Evaluation of KDR rs34231037 as a predictor of sunitinib efficacy in patients with metastatic renal cell carcinoma

Genetic Polymorphisms in VEGFR Coding Genes (FLT1/KDR) on Ranibizumab Response in High Myopia and Choroidal Neovascularization Patients

A severe form of myopia defined as pathologic/high myopia is the main cause of visual impairment and one of the most frequent causes of blindness worldwide. It is characterized by at least 6 diopters or axial length (AL) of eyeball > 26 mm and choroidal neovascularization (CNV) in 5 to 10% of cases. Ranibizumab is a humanized recombinant monoclonal antibody fragment targeted against human vascular endothelial growth factor A (VEGF-A) used in the treatment of CNV. It acts by preventing VEGF-A from interacting with its receptors (VEGFR-1 and -2) encoded by the FLT1 and KDR genes. Several studies found that the KDR and FLT1 genotypes may represent predictive determinants of efficacy in ranibizumab-treated neovascular age-related macular degeneration (nAMD) patients. We performed a retrospective study to evaluate the association of single nucleotide polymorphisms (SNPs) in VEGFR coding genes with the response rate to ranibizumab in patients with high myopia and CNV. In the association study of genotypes in FLT1 with the response to ranibizumab, we found a significant association between two FLT1 variants (rs9582036, rs7993418) with ranibizumab efficacy at the 12-month follow-up. About the KDR gene, we found that two KDR variants (rs2305948, rs2071559) are associated with best-corrected visual acuity (BCVA) improvement and KDR (rs2239702) is associated with lower rates of BCVA worsening considering a 12-month follow-up period.

Biomarkers of Prognosis and Efficacy of Anti-angiogenic Therapy in Metastatic Clear Cell Renal Cancer

In the last decades, the prognosis of metastatic renal cell carcinoma (mRCC) has remarkably improved following the advent of the "targeted therapy" era. The expanding knowledge on the prominent role played by angiogenesis in RCC pathogenesis has led to approval of multiple anti-angiogenic agents such as sunitinib, pazopanib, axitinib, cabozantinib, sorafenib, and bevacizumab. These agents can induce radiological responses and delay cancer progression for months or years before onset of resistance, with a clinically meaningful activity. The need for markers of prognosis and efficacy of anti-angiogenic agents has become more compelling as novel systemic immunotherapy agents have also been approved in RCC and can be administered as an alternative to angiogenesis inhibitors. Anti PD-1 monoclonal antibody nivolumab has been approved in the second-line setting after tyrosine kinase inhibitors failure, while combination of nivolumab plus anti CTLA-4 monoclonal antibody ipilimumab has been approved as first-line therapy of RCC patients at intermediate or poor prognosis. In this review article, biomarkers of prognosis and efficacy of antiangiogenic therapies are summarized with a focus on those that have the potential to affect treatment decision-making in RCC. Biomarkers predictive of toxicity of anti-angiogenic agents have also been discussed.

Phase III Trial of Adjuvant Sunitinib in Patients with High-Risk Renal Cell Carcinoma: Exploratory Pharmacogenomic Analysis

PURPOSE

In the S-TRAC trial, adjuvant sunitinib prolonged disease-free survival (DFS) versus placebo in patients with loco-regional renal cell carcinoma at high risk of recurrence after nephrectomy. An exploratory analysis evaluated associations between SNPs in several angiogenesis- or hypoxia-related genes and clinical outcomes in S-TRAC.

PATIENTS AND METHODS

Blood samples were genotyped for 10 SNPs and one insertion/deletion mutation using TaqMan assays. DFS was compared using log-rank tests for each genotype in sunitinib versus placebo groups and between genotypes within each of three (sunitinib, placebo, and combined sunitinib plus placebo) treatment groups. P values were unadjusted.

RESULTS

In all, 286 patients (sunitinib, n = 142; placebo, n = 144) were genotyped. Longer DFS [HR; 95% confidence interval (CI)] was observed with sunitinib versus placebo for VEGFR1 rs9554320 C/C (HR 0.44; 95% CI, 0.21-0.91; P = 0.023), VEGFR2 rs2071559 T/T (HR 0.46; 95% CI, 0.23-0.90; P = 0.020), and eNOS rs2070744 T/T (HR 0.53; 95% CI, 0.30-0.94; P = 0.028). Shorter DFS was observed for VEGFR1 rs9582036 C/A versus C/C with sunitinib, placebo, and combined therapies (P ≤ 0.05), and A/A versus C/C with sunitinib (P = 0.022). VEGFR1 rs9554320 A/C versus A/A was associated with shorter DFS in the placebo (P = 0.038) and combined (P = 0.006) groups.

CONCLUSIONS

Correlations between VEGFR1 and VEGFR2 SNPs and longer DFS with sunitinib suggest germline SNPs are predictive of improved outcomes with adjuvant sunitinib in patients with renal cell carcinoma. Independent validation studies are needed to confirm these findings.

Single nucleotide polymorphisms as prognostic and predictive biomarkers in renal cell carcinoma

Despite major advances in the knowledge of the molecular basis of renal cell carcinoma, prognosis is still defined using clinical and pathological parameters. Moreover, no valid predictive biomarkers exist to help us selecting the best treatment for each patient. With these premises, we aimed to analyse the expression and to determine the prognostic and predictive value of 64 key single nucleotide polymorphisms in 18 genes related with angiogenesis or metabolism of antiangiogenics in two cohorts of patients with localized and advanced renal cell cancer treated at our institution. The presence of the selected single nucleotide polymorphisms was correlated with clinical features, disease free survival, overall survival and response rate. In patients with localized renal cell cancer, 5 of these polymorphisms in 3 genes involved in angiogenesis predicted for worse disease free survival (VEGFR2: rs10013228; PDGFRA: rs2228230) or shorter overall survival (VEGFR2: rs10013228; VEGFR3: rs6877011, rs307826) (p < 0.05). Rs2071559 in VEGFR2 showed a protective effect (p = 0.01). In the advanced setting, 5 SNPs determined inferior overall survival (IL8: rs2227543, PRKAR1B: rs9800958, PDGFRB: rs2302273; p = 0.05) or worse response rate (VEGFA: rs699947, rs3025010 p ≤ 0.01)). Additionally 1 single nucleotide polymorphism in VEGFB predicted for better response rate rs594942 (p = 0.03). Genetic analysis of renal cell carcinoma patients might provide valuable prognostic/predictive information. A set of SNPs in genes critical to angiogenesis and metabolism of antiangiogenics drugs seem to determine post-surgical outcomes and treatment response in our series.

Population Modeling Integrating Pharmacokinetics, Pharmacodynamics, Pharmacogenetics, and Clinical Outcome in Patients With Sunitinib-Treated Cancer

The tyrosine kinase inhibitor sunitinib is used as first‐line therapy in patients with metastasized renal cell carcinoma (mRCC), given in fixed‐dose regimens despite its high variability in pharmacokinetics (PKs). Interindividual variability of drug exposure may be responsible for differences in response. Therefore, dosing strategies based on pharmacokinetic/pharmacodynamic (PK/PD) models may be useful to optimize treatment. Plasma concentrations of sunitinib, its active metabolite SU12662, and the soluble vascular endothelial growth factor receptors sVEGFR‐2 and sVEGFR‐3, were measured in 26 patients with mRCC within the EuroTARGET project and 21 patients with metastasized colorectal cancer (mCRC) from the C‐II‐005 study. Based on these observations, PK/PD models with potential influence of genetic predictors were developed and linked to time‐to‐event (TTE) models. Baseline sVEGFR‐2 levels were associated with clinical outcome in patients with mRCC, whereas active drug PKs seemed to be more predictive in patients with mCRC. The models provide the basis of PK/PD‐guided strategies for the individualization of anti‐angiogenic therapies.