Sequential Use of the Tyrosine Kinase Inhibitors Sorafenib and Sunitinib in Metastatic Renal Cell Carcinoma: A Retrospective Outcome Analysis

Kidney Cancer, Version 3.2022, NCCN Clinical Practice Guidelines in Oncology

The NCCN Guidelines for Kidney Cancer focus on the screening, diagnosis, staging, treatment, and management of renal cell carcinoma (RCC). Patients with relapsed or stage IV RCC typically undergo surgery and/or receive systemic therapy. Tumor histology and risk stratification of patients is important in therapy selection. The NCCN Guidelines for Kidney Cancer stratify treatment recommendations by histology; recommendations for first-line treatment of ccRCC are also stratified by risk group. To further guide management of advanced RCC, the NCCN Kidney Cancer Panel has categorized all systemic kidney cancer therapy regimens as "Preferred," "Other Recommended Regimens," or "Useful in Certain Circumstances." This categorization provides guidance on treatment selection by considering the efficacy, safety, evidence, and other factors that play a role in treatment selection. These factors include pre-existing comorbidities, nature of the disease, and in some cases consideration of access to agents. This article summarizes surgical and systemic therapy recommendations for patients with relapsed or stage IV RCC.

Outcomes of systemic targeted therapy in recurrent renal cell carcinoma treated with adjuvant sunitinib

OBJECTIVE

To assess the efficacy and tolerability of rechallenge with sunitinib and other targeted therapies (TTs) in patitents with relapsed recurrent renal cell carcinoma (RCC) in the advanced setting.

METHODS

In this multi-institutional retrospective study, patients with relapsed RCC were rechallenged with sunitinib or other systemic TTs as a first-line therapeutic approach after failed adjuvant sunitinib treatment. Patient characteristics, treatments and clinical outcomes were recorded. The primary endpoint was progression-free survival (PFS). Secondary endpoints were objective response rate (ORR) and overall survival (OS).

RESULTS

A total of 34 patients with relapses were recorded, and 25 of these (73.5%) were men. Twenty-five patients were treated with systemic TT: 65% of patients received TT against the vascular endothelial growth factor pathway (including sunitinib), 21.7% received mammalian target of rapamycin inhibitors and 13% received immunotherapy. The median (interquartile range) time to relapse was 20.3 (5.2-20.4) months from diagnosis, and 7.5 months (1.0-8.5) from the end of adjuvant suntinib treatment. At a median follow-up of 23.5 months, 24 of the 25 patients had progressed on first-line systemic therapy. The median PFS was 12.0 months (95% confidence interval [CI] 5.78-18.2). There were no statistical differences in PFS between different treatments or sunitinib rechallenge. PFS was not statistically different in patients relapsing on or after adjuvant suntinib treatment (≤ 6 or >6 months after adjuvant suntinib ending). The ORR was 20.5%. The median OS was 29.1 months (95% CI 16.4-41.8).

CONCLUSIONS

Rechallenge with sunitinib or other systemic therapies is still a feasible therapeutic option that provides patients with advanced or metastastic RCC with additional clinical benefits with regard to PFS and OS after failed response to adjuvant sunitinib.

Outcome of third-line sunitinib after sequential therapy with cytokines and sorafenib in metastatic renal cell carcinoma

Third-line sunitinib is occasionally used for selected patients with metastatic renal cell carcinoma (mRCC). The aim of the present study was to evaluate the clinical significance of third-line sunitinib after failure of first-line cytokine therapy and second-line sorafenib in patients with clear-cell mRCC. A total of 14 consecutive patients with clear-cell mRCC treated with third-line sunitinib between December 2008 and February 2012 were enrolled in the present study. Disease control rate (DCR), progression-free survival (PFS), overall survival (OS), and relative dose intensity (RDI) were compared with those of first-line (n=20) and second-line (n=14) sunitinib treatment. The DCR was 42.9%, the median PFS was 12.0 months, and the median OS was 20.0 months for third-line sunitinib; there were no statistically significant differences compared with first-line and second-line sunitinib. The mean RDI was significantly lower for third-line sunitinib compared with first- and second-line sunitinib (P=0.0003 and 0.0109, respectively). Therefore, third-line sunitinib is an effective treatment option for selected patients with mRCC, as optimized therapeutic efficacy was obtained with a relatively low dose of sunitinib.

Time on Therapy for at Least Three Months Correlates with Overall Survival in Metastatic Renal Cell Carcinoma

With 15 drugs currently approved for the treatment of metastatic renal cell carcinoma (mRCC) and even more combination regimens with immunotherapy on the horizon, there remains a distinct lack of molecular biomarkers for therapeutic efficacy. Our study reports on real-world clinical outcomes of mRCC patients from a tertiary academic medical center treated with empirically selected standard-of-care therapy. We utilized the Stanford Renal Cell Carcinoma Database (RCCD) to report on various outcome measures, including overall survival (OS) and the median number of lines of targeted therapies received from the time of metastatic diagnosis. We found that most metastatic patients did not survive long enough to attempt even half of the available targeted therapies. We also noted that patients who failed to receive a clinical benefit within the first two lines of therapy could still go on to experience clinical benefit in later lines of therapy. The term, “clinical benefit” was assigned to a line of therapy if a patient remained on drug treatment for three months or longer. Moreover, patients with clinical benefit in at least one line of therapy experienced significantly longer OS compared to those who did not have clinical benefit in at least one line of therapy. Developing biomarkers that identify patients who will receive clinical benefit in individual lines of therapy is one potential strategy for achieving rational drug sequencing in mRCC.

Does switching the bacillus Calmette-Guérin strain affect clinical outcome in patients with recurrent non-muscle-invasive bladder cancer after initial bacillus Calmette-Guérin therapy?

PURPOSE

It is still unknown whether switching the bacillus Calmette-Guérin (BCG) strain at the second induction course of BCG therapy has a therapeutic benefit in patients with tumor recurrence after the initial BCG therapy (BCG-relapsing tumor).

MATERIALS AND METHODS

We retrospectively reviewed the clinicopathological features of 97 patients treated with a second induction course of BCG therapy between 1986 and 2014. Among the patients initially treated with BCG Tokyo-172, the second course was either BCG Tokyo-172 in 56 (57.8%) or BCG Connaught in 15 (15.5%). Among those who were initially treated with BCG Connaught, the corresponding numbers were 13 (13.4%) or 13 (13.4%), respectively. Twenty-eight (28.9%) patients were given a different BCG strain at the 2 BCG therapies (switching group), and 69 (71.1%) patients were given the same BCG strain (non-switching group).

RESULT

The 5-year recurrence-free survival rate of the switching group was 64.7 ± 9.6%, which was not significantly different from that of the non-switching group (54.8 ± 6.9%, P = 0.427). Switching or not switching the BCG strain was not significantly associated with tumor recurrence after the second BCG therapy. The 5-year progression-free survival rate of the switching group was 95.4 ± 2.6%, which was also not significantly different from that of the non-switching group (96.0 ± 3.9%, P = 0.674). Patients treated with BCG Tokyo-172 to Tokyo-172 had significantly higher incidences of side effects during the second BCG therapy.

CONCLUSIONS

The results of this study indicate that in patients with a BCG-relapsing tumor after the initial BCG therapy, the same BCG strain as that administered at the initial BCG therapy could be utilized effectively for the second BCG therapy. Patients treated with BCG Tokyo-172 for an initial tumor had a higher incidence of side effects during the second BCG therapy using the same strain.

Targeting tumour microenvironment by tyrosine kinase inhibitor

Tumour microenvironment (TME) is a key determinant of tumour growth and metastasis. TME could be very different for each type and location of tumour and TME may change constantly during tumour growth. Multiple counterparts in surrounding microenvironment including mesenchymal-, hematopoietic-originated cells as well as non-cellular components affect TME. Thus, therapeutics that can disrupt the tumour-favouring microenvironment should be further explored for cancer therapy. Previous efforts in unravelling the dysregulated mechanisms of TME components has identified numerous protein tyrosine kinases, while its corresponding inhibitors have demonstrated potent modulatory effect on TME. Recent works have demonstrated that beyond the direct action on cancer cells, tyrosine kinase inhibitors (TKIs) have been implicated in inactivation or normalization of dysregulated TME components leading to cancer regression. Either through re-sensitizing the tumour cells or reversing the immunological tolerance microenvironment, the emergence of these TME modulatory mechanism of TKIs supports the combinatory use of TKIs with current chemotherapy or immunotherapy for cancer therapy. Therefore, an appropriate understanding on TME modulation by TKIs may offer another mode of action of TKIs for cancer treatment. This review highlights mode of kinase activation or paracrine ligand production from TME components and summarises the findings on the potential use of various TKIs on regulating TME components. At last, the combination use of current TKIs with immunotherapy in the perspectives of efficacy and safety are discussed.

Sunitinib in the treatment of metastatic renal cell carcinoma

Sunitinib is an oral multi-targeted tyrosine kinase inhibitor (TKI) that targets various receptors, including vascular endothelial growth factor receptors (VEGFRs). Sunitinib received approval in 2006 and became a standard treatment option in the first-line treatment of metastatic renal cell cancer (mRCC) after a phase III trial showed superiority compared with interferon alpha (IFN-α). Sunitinib has also shown activity in second-line treatment in several trials. Most of the combination trials with sunitinib with various agents have led to considerable toxicity without improving efficacy. Sunitinib alone causes significant side effects and has a distinct profile with diarrhoea, hypertension, skin effects hypothyroidism, fatigue and nausea of special interest. The recommended dose of sunitinib in mRCC is 50 mg orally daily for 4 weeks, followed by 2 weeks off treatment (4/2 schedule). An alternative 2 weeks on, 1 week off schedule (2/1 schedule) seems to be of similar efficacy and better tolerability and could be more widely used in the future. An intermittent treatment strategy with a stop in remission and re-induction after progression showed efficacy in smaller trials and is currently being evaluated in a phase III trial. Direct comparison of sunitinib with pazopanib in first-line treatment showed a similar efficacy for both TKIs with a distinct toxicity profile. Data from two phase II trials showed that sunitinib has also activity in non-clear cell cancer and is an option due to a lack of better alternatives. Currently, after immune checkpoint inhibitors have shown very promising results in the second-line treatment of RCC, they are being tested in a number of phase III trials in the first-line setting. The future will show the position of sunitinib in the first-line treatment of RCC in the era of the immune checkpoint inhibitors.

Targeting Strategies for Renal Cell Carcinoma: From Renal Cancer Cells to Renal Cancer Stem Cells

Renal cell carcinoma (RCC) is a common form of urologic tumor that originates from the highly heterogeneous epithelium of renal tubules. Over the last decade, targeting therapies to renal cancer cells have transformed clinical care for RCC. Recently, it was proposed that renal cancer stem cells (CSCs) isolated from renal carcinomas were responsible for driving tumor growth and resistance to conventional chemotherapy and radiotherapy, according to the theory of CSCs; this has provided the rationale for therapies targeting this aggressive cell population. Precise identification of renal CSC populations and the complete cell hierarchy will accurately inform characterization of disease subtypes. This will ultimately contribute to more personalized and targeted therapies. Here, we summarize potential targeting strategies for renal cancer cells and renal CSCs, including tyrosine kinase inhibitors, mammalian target of rapamycin inhibitors (mTOR), interleukins, CSC marker inhibitors, bone morphogenetic protein-2, antibody drug conjugates, and nanomedicine. In conclusion, targeting therapies for RCC represent new directions for exploration and clinical investigation and they plant a seed of hope for advanced clinical care.

Improving outcomes in metastatic clear cell renal cell carcinoma by sequencing therapy

Targeted agents have substantially improved outcomes in metastatic clear cell renal cell carcinoma. However, due to multiple mechanisms of evasive resistance, almost all patients progress at some point and may require subsequent therapies. Various agents have been explored after failure of first-line treatment in randomized clinical trials. However, so far few questions about the optimal sequence have been answered. Both everolimus and axitinib have been considered standard of care after failure of first-line VEGF-TKI; sorafenib has been proposed as an additional option. In clinical practice, several factors may influence the choice of subsequent treatment: these include considerations on appropriate drug exposure in first-line, gained insights on prognostic and predictive factors as well as mechanisms of resistance. Once the decision in second-line has been made and treatment has been initiated, treating physicians may already be challenged by the question of what to offer in third- and later lines. Treatment beyond second-line treatment isn't supported by strong evidence, and at this stage of disease, retrospective reports on rechallenge may help to guide decisions. In addition, local treatment approaches including metastasectomy and stereotactic radiosurgery may help to optimize outcomes in all treatment lines.

SWITCH: A Randomised, Sequential, Open-label Study to Evaluate the Efficacy and Safety of Sorafenib-sunitinib Versus Sunitinib-sorafenib in the Treatment of Metastatic Renal Cell Cancer

BACKGROUND

Understanding how to sequence targeted therapies for metastatic renal cell carcinoma (mRCC) is important for maximisation of clinical benefit.

OBJECTIVES

To prospectively evaluate sequential use of the multikinase inhibitors sorafenib followed by sunitinib (So-Su) versus sunitinib followed by sorafenib (Su-So) in patients with mRCC.

DESIGN, SETTING, AND PARTICIPANTS

The multicentre, randomised, open-label, phase 3 SWITCH study assessed So-Su versus Su-So in patients with mRCC without prior systemic therapy, and stratified by Memorial Sloan Kettering Cancer Center risk score (favourable or intermediate).

INTERVENTION

Patients were randomised to sorafenib 400mg twice daily followed, on progression or intolerable toxicity, by sunitinib 50mg once daily (4 wk on, 2 wk off) (So-Su), or vice versa (Su-So).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary endpoint was improvement in progression-free survival (PFS) with So-Su versus Su-So, assessed from randomisation to progression or death during second-line therapy. Secondary endpoints included overall survival (OS) and safety.

RESULTS AND LIMITATIONS

In total, 365 patients were randomised (So-Su, n=182; Su-So, n=183). There was no significant difference in total PFS between So-Su and Su-So (median 12.5 vs 14.9 mo; hazard ratio [HR] 1.01; 90% confidence interval [CI] 0.81-1.27; p=0.5 for superiority). OS was similar for So-Su and Su-So (median 31.5 and 30.2 mo; HR 1.00, 90% CI 0.77-1.30; p=0.5 for superiority). More So-Su patients than Su-So patients reached protocol-defined second-line therapy (57% vs 42%). Overall, adverse event rates were generally similar between the treatment arms. The most frequent any-grade treatment-emergent first-line adverse events were diarrhoea (54%) and hand-foot skin reaction (39%) for sorafenib; and diarrhoea (40%) and fatigue (40%) for sunitinib.

CONCLUSIONS

Total PFS was not superior with So-Su versus Su-So. These results demonstrate that sorafenib followed by sunitinib and vice versa provide similar clinical benefit in mRCC.

PATIENT SUMMARY

We investigated if total progression-free survival (PFS) is improved in patients with advanced/metastatic kidney cancer who are treated with sorafenib and then with sunitinib (So-Su), compared with sunitinib and then sorafenib (Su-So). We found that total PFS was not improved with So-Su compared with Su-So, but both treatment options were similarly effective in patients with advanced/metastatic kidney cancer.

TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT00732914, www.clinicaltrials.gov.

The role of fluorine-18-fluorodeoxyglucose positron emission tomography in evaluating the response to tyrosine-kinase inhibitors in patients with metastatic primary renal cell carcinoma

Background

Positron emission tomography-computed tomography (PET-CT) using fluorodeoxyglucose (FDG) is increasingly used in the evaluation of patients with advanced renal cell carcinoma (RCC), primarily for staging purposes. The aim of this paper is to perform a systematic review about the usefulness of PET-CT using FDG in response assessment after treatment with tyrosine-kinase inhibitors (TKIs) in patients with advanced RCC.

Materials and methods.

The scientific literature about the role of PET-CT using FDG in the assessment of response to treatment with TKIs in patients affected by advanced RCC was systematically reviewed.

Results

Seven studies about the role of PET-CT using FDG in the response assessment after treatment with TKIs (essentially sunitinib and sorafenib) in advanced RCC were retrieved in full-text and analysed, to determine the predictive role of this morpho-functional imaging method on patient outcome.

Conclusions

To date, the role of PET-CT using FDG in evaluating the response to TKIs in metastatic RCC patients is still not well defined, partly due to heterogeneity of available studies; however, PET-CT reveals potential role for the selection of patients undergoing therapy with TKIs. The use of contrast-enhanced PET-CT appears to be promising for a “multi-dimensional” evaluation of treatment response in these patients.

Sequential targeted therapy after pazopanib therapy in patients with metastatic renal cell cancer: efficacy and toxicity

INTRODUCTION/BACKGROUND

Patients with metastatic renal cell carcinoma (mRCC) in whom first-line therapies have failed might derive clinical benefit with sequential targeted agents. Limited data are available on the efficacy and toxicity of subsequent therapies after disease progression during pazopanib therapy.

PATIENTS AND METHODS

Patients with mRCC who received subsequent systemic treatment after pazopanib treatment failure were identified across 7 institutions. Pazopanib was given as first-line therapy in 28 patients and after cytokines therapy in 7 patients. Clinical outcome and toxicity analyses of 2 sequential treatment options (anti-vascular endothelial growth factor [VEGF] or mammalian target of rapamycin inhibitor [mTORi]) is presented.

RESULTS

Subsequent therapy was anti-VEGF in 22 patients and mTORi in 13. One patient who received bevacizumab and temsirolimus combination was excluded. VEGF-targeted therapies included sorafenib (n = 10), sunitinib (n = 3), bevacizumab (n = 2), cediranib (n = 4) and cabozantinib (n = 3). Patients treated with mTORi received everolimus. Median progression-free survival was 5.6 months from the start of subsequent therapy with anti-VEGF and 2.4 months with mTORi (P = .009). Overall survival (OS) was not significantly different (P = .68). Clinical benefit (including partial response and stable disease) on subsequent therapy was observed in 15 patients (64%) and 4 patients (31%) of anti-VEGF- and everolimus-treated patients, respectively (P = .021).

CONCLUSION

In this retrospective study, targeting VEGF was an effective strategy after disease progression during pazopanib treatment, although OS was not different among patients treated with VEGF or mTORi.

Axitinib: a review of its safety and efficacy in the treatment of adults with advanced renal cell carcinoma

Over the last seven years, seven targeted agents have been approved in the treatment of advanced or metastatic renal cell cancer, changing the therapeutic approach and prognosis of the disease dramatically. The latest agent with demonstrated efficacy is axitinib (Inlyta^®). This new generation of tyrosine kinase agent differs from previously existing agents by its greater activity potency of inhibition of vascular endothelial growth factor-receptor (VEGFR1-3). This efficacy has been tested in phase II and III clinical trials. Axitinib is the only targeted agent that benefits from recommended titration, with intra-patient dose escalation. The toxicity profile of the drug is tolerable. This paper reviews the mechanism of action of axitinib, its metabolism, and its pharmacokinetic profile. Clinical data of efficacy and safety is also detailed. The agent has been integrated in the international therapeutic guidelines, as a standard in treatment of renal cell cancer patients, previously treated through antiangiogenic therapy.

Clinical efficacy of targeted biologic agents as second-line therapy of advanced thyroid cancer

Targeted biologic agents showed clinically meaningful efficacy as front-line therapy for advanced radioiodine-refractory and medullary thyroid cancer. The clinical benefit of these agents beyond the front line has yet to be established.

METHODS

We assessed the clinical benefit of targeted agents in patients with advanced differentiated and medullary thyroid cancer treated at a single academic cancer center. We determined efficacy and compared front-line and second-line benefit using biochemical and anatomic response, time to treatment failure, and progression-free survival (PFS). Statistical differences were assessed by t test and chi-square test. Survival curves were generated by the Kaplan-Meier method. Differences in survival were assessed using the log-rank test, and a p value <.05 was considered significant.

RESULTS

We identified 39 patients with advanced differentiated and medullary thyroid cancer treated with targeted biologic agents. Median age was 56.3 years. Overall, 25 men and 14 women participated. Histology showed 23% medullary and 77% differentiated cancer. Nineteen patients progressed on front-line therapy and subsequently received second-line therapy. Targeted agents conferred clinically meaningful benefit in the second-line setting in terms of biochemical response (13.3%), clinical benefit (83.3%), median time to treatment failure (4.0 months; 95% confidence interval: 2.6-8.2), and median PFS (4.6 months; 95% confidence interval: 3.2-8.2). Second-line benefit (median PFS) was more modest in comparison to the front-line setting in both genders (women: 3 months vs. 12.2 months; men: 6 months vs. 19.7 months), in differentiated cancers (4.1 months vs. 15.7 months), and with vascular targeting agents (4.4 months vs. 20.1 months).

CONCLUSION

Patients with advanced thyroid cancer derived meaningful clinical benefit from additional therapy with a biologic agent following disease progression on front-line targeted therapy.

[Case of multiple lung metastases of renal cell carcinoma failing to respond to Interferon-alpha (IFN-alpha) and sunitinib but markedly responding to everolimus]

The case pertains to a 47-year-old male. He consulted our institute regarding a tumor in his right kidney. Endoscopic retroperitoneal nephrectomy of the right kidney was conducted to remove the tumor. The postoperative pathology was Renal Cell Carcinoma (Clear cell carcinoma, pT1b, pNx, V (+), Fuhrman grade 4). Multiple lung metastases were observed upon CT scan the following year. Sunitinib was administered following Interferon alpha (IFN-alpha) therapy; however, the lung metastases became larger, so administration of everolimus at 10 mg/day was commenced. The lung metastatic lesion became smaller upon CT scan from 6 weeks following administration, and it was determined that the therapeutic effect was PR. The PR was still maintained upon CT scan 31 weeks following administration but the lung metastatic lesion still remained; therefore, right lower lobe resection and lymph node biopsy were conducted upon obtaining informed consent. The administration of everolimus at 10 mg/day is still subsequently being continued due to viable tumor cells being observed in the lung metastatic lesion and the lymph node. At present, 43 weeks have past since the start of everolimus administration, but no new metastatic lesions have been observed.

Outcomes of patients with metastatic clear-cell renal cell carcinoma treated with pazopanib after disease progression with other targeted therapies

AIM

The multi-tyrosine kinase inhibitor pazopanib prolongs progression-free survival (PFS) versus placebo in treatment-naive and cytokine-refractory metastatic clear-cell renal cell carcinoma (ccRCC). Outcomes and safety data with pazopanib after targeted therapy (TT) are limited.

METHODS

We retrospectively evaluated records of consecutive patients with metastatic ccRCC who had progressive disease (PD) after TT and received pazopanib from November 2009 through November 2011. Tumour response was assessed by a blinded radiologist using Response Evaluation Criteria In Solid Tumours (RECIST). PFS and overall survival (OS) were estimated by Kaplan-Meier methods.

RESULTS

Ninety-three patients were identified. Median number of prior TTs was 2 (range, 1-5). There were 68 events (PD or death). Among 85 evaluable patients, 13 (15%) had a partial response. Median PFS was 6.5 months (95% CI: 4.5-9.7); median OS was 18.1 months (95% CI: 10.26-NA). Common adverse events (AEs) included fatigue (44%), elevated transaminases (35%), diarrhoea (30%), hypothyroidism (18%), nausea/vomiting (17%), anorexia (14%) and hypertension exacerbation (14%); 91% of AEs were grade 1/2. Eleven patients (12%) discontinued therapy due to AEs. There were no treatment-related deaths.

CONCLUDING STATEMENT

Pazopanib demonstrated efficacy in patients with metastatic ccRCC after PD with other TTs. Toxicity overall was mild/moderate and manageable.

Prolonged exposure to tyrosine kinase inhibitors or early use of everolimus in metastatic renal cell carcinoma: are the two options alike?

We retrospectively analyzed metastatic renal cell carcinoma (RCC) patients treated with 3 targeted agents. Patients started the sequence with a tyrosine kinase inhibitor (TKI), sunitinib or sorafenib, and were divided into 2 groups based on the order in which they received the other reciprocal TKI and everolimus (EVE): TKI-TKI-EVE group (n = 19) and TKI-EVE-TKI group (n = 14). Median progression-free survival (PFS) with first TKI was 13 months in the TKI-TKI-EVE group and 10 months in the TKI-EVE-TKI group. PFS with the second agent showed a trend in favor of the TKI-TKI-EVE sequence, with a median of 11 versus 6.5 months, whereas median PFS with the third agent was 6 months in both groups. Total PFS also showed a trend in favor of the TKI-TKI-EVE sequence with a median of 31 versus 23 months. Median overall survival (OS) was 38 months in both groups, with more patients receiving subsequent treatment in the TKI-EVE-TKI group. The subgroup of patients no long-term responders (≤9 months) to first TKI showed similar outcomes irrespective of the sequence. The subgroup of long-term responders to first TKI (>9 months) who received the other TKI instead of EVE had better outcomes in terms of median PFS with the second agent (13 vs. 5.5 months; p = 0.0271), median total PFS (39.5 vs. 23.5 months; p = 0.0415), and median OS (46 vs. 38 months). In conclusion, no apparent advantage was observed with early use of EVE in advanced RCC, even in those patients who did not benefit long from first-line TKI, whereas long-term duration of first-line TKI seems to be predictor of second-line TKI efficacy.

Sequential therapy in metastatic renal cell carcinoma: pre-clinical and clinical rationale for selecting a second- or subsequent-line therapy with a different mechanism of action

Few types of cancer have had their treatment evolve as rapidly as metastatic renal cell carcinoma (mRCC). Since 2005, six new targeted therapies with proven efficacy have been approved for the treatment of mRCC. The downside is that our knowledge about the mechanisms of action of these therapies and the intrinsic and extrinsic mechanism of resistance has not evolved equally fast, and many questions remain unanswered. The only approved agent to date in the European Union for patients who progress on sunitinib or sorafenib is everolimus. The results of the phase III trial comparing axitinib vs. sorafenib after failure on sunitinib, bevacizumab, temsirolimus, or cytokines have recently been published, and axitinib has recently been licensed by the Food and Drugs Administration. Other phase III trials that are being conducted include a comparison between everolimus plus bevacizumab and everolimus after failure on tyrosine kinase inhibitors, and between temsirolimus and sorafenib after failure on sunitinib. In this article, we will review the available evidence from clinical studies on sequential therapy for mRCC, including those that are still in progress. In addition, information on the mechanism of resistance or tolerance to first-line therapy, recommendations of the main practice guidelines for second-line treatment, potential therapies for third or successive treatment lines, and the major reasons why patients who progress may benefit from a change of mechanism of action will also be discussed.

Safety and Efficacy of Sorafenib in Renal Cell Carcinoma

This article reviews data on sorafenib use in renal cell carcinoma. Mechanisms of actions and pharmacokinetics are briefly described. Major clinical trials are presented, summarizing efficacy and safety of sorafenib. Its place in current treatment of renal cell carcinoma is discussed. Sorafenib is likely to remain one of the mainstays of RCC treatment in coming years.

Treatment selection in metastatic renal cell carcinoma: expert consensus

In metastatic renal cell carcinoma (mRCC), many factors influence clinical decisions, including histology, tumour burden, prognostic factors, comorbidities, and the ability of the patient to tolerate treatment. Progression-free survival (PFS) durations reported from randomized trials of targeted therapies vary considerably, in part because of differences in patient characteristics. For first-line therapy, an estimate of PFS with sunitinib, bevacizumab plus interferon, or sorafenib in a 'general' population is 8-9 months, but each regimen is suitable for different patient categories. For example, sunitinib is suitable for all-prognosis groups, particularly younger, fitter patients; pazopanib for patients with a good or intermediate prognosis; bevacizumab plus interferon for good-prognosis patients or those with indolent disease; and sorafenib for patients at all prognostic risk levels, particularly the elderly and those with comorbidities. Sequential therapy with targeted agents provides significant benefit, and should be considered in all patients who can tolerate such treatment. Level 1 evidence supports sequential use of tyrosine kinase inhibitors, as well as these agents followed by everolimus. We consider how patient characteristics have influenced the results of studies of first-line therapy, and we provide expert opinion on the most appropriate treatment choices for particular patient groups receiving first-line and second-line therapy.

A phase II study of 2-methoxyestradiol nanocrystal colloidal dispersion alone and in combination with sunitinib malate in patients with metastatic renal cell carcinoma progressing on sunitinib malate

BACKGROUND

Current treatment for metastatic renal cell cancer with vascular endothelial growth factor (VEGF) tyrosine kinase inhibitors (TKI) have provided improved overall survival, but complete responses are rare. We conducted a multicenter phase II study to evaluate the objective response rate of 2-methoxyestradiol (2ME2 NCD) alone and in combination with sunitinib for patients with metastatic renal cell carcinoma who have progressed on sunitinib alone.

METHODS

Adults with metastatic kidney cancer were stratified depending on whether they were still taking sunitinib or had discontinued sunitinib therapy at the time of registration. Patients were treated with 2ME2 NCD alone or in combination with sunitinib. The primary endpoint was objective response rate.

RESULTS

In total, 17 patients were enrolled, and 12 were evaluable for response (arm A, n = 7; arm b, n = 5). In arm A, four patients had the best response of stable disease, and three patients developed disease progression. In arm B, three patients had a best response of stable disease, and two patients had disease progression. One patient continued to receive treatment for a total of 14 cycles before developing disease progression. Fatigue was the most common observed toxicities. Thirty five percent of patients required discontinuation of therapy secondary to toxicities.

CONCLUSIONS

2ME2 NCD had minimal anti-tumor activity, with no observed objective responses. The study was terminated because 2ME2 NCD was not found to be tolerable at the recommended phase 2 dose in this patient population. A newer 2ME2 analog is in development with a more favorable toxicity profile and increased potency.

Comparative efficacy of vascular endothelial growth factor (VEGF) tyrosine kinase inhibitor (TKI) and mammalian target of rapamycin (mTOR) inhibitor as second-line therapy in patients with metastatic renal cell carcinoma after the failure of first-line VEGF TKI

Sequential therapy is a standard strategy used to overcome the limitations of targeted agents in metastatic renal cell carcinoma. It remains unclear whether a mammalian target of rapamycin (mTOR) inhibitor is a more effective second-line therapy after first-line vascular endothelial growth factor tyrosine kinase inhibitor (VEGF TKI) has failed than the alternative, VEGF TKI. A clinical database was used to identify all patients with renal cell carcinoma who failed at first-line VEGF TKI and then treated with second-line VEGF TKI or mTOR inhibitors in the Asan Medical Center. Patient medical characteristics, radiological response and survival status were assessed. Of the 83 patients who met the inclusion criteria, 41 received second-line VEGF TKI [sunitinib (n = 16) and sorafenib (n = 25)] and 42 were treated with mTOR inhibitors [temsirolimus (n = 11) and everolimus (n = 31)]. After a median follow-up duration of 23.9 months (95 % CI, 17.8-30.0), progression-free survival was 3.0 months for both groups [hazard ratio (HR, VEGF TKI vs. mTOR inhibitor) = 0.97, 95 % CI 0.59-1.62, P = 0.92]. Overall survival was 10.6 months for the VEGF TKI group and 8.2 months for the mTOR inhibitor group (HR = 0.98, 95 % CI 0.57-1.68, P = 0.94). The two groups did not differ significantly in terms of disease control rate (51 % for VEGF TKI and 59 % for mTOR inhibitor, P = 0.75). Second-line VEGF TKI seems to be as effective as mTOR inhibitors and may be a viable option as a second-line agent after first-line anti-VEGF agents have failed.

Advances in renal cell carcinoma treatment

The treatment of advanced renal cell carcinoma has been completely changed by the development of new therapeutic modalities during the past 3 years. In this time period six targeted agents have been approved for the treatment of advanced or metastatic disease. Phase 3 data support the use of sunitinib, bevacizumab plus interferon-α and pazopanib for patients with low and intermediate risk of clear-cell renal cell carcinoma. In the pivotal study of temsirolimus a significant longer overall survival compared with interferon-α in high-risk disease including non-clear-cell histology was observed. Patients pretreated with cytokines will benefit from sorafenib and pazopanib while everolimus has been shown to increase significantly progression-free survival after previous anti-angiogenesis therapy. In addition to these phase 3 data-based recommendations, several other factors have to be considered for treatment selection, for example, side effect profile and patients' comorbidities. Currently, the sequential use of the available targeted drugs and adjuvant treatment are the subject of ongoing clinical trials. However, medical treatment of renal cell carcinoma remains palliative and surgery remains the only curative approach in patients with localized, locally advanced and limited metastatic disease.

[Systemic and surgical management of metastatic renal cell carcinoma]

Several targeted therapies have become available for first-line (sunitinib, bevacizumab, pazopanib, temsirolimus) and second-line (sorafenib, pazopanib, everolimus) use in recent years. The superior outcomes achieved with these targeted agents have led to replacement of the formerly administered cytokines. New developments have raised the question of whether patients benefit from sequential therapies with tyrosine kinase inhibitors and/or whether combination regimes can improve clinical outcomes. This review gives an overview of the current therapeutic options for first- and second-line treatment in metastatic RCC as well as sequential and combination therapies. Adjuvant and neoadjuvant treatment options are being discussed. Furthermore, this review addresses surgical alternatives in the treatment of RCC.

NCCN Task Force report: optimizing treatment of advanced renal cell carcinoma with molecular targeted therapy

The outcome of patients with metastatic renal cell carcinoma has been substantially improved with administration of the currently available molecularly targeted therapies. However, proper selection of therapy and management of toxicities remain challenging. NCCN convened a multidisciplinary task force panel to address the clinical issues associated with these therapies in attempt to help practicing oncologists optimize patient outcomes. This report summarizes the background data presented at the task force meeting and the ensuing discussion.

Maximising the duration of disease control in metastatic renal cell carcinoma with targeted agents: an expert agreement

With six targeted agents approved (sorafenib, sunitinib, temsirolimus, bevacizumab [+interferon], everolimus and pazopanib), many patients with metastatic renal cell carcinoma (mRCC) will receive multiple therapies. However, the optimum sequencing approach has not been defined. A group of European experts reviewed available data and shared their clinical experience to compile an expert agreement on the sequential use of targeted agents in mRCC. To date, there are few prospective studies of sequential therapy. The mammalian target of rapamycin (mTOR) inhibitor everolimus was approved for use in patients who failed treatment with inhibitors of vascular endothelial growth factor (VEGF) and VEGF receptors (VEGFR) based on the results from a Phase III placebo-controlled study; however, until then, the only licensed agents across the spectrum of mRCC were VEGF(R) inhibitors (sorafenib, sunitinib and bevacizumab + interferon), and as such, a large body of evidence has accumulated regarding their use in sequence. Data show that sequential use of VEGF(R) inhibitors may be an effective treatment strategy to achieve prolonged clinical benefit. The optimal place of each targeted agent in the treatment sequence is still unclear, and data from large prospective studies are needed. The Phase III AXIS study of second-line sorafenib vs. axitinib (including post-VEGF(R) inhibitors) has completed, but the data are not yet published; other ongoing studies include the Phase III SWITCH study of sorafenib-sunitinib vs. sunitinib-sorafenib (NCT00732914); the Phase III 404 study of temsirolimus vs. sorafenib post-sunitinib (NCT00474786) and the Phase II RECORD 3 study of sunitinib-everolimus vs. everolimus-sunitinib (NCT00903175). Until additional data are available, consideration of patient response and tolerability to treatment may facilitate current decision-making regarding when to switch and which treatment to switch to in real-life clinical practice.

Combination or sequencing strategies to improve the outcome of metastatic renal cell carcinoma patients: a critical review

The introduction of novel anti-angiogenic therapies has greatly improved the outcome of patients with metastatic renal cell carcinoma (mRCC). The use of these therapies in combination or sequentially is proposed to provide greater efficacy. We have reviewed completed and ongoing clinical trials in mRCC that have reported efficacy and/or safety data of novel therapies used in combination or sequentially. Bevacizumab appears to be a useful partner when combined with interferon (IFN), while controversial results have been reported when combined with temsirolimus and everolimus. Other combinations appear to have unacceptable tolerability or require dose or schedule optimization. Sequencing data provide a clear indication that multiple lines of treatment may extend survival. The 'ideal' sequence, however, is still unknown. In conclusion, novel therapies used in combination or sequentially have potential to provide optimised treatment and patient outcomes in mRCC. The results from ongoing/planned trials are expected to help shape future therapy.

Continuing response to subsequent treatment lines with tyrosine kinase inhibitors in an adolescent with metastatic renal cell carcinoma

A 14-year-old girl with metastatic renal cell carcinoma was treated with nephrectomy, interferon, and several lines of the targeted agents sorafenib, bevacizumab, sunitinib, and everolimus, either alone or in combination. Treatment was well tolerated, but the patient developed hypothyroidism and significant hypertension with bevacizumab and sunitinib. She responded to all agents and was given radiation treatment twice at the time of symptomatic disease progression; she died 33 months from diagnosis.