Management of Metastatic Renal Cell Carcinoma Following First-Line Immune Checkpoint Therapy Failure: A Systematic Review.

There is a significant gap in the literature concerning the effective management of second-line therapy for patients with metastatic renal cell carcinoma (RCC) who have received immune checkpoint inhibitors (ICIs). Most of the published articles were small multicenter series or phase 2 studies. To our knowledge, a systematic review that comprehensively outlines the range of treatment options available for patients with metastatic RCC who do not respond to first-line ICIs has not yet been conducted. Our aim was to synthesize evidence on second-line therapies for patients with metastatic RCC after initial treatment with ICIs and to offer recommendations on the best treatment regimens based on the current literature. We conducted a search in PubMed, Embase, and the Cochrane Library on 29 February 2024, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We selected articles that met the predetermined inclusion criteria (written in English, retrospective observational studies, prospective series, and randomized trials reporting second-line therapy for metastatic RCC after failure of ICI-based therapy). Relevant articles were identified in the reference lists. The main endpoint was the overall response rate (ORR), with the median progression-free survival (PFS) and overall survival (OS) as secondary endpoints. We included 27 studies reporting the outcomes of 1970 patients. Salvage therapies were classified as targeted therapy (VEGFR TKIs) in 18 studies and ICIs in 8 studies. In studies where TKIs were the second line of choice, the pooled ORR was 34% (95% CI: 30.2-38%). In studies where ICIs, alone or in combination with TKIs, were used as second-line therapies, the ORR was 25.7% (95% CI: 15.7-39.2%). In studies where TKIs and ICIs were the second-line choices, the pooled median PFS values were 11.4 months (95% CI: 9.5-13.6 months) and 9.8 months (95% CI: 7.5-12.7 months), respectively. This systematic review shows that VEGFR TKIs and ICIs are effective second-line therapies following an initial treatment with anti-PD(L)1 alone or in combination. The treatment choice should be personalized, taking into account the patient's response to first-line ICIs, the site of the disease, the type of first-line combination (with or without VEGFR TKIs), and the patient's overall condition.