Sunitinib in patients with metastatic renal cell carcinoma

Localization of sunitinib in in vivo animal and in vitro experimental models by MALDI mass spectrometry imaging

The spatial distribution of an anticancer drug and its intended target within a tumor plays a major role on determining how effective the drug can be at tackling the tumor. This study provides data regarding the lateral distribution of sunitinib, an oral antiangiogenic receptor tyrosine kinase inhibitor using an in vitro animal model as well as an in vitro experimental model that involved deposition of a solution of sunitinib onto tissue sections. All tumor sections were analyzed by matrix-assisted laser desorption/ionization mass spectrometry imaging and compared with subsequent histology staining. Six tumors at four different time points after commencement of in vivo sunitinib treatment were examined to observe the patterns of drug uptake. The levels of sunitinib present in in vivo treated tumor sections increased continuously until day 7, but a decrease was observed at day 10. Furthermore, the in vitro experimental model was adjustable to produce a drug level similar to that obtained in the in vivo model experiments. The distribution of sunitinib in tissue sections treated in vitro appeared to agree with the histological structure of tumors, suggesting that this approach may be useful for testing drug update.

Sunitinib as a paradigm for tyrosine kinase inhibitor development for renal cell carcinoma

OBJECTIVES

To describe the drug development and regulatory approval process for tyrosine kinase inhibitors in renal cell carcinoma using sunitinib as a model drug.

METHODS AND MATERIALS

Key findings from pivotal clinical trials that contributed to regulatory approval and drug development were reviewed.

RESULTS

The pathway of development for sunitinib starts from preclinical models to a phase I clinical trial followed by 2 phase II clinical trials for Food and Drug Administration accelerated approval and a phase III clinical trial for Food and Drug Administration standard approval. After standard approval, optimal dosing and use in the adjuvant setting were further explored. As an established first-line therapy for renal cell carcinoma, sunitinib is now used as a comparator arm for other drugs.

CONCLUSIONS

The development of sunitinib is a model example of "bench to bedside" work in renal cell carcinoma and may provide a framework for the development of other drugs.

Resistance to sunitinib in renal cell carcinoma: From molecular mechanisms to predictive markers and future perspectives

The introduction of agents that inhibit tumor angiogenesis by targeting vascular endothelial growth factor (VEGF) signaling has made a significant impact on the survival of patients with metastasized renal cell carcinoma (RCC). Sunitinib, a tyrosine kinase inhibitor of the VEGF receptor, has become the mainstay of treatment for these patients. Although treatment with sunitinib substantially improved patient outcome, the initial success is overshadowed by the occurrence of resistance. The mechanisms of resistance are poorly understood. Insight into the molecular mechanisms of resistance will help to better understand the biology of RCC and can ultimately aid the development of more effective therapies for patients with this infaust disease. In this review we comprehensively discuss molecular mechanisms of resistance to sunitinib and the involved biological processes, summarize potential biomarkers that predict response and resistance to treatment with sunitinib, and elaborate on future perspectives in the treatment of metastasized RCC.

Phase I trial of sunitinib and temsirolimus in metastatic renal cell carcinoma

BACKGROUND

Preclinical data suggest that anti-vascular endothelial growth factor agents combined with mammalian target of rapamycin inhibitors yield synergistic antitumor effects. A phase I trial with a 3+3 dose escalation design of S with T was stopped after the first dose pair led to 2 of 3 patients experiencing dose-limiting toxicity (DLT).

PATIENTS AND METHODS

To explore multiple potential dosing pairs of S and T, a 2-stage outcome-adaptive Bayesian dose-finding method was designed. The primary objective was to find the MTD of S and T in patients with advanced renal cell carcinoma. A 3-week treatment cycle consisted of daily S, 2 weeks of treatment, 1 week without treatment, and weekly T.

RESULTS

Twenty patients received study drugs; the median number of previous therapies was 1. The number of patients (S and T doses in mg) was: 2 (S, 12.5; T, 6), 1 (S, 25; T, 12.5), 1 (S, 12.5; T, 8), 8 (S, 12.5 alternate 25; T, 9), 2 (S, 25; T, 6), 2 (S, 25 alternate 37.5; T, 6), 2 (S, 37.5; T, 6), and 2 (S, 37.5; T, 8). Six patients required dose reduction, 3 because of Grade 3 stomatitis, 2 because of Grade 3 thrombocytopenia; the mean number of cycles was 6.6 ± 5.3, the mean time during study was 159 ± 120 days. One patient experienced a DLT in cycle 1 and was nonevaluable, 1 had a partial response, 16 had stable disease, and 2 had progressive disease as best response. There were 21 Grade 3/4 adverse events but no treatment-related deaths.

CONCLUSION

The MTD of S and T were not determined because of premature trial closure. S 37.5 mg/d, 2 weeks of treatment, 1 week with no treatment, and T 8 mg to 10 mg weekly are close to the MTD.

Sunitinib re-challenge in advanced renal-cell carcinoma

Despite offering significant clinical benefits in advanced renal-cell carcinoma (RCC), the effectiveness of targeted therapies eventually declines with the development of resistance. Defining optimal sequences of therapy is therefore the focus of much current research. There is also evidence that treatment 're-challenge' may be an effective strategy in some patients. We review evidence to evaluate whether sunitinib may have value as re-challenge therapy in patients who have progressed on prior targeted therapy with sunitinib and/or an alternative tyrosine kinase inhibitor or mammalian target of rapamycin inhibitor. Re-challenge with sunitinib appears to be of clinical benefit, thus representing a feasible therapeutic option for patients with advanced RCC who are refractory to other treatments and are able to receive further therapy. These observations support hypotheses that resistance to targeted agents is transient and can be at least partially reversed by re-introduction of the same agent after a treatment break. Median progression-free survival durations appear to be shorter and response rates lower on re-challenge than following initial treatment, although a wider interval between treatments appears to increase response to sunitinib re-challenge.

Sunitinib in the treatment of advanced solid tumors

Sunitinib is an oral multikinase inhibitor that blocks the vascular endothelial growth factor receptor (VEGFR), platelet-derived growth factor receptor (PDGFR) alpha and beta, c-kit, and other receptors. These attributes have proven to be efficacious in the treatment of metastatic renal cell carcinoma (RCC), unresectable gastrointestinal stromal tumors (GIST), and well-differentiated advanced pancreatic neuroendocrine tumors (PNET). Though activity has been reported in other tumor types, phase III trials have not yet demonstrated improved survival outcomes in these cancers. Most side effects including hypertension, hand-foot syndrome, and diarrhea are generally well manageable. This review will detail the preclinical data leading up to the results of the pivotal phase III clinical trials that have led to the widespread use of sunitinib in advanced RCC, GIST, and PNET.

Sunitinib in metastatic renal cell carcinoma: an ethnic Asian subpopulation analysis for safety and efficacy

AIMS

We evaluated and compared the safety and efficacy of sunitinib in Asian and non-Asian patients with metastatic renal cell carcinoma enrolled in a previously reported global expanded access program.

METHODS

Previously treated and treatment-naïve patients received open-label sunitinib at a starting dose of 50 mg/day for 4 weeks, followed by 2 weeks off treatment, in repeated 6-week cycles. Safety was assessed regularly, tumor measurements were performed per local practice, and survival data collected where possible.

RESULTS

Data were available for 212 Asian patients from Asian sites (Asian-A), 113 Asian patients from non-Asian sites (Asian-O) and 4046 non-Asian patients. The most common grade 3/4 treatment-related adverse events were neutropenia, thrombocytopenia, hand-foot syndrome, diarrhea, asthenia and fatigue. The incidence of many adverse events was greater in Asian-A than in Asian-O or non-Asian patients. Sunitinib efficacy was comparable between Asian and non-Asian patients, with an objective response rate of 18% versus 14%; median progression-free survival of 8.7 versus 10.9 months; and overall survival of 18.9 versus 18.4 months, respectively.

CONCLUSIONS

Sunitinib demonstrated tolerable safety and similar efficacy in Asian and non-Asian patients. Geographic differences in the reported frequency of specific adverse events were noted across Asian patients.

Molecular marker for predicting treatment response in advanced renal cell carcinoma: does the promise fulfill clinical need?

Renal cell carcinoma (RCC) is largely diagnosed incidentally on imaging taken for unrelated reasons. The management of localized lesions is primarily extirpative with excellent results. Treatment of advanced RCC has evolved over recent years with the use of targeted therapies such as tyrosine kinase inhibitors, mammalian target of rapamycin inhibitors, and antibody-mediated therapies. The treatment response to these targeted therapies is highly variable, with no clear clinical method of identifying patients who will benefit from or not tolerate therapy. The field of molecular markers has evolved significantly in the last decade, with a multitude of markers identified that predict treatment response and drug toxicity. The following review critically evaluates those molecular markers that have been assessed for their utility in predicting treatment response in patients with advanced/metastatic renal cell carcinoma (mRCC). Identifying the ideal treatment for these patients will improve responses to therapy, minimize morbidity, and save significant healthcare dollars.

Anti-VEGF Cancer Therapy in Nephrology Practice

Expanded clinical experience with the antivascular endothelial growth factor (VEGF) agents has come with increasing recognition of their renal adverse effects. Although renal histology is rarely sought in antiangiogenic-treated cancer patients, kidney damage related to anti-VEGF is now established. Its manifestations include hypertension, proteinuria, and mainly glomerular thrombotic microangiopathy. Then, in nephrology practice, should we continue to perform kidney biopsy, and what should be done with the anti-VEGF agents in case of renal toxicity?

Review on targeted treatment of patients with advanced-stage renal cell carcinoma: a medical oncologist's perspective

Renal cell carcinomas make up 3% of all cancers and one in four patients is metastatic at time of diagnosis. This cancer is one of the most resistant to cytotoxic chemotherapy. Studies have shown that the efficiency of interferon-alpha and/or interleukin-2 based immune therapies is limited in patients with metastatic renal cell carcinoma but latest advances in molecular biology and genetic science have resulted in better understanding of its biology. Tumor angiogenesis, tumor proliferation and metastasis develop by the activation of signal message pathways playing a role in the development of renal cell carcinomas. Better definition of these pathways has caused an increase in preclinic and clinical studies into target directed treatment of renal cell carcinoma. Many recent studies have shown that numerous anti-angiogenic agents have marked clinical activity. In this article, the focus is on general characteristics of molecular pathways playing a major role in renal cell carcinoma, reviewing clinical information onagents used in the target directed treatment of metastatic lesions.

Fatigue in patients with advanced renal cell carcinoma receiving sunitinib on an intermittent versus continuous dosing schedule in a randomized phase II trial

A phase II trial in advanced renal cell carcinoma (RCC) found no benefit in efficacy or safety between patients receiving oral sunitinib 50 mg/day for 4 weeks followed by 2-week off-treatment (Schedule 4/2) and those receiving 37.5 mg continuous daily sunitinib. We hypothesized that fatigue would have a more variable “on-off” effect with the 4/2 schedule. A total of 292 patients completed two fatigue-related items on Days 1 and 29 of each treatment cycle. Mean absolute slopes were compared across treatments. A planned analysis of item “I feel fatigued” demonstrated that the mean absolute slope was greater in Schedule 4/2 compared to continuous dosing (0.042 vs. 0.032, P = 0.003), and analysis based on the change from Day 1 to Day 29 (0.52 vs. 0.21, P = 0.002) and, separately, Day 29 to the next Day 1 (−0.38 vs. −0.05, P < 0.001) showed the changes to be significantly larger in Schedule 4/2 than continuous dosing. “I have a lack of energy” showed a similar pattern graphically, however, the planned analysis was not statistically significant based on the absolute slopes but was when Day 1 to Day 29 and Day 29 to Day 1 changes were analyzed separately. The 4/2 arm was associated with a greater degree of variability in fatigue reflecting a possible “on-off” effect whereby patients receiving the 4/2 schedule reported less fatigue at the beginning of each cycle compared to Day 29. The findings can inform care for individuals with advanced RCC receiving intermittent dosing of sunitinib.

Acute acalculous cholecystitis in patients with clear cell renal cell carcinoma treated with sunitinib: report of two cases

Although sunitinib is associated with a variety of adverse events, cases of sunitinib-related acute cholecystitis have rarely been reported. We herein report two cases of sunitinib-related acute acalculous cholecystitis in patients with clear cell renal cell carcinoma. In both cases, the gallbladder was surgically removed because it was difficult to improve the patient’s condition with the cessation of sunitinib and non-surgical treatment only. Attention must be paid to the possibility of sunitinib-related acute cholecystitis, which, although uncommon, can be life-threatening.

Oral anticancer drugs: how limited dosing options and dose reductions may affect outcomes in comparative trials and efficacy in patients

Historically, cancer medicine has avoided the problem of unequal dosing by comparing maximum-tolerated doses of intravenous regimens with proportionate dose reductions for toxicity. However, in recent years, with the development of numerous oral anticancer agents, dosing options are arbitrarily and increasingly limited by the size of pills. We contend that an underappreciated consequence of pill size is unequal dosing in comparative clinical trials and that this can have an impact on outcomes. We discuss how comparative effectiveness trials can be unbalanced and how the use of doses that are not sustainable might affect outcomes, especially marginal ones. We further argue that because of their poor tolerability and their limited dosing options, which often result in large dose adjustments in response to toxicity, the real-world clinical effectiveness of oral anticancer agents may be diminished and may not emulate results achieved in registration trials.

Active angiogenesis in metastatic renal cell carcinoma predicts clinical benefit to sunitinib-based therapy

Background:

Sunitinib represents a widely used therapy for metastatic renal cell carcinoma patients. Even so, there is a group of patients who show toxicity without clinical benefit. In this work, we have analysed pivotal molecular targets involved in angiogenesis (vascular endothelial growth factor (VEGF)-A, VEGF receptor 2 (KDR), phosphorylated (p)KDR and microvascular density (MVD)) to test their potential value as predictive biomarkers of clinical benefit in sunitinib-treated renal cell carcinoma patients.

Methods:

Vascular endothelial growth factor-A, KDR and pKDR-Y1775 expression as well as CD31, for MVD visualisation, were determined by immunohistochemistry in 48 renal cell carcinoma patients, including 23 metastatic cases treated with sunitinib. Threshold was defined for each biomarker, and univariate and multivariate analyses for progression-free survival (PFS) and overall survival (OS) were carried out.

Results:

The HistoScore mean value obtained for VEGF-A was 121.6 (range, 10–300); for KDR 258.5 (range, 150–300); for pKDR-Y1775 10.8 (range, 0–65) and the mean value of CD31-positive structures for MVD visualisation was 49 (range, 10–126). Statistical differences for PFS (P=0.01) and OS (P=0.007) were observed for pKDR-Y1775 in sunitinib-treated patients. Importantly, pKDR-Y1775 expression remained significant after multivariate Cox analysis for PFS (P=0.01; HR: 5.35, 95% CI, 1.49–19.13) and for OS (P=0.02; HR: 5.13, 95% CI, 1.25–21.05).

Conclusions:

Our results suggest that the expression of phosphorylated (i.e., activated) KDR in tumour stroma might be used as predictive biomarker for the clinical outcome in renal cell carcinoma first-line sunitinib-treated patients.

Sunitinib resistance in renal cell carcinoma

Of the many targeted therapies introduced since 2006, sunitinib has carved its way to become the most commonly used first-line therapy for the treatment of metastatic renal cell carcinoma (RCC). Despite significant improvements in progression-free survival, 30% of the patients are intrinsically resistant to sunitinib and the remaining 70% who respond initially will eventually become resistant in 6-15 months. While the molecular mechanisms of acquired resistance to sunitinib have been unravelling at a rapid rate, the mechanisms of intrinsic resistance remain elusive. Combination therapy, sunitinib rechallenge and sequential therapy have been investigated as means to overcome resistance to sunitinib. Of these, sequential therapy appears to be the most promising strategy. This mini review summarises our emerging understanding of the molecular mechanisms, and the strategies employed to overcome sunitinib resistance.

The current status of tailor-made medicine with molecular biomarkers for patients with clear cell renal cell carcinoma

Appropriate use of multiple reliable molecular biomarkers in the right context will play a role in tailormade medicine of clear cell renal cell carcinoma (RCC) patients in the future. A total of 11,056 patients from 53 studies were included in this review. The article numbers of the each evidence levels, using the grading system defined by the Oxford Centre for Evidence-based Medicine, in 1b, 2a, 2b, and 3b were 5 (9%), 18 (34%), 29 (55%), and 1 (2%), respectively. The main goal of using biomarkers is to refine predictions of tumor progression, pharmacotherapy responsiveness, and cancer-specific and/or overall survival. Currently, carbonic anhydrase (CA9) and vascular endothelial growth factor (VEGF) in peripheral blood and p53 in tumor tissues are measured to predict metastasis, while VEGF-related proteins in peripheral blood are used to assess pharmacotherapy responsiveness with sunitinib. Furthermore, interleukin 8, osteopontin, hepatocyte growth factor, and tissue inhibitors of metalloproteinases-1 in peripheral blood enable assessment of responsiveness to pazopanib treatment. Other reliable molecular biomarkers include von Hippel–Lindau gene alteration, hypoxia-inducible factor-1a, CA9, and survivin in tumor tissues and VEGF in peripheral blood for predicting cancer-specific survival. In the future, studies should undergo external validation for developing tailored management of clear cell RCC with molecular biomarkers, since individual institutional studies lack the generalization and consistency required to maintain accuracy among different patient series.

Immunologics and chemotherapeutics for renal cell carcinoma

Treatment of metastatic renal cell carcinoma remains a challenge for clinicians. Traditional chemotherapy is ineffective and immunotherapy with interleukin-2 is only occasionally beneficial. The development of numerous agents targeting vascular endothelial growth factor and mammalian target of rapamycin signaling pathways that have been studied in phase III trials have resulted in significant improvement in survival for patients with clear cell renal cell carcinoma. Currently available U.S. Food and Drug Administration-approved first line targeted agents include sunitinib, pazopanib, temsirolimus, and bevacizumab (with interferon), while axitinib, everolimus, and sorafenib are most extensively used following progression as second- or third line therapy. Attempts to augment the activity of these agents by combining them together or with chemotherapy or immunotherapy have not yet proven to improve outcomes. As a result, the sequential use of single agents remains the current standard of care.

Molecular subtyping of metastatic renal cell carcinoma: implications for targeted therapy

BACKGROUND

Renal cell carcinoma (RCC) is known for its ability to metastasize synchronously or metachronously to various anatomic sites. Distinguishing histologic subtypes of metastatic RCC has become increasingly important, as prognosis and therapy can differ dramatically between subtypes. We propose a combination of immunohistochemistry (IHC) and molecular cytogenetics for subtyping metastatic RCC in light of these potential therapeutic implications.

RESULTS

Specimens from 103 cases of metastatic RCC were retrieved, including 32 cases originally diagnosed as metastatic clear cell renal cell carcinoma (CCRCC), 8 as metastatic papillary renal cell carcinoma (PRCC), and 63 metastatic RCC without a specific subtype. Immunohistochemistry was performed with antibodies against cytokeratin 7 (CK7) and alpha-methylacyl-CoA racemase (AMACR). Dual color interphase fluorescence in situ hybridization was utilized to assess for deletion of chromosome 3p and trisomy of chromosomes 7 and 17 in all tumors. Chromosome 3p deletion was detected in 41% of all metastatic RCC specimens, and trisomy of chromosomes 7 and/or 17 was detected in 16%. Of metastatic CCRCC, chromosome 3p deletion was detected in 63%. Of metastatic PRCC, 75% showed trisomy of chromosomes 7 and/or 17. Of the tumors not previously classified, 6% were positive for CK7, and 64% were positive for AMACR; 35% showed chromosome 3p deletion, and 16% showed trisomy of chromosomes 7 and/or 17. Combined analysis of immunohistochemistry and cytogenetics enabled reclassification of 52% of these metastatic tumors not previously classified.

CONCLUSION

Our findings support the utility of immunohistochemistry and cytogenetics for subtyping metastatic RCC.

Efficacy of biological agents in metastatic triple-negative breast cancer

Metastatic triple-negative breast cancer (mTNBC) represents 15% of invasive breast cancers. Prognosis is poor, and there is no specific target therapy but biological agents combined with chemotherapy may be effective. To assess the role of biological agents in metastatic triple-negative breast cancer we performed a systematic review of phase III randomized controlled trials published from January 2006 to February 2013 and presentations at ESMO, ASCO, and SABCS congresses in 2010-2012. We consulted PubMed and ClinicalTrials.gov. Only studies comparing biological agents and chemotherapy versus chemotherapy alone were considered. Relevant statistical variables were log of the hazard ratio and relative variance for progression-free survival (PFS) and overall survival (OS). Of 353 PubMed publications and 229 studies registered on ClinicalTrials.gov, 10 trials were selected and 5293 patients were analyzed: 1546 had mTNBC. Biological agents considered were bevacizumab, sunitinib, sorafenib, lapatinib, iniparib and cetuximab. In addition, a meta analysis of the four studies containing bevacizumab was performed and it showed a PFS improvement with a relative risk reduction of 35% (95% CI: 25-43%). No effect on OS was observed. No PFS and OS benefit was detected with the other agents. No improvement of OS was detected in patients treated with biological agents plus chemotherapy, while a significant PFS improvement was observed only for bevacizumab and cetuximab. The overall impact of these agents on patient survival was not as great as expected, probably because the molecular basis of this illness needs to be better understood so that treatment can be more appropriately tailored.

Optimal management of metastatic renal cell carcinoma: current status

The armamentarium for the systemic therapy of advanced renal cell carcinoma (RCC) has undergone dramatic changes over the past 6 years. While high-dose interleukin (IL)-2 remains an option for highly selected good and intermediate risk patients with clear-cell histology because of durable complete responses in a small fraction of patients, cytokine-based therapy including interferon (IFN) has been supplanted by vascular-endothelial growth factor (VEGF) and mammalian target of rapamycin (mTOR) inhibitors. Treatment decision is initially based on prognostication of the disease. As metastatic RCC (mRCC) is commonly an indolent disease, a period of observation should always been considered. For good and intermediate risk disease, pazopanib, sunitinib or the combination of bevacizumab plus IFN are considered. Notably, recent data suggest non-inferiority for the efficacy of pazopanib compared to sunitinib coupled with a better toxicity profile. A novel VEGF receptor inhibitor, tivozanib, is expected to be approved based on improvement in PFS when compared to sorafenib in the first-line setting. The use of temsirolimus for poor risk disease is supported by a phase III trial dedicated to this group of patients. The role of cytoreductive nephrectomy in the context of VEGF and mTOR inhibitors is being studied in randomized trials. Selected patients with solitary or oligometastatic disease may be eligible for metastatectomy. Following first-line VEGF inhibitors, second-line therapy with everolimus and axitinib have demonstrated benefits in progression-free survival (PFS). One phase III trial comparing sorafenib and temsirolimus in the post-sunitinib setting showed no difference in PFS, the primary endpoint, but did show a superior overall survival for sorafenib. Sorafenib, pazopanib and axitinib have all demonstrated clinical benefit following cytokines. Therapy following first-line mTOR inhibitors remains undefined, although VEGF inhibitors have demonstrated activity in this setting. Optimal sequencing of agents and individualized therapy based on biomarkers is undergoing investigation. Today, the choice of therapy is based on patient and physician decision, which is a function of comorbidities, toxicity profiles and costs. Clinical trials evaluating novel agents and combinations should be preferred when available since agents in the current therapeutic arsenal have not yielded cures despite extending median survival to greater than 2 years. One noteworthy new class of agents that has yielded durable responses is programmed death (PD)-1 inhibitors, which target a T-lymphocyte checkpoint and are heralding a resurgence of immunotherapy. Finally, optimal therapy for non-clear cell RCC remains to be delineated, although sunitinib, everolimus and other VEGFR-TKI or mTOR inhibitors have all demonstrated modest benefit.

Efficacy and safety of sunitinib in elderly patients with metastatic renal cell carcinoma

Background:

We retrospectively analyzed sunitinib outcome as a function of age in metastatic renal cell carcinoma (mRCC) patients.

Methods:

Data were pooled from 1059 patients in six trials. Kaplan–Meier estimates of progression-free survival (PFS) and overall survival (OS) were compared by log-rank test between patients aged <70 (n=857; 81%) and ⩾70 (n=202; 19%) years.

Results:

In first-line patients, median PFS was comparable in younger and older patients, 9.9 vs 11.0 months, respectively (HR, 0.89; 95% CI: 0.73–1.09; P=0.2629), as was median OS, 23.6 vs 25.6 months (HR, 0.93; 95% CI: 0.74–1.18; P=0.5442). Similarly, in cytokine-refractory patients, median PFS was 8.1 vs 8.4 months (HR, 0.79; 95% CI: 0.49–1.28; P=0.3350), while median OS was 20.2 vs 15.8 months (HR, 1.14; 95% CI: 0.73–1.79; P=0.5657). Some treatment-emergent adverse events were significantly less common in younger vs older patients, including fatigue (60% vs 69%), cough (20% vs 29%), peripheral edema (17% vs 27%), anemia (18% vs 25%), decreased appetite (13% vs 29%), and thrombocytopenia (16% vs 25% all P<0.05). Hand–foot syndrome was more common in younger patients (32% vs 24%).

Conclusions:

Advanced age should not be a deterrent to sunitinib therapy and elderly patients may achieve additional clinical benefit.

Targeted therapies in metastatic renal cell carcinoma: the light at the end of the tunnel

The year 2006 will mark a turning point in the daily management of patients with metastatic renal cell carcinoma. The impact of immunotherapy with interferon-alpha or interleukin-2 has been shown to be restricted to a minority of patients. The growing understanding of molecular mechanisms involved in the pathogenesis of the disease, especially clear-cell carcinoma, has led to the development of multiple targeted therapies with significant clinical benefits. Two compounds that predominantly inhibit the tyrosine kinase activity of the vascular endothelial growth factor receptor have been shown to improve the progression-free survival of patients in first- (sunitinib versus interferon-alpha) or second-line (sorafenib versus placebo) treatment. Temsirolimus, an agent that inhibits the serine-threonine kinase activity of the mammalian target of rapamycin, offers better overall survival than interferon in patients with poor-risk characteristics. Further studies are needed to determine the optimal combinations of these agents in metastatic disease and to assess their impact in the adjuvant setting.

New drug therapies for advanced renal cell carcinoma

The incidence of renal cell cancer is increasing and surgery is the only curative treatment for patients presenting with localized disease at diagnosis. The treatment of metastatic renal cell cancer is palliative and, until recently, immunotherapy has been the standard treatment approach with response rates between 10 and 20%. An increase in the appreciation of the biology of this disease has resulted in a number of new 'targeted' therapies being developed. Most notable is the introduction of tyrosine kinase inhibitors with significant activity in both treatment-naive and cytokine-refractory renal cell cancer. Drugs targeting angiogenic pathways also appear promising. These agents are being rapidly introduced into clinical practice, but further studies are needed to establish their optimal place in the management of renal cell cancer and, in particular, the role of combination and/or sequential therapy.

Molecularly targeted therapy in renal cell carcinoma: where do we go from here?

The angiogenic phenotype of renal cell carcinoma results from vascular endothelial growth factor pathway activation. Several different strategies targeting various aspects of the pathway have emerged as clinically relevant therapeutics in metastatic renal cell carcinoma. Key clinical data regarding these approaches are presented in this article. Furthermore, there are several considerations as to the further development of these agents and their appropriate application in metastatic renal cell carcinoma, such as timing of therapy, choice of initial therapy, continued role of debulking nephrectomy and toxicity concerns. These issues are discussed in light of current data and strategies for further drug development are presented.

Outcomes and prognosis in advanced renal cell carcinoma

Breakthroughs in understanding the pathogenesis of renal cell carcinoma have led to recent therapeutic advances in this disease. However, the US FDA approval of sunitinib and sorafenib (and soon temsirolimus) after successful Phase III trials must also be attributed to the work of clinical investigators over the past decade defining the outcomes and major prognostic factors in patients with advanced renal cell carcinoma. Those past studies have been critical in providing a context for the interpretation of future trials with novel agents, optimizing patient selection for specific therapeutic approaches and identifying appropriate variables for patient stratification on randomized trials. This review will focus on studies that define the outcome and prognosis in advanced renal cell carcinoma.

Prognostic biomarkers in renal cell carcinoma

A hallmark of renal cell carcinoma is its variable prognosis. Surgical resection of primary renal cell carcinoma can be curative when the disease is localized. However, approximately 20% of patients with early stages of localized renal cell carcinomas subsequently develop metastasis after the primary tumor is removed. The median survival for patients with metastatic disease is approximately 13 months. Therefore, there is a great need for biomarkers to predict metastasis and prognosis. Many prognostic biomarkers were studied in the past decade. In recent years, several promising biomarkers, including CAIX, B7-H1 and IMP3, have also been identified by large retrospective studies. Further validation of these biomarkers is essential to transfer the research data into clinical practice. Eventually, an outcome prediction model with biomarkers, staging system and other risk factors will identify high-risk patients with likelihood of progression and formulate different follow-up protocols or systematic treatments for these patients.

Vascular endothelial growth factor inhibitor-induced hypertension: from pathophysiology to prevention and treatment based on long-acting nitric oxide donors

Hypertension is the most common adverse effect of the inhibitors of vascular endothelial growth factor (VEGF) pathway-based therapy (VEGF pathway inhibitors therapy, VPI therapy) in cancer patients. VPI includes monoclonal antibodies against VEGF, tyrosine kinase inhibitors, VEGF Traps, and so-called aptamers that may become clinically relevant in the future. All of these substances inhibit the VEGF pathway, which in turn causes a decrease in nitric oxide (NO) and an increase in blood pressure, with the consequent development of hypertension and its final events (e.g., myocardial infarction or stroke). To our knowledge, there is no current study on how to provide an optimal therapy for patients on VPI therapy with hypertension. This review summarizes the roles of VEGF and NO in vessel biology, provides an overview of VPI agents, and suggests a potential treatment procedure for patients with VPI-induced hypertension.

Dysphonia induced by anti-angiogenic compounds

The number of studies reporting the benefit of angiogenesis inhibition is steadily increasing. Anti-angiogenic drugs, used as monotherapy or in association with chemotherapy, have been shown to benefit patients with several different malignancies. Despite the benefits of these therapies, however, each drug has different side effects. This review is specifically focused on analyzing the frequency of one of the complications the most frequently overlooked by physicians, dysphonia. Perhaps this side effect is overlooked because it is not life-threatening, but dysphonia may nevertheless affect quality of life considerably. We reviewed 88 studies concerning treatment with anti-angiogenics (bevacizumab, aflibercept, sunitinib, sorafenib, pazopanib, axitinib and regorafenib) presently approved for clinical use, to review the incidence of dysphonia or voice changes in phase I, II and III closed clinical studies reported in ClinicalTrials.gov until March 2013. We found that almost all studies reported certain degree of dysphonia in the trial arms associated with anti-angiogenic treatment. We discuss these findings in light of the fact that it is not an uncommon side effect in patients exposed to these kinds of drugs. Particularly for treatments with axitinib, aflibercept and regorafenib, the angiogenesis inhibition possibly plays a role by altering the larynx in some way and modifying vocal fold vibrations, leading to dysphonia.

A single-arm phase II Austrian/German multicenter trial on continuous daily sunitinib in primary glioblastoma at first recurrence (SURGE 01-07)

BACKGROUND

Due to the redundancy of molecular pathways simultaneously involved in glioblastoma growth and angiogenesis, therapeutic approaches intervening at multiple levels seem particularly appealing.

METHODS

This prospective, multicenter, single-arm phase II trial was designed to evaluate the antitumor activity of sunitinib, an oral small-molecule inhibitor of several receptor tyrosine kinases, in patients with first recurrence of primary glioblastoma using a continuous once-daily dosing regimen. Patients received a starting dose of sunitinib 37.5 mg, followed by a maintenance dose between 12.5 mg and 50 mg depending on drug tolerability. The primary endpoint was a 6-month progression-free survival (PFS) rate. Secondary endpoints included median PFS, overall survival (OS), safety/toxicity, quality of life, and translational studies on the expression of sunitinib target molecules.

RESULTS

Forty participants were included in this study, and no objective responses were detected. PFS6 was 12.5%, median PFS 2.2 months, and median OS 9.2 months. Five participants (12.5%) showed prolonged stable disease ≥6 months with a median PFS of 16.0 months (range, 6.4-41.4 mo) and a median OS of 46.9 months (range, 21.2-49.2 mo) for this subgroup. c-KIT expression in vascular endothelial cells (n = 14 participants) was associated with improved PFS. The most common toxicities were fatigue/asthenia, mucositis/dermatitis, dysesthesias, gastrointestinal symptoms, cognitive impairment, leukoctopenia, and thrombocytopenia. Two participants (5%) terminated treatment due to toxicity.

CONCLUSION

Continuous daily sunitinib showed minimal antiglioblastoma activity and substantial toxicity when given at higher doses. High endothelial c-KIT expression may define a subgroup of patients who will benefit from sunitinib treatment by achieving prolonged PFS. ClinicalTrials.gov Identifier: NCT00535379.

All anti-vascular endothelial growth factor drugs can induce 'pre-eclampsia-like syndrome': a RARe study

BACKGROUND

Specific therapies that target vascular endothelial growth factor (VEGF) and its receptors have improved the survival of patients with metastatic cancers, but can induce side effects. Renal side effects (proteinuria, hypertension and renal failure) are underestimated.

METHODS

The French RARe (Reins sous traitement Anti-VEGF Registre) study collects data on patients with cancer who had a renal biopsy because of major renal side effects during treatment with anti-VEGF drugs.

RESULTS

We collected 22 renal biopsies performed 16.2±10.6 months after the beginning of treatment; of which 21 had hypertension, mean proteinuria was 2.97±2.00 g/day and mean serum creatinine, 134±117 µmol/L. Thrombotic microangiopathy (TMA) was observed in 21 biopsy specimens, sometimes associated with acute tubular necrosis (ATN; n=4). TMA histological lesions were more important than the biological signs of TMA could suggest. Patients with ATN of >20% had higher serum creatinine levels than those with only TMA (231 versus 95 µmol/L). Nephrin, podocin and synaptopodin were variably down-regulated in all renal biopsies. VEGF was down-regulated in all glomeruli.

CONCLUSION

This study underlines the importance of regular clinical and biological cardiovascular and renal checking during all anti-VEGF therapies for cancer for early detection of renal dysfunction. Collaboration between oncologists and nephrologists is essential. In such cases, renal biopsy might help in appreciating the severity of the renal lesions and after multidisciplinary discussion whether or not it is safe to continue the treatment.

Recent developments in the treatment of renal cell carcinoma

Renal cell carcinoma (RCC) management has been imbued with new interest, in large part due to the recent success of new treatment options for advanced and metastatic disease. This has also been accompanied by less generally well known advances in the understanding of the molecular characterizations of subtypes of RCC with potential to lead to new therapeutic options. Additionally, the urologic oncology community is focusing on nephron-sparing surgical approaches with limited surgery if possible, and in conjunction with interventional radiologists, on ablative procedures for incidentally determined small renal masses. This report reviews some of the new biologic findings of adenocarcinoma of the kidney, and reviews the new therapeutics which continue to change the landscape for treatment of RCC.