A new retrospective analysis reveals that adding chemotherapy to PD-1 inhibitor therapy does not improve outcomes for advanced non-small-cell lung cancer (NSCLC) patients in second-line and subsequent treatment settings.
The study, conducted between April 2017 and October 2019, evaluated 84 patients with advanced NSCLC who received either PD-1/PD-L1 inhibitor monotherapy (n=26) or PD-1 inhibitor plus chemotherapy (n=58) as second-line or later treatment.
Treatment Outcomes and Survival Analysis
The research team found no significant differences in disease control rates (DCRs) and overall survival (OS) between the two treatment approaches. However, the PD-1/PD-L1 inhibitor monotherapy group demonstrated superior progression-free survival (PFS), with the median PFS not reached compared to 4.4 months in the combination therapy group (p=0.02).
In the chemotherapy combination arm, various agents were utilized, including liposome paclitaxel (n=15), nab-paclitaxel (n=12), docetaxel (n=9), pemetrexed (n=6), and other chemotherapy regimens (n=16).
Subgroup Analysis and Prognostic Factors
The study identified key prognostic indicators through univariate and multivariate analyses. The derived neutrophils-to-lymphocyte ratio (dNLR) emerged as an independent prognostic factor for overall survival, while gender was found to be an independent prognostic factor for progression-free survival.
A detailed subgroup analysis of 38 second-line therapy patients showed no significant differences in OS and PFS between the two treatment approaches. However, in patients receiving treatment beyond second line (n=46), the monotherapy group demonstrated significantly longer PFS (median PFS: not reached vs. 4.0 months, p=0.01).
Safety and Adverse Events
The safety profiles were comparable between both groups, with no significant difference in the incidence of adverse events of any grade. However, one patient in the combination therapy group experienced a fatal outcome due to immune-related pneumonitis, highlighting the importance of careful monitoring for immune-related adverse events.
These findings suggest that the addition of chemotherapy to PD-1 inhibitor therapy may not provide additional benefits in the second-line or later treatment setting for advanced NSCLC patients, while potentially introducing additional toxicity risks.
