Within the 99 patients with PD-L1 levels &lt;50%, 38 patients received IO monotherapy (23 pts for standard of care, 5 pts for poor candidacy for chemotherapy, 5 pts for clinical trial, 3 pts for patient refusal, and 2 pts for physician discretion). Survival analysis results are presented in Table 1.

Survival analysis by treatment regimen and PD-L1 level Hazard Ratio VS-G/VS-P 95% CI p-value ipilimumab+nivolumab PFS 0.57 0.04-7.89 0.52 Total n=22 VS-G n=19 VS-P n=3 OS 0.33 0.03-3.47 0.11 pembrolizumab PFS 0.90 0.19-4.31 0.88 Total n=25 VS-G n=20 VS-P n=5 OS 0.33 0.08-1.43 0.01* carboplatin+pemetrexed+pembrolizumab PFS 0.45 0.17-1.19 0.02* Total n=41 VS-G n=30 VS-P n=11 OS 0.61 0.22-1.68 0.27 PD-L1&gt;=50 PFS 0.93 0.34-2.54 0.89 Total n=39 VS-G n=29 VS-P n=10 OS 0.45 0.17-1.20 0.18 PD-L1&lt;50 PFS 0.60 0.22-1.11 0.09 Total n= 99 VS-G n=79 VS-P n=20 OS 0.47 0.21-1.04 0.01* PD-L1&gt;=50 + ICI mono PFS 0.55 0.12-2.65 0.69 Total n=23 VS-G n=18 VS-P n=5 OS 1.25 0.32-4.96 0.75 PD-L1&lt;50 + ICI mono PFS 0.77 1.15-3,91 0.70 Total n=37 VS-G n=30 VS-P n=7 OS 0.24 0.51-1.10 0.0004* Hazard Ratio combination/ICI mono 95% CI p-value PD-L1&lt;50 +VS-G OS 0.70 0.36-1.33 0.24 Total n=76 ICI mono n=30 Combination n=46 PD-L1&lt;50 +VS-P OS 0.45 0.14-1.44 0.006* Total n=20 ICI mono n=7 Combination n=13 Hazard Ratio ICI mono/combination 95% CI p-value PD-L1&gt;=50 +VS-G OS 2.18 0.69-6.90 0.27 Total n=29 ICI mono n=22 Combination n=7 PD-L1&gt;=50 +VS-P OS NA NA 0.21 Total n=10 ICI mono n=3 Combination n=7

Conclusions: Our findings suggest that the prognostic value of the VeriStrat test may vary based on the treatment regimen. In clinical scenarios utilizing ICI monotherapy for patients with PD-L1 levels &lt;50%, the role of VeriStrat seems more significant. A prospective study with a larger sample size for validation is warranted.

Citation Format: Leeseul Kim, Taegyu Um, Young Kwang Chae, Allen Cho. Prognostic value of serum proteomic signature in NSCLC patients on immune checkpoint inhibitors: Impact of treatment regimen and PD-L1 levels [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 7099.