Sunitinib in patients with metastatic renal cell carcinoma

Brain accumulation of sunitinib is restricted by P-glycoprotein (ABCB1) and breast cancer resistance protein (ABCG2) and can be enhanced by oral elacridar and sunitinib coadministration

Sunitinib is an orally active, multitargeted tyrosine kinase inhibitor which has been used for the treatment of metastatic renal cell carcinoma and imatinib-resistant gastrointestinal stromal tumors. We aimed to investigate the in vivo roles of the ATP-binding cassette drug efflux transporters ABCB1 and ABCG2 in plasma pharmacokinetics and brain accumulation of oral sunitinib, and the feasibility of improving sunitinib kinetics using oral coadministration of the dual ABCB1/ABCG2 inhibitor elacridar. We used in vitro transport assays and Abcb1a/1b(-/-) , Abcg2(-/-) and Abcb1a/1b/Abcg2(-/-) mice to study the roles of ABCB1 and ABCG2 in sunitinib disposition. In vitro, sunitinib was a good substrate of murine (mu)ABCG2 and a moderate substrate of human (hu)ABCB1 and huABCG2. In vivo, the systemic exposure of sunitinib after oral dosing (10 mg kg(-1) ) was unchanged when muABCB1 and/or muABCG2 were absent. Brain accumulation of sunitinib was markedly (23-fold) increased in Abcb1a/b/Abcg2(-/-) mice, but only slightly (2.3-fold) in Abcb1a/b(-/-) mice, and not in Abcg2(-/-) mice. Importantly, a clinically realistic coadministration of oral elacridar and oral sunitinib to wild-type mice resulted in markedly increased sunitinib brain accumulation, equaling levels in Abcb1a/1b/Abcg2(-/-) mice. This indicates complete inhibition of the blood-brain barrier (BBB) transporters. High-dose intravenous sunitinib could saturate BBB muABCG2, but not muABCB1A, illustrating a dose-dependent relative impact of the BBB transporters. Brain accumulation of sunitinib is effectively restricted by both muABCB1 and muABCG2 activity. Complete inhibition of both transporters, leading to markedly increased brain accumulation of sunitinib, is feasible and safe with a clinically realistic oral elacridar/sunitinib coadministration.

Novelties of treatment in advanced renal-cell cancer

Therapeutic options in advanced renal-cell cancer have expanded through better understanding of molecular patho­logy and development of novel targeted therapeutics. Vascular endothelial growth factor, the key ligand of angioge­nesis, has a major role in the progression of vascularized kidney tumors and this is the target molecule of modern medications. The three types of the mechanism of action of current therapies are: monoclonal antibodies blocking directly vascular endothelial growth factor ligand (bevacizumab), tyrosine-kinase inhibitors blocking vascular endothelial growth factor receptors (sorafenib, sunitinib, pazopanib) and inhibitors of the intracellular mTOR-kinase (temsirolimus, everolimus). Based on randomized studies, sunitinib, pazopanib or interferon-α-bevacizumab combination should be the first-line therapy in patients with good/moderate prognosis, while temsirolimus is recommended in those with poor prognosis. Following an ineffective cytokine therapy sorafenib or pazopanib are the se­cond-line treatment. In case of tyrosine-kinase inhibitor inefficacy, current evidence favors everolimus. Patient outcome can further be improved by the involvement of more modern and effective target products. Orv. Hetil., 2011, 152, 655–662.

Novel angiogenesis inhibitors: addressing the issue of redundancy in the angiogenic signaling pathway

Angiogenesis, the formation of new blood vessels from established vasculature, is a fundamental process in the growth and metastasis of solid tumours. It is a complex, tightly regulated process that requires the coordinated action of antiangiogenic and proangiogenic factors, the balance of which becomes disturbed during tumour development. Vascular endothelial growth factor (VEGF) and its receptor are the key mediators of angiogenesis and targets for multiple pharmacologic agents. Many patients treated with VEGF inhibitors survive for a longer period; however, eventual resistance is associated with progressive disease and death. Multiple approaches to overcome resistance have been investigated with varying success, including the use of agents that target multiple angiogenic factors or co-administration of angiogenesis inhibitors with standard chemotherapy or radiotherapy. It would appear that the future of angiogenic inhibitors lies in the intelligent combination of multiple targeted agents with other angiogenic inhibitors, as well as more conventional therapies to maximise therapeutic effect.

Future directions of mammalian target of rapamycin (mTOR) inhibitor therapy in renal cell carcinoma

With an explosion of available treatments for metastatic renal cell carcinoma (mRCC) in recent years, it is important to recognize that approved targeted therapies fall broadly into only two mechanistic categories. The first category, vascular endothelial growth factor (VEGF)-directed therapies, includes sunitinib, pazopanib, sorafenib and bevacizumab. The second category includes inhibitors of the mammalian target of rapamycin (mTOR), namely everolimus and temsirolimus. A pivotal trial of everolimus supports use of the agent in patients with mRCC refractory to VEGF- tyrosine kinase inhibitors (TKI) therapy, while pivotal data for temsirolimus supports use in poor-prognosis patients as first-line therapy. Multiple reviews exist to delineate the laboratory and clinical development of mTOR inhibitors. This paper will outline the future applications of these therapies. It will explore ongoing trials evaluating combinations of mTOR inhibitors with other targeted therapies, along with sequencing strategies and biomarker discovery efforts. The application of mTOR inhibitors in unique populations is also described.

Surgical outcomes and complications associated with presurgical tyrosine kinase inhibition for advanced renal cell carcinoma (RCC)

BACKGROUND

Tyrosine kinase inhibitors (TKI) have dramatically changed the management paradigm of advanced renal cell carcinoma (RCC) and are increasingly being used preoperatively to achieve cytoreduction.

OBJECTIVE

To review our case series of post-TKI surgical procedures to add to the current perioperative efficacy and complication profile.

MATERIALS AND METHODS

Between October 2006 and February 2010, 14 cytoreductive nephrectomies, radical nephrectomies, and metastectomies were performed after neoadjuvant sunitinib or sorafenib for advanced RCC. During the same time frame, a control group of 73 consecutive patients underwent radical nephrectomy, cytoreductive nephrectomy, or metastectomy in the absence of prior systemic therapy. We compared the incidence of perioperative complications and outcomes after surgical procedures between the two cohorts.

RESULTS

Median preoperative renal mass size was 11 cm (6.7-24.2 cm). Primary tumor shrinkage was seen in 57%; median shrinkage was 18% (8%-25%). The median treatment period was 17 weeks, and the median time from TKI discontinuation was 2 weeks. Compared with a control group and after adjusting for confounding covariates, presurgical TKI use was not associated with a significant increase in perioperative complications (50% vs. 40%, P = 0.25) or perioperative bleeding (36% vs. 34%, P = 0.97) but was associated with increased incidence and grade of intraoperative adhesions (86% vs. 58%, P = 0.001; grade 3 vs. 1, P = 0.002).

CONCLUSIONS

Compared with the published reports, we observed less hemorrhagic and wound healing issues but a significant increase in incidence and severity of intraoperative adhesions, which can present a formidable technical challenge. Potential reasons for our lower complication rate could be increased time from TKI discontinuation to surgery, longer time to postoperative TKI re-initiation, increased use of preoperative angioembolization, and the lack of preoperative bevacizumab administration. Presurgical TKI therapy can permit effective surgical cytoreduction with a safety and complication profile equivalent to that of non-TKI-nephrectomy; however safety data continue to evolve, and preoperative TKI use requires further prospective investigation.

[Cardiovascular toxicity of anti-angiogenic therapy]

The use of anti-angiogenic therapies has revolutionized the treatment of cancer. However, some of these drugs are associated with cardiovascular damage. An early detection and personalized management is necessary to screen and treat an increase in blood pressure, proteinuria or symptomatic left ventricular dysfunction. Angiotensin-converting enzyme inhibitors and angiotensin II antagonists are the first line treatment of this cardiotoxicity. The interruption of treatment is recommended if cardiac manifestations are uncontrolled, unless the expected benefit is greater than the risks.

Added value of molecular targeted agents in oncology

The treatment of certain cancers has been revolutionised in recent years by the introduction of novel drugs designed to target specific molecular factors implicated in tumour growth. Notable examples include trastuzumab, a humanized monoclonal antibody (mAb) against human epidermal growth factor receptor (HER)-2 in women with HER2-positive breast cancer; rituximab, an anti-CD20 mAb in patients with non-Hodgkin's lymphoma; imatinib, a tyrosine kinase inhibitor in KIT-positive gastrointestinal stromal tumours and sunitinib, another tyrosine kinase inhibitor, in metastatic renal cell carcinoma. For regulatory reasons, new molecular targeted agents are first evaluated in advanced and metastatic disease, wherein they prolong survival. However, their most profound impact has been observed in the adjuvant setting, where they may contribute to curative therapy rather than mere palliation. Expansion in the use of molecular targeted therapies will have important cost implications for health care systems. Although expensive, on a monthly basis, molecular targeted therapies may not be more costly than treatments for other major chronic diseases, especially considering the contribution of cancer to the global disease burden, the associated socioeconomic costs and the long-term benefits of therapy. Nevertheless, the use of these agents must be optimised, in part using molecular biomarkers associated with drug response.

Pazopanib: a multikinase inhibitor with activity in advanced renal cell carcinoma

Treatment options for patients with metastatic renal cell carcinoma (RCC) have changed dramatically, and a new paradigm has evolved. IFN-alpha and IL-2 were previously mainstays of therapy, but since December 2005, six new agents have been approved in the USA for the treatment of advanced RCC. Three of these new agents are multitargeted kinase inhibitors, including sunitinib, sorafenib, and recently pazopanib, two target the mTOR (temsirolimus and everolimus), and one is a humanized monoclonal antibody (bevacizumab in combination with IFN-alpha) that targets VEGF. Sunitinib has emerged as the standard of care for treatment-naive RCC patients, with the recently approved bevacizumab and IFN-alpha combination providing an additional option for this population. The recent approval of pazopanib, based on the results from sequential Phase II and III clinical trials demonstrating improved overall response rates and progression-free survival, provides yet another option for front-line therapy. The current article examines the pazopanib preclinical and clinical data, provides an overview of the development of this tyrosine kinase inhibitor, and provides some speculation concerning its role in RCC therapy.

Sunitinib malate synergistically potentiates anti-tumor effect of gemcitabine in human bladder cancer cells

PURPOSE

Sunitinib malate (Sutent; Pfizer, New York, NY, USA) is a highly selective multi-targeted agent and has been reported to have potent anti-tumor effects against various tumors, including renal cell carcinoma and gastrointestinal stromal tumors. In this study, we explored in vitro the anti-tumor effect and related molecular mechanisms of sunitinib malate against human bladder cancer cell lines. We also determined the synergistic anti-tumor effect between sunitinib and conventional cytotoxic drugs, cisplatin and gemcitabine, in bladder cancer cells.

MATERIALS AND METHODS

Six human cancer cell lines (HTB5, HTB9, T24, UMUC14, SW1710, and J82) were exposed to an escalating dose of sunitinib alone or in combination with cisplatin/gemcitabine, and the cytotoxic effect of the drugs was examined by CCK-8 assay. The synergistic effect between sunitinib and cisplatin/gemcitabine was determined by the combination index (CI) and clonogenic assay. Alterations in cell cycle (cyclin D, B1), survival (p-Akt, t-Akt), and apoptosis (Bax, Bad) regulator expression were analyzed by Western blotting.

RESULTS

Like cisplatin and gemcitabine, sunitinib exerted a dose- and time-dependent anti-tumor effect in bladder cancer cells. However, sunitinib exhibited entirely different sensitivity profiles from cisplatin and gemcitabine. Sunitinib suppressed the expression of cyclin B1, p-Akt, and t-Akt while augmenting the expression of cyclin D and pro-apoptotic Bax and Bad in HTB5 cells. Analysis of the drug combination by the isobolic method and clonogenic assay revealed that sunitinib acts in synergy with gemcitabine in HTB5 cells.

CONCLUSIONS

These results indicate that sunitinib malate has a potent anti-tumor effect and may synergistically enhance the anti-tumor effect of gemcitabine in human bladder cancer cells.

Phase I/II trial of sunitinib plus gefitinib in patients with metastatic renal cell carcinoma

OBJECTIVES

Sunitinib is an oral, multitargeted tyrosine kinase inhibitor of vascular endothelial growth factor and platelet-derived growth factor receptors with proven clinical benefit in patients with metastatic renal cell carcinoma (RCC). This phase I/II study investigated sunitinib in combination with an epidermal growth factor receptor inhibitor, gefitinib, in patients with metastatic RCC.

METHODS

In phase I, patients received sunitinib 37.5 or 50 mg in 6-week cycles (4 weeks on treatment, 2 off) plus gefitinib 250 mg, both once daily, to determine the sunitinib maximum tolerated dose (MTD). Pharmacokinetics was assessed for both drugs. In phase II, patients received sunitinib MTD plus gefitinib to evaluate the safety and antitumor activity of this combination.

RESULTS

Forty-two patients were enrolled: 11 in phase I, and 31 in phase II. In phase I, 2 dose-limiting toxicities were observed with sunitinib 50 mg (grade 2 left ventricular ejection fraction decline and grade 3 fatigue), and 37.5 mg was declared the MTD. Thirteen patients treated at the MTD achieved a partial response (objective response rate: 37%; 95% confidence interval, 22-55) and 12 (34%) had stable disease. Median progression-free survival was 11 months (95% confidence interval, 6-17). The most commonly reported grade 3/4 treatment-related adverse event was diarrhea (14%), the only grade 3/4 adverse event to occur in >2 patients. Pharmacokinetic analyses did not indicate any drug-drug interactions.

CONCLUSIONS

In metastatic RCC, sunitinib plus gefitinib demonstrated comparable efficacy to sunitinib monotherapy with an acceptable safety profile. Dosing, pharmacokinetic profile, and safety support study of sunitinib plus an epidermal growth factor receptor inhibitor in other tumor types.

[Management of side effects of targeted therapies in renal cancer: cutaneous side effects]

Targeted therapies used (angiogenesis inhibitors and mTOR inhibitors) in advanced renal cell carcinoma have a constellation of reaction affecting the skin, hair and nails. This guideline describes the incidence, clinical presentation and treatment of dermatologic side effects that develop with the use of targeted therapies (sunitinib, sorafenib, pazopanib, bevacizumab, everolimus, temsirolimus).

Systemic therapy for metastatic renal cell carcinoma in treatment naïve patients: a risk-based approach

IMPORTANCE OF THE FIELD

Kidney cancer is the ninth most common cancer in the USA, with an annual incidence of approximately 55,000 cases per year. Over 13,000 patients are estimated to die from this disease annually. Cloning of the VHL gene, recognition of the associated abnormalities in sporadic clear-cell carcinoma, and its role as a regulator of the hypoxic response, were important milestones in our understanding of renal-cell carcinoma (RCC) biology and the recognition of the vascular endothelial growth factor (VEGF) dependency of RCC. A variety of clinical features, including histologic features, prognostic factors, and patient history of comorbid illness, provide the framework in which the results of recent clinical trials and regulatory approvals of these agents are utilized to develop treatment recommendations for the largest metastatic patient RCC group, the therapy naïve individual.

AREAS COVERED IN THIS REVIEW

The rationale for use of VEGF-targeted therapy in advanced RCC patients and the recently developed treatment options for these individuals are reviewed. Regulatory approval of sorafenib for the treatment of metastatic RCC (mRCC), was followed by the approval of sunitinib, temsirolimus, bevacizumab plus interferon (IFNα), everolimus, and--most recently--pazopanib. These licences were granted from late 2005 through late 2009, a very short span of 4 years. In treatment-naïve mRCC patients, sunitinib, sorafenib, pazopanib, bevacizumab + IFNα, and temsirolimus were approved by the Food and Drug Administration (FDA) and/or the European Medicines Agency (EMEA). The clinical trials and data supporting these approvals are reviewed.

WHAT WILL THE READER GAIN

This review examines these developments and provides the reader an overview and understanding of available current systemic therapy options for treatment-naïve mRCC patients.

TAKE HOME MESSAGE

As multiple treatment options are now available for treatment-naïve mRCC patients, an understanding of how to utilize this group of agents is required. The use of various clinical features allows a rational approach to therapy selection. These features include prior treatment status, histologic subtype, and prognostic group. Further refinement of therapy selection is required and will require further biologic information as well as comparative randomized trials.

A cost-effectiveness analysis of sunitinib in patients with metastatic renal cell carcinoma intolerant to or experiencing disease progression on immunotherapy: perspective of the Spanish National Health System

AIM

To investigate the cost-effectiveness of sunitinib (50 mg/day, schedule 4/2) vs. best supportive care (BSC) in patients with cytokine-refractory metastatic renal cell carcinoma (mRCC), from the perspective of the Spanish National Health Service.

MATERIAL AND METHODS

A Markov model compared the cost-effectiveness (taking into account drugs; medical visits; laboratory tests; X-rays; terminal care; adverse event management) of sunitinib and BSC across three disease states: no progression, survival with progression and death from mRCC or other causes.

RESULTS

The monthly incremental cost-effectiveness ratio (ICER) values for sunitinib treatment were €6073/progression-free survival month, €25,199/life years and €34,196/quality-adjusted life years (QALY) gained. In 95% of cases, the ICER/QALY values were below the accepted €45,000/QALY threshold. Efficacy and cost of sunitinib had the greatest impact on cost-effectiveness.

CONCLUSION

Sunitinib has a good cost-effectiveness profile in mRCC. The cost per life year and QALY gained is affordable according to current effectiveness thresholds in developed countries.

The incidence and mechanism of sunitinib-induced thyroid atrophy in patients with metastatic renal cell carcinoma

BACKGROUND

To elucidate the incidence and mechanisms of sunitinib-induced thyroid atrophy, we investigated serial volumetric and functional changes, and evaluated histological changes of the thyroid gland in metastatic renal cell carcinoma patients who received sunitinib.

METHODS

Thyroid volume (by computed tomography volumetry) and thyroid function were measured at baseline, during the treatment, and at post-treatment periods. Histological evaluation of the thyroid gland was performed in four autopsied patients.

RESULTS

The median reduction rate in thyroid volume at last evaluation during sunitinib treatment was 30% in all 17 patients. The incidence of hypothyroidism during sunitinib treatment was significantly higher in the high reduction rate group (n=8; more than 50% reduction in volume) than in the low reduction rate group (n=9; less than 50% reduction in volume). Half of the patients in the high reduction rate group exhibited a transient thyroid-stimulating hormone suppression, suggesting thyrotoxicosis during sunitinib treatment. Histological evaluation demonstrated atrophy of thyroid follicles and degeneration of follicular epithelial cells without critical diminution of vascular volume in the thyroid gland.

CONCLUSION

Thyroid atrophy is frequently observed following sunitinib treatment and may be brought about by sunitinib-induced thyrotoxicosis or the direct effects of sunitinib that lead to degeneration of thyroid follicular cells.

Multicenter Phase II Trial of S-1 in Patients With Cytokine-Refractory Metastatic Renal Cell Carcinoma

Purpose

This phase II multicenter trial was conducted to evaluate the activity and safety of S-1 in Japanese patients with metastatic renal cell carcinoma (mRCC). We also examined the relation between response and mRNA expression levels of enzymes involved in the metabolism of fluorouracil (FU).

Methods

Patients with mRCC who had received nephrectomy in whom cytokine-based immunotherapy was ineffective or contraindicated were studied. S-1 was administered orally at 80-, 100-, or 120-mg daily, assigned according to body surface area, on days 1 to 28 of a 42-day cycle. The primary end point was the objective response rate. The mRNA expression levels of FU-related enzymes were measured by reverse-transcriptase polymerase chain reaction in formalin-fixed, paraffin-embedded specimens of tumors obtained at nephrectomy.

Results

A total of 45 eligible patients were enrolled. Eleven (24.4%) of 45 patients had partial responses to S-1, and 28 (62.2%) had stable disease. Median progression-free survival was 9.2 months. The severity of most adverse events was mild to moderate. The most common grade 3/4 drug-related adverse events were neutropenia (8.9%) and anorexia (8.9%). The expression level of thymidylate synthase (TS) mRNA was significantly lower in patients who responded to treatment (t-test, P = .048), and progression-free survival was significantly longer in patients whose TS mRNA expression levels were below the median value, as compared with those with higher levels (log-rank test, P = .006).

Conclusion

S-1 is active against cytokine-refractory mRCC. Quantification of TS mRNA levels in tumors before treatment may facilitate prediction of the response of mRCC to S-1.

Phase II trials of single-agent anti-VEGF therapy for patients with chronic lymphocytic leukemia

Between 2005 and 2008, we conducted separate phase II clinical testing of three distinct anti-VEGF therapies for patients with relapsed/refractory CLL. Collectively, 46 patients were accrued to trials of single-agent anti-VEGF antibody (bevacizumab, n = 13) or one of two receptor tyrosine kinase inhibitors (AZD2171, n = 15; sunitinib malate, n = 18). All patients have completed treatment. Patients received a median of two cycles of bevacizumab, AZD2171, or sunitinib malate. All three trials were closed early due to lack of efficacy. No complete or partial remissions were observed. Individually and collectively, these studies indicate that single-agent anti-VEGF therapy has minimal clinical activity for patients with relapsed/refractory CLL.

Sunitinib as a second-line therapy for advanced GISTs after failure of imatinib: relationship between efficacy and tumor genotype in Korean patients

BACKGROUND

To assess the efficacy and safety of sunitinib with regards to primary genotypes of tumor in Korean patients with advanced gastrointestinal stromal tumors (GISTs) who failed an initial therapy of imatinib.

METHODS

Clinical data were collected from 88 consecutive patients with metastatic/unresectable GISTs treated with sunitinib at the Asan Medical Center.

RESULTS

The median time-to-progression (TTP) and overall survival (OS) times were 7.1 months and 17.6 months, respectively. Of the 74 patients tested for KIT (exons 9, 11, 13, 17) and PDGFRA (exons 12 and 18), patients with KIT exon 9 mutant GIST (n = 11, 14.9%) showed numerically better clinical benefit (objective response or stable disease ≥ 24 weeks) rate (63.6% vs 46.8%, p = 0.504) and TTP (median 13.6 mo vs 6.9 mo, p = 0.631) than those with KIT exon 11 mutant GIST (n = 47, 63.5%). The most common grade 3/4 adverse events included neutropenia (34.1%), thrombocytopenia (33.0%) and hand-foot skin reaction (25.0%).

CONCLUSIONS

Sunitinib is an effective and safe second-line therapy for Korean patients with advanced GIST. The superior efficacy of sunitinib against GISTs with KIT exon 9 mutations appears to be similar in Korean patients to Western experience although statistical significance was not secured.

Genetic polymorphisms associated with a prolonged progression-free survival in patients with metastatic renal cell cancer treated with sunitinib

PURPOSE

The objective of this study was to identify genetic polymorphisms related to the pharmacokinetics and pharmacodynamics of sunitinib that are associated with a prolonged progression-free survival (PFS) and/or overall survival (OS) in patients with clear-cell metastatic renal cell cancer (mRCC) treated with sunitinib.

EXPERIMENTAL DESIGN

A retrospective multicenter pharmacogenetic association study was performed in 136 clear-cell mRCC patients treated with sunitinib. A total of 30 polymorphisms in 11 candidate genes, together with clinical characteristics were tested univariately for association with PFS as primary and OS as secondary outcome. Candidate variables with P < 0.1 were analyzed in a multivariate Cox regression model.

RESULTS

Multivariate analysis showed that PFS was significantly improved when an A-allele was present in CYP3A5 6986A/G [hazard ratio (HR), 0.27; P = 0.032], a CAT copy was absent in the NR1I3 haplotype (5719C/T, 7738A/C, 7837T/G; HR, 1.76; P = 0.017) and a TCG copy was present in the ABCB1 haplotype (3435C/T, 1236C/T, 2677G/T; HR, 0.52; P = 0.033). Carriers with a favorable genetic profile (n = 95) had an improved PFS and OS as compared with noncarriers (median PFS and OS: 13.1 versus 7.5 months and 19.9 versus 12.3 months). Next to the genetic variants, the Memorial Sloan-Kettering Cancer Center prognostic criteria were associated with PFS and OS (HR, 1.99 and 2.27; P < 0.001).

CONCLUSIONS

This exploratory study shows that genetic polymorphisms in three genes involved in sunitinib pharmacokinetics are associated with PFS in mRCC patients treated with this drug. These findings advocate prospective validation and further elucidation of these genetic determinants in relation to sunitinib exposure and efficacy.

Immunological therapy in urological malignancy: novel combination strategies

At present, immunotherapy in urological malignancy is experiencing a renaissance, particularly with the emergence of a host of innovative cancer vaccines. Herein, we will review promising immunotherapeutic approaches and evaluate the data supporting their inclusion in novel combination strategies.

Bilateral papilledema on sunitinib therapy for advanced renal cell carcinoma

We report the case of a 59-year-old man with advanced renal cell carcinoma who developed bilateral papilledema while on therapy with sunitinib, a multi-targeted tyrosine kinase inhibitor (TKI). While papilledema has been reported in association with another TKI (imatinib), the association between sunitinib and papilledema has not previously been reported in the literature.

Identification of a set of genes associated with response to interleukin-2 and interferon-α combination therapy for renal cell carcinoma through genome-wide gene expression profiling

Interleukin (IL)-2 and interferon (IFN)-α combination therapy for metastatic renal cell carcinoma (RCC) improves the prognosis for a subset of patients, while some patients suffer from severe adverse drug reactions with little benefit. To establish a method to predict responses to this combination therapy (approximately 30% response rate), the gene expression profiles of primary RCCs were analyzed using an oligoDNA microarray consisting of 38,500 genes or ESTs, after enrichment of the cancer cell population by laser micro-beam microdissection. The analysis of 10 responders and 18 non-responders identified 24 genes that exhibited significant differential expression between the two groups. In addition, the patients whose tumors did not express HLA-DQA1 or HLA-DQB1 molecules demonstrated poor clinical response. Exclusion of patients with tumors lacking either of these two genes is likely to improve the response rate to IL-2 and IFN-α combination therapy from 30 to 67%, indicating that a simple pretreatment test provides useful information with which to subselect patients with renal cancer in order to improve the efficacy of this treatment and reduce unnecessary medical costs.

Utilizing targeted cancer therapeutic agents in combination: novel approaches and urgent requirements

The rapid development of new therapeutic agents that target specific molecular pathways involved in tumour cell proliferation provides an unprecedented opportunity to achieve a much higher degree of biochemical specificity than previously possible with traditional chemotherapeutic anticancer agents. However, the lack of specificity of these established chemotherapeutic drugs allowed a relatively straightforward approach to their use in combination therapies. Developing a paradigm for combining new, molecularly targeted agents, on the other hand, is substantially more complex. The abundance of molecular data makes it possible, at least in theory, to predict how such agents might interact across crucial growth control networks. Initial strategies to examine molecularly targeted agent combinations have produced a small number of successes in the clinic. However, for most of these combination strategies, both in preclinical models and in patients, it is not clear whether the agents being combined actually hit their targets to induce growth inhibition. Here, we consider the initial approach of the US National Cancer Institute (NCI) to the evaluation of combinations of molecularly targeted anticancer agents in patients and provide a description of several new approaches that the NCI has initiated to improve the effectiveness of combination-targeted therapy for cancer.

Optimizing the use of sunitinib in metastatic renal cell carcinoma: an update from clinical practice

Sunitinib is a reference standard of care for the treatment of metastatic renal cell carcinoma (mRCC). While the tolerability of sunitinib is consistent across clinical studies, the impact of tolerability on clinical benefit necessitates effective therapy management, focusing on optimization of dosing, treatment duration, and management of adverse events. Managing individual tolerability concerns in clinical practice should include patient education and practical management strategies. We review the sunitinib tolerability profile in mRCC and describe practical strategies to manage adverse events in order to maximize clinical benefit. These strategies may allow long-term sunitinib treatment, thereby optimizing the available clinical efficacy.

Kidney Cancer Working Group report

Kidney cancer accounts for approximately 2% of all cancers worldwide, with renal cell carcinoma being the most common form and this report is focused on renal cell carcinoma. Globally, the incidence and mortality rates are increasing by 2-3% per decade. Kidney cancer is less common in Asia compared with the West. Cigarette smoking, obesity, acquired cystic kidney disease and inherited susceptibility are known risk factors for kidney cancer. The National Comprehensive Cancer Network Guidelines recommend surgical excision as first line of treatment for Stage I, II or III kidney cancer patients and Stage IV patients with resectable tumours. Immunotherapy has a 20-year history in treatment of metastatic kidney cancer. High-dose interleukin-2 (IL-2) is administered in some countries, whereas low-dose IL-2 and interferon-alpha (IFN-α) are popular in Japan. Molecular-targeted drugs, including sunitinib, bevacizumab and sorafenib, are being used for previously untreated and refractory patients. Asian and non-Asian populations have shown large differences in the incidences of adverse events with sorafenib and sunitinib.

CONSENSUS STATEMENT

Kidney cancer is relatively uncommon in Asia compared with the West, but its incidence is increasing in more developed Asian nations. Guidelines from the National Comprehensive Cancer Network , etc., for treating metastatic renal cell carcinoma are based on Phase III clinical trials conducted primarily in Western patients. Targeted therapies are now becoming primary recommendations, but efficacy/toxicity data from Asian patients are lacking. Some drugs cause adverse effects in Asians because their recommended dosages are optimal for Caucasians but may be too high for Asians. Further research is necessary to develop optimal treatment strategies for Asians.

Sunitinib in metastatic renal cell carcinoma patients with brain metastases

BACKGROUND

In a broad patient population with metastatic renal cell carcinoma (RCC), enrolled in an open-label, expanded access program (EAP), the safety profile of sunitinib was manageable, and efficacy results were encouraging. Here, the authors report results for patients with baseline brain metastases participating in this global EAP.

METHODS

Previously treated and treatment-naive metastatic RCC patients ≥18 years received sunitinib 50 mg orally, once daily, on Schedule 4/2. Safety was assessed regularly, tumor measurements done per local practice, and survival data collected where possible. Analyses were done in the modified intention-to-treat (ITT) population, consisting of all patients who received ≥1 dose of sunitinib.

RESULTS

As of December 2007, 4564 patients had enrolled in 52 countries. Of these enrollees, 4371 were included in the modified ITT population, of whom 321 (7%) had baseline brain metastases and had received a median of 3 treatment cycles (range 1-25). Reasons for their discontinuation included lack of efficacy (32%) and adverse events (8%). The most common grade 3-4 treatment-related adverse events were fatigue and asthenia (both 7%), thrombocytopenia (6%), and neutropenia (5%), the incidence of which were comparable to that for the overall EAP population. Of 213 evaluable patients, 26 (12%) had an objective response. Median progression-free survival and overall survival were 5.6 months (95% CI, 5.2-6.1) and 9.2 months (95% CI, 7.8-10.9), respectively.

CONCLUSIONS

In patients with brain metastases from RCC, the safety profile of sunitinib was comparable to that in the general metastatic RCC population, and sunitinib showed evidence of antitumor activity.

Covalent crosslinking of tumor antigens stimulates an antitumor immune response

In murine renal cell carcinoma and melanoma models, vaccination with crosslinked tumor antigen in the absence of other adjuvants inhibited the growth of RENCA and B16 tumors. Vaccination with crosslinked antigens (CA9 or gp100) enhanced the cellular immune response as measured by ELISPOT and cytotoxicity assays. Crosslinking antigens enhanced delivery of antigen to bone marrow derived dendritic cells, which were capable of internalizing and processing the antigens. Dendritic cells pulsed with crosslinked antigen were effective in stimulating antigen-specific CD8+ T lymphocyte proliferation and interferon-γ secretion. Crosslinking tumor antigens is a simple and effective strategy for enhancing tumor vaccines.

A phase I study of sunitinib plus capecitabine in patients with advanced solid tumors

PURPOSE

This open-label, phase I, dose-escalation study assessed the maximum-tolerated dose (MTD), safety, pharmacokinetics, and antitumor activity of sunitinib in combination with capecitabine in patients with advanced solid tumors.

PATIENTS AND METHODS

Sunitinib (25, 37.5, or 50 mg) was administered orally once daily on three dosing schedules: 4 weeks on treatment, 2 weeks off treatment (Schedule 4/2); 2 weeks on treatment, 1 week off treatment (Schedule 2/1); and continuous daily dosing (CDD schedule). Capecitabine (825, 1,000, or 1,250 mg/m(2)) was administered orally twice daily on days 1 to 14 every 3 weeks for all patients. Sunitinib and capecitabine doses were escalated in serial patient cohorts.

RESULTS

Seventy-three patients were treated. Grade 3 adverse events included abdominal pain, mucosal inflammation, fatigue, neutropenia, and hand-foot syndrome. The MTD for Schedule 4/2 and the CDD schedule was sunitinib 37.5 mg/d plus capecitabine 1,000 mg/m(2) twice per day; the MTD for Schedule 2/1 was sunitinib 50 mg/d plus capecitabine 1,000 mg/m(2) twice per day. There were no clinically significant pharmacokinetic drug-drug interactions. Nine partial responses were confirmed in patients with pancreatic cancer (n = 3) and breast, thyroid, neuroendocrine, bladder, and colorectal cancer, and cholangiocarcinoma (each n = 1).

CONCLUSION

The combination of sunitinib and capecitabine resulted in an acceptable safety profile in patients with advanced solid tumors. Further evaluation of sunitinib in combination with capecitabine may be undertaken using the MTD for any of the three treatment schedules.

Prospective clinical trial of preoperative sunitinib in patients with renal cell carcinoma

PURPOSE

Sunitinib is an approved treatment for metastatic renal cell carcinoma. We performed a prospective clinical trial to evaluate the safety and clinical response to sunitinib administered before nephrectomy in patients with localized or metastatic clear cell renal cell carcinoma.

MATERIALS AND METHODS

Patients with biopsy proven clear cell renal cell carcinoma were enrolled in the study and treated with 37.5 mg sunitinib malate daily for 3 months before nephrectomy. The primary end point was safety.

RESULTS

In an 18-month period 20 patients were enrolled. The most common toxicities were gastrointestinal symptoms and hematological effects. Grade 3 toxicity developed in 6 patients (30%). No surgical complications were attributable to sunitinib treatment. Of the 20 patients 17 (85%) experienced reduced tumor diameter (mean change -11.8%, range -27% to 11%) and cross-sectional area (mean change -27.9%, range -43% to 23%). Enhancement on contrast enhanced computerized tomography decreased in 15 patients (mean HU change -22%, range -74% to 29%). After tumor reduction 8 patients with cT1b disease underwent laparoscopic partial nephrectomy. Surgical parameters, such as blood loss, transfusion rate, operative time and complications, were similar to those in patients who underwent surgery during the study period and were not enrolled in the trial.

CONCLUSIONS

Preoperative treatment with sunitinib is safe. Sunitinib decreased the size of primary renal cell carcinoma in 17 of 20 patients. Future trials can be considered to evaluate neoadjuvant sunitinib to maximize nephron sparing and decrease the recurrence of high risk, localized renal cell carcinoma.

Modeling bone marrow toxicity using kinase structural motifs and the inhibition profiles of small molecular kinase inhibitors

The cellular function of kinases combined with the difficulty of designing selective small molecule kinase inhibitors (SMKIs) poses a challenge for drug development. The late-stage attrition of SMKIs could be lessened by integrating safety information of kinases into the lead optimization stage of drug development. Herein, a mathematical model to predict bone marrow toxicity (BMT) is presented which enables the rational design of SMKIs away from this safety liability. A specific example highlights how this model identifies critical structural modifications to avoid BMT. The model was built using a novel algorithm, which selects 19 representative kinases from a panel of 277 based upon their ATP-binding pocket sequences and ability to predict BMT in vivo for 48 SMKIs. A support vector machine classifier was trained on the selected kinases and accurately predicts BMT with 74% accuracy. The model provides an efficient method for understanding SMKI-induced in vivo BMT earlier in drug discovery.

How do cost-effectiveness analyses inform reimbursement decisions for oncology medicines in Canada? The example of sunitinib for first-line treatment of metastatic renal cell carcinoma

BACKGROUND

Canadian oncology decision-makers have reimbursed cancer drugs at incremental cost-effectiveness ratios (ICER) higher than those considered acceptable in other therapeutic areas. Sunitinib is a multitargeted receptor tyrosine kinase inhibitor, indicated for metastatic renal-cell carcinoma (MRCC) of clear cell histology. Canadian decision-makers evaluated sunitinib funding in the presence of important data limitations (including interim analysis of a surrogate outcome) and in the context of a high ICER.

METHODS

First, a description was presented of the cost-effectiveness analysis submitted for sunitinib reimbursement decision-making in Canada before conclusive survival evidence had been available. Second, sunitinib access decisions and the oncology drug reimbursement literature were reviewed to explore the interpretation of sunitinib perceived value in the context of the decision-making framework in Canada.

RESULTS

The economic evaluation yielded an ICER of $144K/quality-adjusted life-year gained for sunitinib compared with interferon-alfa. This high ratio was not an insurmountable barrier to access in Canada because all provinces now reimburse sunitinib for first-line treatment of MRCC. In this particular instance, payers were receptive to immature survival data but substantial progression-free gains, for patients with a relatively rare cancer and few treatment options.

CONCLUSION

  This demonstrates that the cost-effectiveness ratio is only one of many factors that affect an access decision in oncology.

VEGF polymorphisms are associated with an increasing risk of developing renal cell carcinoma

PURPOSE

Vascular endothelial cell growth factor is studied in different malignant tumors as a key endothelial cell mitogen. Many single nucleotide polymorphisms in the VEGF gene have been described. We compared VEGF gene polymorphisms between a control group and a renal cancer group.

MATERIALS AND METHODS

This study was performed in 202 control, white, healthy blood donors (control group) and in 51 consecutive patients with renal cell carcinoma. We studied VEGF genotype polymorphisms at positions -2549, -460, -1154, +405 and +936 using polymerase chain restriction fragment length polymorphism, and looked for correlations with clinical data.

RESULTS

No association was found between VEGF gene polymorphism and renal cell carcinoma prognostic parameters. However, in contrast as observed for controls and other polymorphisms the patient group displayed a heterozygote excess (p = 0.0179, 35.9% more than that expected) at the -460 polymorphism. Comparing the control group and the renal cell carcinoma group we detected a significantly increased risk of renal cell carcinoma in subjects with the C-460T polymorphism. T carrier genotypes and the T allele increased the risk of renal cell carcinoma with an OR of 14.15 (95% CI 1.900-105.41, p = 0.0017) and 2.14 (95% CI 1.34-3.419, p = 0.0018), respectively. The genotype at the -2549 polymorphism exhibited a nonsignificant trend for increased risk but the D allele was significantly associated with increased risk (p = 0.0305).

CONCLUSIONS

Our results suggest that the -460 polymorphism is a risk factor for renal cancer. An individual screening test could be proposed for high risk populations.

Overall survival and updated results from a phase II study of sunitinib in Japanese patients with metastatic renal cell carcinoma

BACKGROUND

In a phase II, open-label, multicentre Japanese study, sunitinib demonstrated antitumour activity and acceptable tolerability in metastatic renal cell carcinoma patients. Final survival analyses and updated results are reported.

METHODS

Fifty-one Japanese patients with a clear-cell component of metastatic renal cell carcinoma (25 treatment-naïve; 26 cytokine-refractory) received sunitinib 50 mg orally, once daily (Schedule 4/2). Overall and progression-free survivals were estimated by the Kaplan-Meier method. Objective response rate (per Response Evaluation Criteria in Solid Tumours) and safety were assessed with an updated follow-up.

RESULTS

First-line and pretreated patients received a median 6.0 and 9.5 treatment cycles, respectively. Investigator-assessed, end-of-study objective response rate was 52.0, 53.8 and 52.9% in first-line, pretreated and overall intent-to-treat populations, respectively. The median progression-free survival was 12.2 and 10.6 months in first-line and pretreated patients, respectively. Fourteen patients per group died (56 and 54%), and the median overall survival was 33.1 and 32.5 months, respectively. The most common treatment-related Grade 3 or 4 adverse events and laboratory abnormalities were fatigue (24%), hand-foot syndrome (18%), decreased platelet count (55%), decreased neutrophil count (53%) and increased lipase (49%). No Grade 5 treatment-related adverse events occurred. Forty patients (78%) required dose reduction, and 13 (25%) discontinued, due to treatment-related adverse events.

CONCLUSIONS

With the median overall survival benefit exceeding 2.5 years, and acceptable tolerability, in first-line and pretreated Japanese metastatic renal cell carcinoma patients with Eastern Cooperative Oncology Group performance status 0/1, sunitinib showed a favourable risk/benefit profile, similar to Western studies. However, there was a trend towards greater efficacy and more haematological adverse events in Japanese patients.

Renal cancer resistance to antiangiogenic therapy is delayed by restoration of angiostatic signaling

Treatment of metastatic renal cell cancer (RCC) with antiangiogenic agents that block vascular endothelial growth factor (VEGF) receptor 2 signaling produces tumor regression in a substantial fraction of patients; however, resistance typically develops within 6 to 12 months. The purpose of this study was to identify molecular pathways involved in resistance. Treatment of mice bearing either 786-0 or A498 human RCC xenografts with sorafenib or sunitinib produced tumor growth stabilization followed by regrowth despite continued drug administration analogous to the clinical experience. Tumors and plasma were harvested at day 3 of therapy and at the time of resistance to assess pathways that may be involved in resistance. Serial perfusion imaging, and plasma and tumor collections were obtained in mice treated with either placebo or sunitinib alone or in combination with intratumoral injections of the angiostatic chemokine CXCL9. Sunitinib administration led to an early downmodulation of IFNγ levels as well as reduction of IFNγ receptor and downstream angiostatic chemokines CXCL9 to 11 within the tumor. Intratumoral injection of CXCL9, although producing minimal effects by itself, when combined with sunitinib resulted in delayed resistance in vivo accompanied by a prolonged reduction of microvascular density and tumor perfusion as measured by perfusion imaging relative to sunitinib alone. These results provide evidence that resistance to VEGF receptor therapy is due at least in part to resumption of angiogenesis in association with reduction of IFNγ-related angiostatic chemokines, and that this resistance can be delayed by concomitant administration of CXCL9.

Rationale for targeted therapies and potential role of pazopanib in advanced renal cell carcinoma

Advanced renal cell carcinoma (RCC) remains a challenging, major health problem. Recent advances in understanding the fundamental biology underlying one form of RCC, ie, clear cell (or conventional) RCC, have opened the door to a series of targeted agents, such as the tyrosine kinase inhibitors (TKIs), which have become the standard of care in managing advanced clear cell RCC. Among the newest of these agents to receive Food and Drug Administration approval in this disease is pazopanib. This review will summarize what is known about the fundamental biology that underlies clear cell RCC, the data surrounding the previously approved targeted agents for this disease, including not only the TKIs but also the mTOR inhibitors and the vascular endothelial growth factor-specific agent, bevacizumab, and the newest TKI, pazopanib. It will also explore the potential role for pazopanib relative to the other available agents and where it may fit into the armamentarium for treatment of advanced/metastatic RCC.

Perspectives in drug development for metastatic renal cell cancer

Patients with renal cell carcinoma (RCC) exhibit a spectrum of clinical outcomes, with some patients following an indolent clinical course and others displaying rapidly advancing disease. As evidence points to RCC being largely refractory to traditional chemotherapy and radiotherapy strategies, immunotherapeutic approaches played a dominant role in the management of metastatic RCC for a quarter of a century. Management of this challenging tumor has been revolutionized by the incorporation of molecularly targeted therapies such as inhibitors of pathways involving tyrosine kinase signaling and the mammalian target of rapamycin (mTOR). The improvements in disease stabilization and survival seen with these agents has meant that molecularly targeted therapy now forms the foundation for treating RCC and has resulted in a multitude of studies investigating similar compounds for efficacy in RCC. Despite this, the rationale for using immunomodulatory regimens remains strong and its ongoing place in this era of targeted treatments continues to pose interesting clinical questions. The challenge of maintaining durable responses from our current therapies persists and this review highlights the plethora of options now available in RCC treatment and the directions in which modern management are heading.

Sunitinib: a multitargeted receptor tyrosine kinase inhibitor in the era of molecular cancer therapies

Sunitinib is an oral oxindole multitargeted kinase inhibitor that inhibits certain receptor tyrosine kinases (RTKs). These include vascular endothelial growth factor receptors (VEGFR type 1 and 2), platelet-derived growth factor receptors (PDGFR-alpha and PDGFR-beta), stem cell factor receptor (KIT), FMS-like tyrosine kinase-3 (FLT3), glial cell-line derived neurotrophic factor receptor (RET) and the receptor of macrophage-colony stimulating factor (CSF1R). Examination of the antitumor effect of sunitinib in a variety of cell lines in vitro suggested an antiproliferative activity that is dependent on the presence of constitutively active RTK targets. The use of sunitinib as first-line therapy in advanced renal cell carcinoma (RCC) has improved the overall survival compared with that observed after cytokine therapy, while its administration in patients with gastrointestinal stromal tumors (GISTs) after progression or intolerance to imatinib achieved an objective response of 7%. Sunitinib is currently approved for the treatment of GISTs in this setting, and as first-line therapy for the treatment of advanced RCC. The relatively long half-life of sunitinib and its major metabolite allow for a once-daily dosing schedule. An interesting antitumor activity of sunitinib was reported in phase II studies of patients with a variety of malignancies, such as hepatocellular cancer, pancreatic neuroendocrine tumors, and non-small cell lung cancer; results of phase III studies are urgently anticipated. Fatigue is one of the most common adverse effects of sunitinib, as 50-70% of patients with advanced RCC and GIST complained of this adverse effect. Other adverse effects are diarrhea, anorexia, nausea and vomiting, oral changes and bleeding events. Most toxicities are reversible and should not result in discontinuation of sunitinib. If necessary, dose adjustments or interruptions should be made. Hypothyroidism has been described in the first 2 weeks of sunitinib therapy and its incidence increases progressively with the duration of therapy. Sunitinib may exert its hypertensive activity through a direct effect on the vasculature, while its most important cardiac adverse effect is left ventricular dysfunction. A variety of skin adverse effects have been described with the use of sunitinib such as hand-foot syndrome, yellow discoloration of the skin, dry skin, subungual splinter hemorrhages, acral erythema, and generalized skin rashes. Administration of sunitinib in the adjuvant and neoadjuvant setting of patients with RCC and of its combination with chemotherapy and other targeted therapies are currently under intense investigation.

Biomarkers predicting outcome in patients with advanced renal cell carcinoma: Results from sorafenib phase III Treatment Approaches in Renal Cancer Global Evaluation Trial

PURPOSE

Plasma proteins [vascular endothelial growth factor (VEGF), soluble VEGF receptor 2 (sVEGFR-2), carbonic anhydrase IX (CAIX), tissue inhibitor of metalloproteinase 1 (TIMP-1), and Ras p21] and one tumor gene (VHL) were analyzed to identify prognostic biomarkers or indicators of response to sorafenib in a subset of patients enrolled in the Treatment Approaches in Renal Cancer Global Evaluation Trial.

EXPERIMENTAL DESIGN

Nine hundred three patients with advanced renal cell carcinoma (RCC) were randomized to 400 mg sorafenib twice a day or placebo. Samples collected at baseline and after 3 and 12 weeks were subjected to enzyme-linked immunosorbent assays. VHL exons were sequenced from tumor biopsies.

RESULTS

Baseline biomarker data were available for VEGF (n = 712), sVEGFR-2 (n = 713), CAIX (n = 128), TIMP-1 (n = 123), Ras p21 (n = 125), and VHL mutational status (n = 134). Higher Eastern Cooperative Oncology Group performance status (ECOG PS) score correlated with elevated baseline VEGF (P < 0.0001) and a higher incidence of VHL mutations (P = 0.008), whereas higher Memorial Sloan-Kettering Cancer Center (MSKCC) score correlated with elevated VEGF (P < 0.0001), CAIX (P = 0.027), and TIMP-1 (P = 0.0001). Univariable analyses of baseline levels in the placebo cohort identified VEGF (P = 0.0024), CAIX (P = 0.034), TIMP-1 (P = 0.001), and Ras p21 (P = 0.016) as prognostic biomarkers for survival. TIMP-1 remained prognostic for survival in a multivariable analysis model (P = 0.002) that also included ECOG PS, MSKCC score, and the other biomarkers assayed. In the placebo cohort, TIMP-1 (P < 0.001) and Ras p21 (P = 0.048) levels increased at 12 weeks. In the sorafenib cohort, VEGF levels increased at 3 and 12 weeks of treatment (both weeks P < 0.0001), whereas sVEGFR-2 (both weeks P < 0.0001) and TIMP-1 levels (P = 0.002, week 3; P = 0.006, week 12) decreased.

CONCLUSIONS

VEGF, CAIX, TIMP-1, and Ras p21 levels were prognostic for survival in RCC patients. Of these, TIMP-1 has emerged as being independently prognostic.

Efficacy and safety of sunitinib on metastatic renal cell carcinoma: a single-institution experience

PURPOSE

We assessed the efficacy and safety of the tyrosine kinase inhibitor sunitinib in Korean patients with metastatic renal cell carcinoma (mRCC).

MATERIALS AND METHODS

Between September 2007 and December 2009, all twenty-one patients who had mRCC with a clear-cell component were retrospectively reviewed. Sunitinib was administered orally at a dose of 50 mg daily until disease progression or intolerance to treatment occurred. The primary end point of this study was the objective tumor response assessed by Response Evaluation Criteria in Solid Tumors (RECIST), and the secondary end points were progression-free survival (PFS) and overall survival (OS) rates as well as assessment of adverse effects.

RESULTS

After a median of 17.4 months (range, 5.7-33.1 months) of treatment, 11 patients (52.4%) had an objective response with a complete response in 1 patient (4.8%), and a partial response in 10 patients (47.6%) as the best tumor response. The median PFS was 13.4 months (95% confidence interval [CI], range, 12.3-14.5 months), and the median OS was 28.1 months (95% CI, 21.8-34.4 months). All patients experienced adverse events of some sort, but the studied treatment protocol was well tolerated and most patients experienced reversible grade 1 or 2 toxicities.

CONCLUSIONS

Sunitinib was efficacious in the treatment of metastatic clear-cell RCC, and was well tolerated in Korean patients. Although sunitinib treatment-related adverse events such as hand-foot syndrome and facial/generalized edema were observed with a higher incidence than in Western trials, they were mainly mild to moderate, and readily managed.