Targeted Therapies for Metastatic Renal Cell Carcinoma: An Overview of Toxicity and Dosing Strategies

An Optimized LC-MS/MS Method for Quantification of Sunitinib and N -Desethyl Sunitinib in Human Plasma and Its Application for Therapeutic Drug Monitoring

BACKGROUND

Sunitinib (SUN) malate is an oral, multitargeted, tyrosine kinase inhibitor approved for the treatment of metastatic renal cell carcinoma, imatinib-resistant or imatinib-intolerant gastrointestinal stromal tumors, and pancreatic neuroendocrine tumors. SUN has a narrow therapeutic window and high variability in interpatient pharmacokinetic parameters. Clinical detection methods for SUN and N -desethyl SUN limit the application of SUN to therapeutic drug monitoring. All published methods for quantifying SUN in human plasma require strict light protection to avoid light-induced isomerism or the use of additional quantitative software. To avoid these difficult processes in clinical routines, the authors propose a novel method that merges the peaks of the E -isomer and Z -isomer of SUN or N -desethyl SUN into a single peak.

METHODS

The E -isomer and Z -isomer peaks of SUN or N -desethyl SUN were merged into a single peak by optimizing the mobile phases to decrease the resolution of the isomers. A suitable chromatographic column was selected to obtain a good peak shape. Thereafter, the conventional and single-peak methods (SPM) were simultaneously validated and compared according to the guidelines published by the Food and Drug Administration in 2018 and the Chinese Pharmacopoeia in 2020.

RESULTS

The verification results showed that the SPM was superior to the conventional method in the matrix effect and met the requirements for biological sample analysis. SPM was then applied to detect the total steady-state concentration of SUN and N -desethyl SUN in tumor patients who received SUN malate.

CONCLUSIONS

The established SPM makes the detection of SUN and N -desethyl SUN easier and faster without light protection or extra quantitative software, making it more appropriate for routine clinical use. The clinical application results showed that 12 patients took 37.5 mg per day, with a median total trough steady-state concentration of 75.0 ng/mL.

Supportive therapy and complementary medicine in renal cell carcinoma

PURPOSE

As part of the German interdisciplinary S3-guideline "Diagnosis, Treatment and Followup of Renal Cell Carcinoma", this article aimes to provide guidance regarding the use of supportive therapy and complementary medicine in patients with advanced or metastatic renal cell carcinoma.

METHODS

The German interdisciplinary S3-guidelines are national clinical practice guidelines that implement the highest methodological quality of evidence-based medicine. Recommendations and evidence-based statements are provided according to available evidence.

RESULTS

Supportive and palliative care are important areas of tumor treatment and require knowledge on the management of a variety of issues. This article outlines the management of tumor-related symptoms such as pain, undesired treatment-related effects, palliative care and end-of-life care in patients with renal cell carcinoma.

CONCLUSION

Patients with advanced or metastatic renal cell carcinoma should have access to supportive and palliative care according to their individual needs. There is very limited evidence regarding the impact of complementary medicine for the treatment of patients with renal cell carcinoma.

SOX6 represses tumor growth of clear cell renal cell carcinoma by HMG domain-dependent regulation of Wnt/β-catenin signaling

Sex-determining region Y box (SOXs) are expressed in various cells and control cell fate and differentiation in a multitude of physiologic processes. SOX6, a main representative of SOXs, is involved in the regulation of carcinogenesis in various human malignancies. However, the role of SOX6 in clear cell renal cell carcinoma (ccRCC) remains unclear. In this study, SOX6 expression in ccRCC and its clinical significance were investigated. In vitro and in vivo assays were used to explore the tumor-related function and the underlying molecular mechanism of SOX6 in ccRCC. We confirmed that SOX6 was frequently downregulated in ccRCC tissues and cell lines. Besides, downregulation of SOX6 was significantly associated with larger tumor sizes, advanced tumor stage, higher Fuhrman grades, and its expression could act as an independent prognostic factor for ccRCC (hazards ratio = 0.590, P = .026). Gain/loss-of-function experiments demonstrated that SOX6 could remarkably inhibit tumor cell growth and foci formation in vitro and xenograft tumorigenesis in vivo, respectively. Mechanistically, SOX6 could influence cell cycle by regulating the G1/the S phase transition and had an inhibitory effect on Wnt/β-catenin signaling as well as its target genes, c-Myc and cyclin D1. Interesting, the tumor-suppressive function of SOX6 was proved to be dependent on its specific high-mobility-group (HMG) domain. In general, our findings indicated that SOX6 was a novel tumor suppressor and prognostic biomarker in ccRCC. SOX6 could inhibit tumor growth by negatively regulating the Wnt/β-catenin signaling pathway in an HMG domain-dependent manner in ccRCC, which might provide a novel therapeutic approach for ccRCC.

Novel Targeted Therapies for Metastatic Thyroid Cancer-A Comprehensive Review

The knowledge on thyroid cancer biology has grown over the past decade. Thus, diagnostic and therapeutic strategies to manage thyroid cancer are rapidly evolving. With new insights into tumor biology and cancer genetics, several novel therapies have been approved for the treatment of thyroid cancer. Tyrosine kinase inhibitors (TKIs), such as lenvatinib and sorafenib, have been successfully utilized for the treatment of radioactive iodine (RAI)-refractory metastatic differentiated thyroid cancer (DTC). In addition, pretreatment with mitogen-activated protein kinase (MAPK) inhibitors (trametinib and selumetinib) has been shown to restore RAI avidity in previously RAI-refractory DTCs. Local therapies, such as external beam radiation and radiofrequency/ethanol ablation, have also been employed for treatment of DTC. Vandetanib and cabozantinib are the two TKIs currently approved by the Food and Drug Administration (FDA) for the treatment of medullary thyroid cancer (MTC). Other novel therapies, such as peptide receptor radionuclide therapy and carcinoembryonic antigen (CEA) vaccine, have also been utilized in treating MTC. Ongoing trials on selective rearranged-during-transfection (RET) protooncogene inhibitors, such as LOXO-292 and BLU-667, have demonstrated promising results in the treatment of metastatic MTC resistant to non-selective TKIs. The FDA-approved BRAF/MEK inhibitor combination of dabrafenib and trametinib has revolutionized treatment of BRAFV600E mutation positive anaplastic thyroid cancer. Several other emerging classes of medications, such as gene fusion inhibitors and immune checkpoint inhibitors, are being actively investigated in several clinical trials. In this review, we describe the molecular landscape of thyroid cancer and novel targeted therapies and treatment combinations available for the treatment of metastatic thyroid cancer.

Risk of Dyslipidemia Associated with VEGF/VEGFR Inhibitors: A Meta-Analysis

OBJECTIVE

This meta-analysis was performed to investigate hyperlipidemia in patients with carcinoma treated with vascular endothelial growth factor (VEGF)/vascular endothelial growth factor receptor (VEGFR) inhibitors.

METHODS

We searched for eligible phase II and III studies using PubMed and Embase databases. We then summarized reported occurrences of hyperlipidemia in patients with different cancers. Relative risk ratios (RRs) and 95% confidence intervals (CIs) were calculated by Revman 5 software in meta-analysis.

RESULTS

Eleven trials (4760 subjects) were included in this meta-analysis. Overall, VEGF/VEGFR inhibitors had similar incidence of hypertriglyceridemia (RR = 0.56, 95% CI = 0.24%-1.32%, P = .19), hypercholesterolemia (RR = 1.15, 95% CI = 0.42%-3.16%, P = .78), and LDL elevation (RR = 4.58, 95% CI = 0.80%-26.25%, P = .09) than control drugs, under high heterogeneity. Moreover, subgroup analyses found VEGF/VEGFR inhibitors had higher incidence of hypertriglyceridemia (RR = 1.86, 95% CI = 1.37%-2.52%, P < .001) and hypercholesterolemia (RR = 2.95, 95% CI = 2.02%-4.30%, P = .006) than blank control or placebo control drugs (placebo-controlled-group), although with lower incidence of hypertriglyceridemia (RR = 0.29, 95% CI = 0.12%-0.69%, P < .001) and hypercholesterolemia (RR = 0.39, 95% CI = 0.28%-0.56%, P < .001) than positive control drugs (positive-controlled-groups).

CONCLUSION

The use of VEGF/VEGFR inhibitors, especially the multitargeted VEGFR tyrosine kinase inhibitors (VEGFR-TKIs), was associated with higher risk of hyperlipidemia than the use of placebo, but this risk was less than that associated with mTOR or FGFR inhibitors. It indicated that clinicians need to pay close attention to the occurrence of hyperlipidemia in VEGFR-TKIs therapies.

Potential new therapy of Rapalink-1, a new generation mammalian target of rapamycin inhibitor, against sunitinib-resistant renal cell carcinoma

Sunitinib, a multitargeted receptor tyrosine kinase inhibitor including vascular endothelial growth factor, has been widely used as a first-line treatment against metastatic renal cell carcinoma (mRCC). However, mRCC often acquires resistance to sunitinib, rendering it difficult to treat with this agent. Recently, Rapalink-1, a drug that links rapamycin and the mTOR kinase inhibitor MLN0128, has been developed with excellent therapeutic effects against breast cancer cells carrying mTOR resistance mutations. The aim of the present study was to evaluate the in vitro and in vivo therapeutic efficacy of Rapalink-1 against renal cell carcinoma (RCC) compared to temsirolimus, which is commonly used as a small molecule inhibitor of mTOR and is a derivative of rapamycin. In comparison with temsirolimus, Rapalink-1 showed significantly greater effects against proliferation, migration, invasion and cFolony formation in sunitinib-naïve RCC cells. Inhibition was achieved through suppression of the phosphorylation of substrates in the mTOR signal pathway, such as p70S6K, eukaryotic translation initiation factor 4E-binding protein 1 (4EBP1) and AKT. In addition, Rapalink-1 had greater tumor suppressive effects than temsirolimus against the sunitinib-resistant 786-o cell line (SU-R 786-o), which we had previously established, as well as 3 additional SU-R cell lines established here. RNA sequencing showed that Rapalink-1 suppressed not only the mTOR signaling pathway but also a part of the MAPK signaling pathway, the ErbB signaling pathway and ABC transporters that were associated with resistance to several drugs. Our study suggests the possibility of a new treatment option for patients with RCC that is either sunitinib-sensitive or sunitinib-resistant.

Echocardiography Imaging of Cardiotoxicity

Heart disease is the most important cause of non-cancer death for patients with cancer. Addressing the cardiotoxic effects of anticancer therapies to prevent increased cardiovascular risk in this population is crucial. Echocardiography plays a big role in monitoring cardiotoxicity induced by cancer treatment. Many emerging modalities, including tissue Doppler imaging measures, speckle tracking imaging, and three-dimensional echocardiography, may provide improved sensitivity and specificity to detect cancer treatment-induced cardiotoxicity. Additional research is critical to define the value of both conventional and novel indices in guiding the clinical management of cancer treatment-induced cardiotoxicity.

Clinical Efficacy and Complication Rate of Sunitinib 2/1 Versus 4/2 Schedule for the Treatment of Metastatic Renal Cell Cancer: A Systematic Review and Meta-Analysis

The treatment of renal cell carcinoma has achieved certain curative effects with the innovation of clinical drugs, such as sunitinib. However, the clinical efficacy and complication rate of the sunitinib 2/1 and 4/2 schedule in metastatic renal cell cancer remain unclear. In this study we aimed to resolve this issue by using meta-analysis to provide more theoretical guidance for clinical use. Several outcome measurements were included in this study to compare the 2 schedules such as complete response, partial response, stable disease, progressive disease, progression-free survival, overall survival, and complications. In the contrast analysis, the sunitinib 2/1 and 4/2 schedule resulted in significant improvements in prognosis. However, the sunitinib 2/1 schedule was superior to the 4/2 schedule in terms of controlling stable disease and causing fewer complications.

A critical review on anti-angiogenic property of phytochemicals

Angiogenesis, a process involved in neovascularization, has been found to be associated with several metabolic diseases like cancer, retinopathy etc. Thus, currently, the focus on anti-angiogenic therapy for treatment and prevention of diseases has gained significant attention. Currently available Food and Drug Administration (FDA) approved drugs are targeting either vascular endothelial growth factor or it's receptor, but in the long term, these approaches were shown to cause several side effects and the chances of developing resistance to these drugs is also high. Therefore, identification of safe and cost-effective anti-angiogenic molecules is highly imperative. Over the past decades, dietary based natural compounds have been studied for their anti-angiogenic potential which provided avenues in improving the angiogenesis based therapy. In this review, major emphasis is given to the molecular mechanism behind anti-angiogenic effect of natural compounds from dietary sources.

Sorafenib-induced Prostate Volume Reduction, a New Adverse Effect Detected by Imaging: A Pilot Study

Background

Sorafenib has been used in the treatment of advanced hepatocellular carcinoma (HCC) and renal cell carcinoma (RCC). Sorafenib-associated organ reduction have been reported on imaging, such as thyroid, pancreas and muscle, but there has been no research on prostate volume reduction (PVR).

Methods

We retrospectively analyzed 26 patients (twenty with HCC and six patients with RCC) who underwent sorafenib therapy for 31 to 1225 days (median, 100 days). PVR was estimated by two independent readers using CT volumetry.

Results

The sum of all prostate volumes measured by reader 1 was 24.2 ± 13.8 cm³ on the baseline CT and 20.4 ± 10.6 cm³ on the follow-up CT (p < 0.001), and that measured by reader 2 was 22.3 ± 13.9 cm³ on the baseline CT and 19.2 ± 10.6 cm³ on the follow-up CT (p < 0.001). The concordance correlation coefficient for the prostate volume measured by the two readers was 0.95 on the baseline CT scans and 0.94 on the follow-up CT scans. Sorafenib-associated PVR demonstrated slight dependence to the exposure time (r = -0.23). One patient with benign prostatic hyperplasia (BPH) showed PVR (from 80.4 to 61.5 cm³ [reader 1]; 83.4 to 61.6 cm³ [reader 2]) after sorafenib administration. Sorafenib-associated PVR occurred in patients both with and without underlying liver dysfunction with relative prostate volume changes of 86.7 ± 12.0% and 85.0 ± 9.0%, respectively.

Conclusion

Our study demonstrated significant PVR with sorafenib treatment in patients regardless of the presence of BPH and underlying liver dysfunction.

Risk of regorafenib-induced cardiovascular events in patients with solid tumors: A systematic review and meta-analysis

BACKGROUND

The present comparative meta-analysis was conducted to evaluate the cardiovascular events of regorafenib in patients with solid tumors.

METHODS

Eligible studies from MEDLINE, Google Scholar, Cochrane Library, Clinical key, EBSCO publishing and Ovid, which had reported cardiovascular adverse events potentially caused by regorafenib were absorbed. Data of clinical characteristics and cardiovascular events including hypertension, hemorrhage, thrombosis, and heart failure were extracted from selected literatures for the final analysis. Pooled analysis of cardiovascular adverse events was developed by relative risks (RRs) and corresponding 95% confidence intervals (CIs) with software STATA 13.0 and RevMan 5.3.

RESULTS

Thirty studies including 3813 patients were fit into analysis. The incidences of cardiovascular events of all-grade were: hypertension, 36.8% (95% CI, 29.8%-43.8%), hemorrhage, 8.6% (95% CI, 3.2%-14%), thrombosis, 1.4% (95% CI, 0.1%-2.8%), and heart failure, 2.9% (95% CI, 0.3%-5.6%). The incidences of cardiovascular events of high-grade were: hypertension, 9.9% (95% CI, 7.4%-12.4%), hemorrhage, 1.2% (95% CI, 0.3%-2.2%), thrombosis, 1.6% (95% CI, 0.2%-3.4%), and heart failure, 2.9% (95% CI, 0.3%-5.6%). The RRs and their 95% CIs of all-grade cardiovascular events among patients treated with regorafenib were: hypertension, 4.10 (95% CI, 3.07-5.46; P < .00001), hemorrhage, 2.71 (95% CI, 1.45-5.08; P = .002), thrombosis, 1.27 (95% CI, 0.49-3.27; P = .62), and heart failure, 0.79 (95% CI, 0.16-3.94; P = .77). The RRs and their 95% CIs of high-grade cardiovascular events among patients treated with regorafenib were: hypertension, 5.82 (95% CI, 3.46-9.78; P < .00001), hemorrhage, 0.90 (95% CI, 0.50-1.61; P = .72), thrombosis, 1.28 (95% CI, 0.48-3.41; P = .62), and heart failure, 1.15 (95% CI, 0.23-5.69; P = .86), respectively.

CONCLUSION

The present meta-analysis has demonstrated that regorafenib is associated with an increasing risk of hypertension at all-grade and high-grade, as well as hemorrhage at all-grade. Adequate awareness of cardiovascular adverse events of regorafenib should be established for clinicians.

Pathophysiology of cardiotoxicity from target therapy and angiogenesis inhibitors

The progress in cancer therapy and the increase in number of long-term survivors reveal the issue of cardiovascular side-effects of anticancer drugs. Cardiotoxicity has become a significant problem, and the risks of adverse cardiac events induced by systemic drugs need to be seriously considered. Potential cardiovascular toxicities linked to anticancer agents include arrhythmias, myocardial ischemia and infarction, hypertension, thromboembolism, left ventricular dysfunction, and heart failure. It has been shown that several anticancer drugs seriously affect the cardiovascular system, such as ErbB2 inhibitors, vascular endothelial growth factor (VEGF) inhibitors, multitargeted kinase inhibitors, Abelson murine leukemia viral oncogene homolog inhibitors, and others. Each of these agents has a different mechanism through which it affects the cardiovascular system. ErbB2 inhibitors block the ErbB4/ErbB2 heterodimerization pathway triggered by Neuregulin-1, which is essential for cardiomyocyte survival. VEGF signaling is crucial for vascular growth, but it also has a major impact on myocardial function, and the VEGF pathway is also essential for maintenance of cardiovascular homeostasis. Drugs that inhibit the VEGF signaling pathway lead to a net reduction in capillary density and loss of contractile function. Here, we review the mechanisms and pathophysiology of the most significant cardiotoxic effects of ErbB2 inhibitors and antiangiogenic drugs. Moreover, we highlight the role of cardioncology in recognizing these toxicities, developing strategies to prevent or minimize cardiovascular toxicity, and reducing long-term cardiotoxic effects.

Management of QT prolongation induced by anti-cancer drugs: Target therapy and old agents. Different algorithms for different drugs

The side effects of anticancer drugs still play a critical role in survival and quality of life. Although the recent progresses of cancer therapies have significantly improved the prognosis of oncologic patients, side effects of antineoplastic treatments are still responsible for the increased mortality of cancer survivors. Cardiovascular toxicity is the most dangerous adverse effect induced by anticancer therapies. A survey conducted by the National Health and Nutrition Examination, showed that 1807 cancer survivors followed up for seven years: 51% died of cancer and 33% of heart disease (Vejpongsa and Yeh, 2014). Moreover, the risk of cardiotoxicity persists even with the targeted therapy, the newer type of cancer treatment, due to the presence of on-target and off-target effects related to this new class of drugs. The potential cardiovascular toxicity of anticancer agents includes: QT prolongation, arrhythmias, myocardial ischemia, stroke, hypertension (HTN), thromboembolism, left ventricular dysfunction and heart failure (HF). Compared to other cardiovascular disorders, the interest in QT prolongation and its complications is fairly recent. However, oncologists have to deal with it and to evaluate the risk-benefit ratio before starting the treatment or during the same. Electrolyte abnormalities, low levels of serum potassium and several drugs may favour the acquired QT prolongation. Treatment of marked QT prolongation includes cardiac monitoring, caution in the use or suspension of cancer drugs and correction of electrolyte abnormalities (hypokalaemia, hypomagnesaemia, hypocalcaemia). Syndrome of QT prolongation can be associated with potentially fatal cardiac arrhythmias and its treatment consists of intravenous administration of magnesium sulphate and the use of electrical cardioversion.

Comparison of efficacy, safety, and quality of life between sorafenib and sunitinib as first-line therapy for Chinese patients with metastatic renal cell carcinoma

Background

Sorafenib and sunitinib are widely used as first-line targeted therapy for metastatic renal cell carcinoma (mRCC) in China. This study aimed to compare the efficacy, safety, and quality of life (QoL) in Chinese mRCC patients treated with sorafenib and sunitinib as first-line therapy.

Methods

Clinical data of patients with mRCC who received sorafenib (400 mg twice daily; 4 weeks) or sunitinib (50 mg twice daily; on a schedule of 4 weeks on treatment followed by 2 weeks off) were retrieved. Primary outcomes were overall survival (OS), progression-free survival (PFS), adverse events (AEs), and QoL (SF-36 scores), and secondary outcomes were associations of clinical characteristics with QoL.

Results

Medical records of 184 patients (110 in the sorafenib group and 74 in the sunitinib group) were reviewed. PFS and OS were comparable between the sorafenib and sunitinib groups (both P > 0.05). The occurrence rates of leukocytopenia, thrombocytopenia, and hypothyroidism were higher in the sunitinib group (36.5% vs. 10.9%, P < 0.001; 40.5% vs. 10.9%, P < 0.001; 17.6% vs. 3.6%, P = 0.001), and that of diarrhea was higher in the sorafenib group (62.7% vs. 35.2%, P < 0.001). There was no significant difference in SF-36 scores between the two groups. Multivariate analysis indicated that role-physical and bodily pain scores were associated with the occurrence rate of grade 3 or 4 AEs (P = 0.017 and 0.005).

Conclusions

Sorafenib has comparable efficacy and lower toxicity profile than sunitinib as first-line therapy for mRCC. Both agents showed no significant impact on QoL of patients.

Biological toxicities as surrogate markers of efficacy in patients treated with mTOR inhibitors for metastatic renal cell carcinoma

Background

Metabolic toxicities of mTOR inhibitors (mTORi) are well characterized. The purpose of the study was to investigate the relationship between these metabolic toxicities and mTORi efficacy.

Methods

From 2007 to 2011, metabolic toxicities were retrospectively collected in patients treated with an mTORi (everolimus, temsirolimus) for a metastatic renal cell carcinoma (mRCC) in a single institution. Patients were eligible if they have received an mTORi for at least 28 days. Changes in the following parameters were analyzed: lymphocytes, serum creatinine, glycemia, serum phosphate, liver transaminases, cholesterol, and triglycerides. The efficacy was assessed by progression-free survival (PFS) and tumor response.

Results

Data were collected from seventy-five patients (everolimus = 44 patients; temsirolimus = 31 patients). Six patients exhibited a partial response, 42 a stable disease and 15 had a progressive disease (12 missing). After a median follow-up of 12.8 months, the median PFS was 6.7 months (95% confidence interval: 4.0-9.1 months). Patients with CB had a statistically more severe absolute increase of glycemia and absolute decrease in phosphatemia (p = 0.002 and p = 0.02 respectively). The Progression Free Survival was significantly higher with the onset rate of hypophosphatemia (p = 0.03) and hyperglycemia (p = 0.001) and lower with the onset rate of lymphopenia (p = 0.004).

Conclusions

Hyperglycemia, hypophosphatemia and lymphopenia, were significantly associated with tumor response and/or PFS. Those events, as well as their onset rate, should be prospectively monitored as predictors of response to mTORi.

Organ Atrophy Induced by Sorafenib and Sunitinib - Quantitative Computed Tomography (CT) Evaluation of the Pancreas, Thyroid Gland and Spleen

Background

To evaluate organ atrophy induced by sorafenib and sunitinib, we retrospectively reviewed the CT scans of renal cell carcinoma (RCC) patients receiving molecular targeted therapy (MTT) using sorafenib or sunitinib, and performed volumetric analysis of the pancreas, thyroid gland, and spleen.

Material/Methods

Thirteen RCC patients receiving MTT were assigned as the evaluation cases (MTT group), while thirteen additional RCC patients not receiving MTT were retrieved as the Control group. We evaluated the baseline and follow-up CT studies. The volume of the three organs estimated by CT volumetry was compared between the baseline and follow-up CTs. The atrophic ratio of the organ volume in the follow-up CT to that in the baseline CT was calculated, and compared between the MTT and Control groups.

Results

All measured organs in the MTT group showed statistically significant volume loss, while no significant change was observed in the Control group. Mean atrophic ratio in the MTT group was 0.74, 0.58, and 0.82 for the pancreas, thyroid and spleen, respectively. The differences in atrophic ratios between both groups were all statistically significant (P<0.05).

Conclusions

Single-agent sorafenib or sunitinib therapy induced statistically significant atrophy in the pancreas, thyroid, and spleen.

Judicious Toggling of mTOR Activity to Combat Insulin Resistance and Cancer: Current Evidence and Perspectives

The mechanistic target of rapamycin (mTOR), via its two distinct multiprotein complexes, mTORC1, and mTORC2, plays a central role in the regulation of cellular growth, metabolism, and migration. A dysregulation of the mTOR pathway has in turn been implicated in several pathological conditions including insulin resistance and cancer. Overactivation of mTORC1 and disruption of mTORC2 function have been reported to induce insulin resistance. On the other hand, aberrant mTORC1 and mTORC2 signaling via either genetic alterations or increased expression of proteins regulating mTOR and its downstream targets have contributed to cancer development. These underlined the attractiveness of mTOR as a therapeutic target to overcome both insulin resistance and cancer. This review summarizes the evidence supporting the notion of intermittent, low dose rapamycin for treating insulin resistance. It further highlights recent data on the continuous use of high dose rapamycin analogs and related second generation mTOR inhibitors for cancer eradication, for overcoming chemoresistance and for tumor stem cell suppression. Within these contexts, the potential challenges associated with the use of mTOR inhibitors are also discussed.

Hypertension and Angiotensin System Inhibitors in Patients with Metastatic Renal Cell Carcinoma

Arterial hypertension (HTN) is a class effect of anti-vascular endothelial growth factor (VEGF) therapies, including the monoclonal antibody bevacizumab. Data are conflicting regarding the role of the renin-angiotensin system on angiogenesis and recent data suggest that the use of angiotensin system inhibitors (ASIs; angiotensin receptor blockers or angiotensin-converting enzyme inhibitors) is associated with improved survival in metastatic renal cell carcinoma (mRCC), particularly when used with VEGF targeted therapies. The aim of this review is to discuss the available treatment options for mRCC and associated incidence of hypertension as well as summarize the known data about ASIs use and mRCC. Additionally, given that the optimal management of HTN remains unclear, we will focus on prevention strategies and propose potential therapeutic approaches.

The Nephrologist's Tumor: Basic Biology and Management of Renal Cell Carcinoma

Kidney cancer, or renal cell carcinoma (RCC), is a disease of increasing incidence that is commonly seen in the general practice of nephrology. However, RCC is under-recognized by the nephrology community, such that its presence in curricula and research by this group is lacking. In the most common form of RCC, clear cell renal cell carcinoma (ccRCC), inactivation of the von Hippel-Lindau tumor suppressor is nearly universal; thus, the biology of ccRCC is characterized by activation of hypoxia-relevant pathways that lead to the associated paraneoplastic syndromes. Therefore, RCC is labeled the internist's tumor. In light of this characterization and multiple other metabolic abnormalities recently associated with ccRCC, it can now be viewed as a metabolic disease. In this review, we discuss the basic biology, pathology, and approaches for treatment of RCC. It is important to distinguish between kidney confinement and distant spread of RCC, because this difference affects diagnostic and therapeutic approaches and patient survival, and it is important to recognize the key interplay between RCC, RCC therapy, and CKD. Better understanding of all aspects of this disease will lead to optimal patient care and more recognition of an increasingly prevalent nephrologic disease, which we now appropriately label the nephrologist's tumor.

Changes in metabolic profile, iron and ferritin levels during the treatment of metastatic renal cancer - A new potential biomarker?

Metastatic renal cell carcinoma (mRCC) develops in approximately 33% of all renal cancer patients. First line treatment of mRCC includes drugs such as sunitinib, temsirolimus and pazopanib, with overall survival now reaching up to 43,6months in patients with favorable-risk metastatic disease. Several side-effects in mRCC treatment, such as hypothyroidism, can be used as positive prognostic factors and indicate good response to therapy. Hypercholesterolemia and hypertriglyceridemia independent of hypothyroidism are reported as side-effects in temsirolimus treatment and recently in sunitinib treatment, but the exact mechanism and significance of the changes remains elusive. Most likely, metabolic changes are caused by inhibition of mechanistic target of rapamycin (mTOR), a positive target of tumor growth suppression, but also a regulator of iron homeostasis. There are no clinical studies reporting changes in iron and ferritin levels during mRCC biotherapy, but we hypothesize that inhibition of mTOR will also affect iron and ferritin levels. If both lipid and iron changes correlate, there is a high possibility that both changes are primarily caused by mTOR inhibition and the level of change should correlate with the inhibition of mTOR pathway and hence the efficacy of targeted treatment. We lastly hypothesize that mRCC biotherapy causes hypercholesterolemia with a possibly improved cholesterol profile due to increase HDL/LDL ratio, so statins might not have a role as supplementary treatment, whereas a sharp rise in triglyceride levels seems to be the primary target for additional therapy.

GLI2 expression levels in radical nephrectomy specimens as a predictor of disease progression in patients with metastatic clear cell renal cell carcinoma following treatment with sunitinib

The aim of the present study was to investigate the role of the Hedgehog signaling pathway in the progression of metastatic clear cell renal cell carcinoma (m-ccRCC) as well as the molecular targets of sunitinib, an inhibitor of multiple tyrosine kinases. A total of 39 patients subjected to radical nephrectomy who were diagnosed with m-ccRCC and were subsequently treated with sunitinib were enrolled in the present study. The expression levels of the Hedgehog signaling proteins (GLI1, GLI2, cyclin D1, cyclin E and transforming growth factor-β) and major molecular targets of sunitinib [vascular endothelial growth factor receptor (VEGFR)-1 and −2, and platelet-derived growth factor receptor-α and -β] in primary RCC specimens were assessed by immunohistochemical staining. The expression levels of GLI2, VEGFR-1, VEGFR-2 and pre-treatment C-reactive protein as well as the Memorial Sloan-Kettering Cancer Center risk were identified as significant predictors of progression-free survival (PFS). Of these, only GLI2 expression was independently correlated to PFS according to multivariate analysis. Furthermore, treatment with sunitinib resulted in a marked inhibition of GLI2 expression in the parental human RCC ACHN cell line, but not in ACHN cells with acquired resistance to sunitinib. These findings suggested that GLI2 may be involved in the acquisition of resistance to sunitinib in RCC; thus, it may be useful to consider the expression levels of GLI2 in addition to conventional prognostic parameters when selecting m-ccRCC patients likely to benefit from treatment with sunitinib.

Drug-induced hepatotoxicity in cancer patients - implication for treatment

INTRODUCTION

All anticancer drugs can cause idiosyncratic liver injury. Therefore, hepatoprotective agents assume particular importance to preserve liver function. Hepatic injury represents 10% of cases of acute hepatitis in adults; drug-related damage is still misjudged because of relative clinical underestimation and difficult differential diagnosis. Chemotherapeutic agents can produce liver toxicity through different pathways, resulting in different categories of liver injuries, but these drugs are not homogeneously hepatotoxic. Frequently, anticancer-induced hepatotoxicity is idiosyncratic and influenced by multiple factors.

AREAS COVERED

The aim of this paper is to perform a review of the literature regarding anticancer-induced liver toxicity. We described hepatotoxicity mechanisms of principal anticancer agents and respective dose reductions. Furthermore, we reviewed studies on hepatoprotectors and their optimal use. Tiopronin, magnesium isoglycyrrhizinate and S-Adenosylmethionine (AdoMet) demonstrated, in some small studies, a potential hepatoprotective activity.

EXPERT OPINION

Actually, in the literature only small experiences are reported. Even though hepatoprotective agents seem to be useful in the oncologic setting, the lack of well-designed prospective Phase III randomized controlled trials is a major limit in the introduction of hepatoprotectors in cancer patients and these kind of studies are warranted to support their use and to give further recommendations for the clinical practice.

Kinase signalling pathways in endometriosis: potential targets for non-hormonal therapeutics

BACKGROUND

Endometriosis, the growth of endometrial tissue outside the uterine cavity, is associated with chronic pelvic pain, subfertility and an increased risk of ovarian cancer. Current treatments include the surgical removal of the lesions or the induction of a hypoestrogenic state. However, a reappearance of the lesion after surgery is common and a hypoestrogenic state is less than optimal for women of reproductive age. Additional approaches are required. Endometriosis lesions exist in a unique microenvironment characterized by increased concentrations of hormones, inflammation, oxidative stress and iron. This environment influences cell survival through the binding of membrane receptors and a subsequent cascading activation of intracellular kinases that stimulate a cellular response. Many of these kinase signalling pathways are constitutively activated in endometriosis. These pathways are being investigated as therapeutic targets in other diseases and thus may also represent a target for endometriosis treatment.

METHODS

To identify relevant English language studies published up to 2015 on kinase signalling pathways in endometriosis, we searched the Pubmed database using the following search terms in various combinations; 'endometriosis', 'inflammation', 'oxidative stress', 'iron', 'kinase', 'NF kappa', 'mTOR', 'MAPK' 'p38', 'JNK', 'ERK' 'estrogen' and progesterone'. Further citing references were identified using the Scopus database and finally current clinical trials were searched on the clinicaltrials.gov trial registry.

RESULTS

The current literature on intracellular kinases activated by the endometriotic environment can be summarized into three main pathways that could be targeted for treatments: the canonical IKKβ/NFκB pathway, the MAPK pathways (ERK1/2, p38 and JNK) and the PI3K/AKT/mTOR pathway. A number of pharmaceutical compounds that target these pathways have been successfully trialled in in vitro and animal models of endometriosis, although they have not yet proceeded to clinical trials. The current generation of kinase inhibitors carry a potential for adverse side effects.

CONCLUSIONS

Kinase signalling pathways represent viable targets for endometriosis treatment. At present, however, further improvements in clinical efficacy and the profile of adverse effects are required before these compounds can be useful for long-term endometriosis treatment. A better understanding of the molecular activity of these kinases, including the specific extracellular compounds that lead to their activation in endometriotic cells specifically should facilitate their improvement and could potentially lead to new, non-hormonal treatments of endometriosis.

Influence of Sorafenib and Bevacizumab on pancreatic volume - A monocentric CT based analysis

BACKGROUND/OBJECTIVES

Angiogenesis plays a central role in tumor growth and metastasis and tyrosine kinases are crucial in the modulation of growth factor signaling. Several side effects of tyrosine kinase inhibitors have been reported, including diarrhea due to pancreatic insufficiency. The suspected mechanism is the anti-angiogenetic effect of the inhibited vascular endothelial growth factor (VEGF) causing a disturbance of the microvasculation. The aim of the present study was to determine the volume of the pancreas before and after a therapy both with the multi-tyrosine kinase inhibitor Sorafenib and Bevacizumab, which is a humanized monoclonal immunoglobulin G1 antibody against VEGF.

METHODS

Retrospective monocentric study including 42 patients who received either Sorafenib, Bevacizumab combined with Flourouracil and/or Irinotecan, or singly Flourouracil and Irinotecan for different non-pancreatic malignancies. The volume of the pancreas was measured before and after therapy by CT-scan based volumetry.

RESULTS

The pancreatic volume was statistically significantly lower after treatment with Sorafenib (75.4 mL vs. 71.0 mL; p = 0.006) or Bevacizumab and Fluorouracil ± Irinotecan (71.8 mL vs. 62.6 mL; p = 0.020). The pancreatic volume did not change statistically significantly after treatment with Fluorouracil ± Irinotecan only (51.1 mL vs. 49.9 mL; p = 0.142).

CONCLUSIONS

Pancreatic volume decreases statistically significantly under treatment with both the multi-tyrosine kinase inhibitor Sorafenib and the angiogenesis inhibitor Bevacizumab. This volume reduction is most likely due to a reduced microvasculation by inhibition of VEGF.

Adverse reactions in mRCC patients documented in routine practice by German office-based oncologists and uro-oncologists

Background Signal transduction inhibitors (STIs) have considerably improved treatment of advanced/metastasized renal cell carcinoma (mRCC). Most safety data for these drugs are derived from clinical trials. The purpose of this study was to evaluate which adverse drug reactions are documented during first-line treatments in routine clinical practice. Patients and methods The ongoing prospective German mRCC clinical registry is recruiting patients in 110 oncology and urology outpatient centers. Data from the first 250 patients who had completed first-line treatment were analyzed regarding adverse drug reactions (ADRs) documented in patients' medical records. Results Patients were older than in clinical trials and had comorbidities. Patients were treated with the STIs sunitinib (61%), temsirolimus (14%), sorafenib (10%), or bevacizumab combined with interferon (6%). About 520 ADRs were documented, of which 29% resulted in treatment modifications. The most frequently affected organ system was the gastrointestinal system. The most frequently documented ADRs were mucositis/stomatitis (14%), fatigue (14%), diarrhea (12%), and nausea (12%). Conclusions In routine practice, mRCC first-line treatments using STIs frequently lead to ADRs partly necessitating treatment modifications. The pattern of reported ADRs is similar to that reported in clinical trials, but frequencies of events differ, especially for symptoms of multifactorial origin that are not immediately associated with the treatment. These results indicate that perception and documentation of adverse reactions is different between clinical trials and routine practice, and that reviews of patients' medical records might not be the best method to assess safety in routine practice.

Management of poor-risk metastatic renal cell carcinoma: current approaches, the role of temsirolimus and future directions

Targeted therapies have substantially improved outcomes in metastatic renal cell carcinoma (mRCC). As expected, poor-risk patients have the worst outcomes. Temsirolimus is currently the only agent licensed for treatment of poor-risk mRCC patients. It is associated with meaningful improvements in survival and quality of life, highlighting the importance of correctly stratifying risk in mRCC patients so they receive optimal treatment. Currently, data for other targeted therapies in poor-risk patients are relatively sparse. Optimizing outcomes in these patients is the subject of ongoing research, including studies of biomarkers and studies to elucidate the role of nephrectomy and neoadjuvant targeted therapy in poor-risk mRCC patients. The impacts of novel combinations including temsirolimus have also been explored to further improve outcomes.

Pharmacoeconomic and clinical implications of sequential therapy for metastatic renal cell carcinoma patients in Central and Eastern Europe

INTRODUCTION

The incidence and mortality rates of kidney cancer in the Central and Eastern European (CEE) region are among the highest in the world. Access to second and subsequent lines of metastatic renal cell carcinoma (mRCC) therapies is highly varied in the region. Despite the increasing body of evidence supporting the clinical benefit of multiple lines of treatment, access to treatment beyond first line is restricted in many of these countries.

AREAS COVERED

The adoption of targeted therapies for the first-line treatment of mRCC in the region was slow and faced many obstacles. In order to evaluate the current status of treatment beyond the first-line setting in the CEE region, this review examines the availability and reimbursement of mRCC drugs and clinical practice in institutions that treat patients with mRCC.

EXPERT OPINION

This review highlights the need to raise awareness among physicians, payers and regulators on clinical trial and cost-effectiveness data regarding the treatment of mRCC beyond the first line. The obstacles to mRCC drug access highlighted in this review need to be overcome to ensure that patients are receiving the best treatment available.

Dose-Dependent Mutation Rates Determine Optimum Erlotinib Dosing Strategies for EGFR Mutant Non-Small Cell Lung Cancer Patients

BACKGROUND

The advent of targeted therapy for cancer treatment has brought about a paradigm shift in the clinical management of human malignancies. Agents such as erlotinib used for EGFR-mutant non-small cell lung cancer or imatinib for chronic myeloid leukemia, for instance, lead to rapid tumor responses. Unfortunately, however, resistance often emerges and renders these agents ineffective after a variable amount of time. The FDA-approved dosing schedules for these drugs were not designed to optimally prevent the emergence of resistance. To this end, we have previously utilized evolutionary mathematical modeling of treatment responses to elucidate the dosing schedules best able to prevent or delay the onset of resistance. Here we expand on our approaches by taking into account dose-dependent mutation rates at which resistant cells emerge. The relationship between the serum drug concentration and the rate at which resistance mutations arise can lead to non-intuitive results about the best dose administration strategies to prevent or delay the emergence of resistance.

METHODS

We used mathematical modeling, available clinical trial data, and different considerations of the relationship between mutation rate and drug concentration to predict the effectiveness of different dosing strategies.

RESULTS

We designed several distinct measures to interrogate the effects of different treatment dosing strategies and found that a low-dose continuous strategy coupled with high-dose pulses leads to the maximal delay until clinically observable resistance. Furthermore, the response to treatment is robust against different assumptions of the mutation rate as a function of drug concentration.

CONCLUSIONS

For new and existing targeted drugs, our methodology can be employed to compare the effectiveness of different dose administration schedules and investigate the influence of changing mutation rates on outcomes.

Development of chronic myeloid leukaemia in patients treated with anti-VEGF therapies for clear cell renal cell cancer

Tyrosine kinase inhibitors are novel therapies targeting specific cellular signalling pathways. Sunitinib and sorafenib primarily block tyrosine kinase receptors involved in the progression of many tumours, including clear cell renal cell cancer (ccRCC). Although developed to target selected receptors, it is becoming apparent that they inhibit other kinases; this may result in the development of unexpected side effects. This is potentially dangerous as kinases on noncancerous cells are also inhibited. TKI off-target effects contributing to cardiotoxicity, hypothyroidism, hypertension, fatigue, hair depigmentation, hand-foot syndrome and gastrointestinal perforation have been described. We report three patients (3/412) treated with sunitinib and sorafenib who developed chronic myeloid leukaemia (CML) during treatment for ccRCC, proposing a molecular mechanism of tyrosine kinase inhibitors action on bone marrow cells that might be co-responsible for CML development.

Overview and management of toxicities associated with systemic therapies for advanced renal cell carcinoma

The advent of novel targeted agents for metastatic renal cell carcinoma (RCC) has offered clinical benefits over traditional immunotherapy (e.g., interleukin-2 and interferon-α) in both efficacy and safety profiles. The major classes of these targeted therapies for metastatic RCC include the tyrosine-kinase inhibitors, monoclonal antibody against vascular endothelial growth factor, and inhibitors of the mammalian target of rapamycin. Most recently, the success of immune checkpoint inhibitors--notably antibodies directed against programmed death-1 and its ligand--has also been demonstrated in RCC. With such progress in therapy, early detection, and subsequent management of treatment-related adverse events allow for patients to remain on active therapy for as long as possible and also enhance the probability of patients tolerating subsequent second line options. However, despite such impressive gains in efficacy with these new agents, therapeutic progress are primarily palliative in nature--hence, the critical importance of minimizing discomfort and potential harm in this patient population cannot be understated.

Therapeutic effects and associated adverse events of multikinase inhibitors in metastatic renal cell carcinoma: A meta-analysis

This study aimed to compare the therapeutic effects and adverse events of the multikinase inhibitors sorafenib, sunitinib, pazopanib and axitinib in advanced renal cell carcinoma (RCC). A meta-analysis of randomized controlled trials was performed to assess the effects of multikinase inhibitors among patients with advanced RCC. The data of median progression-free survival (PFS), median overall survival (OS), progressive disease rate (PDR), objective response rate (ORR) and grade 3/4 adverse events were extracted to assess therapeutic effects and toxicity, respectively. It was found that multikinase inhibitors are more effective in extending PFS [hazard ratio (HR)=0.58; 95% confidence interval (CI): 0.45-0.74; P<0.0001), controlling tumor progression [relative risk (RR)=0.67; 95% CI: 0.55-0.83; P=0.0002) and ORR (RR=2.93; 95% CI: 1.40-6.14; P=0.004) compared with placebo or interferon-α. Patients treated with multikinase inhibitors had significantly higher rates of grade 3 or 4 hypertension (RR=6.00; 95% CI: 3.36-10.69; P<0.00001), diarrhea (RR=5.84; 95% CI: 3.06-11.16; P<0.00001), nausea (RR=2.30; 95% CI: 1.16-4.54; P=0.02), vomiting (RR=1.84; 95% CI: 1.00-3.41; P=0.05) and hand-foot skin reaction (RR=11.78; 95% CI: 5.16-26.93; P<0.00001). Multikinase inhibitors can significantly control disease progress and improve the ORR. However, they are also associated with a higher risk of grade 3 and 4 hypertension and gastrointestinal events. Proper management of these events is necessary to improve patient quality of life.

Social-ecological correlates of physical activity in kidney cancer survivors

PURPOSE

Previous studies in cancer survivors have examined behavioral correlates of physical activity (PA), but no study to date has adopted a broader social-ecological framework in understanding PA. This study examined the associations among demographic, medical, social-cognitive, and environmental correlates of meeting PA guidelines among kidney cancer survivors (KCS).

METHODS

All 1985 KCS diagnosed between 1996 and 2010 identified through a Canadian provincial registry were mailed a survey that consisted of medical, demographic, and social-cognitive measures, as well as PA as measured by the Godin Leisure Time Exercise Questionnaire. Environmental constructs were also assessed for both self-report and objective measures using geographic information systems (GIS). A series of binary logistic regression analyses were conducted in this cross-sectional study.

RESULTS

Completed surveys with geographical information were received from 432 KCS with M age = 64.4 ± 11.1 years, 63.2 % male, and 82.2 % having localized kidney cancer. In the final multivariate model, meeting PA guidelines was associated with disease stage (OR = 0.25, p = .005), having drug therapy (OR = 3.98, p = .009), higher levels of instrumental attitudes (OR = 1.66, p = .053), higher levels of intention (OR = 1.72, p = .002), and the perceived presence of many retail shops in the neighborhood (OR = 1.37, p = .032).

CONCLUSIONS

Meeting PA guidelines in KCS were associated with various aspects of the social-ecological model.

IMPLICATIONS FOR CANCER SURVIVORS

Understanding the social-ecological correlates for PA can provide insight into future interventions designed to increase PA in KCS. Prime targets for PA promotion should consider treatment-related factors, promote the benefits of PA, and enhance positive perceptions of the built environment.

Long-term therapy with sorafenib is associated with pancreatic atrophy

BACKGROUND

Although the short-term adverse effects of sorafenib are well known, few data exist on long-term toxicity. The objective of the present study was to investigate the prevalence of pancreatic atrophy among a cohort of patients with hepatocellular carcinoma (HCC) who were treated with sorafenib for ≥2 y.

METHODS

Between March 2007 and December 2013, 31 patients with HCC who were treated with sorafenib for ≥2 y were identified. The effect of pancreatic atrophy and enhancement on incidence of adverse events, tumor response, and overall survival (OS) were assessed.

RESULTS

Thirty-one patients with HCC were treated with sorafenib for ≥2 y and met inclusion criteria; 11 patients (35.5%) were Barcelona-clinic liver cancer stage B, whereas 20 patients (64.5%) were Barcelona-clinic liver cancer stage C. Median duration of treatment with sorafenib was 35.2 mo. Pancreatic atrophy and a decrease in pancreatic enhancement occurred in 24 patients (77.4%) and 15 patients (48.4%), respectively. On the basis of the modified response evaluation criteria in solid tumors, four patients (12.9%) had a complete response, 10 patients (32.3%) had a partial response, and 17 patients (54.8%) had stable disease. Patients treated with sorafenib with pancreatic atrophy had a median OS of 49.4 mo (95% confidence interval, 41.2-57.5 mo) compared with 31.2 mo (95% confidence interval, 25.7-36.7 mo) among patients who did not develop pancreatic atrophy (P = 0.009). In contrast, survival was not associated with decreased versus normal enhancement of the pancreas (OS, 47.7 mo versus 41.7 mo, respectively; P = 0.739).

CONCLUSIONS

Pancreatic atrophy occurred in many HCC patients after 2 y of treatment with sorafenib. Patients who experienced pancreatic atrophy had a better tumor response and OS.

The prevention, detection and management of cancer treatment-induced cardiotoxicity: a meta-review

BACKGROUND

The benefits associated with some cancer treatments do not come without risk. A serious side effect of some common cancer treatments is cardiotoxicity. Increased recognition of the public health implications of cancer treatment-induced cardiotoxicity has resulted in a proliferation of systematic reviews in this field to guide practice. Quality appraisal of these reviews is likely to limit the influence of biased conclusions from systematic reviews that have used poor methodology related to clinical decision-making. The aim of this meta-review is to appraise and synthesise evidence from only high quality systematic reviews focused on the prevention, detection or management of cancer treatment-induced cardiotoxicity.

METHODS

Using Cochrane methodology, we searched databases, citations and hand-searched bibliographies. Two reviewers independently appraised reviews and extracted findings. A total of 18 high quality systematic reviews were subsequently analysed, 67 % (n = 12) of these comprised meta-analyses.

RESULTS

One systematic review concluded that there is insufficient evidence regarding the utility of cardiac biomarkers for the detection of cardiotoxicity. The following strategies might reduce the risk of cardiotoxicity: 1) The concomitant administration of dexrazoxane with anthracylines; 2) The avoidance of anthracyclines where possible; 3) The continuous administration of anthracyclines (>6 h) rather than bolus dosing; and 4) The administration of anthracycline derivatives such as epirubicin or liposomal-encapsulated doxorubicin instead of doxorubicin. In terms of management, one review focused on medical interventions for treating anthracycline-induced cardiotoxicity during or after treatment of childhood cancer. Neither intervention (enalapril and phosphocreatine) was associated with statistically significant improvement in ejection fraction or mortality.

CONCLUSION

This review highlights the lack of high level evidence to guide clinical decision-making with respect to the detection and management of cancer treatment-associated cardiotoxicity. There is more evidence with respect to the prevention of this adverse effect of cancer treatment. This evidence, however, only applies to anthracycline-based chemotherapy in a predominantly adult population. There is no high-level evidence to guide clinical decision-making regarding the prevention, detection or management of radiation-induced cardiotoxicity.

Sunitinib dosing schedule 2/1 improves tolerability, efficacy, and health-related quality of life in Chinese patients with metastatic renal cell carcinoma

PURPOSE

To assess the efficacy and tolerability of sunitinib dosing schedule of 2 weeks on and 1 week off (schedule 2/1) vs. the traditional schedule of 4 weeks on and 2 week off (schedule 4/2) and its influence on health-related quality of life (HRQoL) in Chinese patients with metastatic renal cell carcinoma (mRCC).

MATERIALS AND METHODS

A retrospective analysis of 108 patients with mRCC who were treated with sunitinib regimens (50mg daily) between January 2009 and July 2013 was undertaken. Overall, 3 groups of patients were studied according to the dosing schedule they received: schedule 4/2 (n = 50), transitional schedule 2/1 (T2/1; patients switched from schedule 4/2 to 2/1; n = 26), and initial schedule 2/1 (I2/1; n = 32). The tumor response, progression-free survival (PFS) time, adverse events, and HRQoL were assessed and compared among the groups.

RESULTS

The incidences of diarrhea, fatigue, hand-foot syndrome, and neutropenia induced by the treatment of sunitinib were all significantly less common with schedule I2/1 and T2/1 than with schedule 4/2 (P<0.05). Although there was no statistically significant difference in the tumor response among the 3 groups, the median PFS time was significantly longer with schedule I2/1 than with schedules T2/1 and 4/2 (11.2 vs. 9.4 and 9.5mo, respectively, P = 0.030), and HRQoL (as determined by 19-item Functional Assessment of Cancer Therapy Kidney Symptom Index scores) was better.

CONCLUSIONS

Treatment with sunitinib 50mg daily using a 2/1 dosing schedule can provide better tolerability and a longer PFS with better HRQoL in Chinese patients with mRCC than the traditional schedule 4/2.

Efficacy and tolerability of a low-dose, 2-week administration of sunitinib followed by a week rest (2/1 schedule) for metastatic renal cell carcinoma: a single center experience of six cases

Background

Sunitinib, an oral multitarget tyrosine kinase inhibitor and standard first-line treatment for metastatic renal cell carcinoma (mRCC), is generally administered on a 6-week schedule (4 weeks on/2 weeks off). However, drug toxicity often leads to temporary treatment interruption, resulting in reduced treatment efficacy. In this report, we investigated whether sunitinib administration of at a dose of 25 mg/day in a 2-weeks-on/1-week-off cycle would reduce the incidence of drug-related side effects while maintaining drug efficacy.

Findings

A total of six patients with mRCC were orally administered sunitinib at a dose of 25 mg/day in a 2-weeks-on/1-week-off regimen until intolerable toxicities occurred. All enrolled patients were assessed for toxicity and response. The median treatment period was 24 months (range, 9–40 months). Objective responses were as follows: disease stabilization of >6 months was achieved in all patients. The most important toxicities were neutropenia, fatigue, and proteinuria, but all were controlled.

Conclusions

Oral sunitinib at 25 mg/day in a 2-weeks-on/1-week-off regimen to Japanese patients can avoid drug-related toxicities while achieving the same dose intensity as a 6-week schedule. Because these data were derived from a small number of patients, future prospective studies of modified sunitinib administration schedules are warranted.

Population pharmacokinetic analysis of axitinib in healthy volunteers

AIMS

Axitinib is a potent and selective second generation inhibitor of vascular endothelial growth factor receptors 1, 2 and 3 approved for second line treatment of advanced renal cell carcinoma. The objectives of this analysis were to assess plasma pharmacokinetics and identify covariates that may explain variability in axitinib disposition following single dose administration in healthy volunteers.

METHODS

Plasma concentration-time data from 337 healthy volunteers in 10 phase I studies were analyzed, using non-linear mixed effects modelling (nonmem) to estimate population pharmacokinetic parameters and evaluate relationships between parameters and food, formulation, demographic factors, measures of renal and hepatic function and metabolic genotypes (UGT1A1*28 and CYP2C19).

RESULTS

A two compartment structural model with first order absorption and lag time best described axitinib pharmacokinetics. Population estimates for systemic clearance (CL), central volume of distribution (Vc ), absorption rate constant (ka ) and absolute bioavailability (F) were 17.0 l h(-1) , 45.3 l, 0.523 h(-1) and 46.5%, respectively. With axitinib Form IV, ka and F increased in the fasted state by 207% and 33.8%, respectively. For Form XLI (marketed formulation), F was 15% lower compared with Form IV. CL was not significantly influenced by any of the covariates studied. Body weight significantly affected Vc , but the effect was within the estimated interindividual variability for Vc .

CONCLUSIONS

The analysis established a model that adequately characterizes axitinib pharmacokinetics in healthy volunteers. Vc was found to increase with body weight. However, no change in plasma exposures is expected with change in body weight; hence no dose adjustment is warranted.

Hepatotoxicity of molecular targeted therapy

A constant increase in occurrence of neoplasms is observed; hence new methods of therapy are being intensively researched. One of the methods of antineoplastic treatment is molecular targeted therapy, which aims to influence individual processes occurring in cells. Using this type of medications is associated with unwanted effects resulting from the treatment. Liver damage is a major adverse effect diagnosed during targeted therapy. Drug-induced liver damage can occur as necrosis of hepatocytes, cholestatic liver damage and cirrhosis. Hepatotoxicity is evaluated on the basis of International Consensus Criteria. Susceptibility of the liver to injury is connected not only with toxicity of the used medications but also with metastasis, coexistence of viral infections or other chronic diseases as well as the patient's age. It has been proven that in most cases the liver injury is caused by treatment with multikinase inhibitors, in particular tyrosine kinase inhibitors. The Food and Drug Administration (FDA) ordered the inclusion of additional labels – so-called “black box warnings” – indicating increased risk of liver injury when treating with pazopanib, sunitinib, lapatinib and regorafenib. A meta-analysis published in 2013 showed that treating neoplastic patients with tyrosine kinase inhibitors can increase the risk of drug-induced liver damage at least twofold. Below the mechanisms of drug-induced liver injury and hepatotoxic effects of molecular targeted therapy are described.

Bevacizumab-related toxicities in the National Cancer Institute malignant glioma trial cohort

Bevacizumab is an antiangiogenic agent approved for recurrent glioblastoma due to high response rates. Prior reviews focused on severe or cardiovascular bevacizumab toxicities. We performed a comprehensive review of toxicities experienced among 210 patients enrolled in 3 phase II bevacizumab trials for recurrent malignant gliomas at the National Cancer Institute. No bevacizumab toxicities were experienced by 20 % patients, 40.2 % on monotherapy versus ≤9.5 % on combination therapy. Hypertension and proteinuria occurred in ~25 %. Fatigue, hypophosphatemia, aspartate aminotransferase elevation, rashes were common. Low grade headache, hoarseness, myalgias/arthralgias, liver enzyme elevation, azotemia and electrolyte abnormalities were noted. Rare severe toxicities, including thrombosis, hemorrhage, wound complications and colonic perforations, occurred at rates seen in other diseases. Leukopenia and neutropenia occurred solely with combination therapy, while thrombocytopenia occurred in 12.5 % on bevacizumab monotherapy. Thrombocytopenia was generally mild, but severe in (1.4 %) and increased in frequency with prolonged or combination therapy. Bevacizumab-related deaths occurred in 4 (1.9 %) patients, including brain ischemia (n = 1) and sudden unexplained deaths (n = 2). Prior hypertension increased the odds of hypertension by ≥3.4-fold (p < 0.001) and grade 3+ hypertension by ≥11.2 (p < 0.001). Prior hypertension increased the odds of hypophosphatemia by 2.4-fold (p = 0.011), but failed to predict proteinuria or azotemia. Age did not greatly impact toxicity. Hypertension, proteinuria and hypophosphatemia often occurred concurrently, more frequently and severely with prolonged use. Our study shows bevacizumab monotherapy is well tolerated, but toxicity increases with combination therapy. Balancing the risks and benefits of bevacizumab requires understanding the spectrum of bevacizumab toxicities and predisposing factors.

Recognizing and managing left ventricular dysfunction associated with therapeutic inhibition of the vascular endothelial growth factor signaling pathway

OPINION STATEMENT

Therapeutic inhibition of the vascular endothelial growth factor (VEGF) signaling pathway (VSP) is increasingly employed in the contemporary treatment of many cancer types. VSP inhibitors include the anti-VEGF monoclonal antibody (bevacizumab), soluble VEGF receptors (VEGF Trap), and small molecule tyrosine kinase inhibitors (TKIs) targeting the intracellular kinase domain of VEGF receptors. These agents are associated with cardiovascular toxicities such as hypertension, thrombosis, myocardial ischemia, and left ventricular (LV) dysfunction. Data on VSP inhibitor-associated LV dysfunction are largely limited to retrospective studies. Prospective studies are needed to establish the clinical significance of VSP inhibitor-associated LV dysfunction in the general population. Pre-clinical models of VSP inhibitor-associated LV dysfunction have identified mechanisms of cardiotoxicity and may improve our understanding of the pathophysiology underlying other cardiomyopathies. This review provides an overview of LV dysfunction that can occur in patients treated with VSP inhibitors. Potential strategies for clinical detection and management of this cardiotoxicity are explored, while acknowledging that currently available data specific to VSP-inhibitor LV dysfunction are limited. Avenues for future research are suggested.

A design principle underlying the paradoxical roles of E3 ubiquitin ligases

E3 ubiquitin ligases are important cellular components that determine the specificity of proteolysis in the ubiquitin-proteasome system. However, an increasing number of studies have indicated that E3 ubiquitin ligases also participate in transcription. Intrigued by the apparently paradoxical functions of E3 ubiquitin ligases in both proteolysis and transcriptional activation, we investigated the underlying design principles using mathematical modeling. We found that the antagonistic functions integrated in E3 ubiquitin ligases can prevent any undesirable sustained activation of downstream genes when E3 ubiquitin ligases are destabilized by unexpected perturbations. Interestingly, this design principle of the system is similar to the operational principle of a safety interlock device in engineering systems, which prevents a system from abnormal operation unless stability is guaranteed.

Characterizing fatigue associated with sunitinib and its impact on health-related quality of life in patients with metastatic renal cell carcinoma

BACKGROUND

Using phase 3 trial data for sunitinib versus interferon (IFN)-α in treatment-naive patients with metastatic renal cell carcinoma, retrospective analyses characterized sunitinib-associated fatigue and its impact on patient-reported health-related quality of life (HRQoL).

METHODS

Patients received sunitinib at a dose of 50 mg/day on a schedule of 4 weeks on/2 weeks off (375 patients) or IFN-α at a dose of 9 MU subcutaneously 3 times per week (360 patients). HRQoL was self-assessed using the Functional Assessment of Cancer Therapy-Kidney Symptom Index-15-item (FKSI-15) questionnaire, with fatigue assessed using its Disease-Related Symptoms subscale. Fatigue was also assessed by providers using Common Terminology Criteria for Adverse Events (CTCAE). A repeated-measures model (M1) and random intercept-slope model (M2) characterized sunitinib-associated fatigue over time. Another repeated-measures model examined the relationship between HRQoL scores and CTCAE fatigue grade.

RESULTS

M1 demonstrated that the initial increase in patient-reported fatigue with sunitinib was worst during cycle 1, with mean values numerically better at subsequent cycles; most pairwise comparisons of consecutive CTCAE fatigue cycle means were not found to be statistically significant. M2 demonstrated that the overall trend (slope) for patient-reported and CTCAE fatigue with sunitinib was not statistically different from 0. The relationship between most HRQoL scores and CTCAE fatigue was close to linear regardless of treatment, with lower scores (worse HRQoL) corresponding to higher fatigue grade. The majority of HRQoL scores were better with sunitinib versus IFN-α for the same CTCAE fatigue grade.

CONCLUSIONS

Patients reported worse fatigue during the first sunitinib cycle. However, in subsequent consecutive cycles, less fatigue was reported with no statistically significant worsening. CTCAE fatigue assessment may not fully capture patient treatment experience.