First-Line Immunotherapy Combinations in Advanced Renal Cell Carcinoma: A Rapid Review and Meta-Analysis

BACKGROUND: Combination or multi-agent therapy including immune checkpoint inhibitors has shifted the landscape of the treatment of advanced/metastatic renal cell carcinoma. There are several approved immune checkpoint inhibitor (ICI) combinations featuring antibodies against programmed cell death protein 1 (PD-1) receptor or its ligand 1 (PD-L1) combined with other immune checkpoint inhibitors, multi-targeted tyrosine kinase inhibitors (TKIs), or other agents active in renal cell carcinoma. OBJECTIVE: This study aims to compile the evidence of available first-line combination therapies compared to sunitinib monotherapy in advanced renal cell carcinoma. METHODS: A systematic literature search was conducted according to the PRISMA statement to identify all randomized Phase III clinical trial data in previously untreated metastatic renal cell carcinoma featuring an immune checkpoint inhibitor combination compared against sunitinib. A two-stage selection process was utilized to determine eligible studies. Of a total of 124 studies and 94 additional abstracts, 6 studies were considered for final analysis. These studies were evaluated for progression free survival (PFS), overall survival (OS), Grade III or higher adverse events (AEs), objective response rate (ORR), and complete response rate (CRR). RESULTS: 6 studies with 5,121 patients met our search criteria. For OS, ICI combination therapy was favored over sunitinib with an estimated combined hazard ratio of 0.74 (0.67–0.81 95% CI). For PFS, ICI combination therapy was favored over sunitinib with an estimated combined hazard ratio of 0.65 (0.52–0.82, 95% CI). The combination of nivolumab and ipilimumab had the longest duration of response and less incidence of grade III or higher adverse events compared to the combination of anti-PD-1/PD-L1 with TKI. The combination of anti-PD-1/PD-L1 with TKI had higher rates of overall response and longer PFS than the combination of nivolumab/ipilimumab. CONCLUSIONS: This meta-analysis supports the recommendation of immune checkpoint inhibitor combination therapy over sunitinib monotherapy for previously untreated advanced renal cell carcinoma by virtue of improved PFS and OS. The choice of which ICI combination therapy to use may be guided by patient-specific characteristics including IMDC risk status, adverse effect profile, and need for early response.