Baseline Characteristics
The baseline clinical characteristics of the enrolled patients are summarized in Table 1. The median age was 64 years, with males comprising the majority (76%). Approximately 82% of the patients had undergone nephrectomy, though nearly half presented with primary metastatic disease, requiring systemic treatment after a median of 3.3 months from initial diagnosis. Following IMDC stratification, 72.2% of the patients were classified in the intermediate-risk group. The most common sites of distant metastases were the lungs, followed by non-regional lymph nodes and bones.
Blood biomarkers and their change during treatment
Based on the ROC curve analysis (see Supplementary Materials, Tables 1S, 2S, and 3S for detailed analysis), the cut-off values were determined as follows: 2.44 for NLR, 181 for PLR, and 2.83 for LMR. At the initiation of treatment, 56.5% (n=65) of patients had elevated NLR levels, 46.1% (n=53) had elevated PLR, 48.7% (n=56) had elevated LMR, and 9.6% (n=11) had elevated eosinophil and monocyte counts. The medians, interquartile ranges (IQR), and distributions of these biomarkers are presented in Table 2.
After three months of treatment, significant increases were observed in eosinophil and monocyte levels, while PLR levels decreased. Before PD, a substantial increase in NLR and a decrease in LMR were noted. These trends are visualized through box plots, which can be found in the Supplementary Materials (Figure 4S).
Treatment efficacy according to blood biomarkers
During a median follow-up of 11.8 months (IQR: 5.1-19.8), patients received a median of 7 cycles of the NIVO+IPI regimen (IQR: 4-14), over a median treatment duration of 6.5 months (IQR: 2.5-12 months). The best overall response according to CT scans indicated CR or partial response (PR) in 40% of patients (n=46), stable disease (SD) in 34.8% (n=40), and PD in 25.2% (n=29), leading to a DCR of 76.5% (n=88) and an ORR of 42.6% (n=49). The median PFS was 12.8 months (95% CI: 5.7-28.1), while the median OS reached 27.3 months (95% CI: 16-not reached).
Patients who experienced a ≥25% increase in NLR had a significantly shorter median PFS compared to those with an NLR increase of <25% (8.2 months, IQR: 3.1-24.7 vs. 17.5 months, IQR: 8.6-28.1, p=0.015, Figure 1A). A similar trend was observed for patients with a ≥25% increase in PLR (6.8 months, IQR: 2.8-8.3 vs. 17.4 months, IQR: 8.4-28.1, p<0.001, Figure 1B).
In a linear regression analysis, the values of NLR and PLR after three months were significantly correlated with PFS (β = -0.2, p=0.02 for NLR; β = -0.2, p=0.04 for PLR), indicating that an increase in these biomarkers was associated with shorter PFS (Figure 1C and 1D). No significant relationship was observed for other laboratory parameters (details provided in the Supplementary Materials, Figure 5S).
Factors Influencing Survival
In the univariate Cox regression analysis, age > 65 years was associated with a significantly lower risk of PD (HR = 0.5, 95% CI: 0.3-0.8, p = 0.01), while elevated PLR ³ 181 (Figure 2D), assessed 3 months after initiating NIVO+IPI, was linked to a higher risk of PD (HR = 2.4, 95% CI: 1.3-4.5, p = 0.008). In multivariate analysis, both factors remained significant: age > 65 years showed an even stronger protective effect on PFS (HR = 0.3, 95% CI: 0.2-0.7, p = 0.002), and PLR 2 further increased the risk of progression (HR = 2.9, 95% CI: 1.5-5.6, p = 0.001). These findings suggest that both advanced age and elevated PLR after 3 months are independent predictors of PFS in this cohort.
For OS, univariate Cox regression analysis identified several significant factors. Karnofsky performance status (KPS) and metastases to the central nervous system (CNS) were associated with an increased risk of mortality (HR = 2.7, 95% CI: 1.2-6, p = 0.02; HR = 3.4, 95% CI: 1.2-11.3, p = 0.05, respectively). Elevated NLR ³2.44 and PLR ³181 (Figure 1A and 2C), both measured 3 months after treatment initiation were also associated with worse OS (HR = 2.6, 95% CI: 1.1-6.4, p = 0.04; HR = 3.9, 95% CI: 1.6-9.4, p = 0.003, respectively). Interestingly, elevated eosinophils after 3 months (Figure 2B) were linked to better OS (HR = 0.2, 95% CI: 0.04-0.7, p = 0.01).
In the multivariate Cox regression analysis, KPS remained a significant predictor of worse OS (HR = 3.3, 95% CI: 1.1-8.2, p = 0.04), as did CNS metastases (HR = 5.9, 95% CI: 1.2-27.7, p = 0.03). However, the effects of NLR and PLR were no longer statistically significant (HR = 0.8, 95% CI: 0.2-2.7, p = 0.07; HR = 3.0, 95% CI: 0.9-9.3, p = 0.07). Elevated eosinophils after 3 months continued to be associated with a significantly reduced risk of mortality (HR = 0.2, 95% CI: 0.04-0.9, p = 0.05). These findings indicate that KPS, CNS metastases, and eosinophil levels are key independent predictors of OS in patients treated with NIVO+IPI in RCC.
No associations were observed between other clinical parameters and PFS or OS (see Table 1S in the Supplementary Materials for details).