The Emerging Role of Combination Angiogenesis Inhibitors and Immune Checkpoint Inhibitors in the Treatment of Metastatic Renal Cell Cancer

Abstract

The advent of vascular endothelial growth factor (VEGF) tyrosine kinase inhibitors (TKIs) a decade ago revolutionized the treatment paradigm in advanced metastatic clear cell renal cell carcinoma (RCC) with improved survival rates compared to the pre-TKI era. Monotherapy with VEGF TKIs has remained first-line. However, sequencing of different TKIs, mammalian target of rapamycin (mTOR) inhibitors, or immune checkpoint inhibitors (ICIs) has been the subject of controversy in the treatment landscape of metastatic RCC. First-line treatment further evolved with the approval of nivolumab plus ipilimumab in intermediateand poor-risk patients based on an overall survival (OS) benefit demonstrated in the CheckMate214 trial as well as a progression-free survival (PFS) benefit of cabozantinib in the CABOSUN trial. Optimal sequencing, patient selection, and understanding resistance pathways continue to be prominent concerns. Efforts to bypass resistance mechanisms have led to the study of combination therapies. Given enhancement of immune checkpoint inhibitor (ICI) T-cell mediated effects by VEGF-mediated immunosuppression, the combination of VEGF inhibitors and ICIs in treatment-naı̈ve locally advanced and metastatic RCC has shown promise. Available results of phase III trials utilizing these combinations are discussed herein.