Abstract
BACKGROUND: Due to the increasing number of trials with immune checkpoint inhibitors (ICIs) in the first-line therapy of non-small cell lung cancer (NSCLC) patients, we performed a systematic review and meta-analyses to investigate the difference between anti PD-1 and PD-L1 antibodies, used alone or in combination with chemotherapy, through adjusted indirect analysis to minimize the potential bias regarding overall survival (OS), progression-free survival (PFS), overall response rate (ORR) and grade 3-5 adverse events (AEs). METHODS: A systematic review of studies reporting clinical outcomes and toxicity associated with first-line therapy employing anti-PD1 or anti-PD-L1 antibodies alone, or in combination with chemotherapy, to treat metastatic, treatment-naïve NSCLC patients was performed. Primary outcomes were OS, PFS, ORR and grade 3-5 AEs. We used a random-effects model to generate pooled estimates for proportions. Meta-analyses using pooled risk ratios were performed for binary outcomes from comparative studies with the random effects model. RESULTS: A total of 13 eligible studies met our eligibility criteria, including 7673 patients. In the ICI-chemotherapy combination subgroup, we observed that anti-PD1 therapy was associated with better OS (p = 0.022) and PFS (p = 0.029) compared with anti-PD-L1 therapy. In the monotherapy subgroup, there was no statistical difference between the use of anti-PD-1 and anti-PD-L1 for OS and PFS. With regard to ORR and toxicity, in the ICI-chemotherapy combination subgroup, we observed a trend of better ORR (p = 0.12) with the use of anti-PD1 therapy and less frequent grade 3-5 AEs compared to the use of anti-PD-L1 therapy (p = 0.0302). In the monotherapy subgroup, there was no statistical difference between the use of anti-PD-1 and anti-PD-L1 regarding ORR and toxicity. CONCLUSIONS: Our study suggests that PD-1 drug plus chemotherapy is superior to anti-PD-L1 plus chemotherapy for NSCLC; nevertheless, as monotherapy, both strategies appear to be similar.