2024 Asia Conference on Lung Cancer (ACLC) - Poster & ePosters-PP01.58

PP01.58 - Mansi Sharma

Pdf Summary

This study explores the use of circulating tumor DNA (ctDNA) as a predictive biomarker for treatment response in advanced non-small cell lung cancer (NSCLC) patients treated with nivolumab, an immune checkpoint inhibitor. Conducted at a single center in India, the study included 44 NSCLC patients who received second-line treatment with nivolumab and underwent PET-CT scans every six cycles. Researchers collected peripheral blood samples from patients at baseline and after four therapy cycles, measuring ctDNA using the qubit dsDNA HS assay and next-generation sequencing via the Oncomine Pancancer Assay.<br /><br />The study identified prevalent genetic alterations, notably TP53 (detected in 82% of patients), as well as KRAS and PTEN among others. A molecular response—defined by a 50% change in ctDNA variant allele frequency (VAF)—was observed in patients with partial response (PR), stable disease (SD), and two patients with progressive disease (PD).<br /><br />Notably, patients exhibiting a 50% ctDNA response experienced a median progression-free survival (PFS) of 5.8 months, compared to 3.9 months for non-responders, although this difference was not statistically significant (p=0.06). Baseline ctDNA concentrations were predictive of PFS, where patients with baseline ctDNA levels below 0.3 ng/µL had better outcomes.<br /><br />In terms of overall survival (OS), responders had a median OS of 13.3 months, significantly higher than the 4 months observed in non-responders. The study suggests that ctDNA monitoring could serve as an early predictor of treatment response, offering advantages over traditional radiologic evaluations.<br /><br />These findings underscore the potential of liquid biopsy technologies for guiding treatment decisions and improving prognostic accuracy in NSCLC patients undergoing immunotherapy. Correspondence can be directed to Ullas Batra at ullasbatra@gmail.com.

Keywords

circulating tumor DNA

ctDNA

non-small cell lung cancer

NSCLC

nivolumab

immune checkpoint inhibitor

progression-free survival

overall survival

liquid biopsy

treatment response