Adjuvant immunotherapy for renal cell cancer: a review of the literature

Study objective: to summarize the available data on recurrence-free survival (RFS) with the use of immune checkpoint inhibitors (ICIs) in patients with renal cell cancer (RCC) in adjuvant mode and assess the overall safety profile of ICI use in this category of patients. Materials and Methods. Using PubMed, Embase, and conference proceedings, publications of randomized controlled phase III trials comparing immune checkpoint inhibitors (ICTs) with placebo/supervised therapy in adjuvant renal cell cancer were selected. The primary outcome of interest was RFS. Secondary outcomes included adverse events of ≥3 severity (AEs), including those related to immunity, and treatment discontinuation due to AEs. The results were compared with those of a published meta-analysis. Results. Among the four studies analyzed, one showed a statistically significant advantage in RFS. There was pronounced clinical and statistical heterogeneity, related both to clinical differences in terms of inclusion criteria, cohort composition, and therapeutic intervention, as well as to statistical considerations. The pooled results of the four studies did not demonstrate a significant benefit with respect to RFS overall (hazard ratio [HR] 0.85; 95% confidence interval [CI] 0.69-1.04), but there was an increase in RFS with adjuvant immunotherapy among patients with PD-L1 positive expression (HR 0.72; 95% CI 0.55-0.94) and sarcomatoid-like features (HR 0.59; 95% CI 0.38-0.91). Conclusion. To date, the evidence base for immune checkpoint inhibitors as adjuvant therapy for PCP is mixed, as conclusions are limited by the considerable heterogeneity of studies. However, the results of the analysis suggest that patients with PD-L1 positive expression or sarcomatoid differentiation are more likely to benefit from adjuvant immunotherapy