Patterns of care among patients receiving sequential targeted therapies for advanced renal cell carcinoma: A retrospective chart review in the USA

OBJECTIVES

To assess real-world treatment patterns of targeted therapies after failure of first-line tyrosine kinase inhibitors in patients with advanced renal cell carcinoma.

METHODS

A large, retrospective review of medical charts of patients with advanced renal cell carcinoma in the USA was carried out. Descriptive statistics were used to summarize physicians' and patients' characteristics, treatment sequences, and reasons for treatment choices. P-values were calculated using χ² -tests for categorical variables and Wilcoxon rank-sum tests for continuous variables. A descriptive comparison was carried out between current results and those of a previous treatment pattern study conducted in 2012 to identify changes in treatment patterns over time.

RESULTS

Sunitinib and everolimus remained the most commonly-used first and second targeted therapies, respectively. Among patients who continued to a third targeted therapy, everolimus and axitinib were the most commonly-used treatments after second targeted therapy with a tyrosine kinase inhibitor and a mammalian target of rapamycin inhibitor, respectively. The use of pazopanib as first targeted therapy, and of axitinib and sorafenib as second targeted therapies, increased over time. Efficacy, treatment guidelines and a different mechanism of action were the main reasons given by physicians for choosing among second targeted therapies after failure of a first tyrosine kinase inhibitor.

CONCLUSIONS

The results of the present study document patterns of care during a period of rapid and ongoing therapeutic advancement in advanced renal cell carcinoma. Sequencing of therapies warrants ongoing analysis in light of new agents entering the advanced renal cell carcinoma treatment landscape.

The role of mTOR inhibition as second-line therapy in metastatic renal carcinoma: clinical evidence and current challenges

INTRODUCTION

Sequential treatment with targeted agents is the standard of care for patients with metastatic renal cell carcinoma (mRCC). Although first-line therapy with tyrosine kinase inhibitors (TKIs) is recommended for most patients, eventually all patients become resistant to them. Therefore, optimal selection of second-line therapy is crucial. Areas covered: We have reviewed the recent literature through pubmed search and recent congress presentations to briefly describe the clinical evidence for mTOR inhibition as a valid strategy in the treatment of mRCC after progression during anti-VEGFR therapy. In addition, we outline the management of adverse events associated with these agents, highlighting the importance of switching to an alternative mechanism of action to overcome resistance to TKI and to decrease cumulative toxicity associated with sequential treatments of the same type. Expert commentary: The choice of subsequent therapy after progression to first-line is not clear. Although the new drugs cabozantinib and nivolumab have shown to be superior that everolimus, still it is unknown which patients may benefit from these therapies in second-line, so treatment should be personalized to each patient and should consider approaches with different mechanisms of action.

Optimizing patient adherence to targeted therapies in renal cell carcinoma

The current standard of care for treating metastatic renal cell carcinoma is sequential therapy with vascular endothelial growth factor-targeted agents (i.e., axitinib, bevacizumab, pazopanib, sorafenib, and sunitinib) and mammalian target of rapamycin inhibitors (i.e., everolimus and temsirolimus). To maximize adherence to and persistence with targeted therapy, which should help improve clinical benefit, a clear understanding of the tolerability profiles of these agents and implementation of early, appropriately aggressive adverse event (AE) prevention and management strategies are key. Active and aggressive AE management should improve the quality of life of patients during the course of their treatment. Nurses are in a unique position to educate patients on the potential AEs they may experience and their prevention and management. This article reviews the safety and tolerability of currently available targeted therapies recommended for use in the second-line treatment setting, as well as their management in the context of maximizing clinical outcomes and patient quality of life.

IL-8 induces the epithelial-mesenchymal transition of renal cell carcinoma cells through the activation of AKT signaling

The epithelial-mesenchymal transition (EMT) process has increasingly been examined due to its role in the progression of human tumors. Renal cell carcinoma (RCC) is one of the most common urological tumors that results in patient mortality. Previous studies have demonstrated that the EMT process is closely associated with the metastasis of RCC; however, the underlying molecular mechanism has not been determined yet. The present study revealed that interleukin (IL)-8 was highly expressed in metastatic RCC. IL-8 could induce the EMT of an RCC cell line by enhancing N-cadherin expression and decreasing E-cadherin expression. Furthermore, IL-8 could induce AKT phosphorylation, and the phosphatidylinositol-4,5-bisphosphate 3-kinase inhibitor LY294002 could inhibit the EMT of RCC cells that was induced by IL-8. Therefore, these results suggest that IL-8 is able to promote the EMT of RCC through the activation of the AKT signal transduction pathway, and this may provide a possible molecular mechanism for RCC metastasis.

Treatment patterns in metastatic renal cell carcinoma: a retrospective review of medical records from US community oncology practices

BACKGROUND

Vascular endothelial growth factor (VEGF) inhibitors, including targeted therapy with tyrosine kinase inhibitors (TKIs) and the angiogenesis inhibitor bevacizumab, and mammalian target of rapamycin (mTOR) inhibitors are now the standard of care for metastatic renal cell carcinoma (mRCC). However, real-world treatment patterns are not well characterized.

OBJECTIVE

To describe treatment patterns during the first, second, and third lines of targeted therapies for mRCC among community oncologists in the US.

METHODS

Participating physicians recruited from a nationwide panel each identified up to 15 adult mRCC patients who initiated a second therapy after January 2010. Information extracted from medical records included types of targeted therapies, reasons for treatment choices, patterns of treatment discontinuation, and dose adjustments.

RESULTS

Thirty-six physicians contributed charts from 433 mRCC patients. Seventy-seven percent of patients received a VEGF inhibitor as first targeted therapy; 23% received an mTOR inhibitor. Among first-line VEGF users, second-line treatments were 66% mTOR and 34% VEGF inhibitors. Among first-line mTOR users, second-line treatments were 94% VEGF and 6% mTOR inhibitors. Sunitinib followed by everolimus was the most commonly used treatment sequence. Estimated median duration for second targeted therapy was 8.6 months, and median overall survival (OS) and progression-free survival (PFS) were 27.4 and 10.8 months, respectively. Efficacy, treatment guidelines and mechanism of action were the most important considerations for treatment choice.

LIMITATIONS

LIMITATIONS include no adjustment for baseline characteristics, possible difference between physician-defined progression and central review in the clinical trial setting, and limited data availability for axitinib during the study period.

CONCLUSION

In this large retrospective chart review among community oncologists, VEGF-mTOR-VEGF was the most common treatment sequence for mRCC. The most common drugs were sunitinib in the first line and everolimus in the second line.

A phase I dose escalation study of oral c-MET inhibitor tivantinib (ARQ 197) in combination with gemcitabine in patients with solid tumors

BACKGROUND

Tivantinib (ARQ 197) is an orally available, non-adenosine triphosphate competitive, selective c-MET inhibitor. The primary objective of this study was to evaluate the safety, tolerability and to establish the recommended phase II dose (RP2D) of tivantinib and gemcitabine combination.

PATIENTS AND METHODS

Patients with advanced or metastatic solid tumors were treated with escalating doses of tivantinib (120-360 mg capsules) in combination with gemcitabine (1000 mg/m(2) weekly for 3 of 4 weeks). Different schedules of administration were tested and modified based on emerging preclinical data. Tivantinib was given continuously, twice a day (b.i.d.) for 2, 3 or 4 weeks of a 28-day cycle or on a 5-day on, 2-day off schedule (the day before and day of gemcitabine administration).

RESULTS

Twenty-nine patients were treated with gemcitabine and escalating doses of tivantinib: 120 mg b.i.d. (n = 4), 240 mg b.i.d. (n = 6) and 360 mg b.i.d. (n = 19). No dose-limiting toxicities were observed in escalation. The RP2D was 360 mg b.i.d. daily, and 45 additional patients were enrolled in the expansion cohort. Grade ≥3 treatment-related toxicities were observed in 54 of 74 (73%) patients with the most common being neutropenia (43%), anemia (30%), thrombocytopenia (28%) and fatigue (15%). There was one treatment-related death due to neutropenia. Administration of gemcitabine did not affect tivantinib concentration. Fifty-six patients were assessable for response. Eleven (20%) patients achieved a partial response and 26 (46%) had stable disease (SD), including 15 (27%) who achieved SD for over 4 months. Ten of 37 patients with clinical benefit had prior exposure to gemcitabine.

CONCLUSION

The combination of tivantinib at its monotherapy dose and standard dose gemcitabine was safe and tolerable. Early signs of antitumor activity may warrant further development of this combination in nonsmall-cell lung cancer, ovarian, pancreatic and cholangiocarcinoma.

CLINICALTRIALSGOV IDENTIFIER

NCT00874042.

Management of metastatic renal cell carcinoma patients with poor-risk features: current status and future perspectives

With seven agents approved for renal cell carcinoma within the past few years, there has undoubtedly been progress in treating this disease. However, patients with poor-risk features remain a challenging and difficult-to-treat population, with the mTOR inhibitor, temsirolimus, the only agent approved in the first-line setting. Phase III trial data are still lacking VEGF-pathway inhibitors in patients with poor prognostic features. Poor-risk patients need to be considered as a heterogeneous population. Further understanding of biomarkers can lead to a better selection of patients who may benefit the most from treatment and improvements in prognosis. The presence of poor Karnofsky scores and liver or CNS disease may affect the outcome of these patients much more than other identified factors. This consideration may provide the rationale to further stratify poor-risk patients further subgroups destined to receive either cure or palliation.

Acquired resistance to sunitinib in human renal cell carcinoma cells is mediated by constitutive activation of signal transduction pathways associated with tumour cell proliferation

WHAT'S KNOWN ON THE SUBJECT? AND WHAT DOES THE STUDY ADD?: Although there have been a few studies investigating the molecular mechanism mediating the acquisition of resistance to molecular-targeted agents, including sunitinib, by renal cell carcinoma (RCC) cells, this mechanism remains largely unclear. The maintenance of protein kinase activation during sunitinib treatment may be involved in the acquisition of a phenotype resistant to sunitinib in RCC, and additional treatment with agents targeting activated protein kinases could be a promising approach for overcoming resistance to sunitinib in RCC.

OBJECTIVE

To characterise the mechanism involved in the acquired resistance to sunitinib, a potential inhibitor of multiple receptor tyrosine kinases (RTKs), in renal cell carcinoma (RCC).

MATERIALS AND METHODS

A parental human RCC cell line, ACHN (ACHN/P), was continuously exposed to increasing doses of sunitinib, and a cell line resistant to sunitinib (ACHN/R), showing an ≈5-fold higher IC50 (concentration that reduces the effect by 50%) than that of ACHN/P, was developed.

RESULTS

ACHN/R appeared to acquire significant cross resistance to sorafenib; however, there were no significant differences in sensitivities to the Mammalian target of rapamycin inhibitors, temsirolimus and everolimus, between ACHN/P and ACHN/R. After sunitinib treatment, the expression levels of phosphorylated Akt and p44/42 mitogen-activated protein kinase in ACHN/P, but not those in ACHN/R, were significantly inhibited. RTK assay showed that treatment of ACHN/P with sunitinib resulted in the marked downregulation of several phosphorylated RTKs compared with that of ACHN/R. Additional treatment with a specific inhibitor of Akt significantly increased the sensitivity of ACHN/R to sunitinib, but not that of ACHN/P. There were no significant differences between in vivo growth patterns of ACHN/P and ACHN/R in mice before and after the administration of sunitinib; however, the proportion of cells positive for TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling) staining in ACHN/P tumour was significantly greater than that in ACHN/R tumour in mice treated with sunitinib.

CONCLUSION

The maintenance of protein kinase activation during sunitinib treatment may be involved in the acquisition of resistant phenotype to sunitinib in RCC cells.

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.

Everolimus in metastatic renal cell carcinoma: Subgroup analysis of patients with 1 or 2 previous vascular endothelial growth factor receptor-tyrosine kinase inhibitor therapies enrolled in the phase III RECORD-1 study

INTRODUCTION

In the phase III RECORD-1 trial (ClinicalTrials.gov: NCT00410124), patients with metastatic renal cell carcinoma (mRCC) who progressed on previous vascular endothelial growth factor receptor-tyrosine kinase inhibitor (VEGFr-TKI) therapy were randomised 2:1 to everolimus 10mg once daily (n=277) or placebo (n=139). Median progression-free survival (PFS) was 4.9months with everolimus and 1.9months with placebo (hazard ratio [HR], 0.33; P<.001). This preplanned, prospective sub-analysis evaluated PFS benefit of everolimus versus placebo in patients who had previously received 1 or 2 VEGFr-TKIs.

PATIENTS AND METHODS

Median PFS was estimated using the Kaplan-Meier method, and Cox proportional hazards model was used to analyse differences in PFS.

RESULTS

All patients (100%) received ⩾1 previous VEGFr-TKI; 26% of patients received 2 previous VEGFr-TKIs. Among patients who received 1 previous VEGFr-TKI, median PFS was 5.4months with everolimus and 1.9months with placebo (HR, 0.32; 95%confidence interval [CI], 0.24-0.43; P<.001). Among patients who received 2 previous VEGFr-TKIs, median PFS was 4.0months with everolimus and 1.8months with placebo (HR, 0.32; 95%CI, 0.19-0.54; P<.001). The everolimus safety profile was similar for both groups.

CONCLUSIONS

Everolimus was associated with prolonged PFS relative to placebo in patients who received 1 or 2 previous VEGFr-TKIs. Patients who received only 1 previous VEGFr-TKI had apparently longer PFS with everolimus in reference to those who received 2 previous VEGFr-TKIs. These results support the use of everolimus as the standard of care in patients who fail initial VEGFr-TKI therapy.