Biomarkers of Angiogenesis and Clinical Outcomes to Cabozantinib and Everolimus in Patients with Metastatic Renal Cell Carcinoma from the Phase III METEOR Trial

Gene expression of prostate-specific membrane antigen (FOLH1) in clear cell renal cell carcinoma predicts angiogenesis and response to tyrosine kinase inhibitors

PURPOSE

Combination systemic therapies (CSTs) of immuno-oncologic (IO) and VEGF-inhibiting agents (VEGFi) have become the standard of care for management of metastatic clear cell renal cell carcinoma (m-ccRCC). However, treatment outcomes vary between patients, with no established biomarkers to determine optimal CST regimens (IO/IO or IO/VEGFi). Prostate Specific Membrane Antigen (PSMA), encoded by the FOLH1 gene, is a marker of tumor neovasculature in ccRCC, the downstream target of VEGFi. We evaluated the relation between FOLH1 expression and angiogenesis, as well as clinical outcomes, in 5 m-ccRCC ST trials.

MATERIALS AND METHODS

using Spearman's rank correlation (SPRC) test, we assessed the correlation between FOLH1 expression and gene expression signature (GES) scores corresponding to angiogenic and immunologic features of the tumor microenvironment (TME) of m-ccRCC in our trial cohorts. Using Cox proportional hazard regression (Cox-PHR), we assessed the association between FOLH1 expression level, summarized by within-study quantiles (qFOLH1), and progression-free and overall survival (PFS, OS).

RESULTS

Increased FOLH1 expression was significantly associated with higher TME angiogenesis GES scores (SPRC +0.5, P < 0.001), but did not consistently correlate with immune feature GES scores. Meta-analysis of PFS in the sunitinib TKI arm of trial cohorts showed an overall positive association with qFOLH1 (HR = 0.89; 95% CI = 0.85-0.94, P < 0.0001). qFOLH1 was not significantly associated with OS in the sunitinib arms of the two trials with OS data (COMPARZ, HR 0.87, 95% CI 0.71-1.07, P = 0.17; and Checkmate-214, HR 0.89, 95% CI 0.67-1.17, P = 0.70).

CONCLUSIONS

PSMA-encoding FOLH1 gene expression correlates with neoangiogenesis and predicts PFS in m-ccRCC patients treated with sunitinib TKI, suggesting that PSMA PET could be explored as a noninvasive biomarker for guiding CST choice (IO/IO or IO/VEGFi) as well as prediction of treatment response to VEGFi in m-ccRCC patients.

Dynamic Changes in Serum Immunoglobulin G Predict Clinical Response and Prognosis in Metastatic Clear-cell Renal Cell Carcinoma

Background and objective

Systemic treatments involving immunotherapy-tyrosine kinase inhibitor (IO-TKI) combinations and TKI monotherapy have significantly improved outcomes for patients with metastatic clear-cell renal cell carcinoma (mccRCC). However, there are no biomarkers for predicting the efficacy of these treatments. Our aim was to investigate the prognostic and therapeutic significance of serum immunoglobulin G (IgG) in patients with mccRCC patients receiving systemic therapy.

Methods

We included 318 patients with mccRCC who received TKI or IO-TKI therapy. Patients were classified into groups according to whether they had an increase or decrease in serum IgG after systemic treatment. The association between baseline serum IgG and the objective response rate (ORR) was compared between the groups using a t test. The association of the change in serum IgG with progression-free survival (PFS) and overall survival (OS) was evaluated via Cox proportional-hazards regression, and survival curves were generated using the Kaplan-Meier method.

Key findings and limitations

Baseline serum IgG was not significantly associated with ORR (p = 0.055). After 3-mo systemic therapy, 133 patients (42%) exhibited an increase in serum IgG. The group with an IgG increase had significantly poorer median PFS (5.6 vs 16.2 mo; hazard ratio [HR] 3.36, 95% confidence interval [CI] 2.58-4.36; p < 0.001) and OS (26.0 vs 52.2 mo; HR 2.26, 95% CI 1.66-3.08; p < 0.001) than the group with an IgG decrease. Multivariable analysis revealed that an increase in serum IgG after 3-mo systemic therapy was an independent risk factor for both PFS (HR 3.28, 95% CI 2.51-4.30; p < 0.001) and OS (HR 1.94, 95% CI 1.41-2.68; p < 0.001). An increase in serum IgG after 1-mo treatment (n = 160) was also significantly associated with poorer median PFS (7.9 vs 13.7 mo; HR 1.62, 95% CI 1.13-2.32; p = 0.008) and OS (32.6 vs 50.5 mo; HR 1.68, 95% CI 1.09-2.59; p = 0.017).

Conclusions and clinical implications

The change in serum IgG after 3-mo systemic therapy can predict the therapeutic effect and prognosis for patients with mccRCC. This predictive value was observed as early as 1 mo after treatment initiation. Our findings highlight the potential of serum IgG as a predictive biomarker in this setting. Further validation is required in large prospective studies.

Patient summary

We found that for patients with metastatic kidney cancer, changes in the level of an antibody called immunoglobulin G (IgG) in blood during systemic treatment can predict their overall response. Early measurement of IgG could help doctors in personalizing treatment plans and might possibly improve the effectiveness of treatment for these patients.

Molecular mechanisms and clinical relevance of endothelial cell cross-talk in clear cell renal cell carcinoma

Background

Clear cell renal cell carcinoma (ccRCC) is the most common renal cancer in adults and stands out as one of the most vascularized and immune-infiltrated solid tumors. Overproduction of vascular endothelial growth factor A promotes uncontrolled growth of abnormal vessels and immunosuppression, and the tumor microenvironment (TME) has a prominent role in disease progression, drug targeting and drug response, and for patient outcome.

Methods

Studies of experimental models, large-scale omics approaches, and patient prognosis and therapy prediction, using gene expression signatures and tissue biomarker analysis, have been reviewed for enhanced understanding of the endothelium in ccRCC and the interplay with the surrounding TME.

Results

Preclinical and clinical studies have discovered molecular mechanisms of endothelial cross-talk of relevance for disease progression, patient prognosis, and therapy prediction. There is, however, a lack of representative ccRCC experimental models. Omics approaches have identified clinically relevant subsets of angiogenic and immune-infiltrated tumors with distinct molecular signatures and distinct endothelial cell and immune cell populations in patients.

Conclusions

Recent genetically engineered ccRCC mouse models together with emerging evidence from single cell RNA sequencing data open up for future validation studies, including multiplex imaging of ccRCC patient cohorts. These studies are of importance for therapy benefit and personalized treatment of ccRCC patients.

Targeting oncogenic kinases: Insights on FDA approved tyrosine kinase inhibitors

Protein kinases play pivotal roles in various biological functions, influencing cell differentiation, promoting survival, and regulating the cell cycle. The disruption of protein kinase activity is intricately linked to pathways in tumor development. This manuscript explores the transformative impact of protein kinase inhibitors on cancer therapy, particularly their efficacy in cases driven by targeted mutations. Focusing on key tyrosine kinase inhibitors (TKIs) like Bcr-Abl, Epidermal Growth Factor Receptor (EGFR), and Vascular Endothelial Growth Factor Receptor (VEGFR), it targets critical kinase families in cancer progression. Clinical trial details of these TKIs offer insights into their therapeutic potentials. Learning from FDA-approved kinase inhibitors, the review dissects trends in kinase drug development since imatinib's paradigm-shifting approval in 2001. TKIs have evolved into pivotal drugs, extending beyond oncology. Ongoing clinical trials explore novel kinase targets, revealing the vast potential within the human kinome. The manuscript provides a detailed analysis of advancements until 2022, discussing the roles of specific oncogenic protein kinases in cancer development and carcinogenesis. Our exploration on PubMed for relevant and significant TKIs undergoing pre-FDA approval phase III clinical trials enriches the discussion with valuable findings. While kinase inhibitors exhibit lower toxicity than traditional chemotherapy in cancer treatment, challenges like resistance and side effects emphasize the necessity of understanding resistance mechanisms, prompting the development of novel inhibitors like osimertinib targeting specific mutant proteins. The review advocates thorough research on effective combination therapies, highlighting the future development of more selective RTKIs to optimize patient-specific cancer treatment and reduce adverse events.

[Peculiarities of angiogenesis in clear cell renal cancer]

A literature search was conducted to review papers on the results of studies of clear cell renal cancer (CCRC) vascularization. Numerous data on the relationship between tumor pathogenesis and its vascularization have been revealed, which indicates the multifactorial nature of CCRC development and the significant role of angiogenesis in this process. It should be taken into account that patients with CCRC may have impaired vessel formation even before tumor development. To evaluate normal and pathologic angiogenesis, a pathohistologic study using immunohistochemistry is certainly necessary. Due to the significant role of angiogenesis in the development and course of CCRC, the use of drugs that suppress the formation of the vascular network in the tumor is relevant and advisable. To date, many drugs have been developed and introduced into clinical practice to inhibit angiogenesis. However, such drugs have not lived up to the expectations placed due to the frequent and rapidly developing drug resistance. Timely detection of pre-tumor and tumor processes, as well as effective treatment of cancer, including CCRC, is possible only with close cooperation between pathomorphologists and oncologists.

3D Ultrasound-Guided Photoacoustic Imaging to Monitor the Effects of Suboptimal Tyrosine Kinase Inhibitor Therapy in Pancreatic Tumors

Pancreatic cancer is a disease with an incredibly poor survival rate. As only about 20% of patients are eligible for surgical resection, neoadjuvant treatments that can relieve symptoms and shrink tumors for surgical resection become critical. Many forms of treatments rely on increased vulnerability of cancerous cells, but tumors or regions within the tumors that may be hypoxic could be drug resistant. Particularly for neoadjuvant therapies such as the tyrosine kinase inhibitors utilized to shrink tumors, it is critical to monitor changes in vascular function and hypoxia to predict treatment efficacy. Current clinical imaging modalities used to obtain structural and functional information regarding hypoxia or oxygen saturation (StO2) do not provide sufficient depth penetration or require the use of exogenous contrast agents. Recently, ultrasound-guided photoacoustic imaging (US-PAI) has garnered significant popularity, as it can noninvasively provide multiparametric information on tumor vasculature and function without the need for contrast agents. Here, we built upon existing literature on US-PAI and demonstrate the importance of changes in StO2 values to predict treatment response, particularly tumor growth rate, when the outcomes are suboptimal. Specifically, we image xenograft mouse models of pancreatic adenocarcinoma treated with suboptimal doses of a tyrosine kinase inhibitor cabozantinib. We utilize the US-PAI data to develop a multivariate regression model that demonstrates that a therapy-induced reduction in tumor growth rate can be predicted with 100% positive predictive power and a moderate (58.33%) negative predictive power when a combination of pretreatment tumor volume and changes in StO2 values pretreatment and immediately posttreatment was employed. Overall, our study indicates that US-PAI has the potential to provide label-free surrogate imaging biomarkers that can predict tumor growth rate in suboptimal therapy.

An Evaluation of Cabozantinib for the Treatment of Renal Cell Carcinoma: Focus on Patient Selection and Perspectives

Cabozantinib is an oral tyrosine kinase inhibitor (TKI) with activity against several receptors involved in the angiogenesis pathway, including vascular endothelial growth factor receptor (VEGFR), c-MET and AXL. The antiangiogenic properties of cabozantinib led to its use as a monotherapy for the treatment of metastatic renal cell cancer (RCC), and quickly resulted in this treatment becoming part of the standard of care for these tumors. Since the advent of immune checkpoint inhibitors (ICIs), new standards of care have emerged in first-line settings, involving dual ICI or ICI-VEGF-TKI (including ICI-cabozantinib) combination treatments, and leading to a more complex algorithm of care. Cabozantinib remains an option in second-line settings and is still a first-line standard of care treatment in cases where the use of ICIs is contraindicated. This review focuses on the selection of patients who may benefit most from cabozantinib therapy, including those with bone and brain metastases and those with a non-clear cell RCC histology. The need to consider disease-related symptoms, comorbidities, age, drug interactions and biomarker analyses in the choice of therapeutic strategy is also highlighted. Finally, the perspectives for the use of cabozantinib in RCC treatment are discussed.