# Comparison of Effectiveness of Programmed Death Protein 1 and Programmed Death Ligand 1 Inhibitors in Extensive-Stage Small-Cell Lung Cancer: A Meta-Analysis of Randomized Controlled Trials and Observational Studies

## TL;DR

This study compares PD-1 and PD-L1 inhibitors in treating advanced small-cell lung cancer and finds both are more effective than chemotherapy alone, but no significant difference between them.

## Contribution

The study provides a meta-analysis comparing PD-1 and PD-L1 inhibitors in extensive-stage small-cell lung cancer, highlighting the lack of head-to-head trials.

## Key findings

- PD-1 and PD-L1 inhibitors improve overall and progression-free survival compared to chemotherapy alone.
- No significant difference in efficacy was found between PD-1 and PD-L1 inhibitors.
- Head-to-head trials comparing these inhibitors are currently lacking.

## Abstract

This meta-analysis aimed to compare the efficacy of programmed death protein 1 (PD-1) inhibitors and programmed death ligand 1 (PD-L1) inhibitors in patients with extensive-stage small-cell lung cancer. The present meta-analysis was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Relevant studies were identified through searches of databases including PubMed, Embase, and the Cochrane Library, as well as prominent oncology conferences. The search was conducted from the inception of the databases up to January 31, 2024. A total of 10 studies were included in this meta-analysis. Among these studies, six were randomized trials, while four were observational studies. The pooled meta-analysis showed that PD-1 and PD-L1 inhibitors are more effective in improving overall survival and progression-free survival compared to chemotherapy alone. However, when comparing PD-1 and PD-L1 inhibitors, there was no significant difference between the two groups regarding overall survival and progression-free survival. It is important to note that there is no head-to-head trial comparing these two interventions in patients with extensive-stage small-cell lung cancer. Therefore, future prospective trials are needed to define optimal therapeutic approaches in this patient population.