Differences in oncological and toxicity outcomes between programmed cell death-1 and programmed cell death ligand-1 inhibitors in metastatic renal cell carcinoma: A systematic review and meta-analysis.

BACKGROUND

The programmed cell death ligand-1 (PD-L1)/programmed cell death-1 (PD-1) pathway is important in metastatic renal cell carcinoma (mRCC). However, some dissimilarities between anti-PD-1 and anti-PD-L1 inhibitors have emerged. We aimed to assess differences between anti-PD-1 and anti-PD-L1 combination immunotherapies as first-line treatments in mRCC patients.

METHODS

Multiple databases (PubMed, Web of Science, and Scopus) were searched for articles published until March 2021. Studies were eligible if they compared overall survival (OS), progression-free survival (PFS), objective response rates (ORR), complete response rates (CRR), and adverse events.

RESULTS

Five studies met the eligibility criteria. PD-1 combination therapy was associated with significantly better OS and PFS and higher ORR and CRR than sunitinib (hazard ratio [HR]: 0.60, 95% confidence interval [CI]: 0.40-0.89; HR: 0.52, 95% CI: 0.37-0.75; odds ratio [OR]: 3.20, 95% CI: 2.18-4.68; and OR: 3.05, 95% CI: 2.13-4.37, respectively; P < 0.001). For all oncological outcomes, anti-PD-1 agents were superior to anti-PD-L1 agents based on HR and OR (OS: HR = 0.88, PFS: HR = 0.76, ORR: OR = 1.85, and CRR: OR = 2.24). Conversely, anti-PD-L1 agents were superior to anti-PD-1 agents in their safety profiles. In network meta-analyses, pembrolizumab plus lenvatinib seemed the worst tolerated anti-PD-1 combination therapy.

CONCLUSIONS

Our analysis indicates the superior oncologic benefits of first-line anti-PD-1 combination therapies over anti-PD-L1 combination therapies in mRCC patients. This biological difference is of vital importance for clinical treatment decision making and the design of future rational combination therapy trials in mRCC.