Reliable biomarkers in renal cell carcinoma (RCC) remain elusive. While several markers have been shown to be associated with prognosis, and may aid in risk assessment, predictive biomarkers of response to immune checkpoint inhibitors (ICIs) have not been established. Previous studies have shown that a high pretreatment neutrophil-lymphocyte ratio (NLR) is a negative prognostic factor in RCC. However, a clinically useful cut-off for the predictive and prognostic value of NLR has not been well defined. We conducted a retrospective analysis of 132 patients with previously untreated metastatic clear cell RCC (ccRCC) who received first line ICI-based therapy. ICI-based therapy included anti-PD-1/PD-L1 alone or in combination with anti-CTLA-4 or VEGF-TKI. Platelet, haemoglobin, neutrophil and lymphocyte counts were collected prior to treatment and at 12-weeks after treatment initiation. Radiologic response at 12-weeks and overall survival (OS) data was also collected. Low haemoglobin, high platelet count, and NLR ≥3 were statistically significant negative predictive biomarkers when assessed at 12-weeks, but not at baseline. Median OS was shorter in patients with low haemoglobin (20.3 months vs. 51.6 months, P = .009), high platelet count (14.3 months vs. 43.8 months, P = .003), and NLR ≥ 3 (17.5 months vs. 40.3 months, P < .001) at 12-weeks. In an IMDC-risk adjusted analysis, only NLR ≥3 at 12-weeks remained statistically significant (OR of 2.11, P = .003) A dynamic change towards lower absolute NLR overtime was associated with longer OS. In patients who had baseline NLR ≥ 3, those who achieved NLR < 3 at 12-weeks demonstrated significant longer median OS compared to those whose NLR remained persistently ≥ 3 (40.3 months vs. 14.7 months, P = .004). NLR ≥3, low haemoglobin and elevated platelet count after 12-weeks of ICI-based first line therapy were negatively prognostic and predictive in patients with metastatic RCC. Normalization of NLR in patients with baseline elevation was associated with longer median OS and response to therapy. These results suggest that monitoring of routine haematologic biomarkers during therapy may provide important predictive and prognostic information, beyond what is available with baseline risk assessment scoring systems.

Background/Objectives: Most patients with metastatic renal cell carcinoma (mRCC) progress on first-line immune checkpoint inhibitor (ICI). Subsequent vascular endothelial growth factor (VEGF) tyrosine kinase inhibitor (TKI) is standard. Due to the rapid evolution in treatment landscape, data directly comparing outcomes of VEGF-TKI following ICI versus VEGF-TKI alone are limited. This scoping review aimed to explore whether VEGF-TKI following prior ICI is associated with improved outcome, potentially reflecting a treatment sequence effect. Methods: PubMed/MEDLINE and ClinicalTrials.gov were searched systematically to identify phase 2/3 prospective clinical trials that investigated VEGF-TKI in patients who had progressed after ≥1 therapy published from 2004. Included studies were summarised by prior therapy and reported outcomes. Data from subgroups/arms were extracted and weighted overall response rate (ORR), progression free survival (PFS) and overall survival (OS) calculated for patients pretreated with VEGF-TKI versus ICI. An exploratory, hypothesis generating analysis was performed comparing outcomes between patients who received prior VEGF-TKI only or ICI-based therapy. Results: In total, 17 clinical trials were included: 2538 patients had prior VEGF-TKI (15 subgroups/arms) and 724 prior ICI-based therapy (11 subgroups/arms). In prior VEGF-TKI, weighted mORR was 8% (IQR 6–16%) versus 28% (IQR 20–41%) post-ICI. Weighted mPFS was 3.9 m (IQR 3.6–5.4) with prior VEGF-TKI versus 8.3 m (IQR 7.4–10.3) in prior ICI group. Weighted mOS was 15.2 m (IQR 11.1–16.6) versus 22.1 m (IQR 10.9–22.1) with prior ICI. Conclusions: Improved outcomes in ICI pretreated population in this exploratory analysis suggests ongoing biological benefit of ICI therapy. As prospective 2L randomised studies are not feasible, we conclude that VEGF therapy in pretreated mRCC is at least as good, if not better, since the introduction of 1st line ICI.