Pazopanib for the treatment of patients with advanced renal cell carcinoma

CORO6 Promotes Cell Growth and Invasion of Clear Cell Renal Cell Carcinoma via Activation of WNT Signaling

Renal cell carcinoma (RCC) constitutes the most lethal type of genitourinary cancer. Understanding of RCC tumor biology helps to identify novel targets and develop directed treatments for patients with this type of cancer. Analysis from both The Cancer Genome Atlas Kidney Renal Clear Cell Carcinoma dataset and our RCC samples demonstrated that the expression level of CORO6 was significantly higher in RCC patients than in normal kidney tissues, and its level was highly associated with tumor stage and grade. Importantly, CORO6 expression level was an independent predictor of tumor metastasis and overall survival in RCC patients. Our cell line data also confirmed that CORO6 knockdown could suppress RCC cell growth as well as cell migration and invasion. The depletion of CORO6 led to cell cycle arrest at the G0/G1 phase and caused cell apoptosis. Further, mechanistic dissection showed that CORO6 mediated RCC cell growth, and cell invasion relied on WNT signaling. Moreover, the in vivo data suggested that CORO6 knockdown indeed suppressed RCC tumor growth. Overall, our study defines the oncogenic role of CORO6 in RCC progression and provides a rationale for developing CORO6-targeted therapies for improved treatment of RCC patients.

First-Line Pazopanib Treatment in Metastatic Renal Cell Carcinoma: Real-World Data From a Single Chinese Center

The response to pazopanib in patients with metastatic renal cell carcinoma (mRCC) has been found to differ in Western and Eastern populations. Here, we analyzed the efficacy and side effects of pazopanib as first-line therapy in 31 consecutive patients with mRCC who were treated at a single Chinese center. Thirty-one consecutive patients with mRCC (20 males and 11 females, median age 59 years) were treated with pazopanib between October 2017 and July 2019. All patients had received a pathological diagnosis of RCC by prior radical nephrectomy or biopsy. All cases were treated with pazopanib (800 mg/day orally) as first-line therapy. Administration was continued until disease progression or unacceptable toxicities occurred. Objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS), overall survival (OS), and safety were evaluated. Twenty-nine patients were eligible for final analysis. At the median follow-up of 12.7 months, 34.5% (10/29) patients achieved a partial response (PR), 41.4% (12/29) patients had stable disease (SD), seven (24.1%) patients had disease progression (PD), and one patient had died. The ORR and DCR were 34.5% and 75.9%, respectively, and the median PFS was 10.1 months (95% confidence interval, 4.1–17.7 months). OS could not be determined. The most common side effects were fatigue (11 cases, 37.9%), hand-foot syndrome (10 cases, 34.5%), change of hair color (10 cases, 34.5%), elevated alanine transaminase (ALT)/aspartate transaminase (AST) (10 cases, 34.5%), hypertension (seven cases, 24.1%), neutropenia (three cases, 10.3%), anemia (three cases, 10.3%), thrombocytopenia (two cases, 6.9%), and diarrhea (one cases, 3.4%). Major (grade 3 or higher) adverse events included hand-foot syndrome (two cases, 6.9%) and thrombocytopenia (one case, 3.4%). Most adverse events were ameliorated by dose reduction or treatment interruption. Remissions occurred in almost all patients with local recurrence or pulmonary metastases, whereas PD occurred in patients with bone, liver or brain metastases. Our real-world data suggest that pazopanib is definitely efficacious as first-line therapy for mRCC, with well-tolerated side effects. Different metastatic lesions may have different sensitivity to pazopanib. An additional, large sample, multicenter, prospective study is needed to confirm our results.

HPLC-MS/MS coupled with equilibrium dialysis method for quantification of free drug concentration of pazopanib in plasma

Background

The selective occurrence of hepatotoxicity observed with use of pazopanib may be attributed to its high level of plasma protein binding and low hepatic extraction ratio. The primary objective was to investigate changes in free drug concentration amongst patients with varying albumin concentrations.

Methods

A HPLC-MS/MS method using C18 column (4.6 × 150 mm, 5 μm) with ESI source in positive mode had been developed and validated for the quantitative determination of free pazaopanib concentration in human plasma. Prior to sample preparation, patient samples were subjected to 6-hour equilibrium dialysis with molecular weight cut-off set at 8000 Da.

Results

The calibration curves were linear over the range of 5–1000 ng/mL, with a lower limit of quantification of 5 ng/mL. The intra-day and inter-day precisions and accuracies were all within ± 15 %, at 3 different quality controls. Higher median fraction unbound of pazopanib were observed in patients (n = 17) with lower than normal albumin concentrations.

Conclusion

With the developed assay, monitoring of plasma free concentrations may be evaluated as an indicator of pazopanib exposure in patients.

Patient-specific organotypic blood vessels as an in vitro model for anti-angiogenic drug response testing in renal cell carcinoma

Background

Anti-angiogenic treatment failure is often attributed to drug resistance, unsuccessful drug delivery, and tumor heterogeneity. Recent studies have speculated that anti-angiogenic treatments may fail due to characteristics inherent to tumor-associated blood vessels. Tumor-associated blood vessels are phenotypically different from their normal counterparts, having defective or permeable endothelial monolayers, abnormal sprouts, and abnormal vessel hierarchy. Therefore, to predict the efficacy of anti-angiogenic therapies in an individual patient, in vitro models that mirror individual patient's tumor vascular biology and response to anti-angiogenic treatment are needed.

Methods

We used a microfluidic in vitro organotypic model to create patient-specific biomimetic blood vessels from primary patient-specific tumor endothelial cells (TEnCs) and normal endothelial cells (NEnC). We assessed number of sprouts and vessel organization via microscopy imaging and image analysis. We characterized NEnC and TEnC vessel secretions via multiplex bead-based ELISA.

Findings

Using this model, we found that TEnC vessels exhibited more angiogenic sprouts than NEnC vessels. We also found a more disorganized and gap-filled endothelial monolayer. NEnCs and TEnC vessels exhibited heterogeneous functional drug responses across the five patients screened, as described in the clinic.

Interpretation

Our model recapitulated hallmarks of TEnCs and NEnCs found in vivo and captured the functional and structural differences between TEnC and NEnC vessels. This model enables a platform for therapeutic drug screening and assessing patient-specific responses with great potential to inform personalized medicine approaches.

Funding

NIH grants R01 EB010039, R33 CA225281, R01CA186134 University of Wisconsin Carbone Cancer Center (CA014520), and University of Wisconsin Hematology training grant T32 HL07899.

Tyrosine kinase inhibitors in the treatment of advanced renal cell carcinoma: focus on pazopanib

Advances in our understanding of renal cancer biology have led to a new treatment paradigm in renal cancer. Tyrosine kinase inhibitors (TKI), that target the intracellular kinase domain of the VEGF receptor, have become established as the most successful class of agent in this disease. Three TKIs are currently approved for use in patients with advanced disease. Newer, more potent inhibitors have reached phase III clinical testing, meaning others are likely to follow. In 2009, pazopanib became the most recent TKI to receive FDA approval. This review sets out to discuss the key opportunities and challenges associated with TKI use in RCC, focusing particularly on pazopanib. We also review the current place of pazopanib in the management of patients with advanced disease, in what is a rapidly evolving therapeutic landscape.

Pilot trial of interleukin-2 and zoledronic acid to augment γδ T cells as treatment for patients with refractory renal cell carcinoma

Prior to the advent of VEGF-targeted therapies, renal cell carcinoma (RCC) was among the few solid tumors shown to respond to cytokine-based therapies such as interleukin-2 (IL-2) and interferon alpha. Previous work has shown that aminobisphosphonates, including zoledronic acid (ZA), are capable of activating human Vγ9 Vδ2 T cells in vitro, and these cells can be further expanded with IL-2. Moreover, these Vγ9 Vδ2 T cells have cytolytic activity in vitro to multiple human tumor cell lines. In the current report, we have conducted a pilot trial in patients with metastatic RCC, evaluating different doses of ZA in combination with low-dose IL-2 to determine whether combining these agents can promote in vivo proliferation of Vγ9 Vδ2 T cells and elicit an antitumor response. In 12 patients evaluated, no objective clinical responses were observed by RECIST criteria; however, two patients experienced prolonged stable disease. A modest increase in Vγ9 Vδ2 T-cell frequency could be detected by Day 8 of therapy in four of the nine patients who received at least one cycle of therapy, but not to the magnitude anticipated from preclinical models. Repeated administration of IL-2 and ZA resulted in both a diminished in vivo percentage of Vγ9 Vδ2 T cells as well as impaired expansion in vitro after the first cycle of therapy. These results suggest that repeated administration of IL-2 and ZA, at the doses and schedules used in this trial, may actually inhibit the proliferative capacity of Vγ9 Vδ2 T cell in patients with metastatic RCC.