Phase II study of sunitinib as first-line treatment of urothelial cancer patients ineligible to receive cisplatin-based chemotherapy: baseline interleukin-8 and tumor contrast enhancement as potential predictive factors of activity

Molecular biology and targeted therapies for urothelial carcinoma

Metastatic urothelial cancer (UC) is associated with poor prognosis. In the first-line setting, platinum-based chemotherapy is the standard of care but resistance rapidly occurs. With no validated treatment proven to increase survival after platinum failure, there is an urgent unmet medical need to develop new and efficacious cytotoxic agents. A better understanding of the molecular signaling pathways regulating UC has led to the development of new and innovative therapeutic strategies. Despite this, many recent drugs show only modest activity as single agents, and combining them with standard chemotherapy does not seem to enhance efficacy. Ongoing research is producing, however, a generation of new drugs that are showing promising results in clinical trials. This paper aims to review the most important mechanisms in bladder cancer tumorigenesis and describe the new therapeutic options currently undergoing evaluation in clinical trials.

Targeted therapy in advanced bladder cancer: what have we learned?

Despite advances in the treatment of other genitourinary malignancies, no novel therapies have been approved by the US Food and Drug Administration for urothelial carcinoma (UC) in the last 20 years. To date, no clinical trials of targeted agents in UC have led to improvements in survival compared with cytotoxic therapy. This article outlines representative trials of targeted therapies in UC and discusses the significance of genetic preselection in trial design as a method to optimize responses to these agents, thus, hopefully expanding the armamentarium of treatment options against this lethal disease.

Optimal treatment for metastatic bladder cancer

Metastatic bladder cancer is a lethal disease. Cisplatin-based chemotherapy, including the combination regimens gemcitabine-cisplatin and methotrexate-vinblastine-doxorubicin-cisplatin, are the standard first-line therapies. Second-line therapies have modest activity and no significant improvement in patient outcomes. Agents targeting growth, survival, and proliferation pathways have been added to cytotoxic therapy with limited added benefit to date. Modulating host immune response to cancer-associated antigens appears promising, with multiple new therapeutic approaches being pursued. Next-generation sequencing of invasive urothelial carcinoma has provided insights into the biology of this disease and potential actionable targets. Alterations in the receptor tyrosine kinase/Ras pathway and the phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin pathway represent potential therapeutic targets in advanced disease, and novel agents are in development. Recent data from the Cancer Genome Atlas Research Network bladder cancer cohort and other efforts suggest that mutations in chromatin-regulatory genes are very common in invasive bladder tumors, and are more frequent than in other studied tumors. The discovery of new genomic alterations challenges drug development to change the course of this disease.

First-line treatment of metastatic disease: cisplatin-ineligible patients

More than 50% of patients with advanced urothelial carcinoma are not eligible for the standard treatment with cisplatin-based chemotherapy. In general, cisplatin-ineligible patients with metastatic urothelial cancer experience poor outcomes with standard treatment, although substantial heterogeneity exists. Baseline variables associated with poor prognosis include borderline performance status, presence of visceral metastases, liver metastases, and low hemoglobin. Although no standard treatment has been defined for cisplatin-ineligible patients, recommendations regarding carboplatin-based combination chemotherapy versus single-agent chemotherapy versus best supportive care are typically based on performance status and renal function. The clinical development of novel agents is of considerable interest.

Future directions and targeted therapies in bladder cancer

There are substantial unmet needs for patients with metastatic urothelial carcinoma (UC). First-line cisplatin-based chemotherapy regimens yield a median survival of 12 to 15 months and long-term survival in 5% to 15%. Salvage systemic therapy yields a median survival of 6 to 8 months. Hence, the discovery of novel therapeutic targets is of paramount importance. Recent molecular analyses have provided insights regarding molecular tumor tissue alterations on multiple platforms. A multidisciplinary effort using innovative clinical trial designs and exploiting preclinical signals of robust activity guided by predictive biomarkers may provide much needed clinical advances in therapy for advanced UC.

Dovitinib: rationale, preclinical and early clinical data in urothelial carcinoma of the bladder

INTRODUCTION

Bladder cancer (BC) is the third and fifth cancer in men in terms of incidence and mortality in the US. Overexpression and mutations of fibroblast growth factor receptor 3 (FGFR3) are frequently found in BC and can represent a very interesting therapeutic target. Different FGFR3-targeted strategies have been investigated through in vitro and in vivo settings, including FGFR3 tyrosine kinase inhibitors such as dovitinib .

AREAS COVERED

The authors review the data that provide a scientific rationale for FGFR3-targeted therapy in BC. They also provide an evaluation of the currently available in vitro and in vivo data on the use of dovitinib in BC patients.

EXPERT OPINION

The development and progression of BC rely on a very complex signaling network that involves many different receptors aside from FGFR3 and VEGFR2. The involved signaling network can also be very different from one BC to the other, and can also evolve through time in the same patient. Inhibiting only one single target may thus not be sufficient to achieve a complete downstream oncogenic signaling blockage. Additionally, in vitro data on the use of neutralizing monoclonal antibodies targeting FGFR3 show that it can be a more efficient strategy to reach the same goal, with the potential advantage of less toxicity.

Serum interleukin-8 reflects tumor burden and treatment response across malignancies of multiple tissue origins

PURPOSE

Interleukin-8 (IL8) is a chemokine produced by malignant cells of multiple cancer types. It exerts various functions in shaping protumoral vascularization and inflammation/immunity. We evaluated sequential levels of serum IL8 in preclinical tumor models and in patients to assess its ability to estimate tumor burden.

EXPERIMENTAL DESIGN

IL8 levels were monitored by sandwich ELISAs in cultured tumor cells supernatants, tumor-xenografted mice serum, and in samples from 126 patients with cancer. We correlated IL8 serum levels with baseline tumor burden and with treatment-induced changes in tumor burden, as well as with prognosis.

RESULTS

IL8 concentrations correlated with the number of IL8-producing tumor cells in culture. In xenografted neoplasms, IL8 serum levels rapidly dropped after surgical excision, indicating an accurate correlation with tumor burden. In patients with melanoma (n = 16), renal cell carcinoma (RCC; n = 23), non-small cell lung cancer (NSCLC; n = 21), or hepatocellular carcinoma (HCC; n = 30), serum IL8 concentrations correlated with tumor burden and stage, survival (melanoma, n = 16; RCC, n = 23; HCC, n = 33), and objective responses to therapy, including those to BRAF inhibitors (melanoma, n = 16) and immunomodulatory monoclonal antibodies (melanoma, n = 8). IL8 concentrations in urine (n = 18) were mainly elevated in tumors with direct contact with the urinary tract.

CONCLUSIONS

IL8 levels correlate with tumor burden in preclinical models and in patients with cancer. IL8 is a potentially useful biomarker to monitor changes in tumor burden following anticancer therapy, and has prognostic significance.

Targeted therapies in urothelial carcinoma

PURPOSE OF REVIEW

Greater understanding of the biology and genetics of urothelial carcinoma is helping to identify and define the role of molecules and pathways appropriate for novel-targeted therapies. Here, we review the targeted therapies that have been reported or are in ongoing urothelial carcinoma clinical trials, and highlight molecular targets characterized in preclinical and clinical studies.

RECENT FINDINGS

Trials in nonmuscle-invasive bladder cancer are evaluating the role of immunotherapy and agents targeting vascular endothelial growth factor (VEGF) or fibroblast growth factor receptor-3. In muscle-invasive bladder cancer, neoadjuvant studies have focused on combining VEGF agents with chemotherapy; adjuvant studies are testing vaccines and agents targeting the human epidermal growth factor receptor 2, p53, and Hsp27. In the first-line treatment of metastatic urothelial carcinoma, tubulin, cytotoxic T-lymphocyte antigen 4, Hsp27, and p53 are novel targets in clinical trials. The majority of targeted agents studied in urothelial carcinoma are in the second-line setting; new targets include CD105, polo-like kinase-1, phosphatidylinositide 3-kinases (PI3K), transforming growth factor β receptor/activin receptor-like kinase β, estrogen receptor, and the hepatocyte growth factor receptor (HGFR or MET).

SUMMARY

Development of targeted therapies for urothelial carcinoma is still in early stages, consequently there have been no major therapeutic advances to date. However, greater understanding of urothelial carcinoma and solid tumor biology has resulted in a proliferation of clinical trials that could lead to significant advances in treatment strategies.

PF-03446962, a fully-human monoclonal antibody against transforming growth-factor β (TGFβ) receptor ALK1, in pre-treated patients with urothelial cancer: an open label, single-group, phase 2 trial

Despite a compelling preclinical rationale for the use of anti-angiogenic drugs in urothelial cancer (UC), short-living responses have been observed in clinical trials. PF-03446962 is a novel monoclonal antibody against Activin Receptor-Like Kinase-1 (ALK1), a type I subclass of the TGFβ receptor, with dose-dependent anti-angiogenic activity. An open label, single-group, phase 2 trial of PF-03446962 was conducted in salvage setting. Patients failing at least one chemotherapy regimen were eligible. Design provided PF-03446962 10 mg/Kg intravenously fortnightly until disease progression (PD) or unacceptable toxicity. Two-month progression-free survival (PFS) was the primary endpoint. The trial was registered with ClinicalTrials.gov, number NCT01620970. Fourteen patients were enrolled from October 2012 to July 2013. Median age was 64 years (interquartile range [IQR]: 58.2-69.5), 9 patients had a Bellmunt score of 1-2, median number of prior drugs was 3. One stable disease and 13 PD were recorded and the study met the futility stopping rule of interim analysis. Median PFS was 1.8 months (95 %CI, 1.4-2.0). After a median follow up of 7.4 months (IQR 4.5-10.9), 8 patients are alive. Median overall survival (OS) was 8 months (95 %CI, 2.9-not estimable). Most common toxicities were thrombocytopenia (G1-2 in 5 cases, persistent G3 in one, with 3 dose delays and 1 dose interruption), fatigue and abdominal pain (G1-2 in 4 cases each). Impairment of quality of life (ESAS score) was observed as well as an increase from baseline to +2 month median levels of vascular endothelial growth factor (VEGF) and interleukin-8. PF-03446962 had no activity as single drug in refractory UC and we do not recommend further investigation outside of the combination with agents targeting the VEGF receptor axis.

Exogenous norepinephrine attenuates the efficacy of sunitinib in a mouse cancer model

Background

Sunitinib alone exhibits satisfactory efficacy in several mouse homografts and xenografts but unsatisfactory efficacy in many kinds of solid tumors in clinic. Different from animals, receiving a diagnosis of cancer impacts chronic stress on patients. Here, we examine whether norepinephrine (NE), one of the most potent stress related hormones, leads to the difference in the efficacy of sunitinib between clinical and preclinical trials.

Methods

The influence of NE on mouse melanoma B16F1 cells under sunitinib was evaluated in vitro and in vivo. The β-AR/cAMP/PKA (β-adrenoceptor/cyclic adenosine monophosphate/protein kinase A) signaling pathway was also evaluated in human lung adenocarcinoma cells.

Results

We found that NE upregulated the expression of VEGF, IL-8 and IL-6 in vitro and stimulated tumor growth in vivo, which was mediated by β-AR/cAMP/PKA signaling pathway and could be inhibited by propranolol, a β-blocker for hypertension for decades.

Conclusions

This research indicates exogenous norepinephrine attenuates the efficacy of sunitinib, and a combination of sunitinib and propranolol might be suggested as a new strategy in solid tumor in clinic.

Identification of tissue microRNAs predictive of sunitinib activity in patients with metastatic renal cell carcinoma

Purpose

To identify tissue microRNAs predictive of sunitinib activity in patients with metastatic renal-cell-carcinoma (MRCC) and to evaluate in vitro their mechanism of action in sunitinib resistance.

Methods

We screened 673 microRNAs using TaqMan Low-density-Arrays (TLDAs) in tumors from MRCC patients with extreme phenotypes of marked efficacy and resistance to sunitinib, selected from an identification cohort (n = 41). The most relevant differentially expressed microRNAs were selected using bioinformatics-based target prediction analysis and quantified by qRT-PCR in tumors from patients presenting similar phenotypes selected from an independent cohort (n = 101). In vitro experiments were conducted to study the role of miR-942 in sunitinib resistance.

Results

TLDAs identified 64 microRNAs differentially expressed in the identification cohort. Seven candidates were quantified by qRT-PCR in the independent series. MiR-942 was the most accurate predictor of sunitinib efficacy (p = 0.0074). High expression of miR-942, miR-628-5p, miR-133a, and miR-484 was significantly associated with decreased time to progression and overall survival. These microRNAs were also overexpressed in the sunitinib resistant cell line Caki-2 in comparison with the sensitive cell line. MiR-942 overexpression in Caki-2 up-regulates MMP-9 and VEGF secretion which, in turn, promote HBMEC endothelial migration and sunitinib resistance.

Conclusions

We identified differentially expressed microRNAs in MRCC patients presenting marked sensitivity or resistance to sunitinib. MiR-942 was the best predictor of efficacy. We describe a novel paracrine mechanism through which high miR-942 levels in MRCC cells up-regulates MMP-9 and VEGF secretion to enhance endothelial migration and sunitinib resistance. Our results support further validation of these miRNA in clinical confirmatory studies.

Chemotherapeutic and targeted biological agents for metastatic bladder cancer: a comprehensive review

The American Cancer Society estimates that 73 510 new cases of bladder cancer will be diagnosed and 15 000 deaths will result this year. The paper summarizes the clinical evidence for the use of platinum-based, non-platinum-based and new targeted biological agents, while reporting the future directions in the treatment of metastatic bladder cancer. For cisplatin-base regimens, the combination of methotrexate, vinblastine, doxorubicin and cisplatin (M-VAC) has been the mainstream treatment for both advanced and metastatic bladder cancers. It showed significant improvement in the complete response rate and overall survival time in comparison with single-agent cisplatin. For cisplatin-ineligible patients, namely patients with renal impairment, symptomatic cardiac disease and poor performance status, alternative therapies consisting of paclitaxel, gemcitabine and carboplatin were shown to be of benefit. Pemetrexed and vinflunine have also shown effectiveness, with small but demonstrable overall survival benefits. Gemcitabine-based doublet therapies (combined with paclitaxel, docetaxel, irinotecan, oxaliplatin or epirubicin) have all been shown to be effective and well-tolerated. Several new targeted therapies, such as gefetinib, sorafenib and lapatinib, have received attention in recent years; however, their effectiveness as single agents in a relapse setting have not been optimal and more studies are warranted.

A phase II safety and efficacy study of the vascular endothelial growth factor receptor tyrosine kinase inhibitor pazopanib in patients with metastatic urothelial cancer

BACKGROUND

Vascular endothelial growth factor (VEGF) is produced by bladder cancer cell lines in vitro and expressed in human bladder tumor tissues. Pazopanib is a vascular endothelial receptor tyrosine kinase inhibitor with anti-angiogenesis and anti-tumor activity in several preclinical models. A 2-stage phase II study was conducted to assess the activity and toxicity profile of pazopanib in patients with metastatic, urothelial carcinoma.

METHODS

Patients with one prior systemic therapy for metastatic urothelial carcinoma were eligible. Patients received pazopanib at a dose of 800 mg orally for a 4-week cycle.

RESULTS

Nineteen patients were enrolled. No grade 4 or 5 events were experienced. Nine patients experienced 11 grade 3 adverse events. Most common toxicities were anemia, thrombocytopenia, leucopenia, and fatigue. For stage I, none of the first 16 evaluable patients were deemed a success (complete response or partial response) by the Response Evaluation Criteria In Solid Tumors criteria during the first four 4-week cycles of treatment. Median progression-free survival was 1.9 months. This met the futility stopping rule of interim analysis, and therefore the trial was recommended to be permanently closed.

CONCLUSIONS

Pazopanib did not show significant activity in patients with urothelial carcinoma. The role of anti-VEGF therapies in urothelial carcinoma may need further evaluation in rational combination strategies.

Synergistic effect between cisplatin and sunitinib malate on human urinary bladder-cancer cell lines

The aim of this paper is to analyse sunitinib malate in vitro ability to enhance cisplatin cytotoxicity in T24, 5637, and HT1376 human urinary bladder-cancer cell lines. Cells were treated with cisplatin (3, 6, 13, and 18 μM) and sunitinib malate (1, 2, 4, 6, and 20 μM), either in isolation or combined, over the course of 72 hours. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay, acridine orange, and monodansylcadaverine staining and flow cytometry were performed. The combination index (CI) was calculated based on the Chou and Talalay method. In isolation, cisplatin and sunitinib malate statistically (P < 0.05) decrease cell viability in all cell lines in a dose-dependent manner, with the presence of autophagic vacuoles. A cell cycle arrest in early S-phase and in G₀/G₁-phase was also found after exposure to cisplatin and sunitinib malate, in isolation, respectively. Treatment of urinary bladder-cancer cells with a combination of cisplatin and sunitinib malate showed a synergistic effect (CI < 1). Autophagy and apoptosis studies showed a greater incidence when the combined treatment was put into use. This hints at the possibility of a new combined therapeutic approach. If confirmed in vivo, this conjugation may provide a means of new perspectives in muscle-invasive urinary bladder cancer treatment.

Analysis of plasma cytokines and angiogenic factors in patients with pretreated urothelial cancer receiving Pazopanib: the role of circulating interleukin-8 to enhance the prognostic accuracy

Background:

Pazopanib achieved the end point of clinical activity in pretreated patients with urothelial cancer in a single-group, phase 2 trial. The objective was to identify biological predictors of clinical benefit to pazopanib in these patients.

Methods:

EDTA blood samples were collected at baseline (T0) and after 4 weeks (T1) of treatment, together with radiological imaging in all 41 patients to analyse plasma circulating angiogenic factor levels by multiplex ELISA plates. Changes from T0 to T1 in marker levels were matched with response with the covariance analysis. Univariable and multivariable analyses evaluated the association with overall survival (OS), adjusted for prespecified clinical variables. Net reclassification improvement (NRI) tested the performance of the recognised Cox model.

Results:

Increasing IL8^T1 level associated with lower response probability at covariance analysis (P=0.010). Both IL8^T0 (P=0.019) and IL8^T1 (P=0.004) associated with OS and the prognostic model, including clinical variables and IL8^T1 best-predicted OS after backward selection. The NRI for this model was 39%.

When analysed as a time-varying covariate, IL8^T1 level<80 pg ml⁻¹ portended significantly greater response (∼80%) and 6-month OS (∼60%) probability than level⩾80.

Conclusion:

IL8-level changes during pazopanib allowed for a prognostic improvement and were associated with response probability.

Emerging drugs for urothelial carcinoma

INTRODUCTION

Advanced urothelial carcinoma is associated with a poor prognosis. In the metastatic setting, the response rate to first-line, cisplatin-containing chemotherapy is high, but survival is poor. Second-line treatment options are limited. Advanced age at diagnosis and the presence of comorbidities often preclude treatment with cisplatin-containing regimens.

AREAS COVERED

This review addresses the current therapy of urothelial carcinoma, the unmet needs in treatment and the status of drug development in this disease. The molecular targets identified and efforts to incorporate targeted agents into therapy will be addressed.

EXPERT OPINION

There have been no major advances in the treatment of urothelial carcinoma in three decades. Despite high response rates in the first-line setting, survival is limited. Major impediments to improved outcomes include poor durability of response to first-line chemotherapy and lack of second-line treatments. Better understanding in tumor biology has identified multiple targets in urothelial carcinoma; however, such discoveries have yet to lead to the incorporation of targeted agents into the routine treatment of urothelial carcinoma. Multiple ongoing clinical trials are investigating the use of targeted agents in urothelial carcinoma. Continued efforts are underway to better understand the molecular drivers of disease and such efforts are likely to identify additional therapeutic targets.

Molecular targets on the horizon for kidney and urothelial cancer

As whole-genome sequencing technology rapidly advances, the insights gained from deciphering cancer genomes are shifting the paradigm in the diagnosis and treatment of cancer with the promise of individualized treatment for each patient. Information gained in this way is extensive for certain cancers, but fairly limited in renal cell carcinomas and urothelial carcinoma. Mutations in multiple, potentially druggable genes have been identified in urothelial carcinomas; however, the association between molecular alterations and clinical outcome has not yet been robustly demonstrated. Data in this area are emerging in renal cell carcinoma, leading to the development of targeted agents that have improved overall survival. Unfortunately, these treatments rarely yield complete responses, are not curative, and development of resistance ensues. This Review will focus on the biology of non-hormonally driven urological cancers. We discuss how approaches using whole-genome sequencing can facilitate the discovery of biomarkers of drug sensitivity in both renal cell carcinomas and urothelial carcinomas. For renal cell carcinomas, we will describe how genomic and epigenomic mining has uncovered novel genes and pathways involved in tumorigenesis, tumour classification and mechanisms of resistance in the various subsets of this disease and the potential for exploiting these discoveries in the clinic.

Pazopanib and sunitinib trigger autophagic and non-autophagic death of bladder tumour cells

BACKGROUND

Tyrosine kinase inhibitors (TKI) such as sunitinib and pazopanib display their efficacy in a variety of solid tumours. However, their use in therapy is limited by the lack of evidence about the ability to induce cell death in cancer cells. Our aim was to evaluate cytotoxic effects induced by sunitinib and pazopanib in 5637 and J82 bladder cancer cell lines.

METHODS

Cell viability was tested by MTT assay. Autophagy was evaluated by western blot using anti-LC3 and anti-p62 antibodies, acridine orange staining and FACS analysis. Oxygen radical generation and necrosis were determined by FACS analysis using DCFDA and PI staining. Cathepsin B activation was evaluated by western blot and fluorogenic Z-Arg-Arg-AMC peptide. Finally, gene expression was performed using RT-PCR Profiler array.

RESULTS

We found that sunitinib treatment for 24 h triggers incomplete autophagy, impairs cathepsin B activation and stimulates a lysosomal-dependent necrosis. By contrast, treatment for 48 h with pazopanib induces cathepsin B activation and autophagic cell death, markedly reversed by CA074-Me and 3-MA, cathepsin B and autophagic inhibitors, respectively. Finally, pazopanib upregulates the α-glucosidase and downregulates the TP73 mRNA expression.

CONCLUSION

Our results showing distinct cell death mechanisms activated by different TKIs, provide the biological basis for novel molecularly targeted approaches.

Clinical activity of sorafenib in a previously treated advanced urothelial cancer patient

A male patient, with advanced urothelial carcinoma, who had previously received cisplatin, was treated with sorafenib off-licence for 10.7 months. Evaluation of tumour response with computed tomography scans indicated a reduction in tumour size and necrosis of the metastases within 2 months. Progression-free survival was 10.5 months. Side effects were manageable and not beyond the National Cancer Institute Common Terminology Criteria for Adverse Events version 3.0 grade 2. Molecular profiling of two of the proposed targets of sorafenib, platelet-derived growth factor receptor β and vascular endothelial growth factor receptor 2, of the patient's tumour lesion showed high and intermediate expression levels in the tumour as compared with the surrounding non-neoplastic tissue. In contrast to previous reports, we report a clinically meaningful effect of sorafenib in a patient with advanced urothelial carcinoma. Hence, it appears that a fraction of patients with this disease are sensitive to this compound. To identify subpopulations of responders, we propose that clinical trials evaluating sorafenib and other targeted drugs should be biomarker-driven and designed with endpoints that consider the mode of action of the specific compound.

Targeted agents in second-line bladder cancer therapy

The treatment of metastasized urothelial cancer has been evolving in recent years. In particular, in the second-line setting after the failure of platinum-containing therapy, options are few and besides vinflunine, the recently approved standard in Europe, well-designed highly selective clinical trials may be possible alternatives for patients in this palliative situation. However, targeted therapy approaches have not achieved the same results in urothelial cancer as for instance in renal cell carcinoma. Many of the new targeted drugs have been investigated as single agents in phase II clinical trials without convincing oncologic outcome. This review aims to highlight the most relevant clinical studies examining targeted agents in the second-line setting of metastasized transitional carcinoma of the urothelium.

New therapeutic targets in the management of urothelial carcinoma of the bladder

Urothelial carcinoma of the bladder, despite the myriad of treatment approaches and our progressively increasing knowledge into its disease processes, remains one of the most clinically challenging problems in modern urological clinical practice. New therapies target biomolecular pathways and cellular mediators responsible for regulating cell growth and metabolism, both of which are frequently overexpressed in malignant urothelial cells, with the intent of inducing cell death by limiting cellular metabolism and growth, creating an immune response, or selectively delivering or activating a cytotoxic agent. These new and novel therapies may offer a potential for reduced toxicity and an encouraging hope for better treatment outcomes, particularly for a disease often refractory or not amenable to the current therapeutic approaches.

Antiangiogenic Agents, Chemotherapy, and the Treatment of Metastatic Transitional Cell Carcinoma

A 69-year-old man with a 100 pack-year history of smoking developed gross hematuria. His medical history included hypertension, a silent myocardial infarction, and a cerebrovascular accident complicated by seizures. Cystoscopy and biopsy showed a 4-cm mass at the right ureteral orifice positive for a high-grade papillary transitional cell carcinoma (TCC) with muscularis propria invasion (Fig 1). The computed tomography (CT)/positron emission tomography (PET) scan of the chest, abdomen, and pelvis showed hydronephrosis and hydroureter with marked cortical thinning and multiple bilateral PET-avid pulmonary nodules, with the largest in the left upper lung measuring 3.0 × 2.5 cm (Figs 2A, 3A), biopsy of which showed invasive high-grade urothelial carcinoma. The patient consented to join a clinical trial for metastatic TCC (USON [US Oncology Network study] 06040) involving treatment with gemcitabine, cisplatin, and sunitinib (GCS) 37.5 mg per day.1Four days later, he experienced a 10-day hospitalization for acute pancreatitis and neutropenia. Sunitinib was discontinued, and he completed four additional cycles of GC. CT/PET showed that the right ureteral mass and all lung nodules had regressed or disappeared (Figs 2B, 3B). The largest remaining lung nodule at 1.4 cm showed no metabolic activity. He underwent a radical cystoprostatectomy and right nephroureterectomy, disclosing residual high-grade urothelial carcinoma infiltrating the full thickness of the ureteral wall. There was carcinoma in situ of the bladder, and 42 nodes were negative for cancer. The surgery was followed by a small, uncomplicated myocardial infarction. A scheduled left thoracotomy to remove the remaining nodule was cancelled. No additional chemotherapy was administered, and the patient remains free of recurrence 2 years from initiation of chemotherapy. The 1.4-cm nodule has calcified and remains stable and metabolically inactive. He has no sequelae of chemotherapy or surgery, with a creatinine level of 1.35 mg/dL.

Advanced Urothelial Carcinoma: Overcoming Treatment Resistance through Novel Treatment Approaches

The current standard of care for metastatic urothelial carcinoma is cisplatin-based chemotherapy but treatment is generally not curative. Mechanisms of resistance to conventional cytotoxic regimens include tumor cell drug efflux pumps, intracellular anti-oxidants, and enhanced anti-apoptotic signaling. Blockade of signaling pathways with small molecule tyrosine kinase inhibitors has produced dramatic responses in subsets of other cancers. Multiple potential signaling pathway targets are altered in Urothelial carcinoma (UC). Blockade of the PI3K/Akt/mTOR pathway may prove efficacious because 21% have activating PI3K mutations and another 30% have PTEN inactivation (which leads to activation of this pathway). The fibroblast growth factor receptor 3 protein may be overactive in 50–60% and agents which block this pathway are under development. Blockade of multiple other pathways including HER2 and aurora kinase also have potential efficacy. Anti-angiogenic and immunotherapy strategies are also under development in UC and are discussed in this review. Novel therapeutic approaches are needed in UC. We review the various strategies under investigation and discuss how best to evaluate and optimize their efficacy.

Targeting molecular aberrations in urothelial carcinoma: are we almost there?

Advances in tumor biology and cancer genetics have led to the development of effective targeted therapies in oncology over the past decade. However, targeted drug development for urothelial carcinoma has been slower than for some other malignancies. The path forward in drug development is through a better understanding of the aberrant pathways driving urothelial tumor development. Steady progress has been made in the characterization of genomic alterations in urothelial carcinoma. The Cancer Genome Atlas (TCGA) project is well underway in the analysis of a large set of urothelial cancer specimens using multiple approaches and technologies. In addition, there are already many well-established mutations and genetic alterations in urothelial carcinoma that likely contribute in an important way to tumor development. In addition, urothelial cancer genome-wide association studies have identified common variants associated with urothelial cancer risk and protein expression that can potentially be therapeutically targeted. Furthermore, the MET pathway has emerged as an exciting target in multiple tumors, including urothelial carcinoma. Our knowledge of how to clinically target many emerging molecular aberrations in urothelial cancer is still in the early stages of development. However, there is much promise in the ongoing research being conducted in urothelial cancer molecular pathogenesis.

A randomized phase II study of gemcitabine and carboplatin with or without cediranib as first-line therapy in advanced non-small-cell lung cancer: North Central Cancer Treatment Group Study N0528

INTRODUCTION

The purpose of this study was to assess the safety and efficacy of gemcitabine and carboplatin with (arm A) or without (arm B) daily oral cediranib as first-line therapy for advanced non-small-cell lung cancer.

METHODS

A lead-in phase to determine the tolerability of gemcitabine 1000 mg/m on days 1 and 8, and carboplatin on day 1 at area under curve 5 administered every 21 days with cediranib 45 mg once daily was followed by a 2 (A):1 (B) randomized phase II study. The primary end point was confirmed overall response rate (ORR) with 6-month progression-free survival (PFS6) rate in arm A as secondary end point. Polymorphisms in genes encoding cediranib targets and transport were correlated with treatment outcome.

RESULTS

On the basis of the safety assessment, cediranib 30 mg daily was used in the phase II portion. A total of 58 and 29 evaluable patients were accrued to arms A and B. Patients in A experienced more grade 3+ nonhematologic adverse events, 71% versus 45% (p = 0.01). The ORR was 19% (A) versus 20% (B) (p = 1.0). PFS6 in A was 48% (95% confidence interval: 35%-62%), thus meeting the protocol-specified threshold of at least 40%. The median overall survival was 12.0 versus 9.9 months (p = 0.10). FGFR1 rs7012413, FGFR2 rs2912791, and VEGFR3 rs11748431 polymorphisms were significantly associated with decreased overall survival (hazard ratio 2.78-5.01, p = 0.0002-0.0095).

CONCLUSIONS

The trial did not meet its primary end point of ORR but met its secondary end point of PFS6. The combination with cediranib 30 mg daily resulted in increased toxicity. Pharmacogenetic analysis revealed an association of FGFR and VEGFR variants with survival.

Gemcitabine, Cisplatin, and sunitinib for metastatic urothelial carcinoma and as preoperative therapy for muscle-invasive bladder cancer

BACKGROUND

Data support chemotherapy combined with antiangiogenic therapy in metastatic urothelial cancer (mUC) and muscle-invasive bladder cancer (MIBC). We investigated the efficacy and safety of gemcitabine, cisplatin, and sunitinib (GCS) in mUC and MIBC in parallel phase II trials.

PATIENTS AND METHODS

Trial 1 enrolled 36 patients with mUC who were chemotherapy naive; trial 2 enrolled 9 patients with MIBC. The primary endpoints for trials 1 and 2 were response rate and pathologic complete response, respectively. GCS was given as first-line treatment for patients with mUC and as neoadjuvant therapy for patients with MIBC. The Simon minimax 2-stage design was used for an objective response rate in trial 1 and for the pathologic complete response rate in trial 2.

RESULTS

The initial trial 1 GCS dose was gemcitabine 1000 mg/m(2) intravenously, days 1 and 8; cisplatin 70 mg/m(2) intravenously, day 1; and sunitinib 37.5 mg orally daily, days 1 to 14 of a 21-day cycle. These doses proved intolerable. The doses of gemcitabine and cisplatin were subsequently reduced to 800 and 60 mg/m(2), respectively, without an improvement in drug delivery, and the trial was closed. This lower-dose regimen was applied in trial 2, which was stopped early due to excess toxicity. Grade 3 to 4 hematologic toxicities occurred in 70% (23/33) of patients in trial 1 and 22% (2/9) of patients in trial 2. In trial 1, the response rate was 49% (95% CI, 31%-67%); in trial 2, the pathologic complete response was 22% (2/9). Due to early closure secondary to toxicity, the sample sizes of both trials were small.

CONCLUSIONS

Delivery of GCS was hampered by excessive toxicity in both advanced and neoadjuvant settings.

Circulating biomarkers of response to sunitinib in gastroenteropancreatic neuroendocrine tumors: current data and clinical outlook

After years of limited progress in the treatment of patients with advanced-stage gastroenteropancreatic neuroendocrine tumors (GEP-NETs), strategies using targeted agents have been developed on the basis of increased knowledge of the biology of these tumors. Some of these agents, targeting vascular endothelial growth factor (VEGF) and the mammalian target of rapamycin (mTOR) pathway, have shown efficacy in randomized clinical trials. The tyrosine kinase inhibitor sunitinib and the mTOR inhibitor everolimus have received international approval for the treatment of advanced well differentiated pancreatic NETs after showing survival benefit in randomized phase III trials. There is now an imperative need to identify biomarkers of the biologic activity of such targeted therapies in specific disease contexts, as well as new markers of response and prognosis. This approach may allow rational development of drugs and early identification of patients who may obtain benefit from treatments. In this article, we review recent developments in circulating biomarkers of the clinical benefit of targeted therapies for GEP-NET, including soluble proteins and circulating cells, with an emphasis on sunitinib. No validated molecular biomarkers are yet integrated into clinical practice for sunitinib in NET, although some markers have shown correlation with clinical outcomes and may be implicated in resistance. The VEGF-pathway proteins and interleukin-8 (IL-8) are possibly prognostic in GEP-NET; other possible soluble markers of the activity of sunitinib and everolimus include stromal cell-derived factor 1α, chromogranin A, and neuron-specific enolase. We additionally discuss treatment-induced modulation of circulating endothelial cells and progenitors and subpopulations of cells of the myeloid lineage. These candidate markers should be considered in the development of future combination or sequential therapies.

Pazopanib in advanced and platinum-resistant urothelial cancer: an open-label, single group, phase 2 trial

BACKGROUND

The development of new drugs for patients with refractory urothelial cancer is still an unmet medical need. Preclinical evidence lends support to a rationale for targeting of the VEGF or platelet-derived growth-factor axis. We therefore investigated the activity and safety of pazopanib, a multitarget drug with antiangiogenic activity, in patients with urothelial cancer.

METHODS

In an open-label, single-group, phase 2 study, patients (aged ≥18 years) with relapsed or refractory urothelial cancer were given pazopanib 800 mg per day, orally. They were treated until disease progression or prohibitive toxicity occurred. The primary endpoint was the proportion of patients who achieved a confirmed objective response, defined as complete or partial response, after independent review, and was analysed by intention to treat. The trial is registered with ClinicalTrials.gov, number NCT01031875.

FINDINGS

The trial has been completed. 21 (51%) of 41 patients enrolled were given pazopanib as third-line or further-line treatment. 26 (63%) patients had an Eastern Cooperative Oncology Group performance status of 1 or 2. Seven patients had a confirmed objective response (17·1%, 95% CI 7·2-32·1), all of which were partial responses. The most frequent treatment-related grade 3 adverse events were hypertension (three [7%]), fatigue (two [5%]), and gastrointestinal and vaginal fistulisations (two each [5%]). One patient died as a result of duodenal fistulisation that was related to tissue response of bulky tumour masses.

INTERPRETATION

Pazopanib has single-agent activity in patients with heavily pretreated metastatic urothelial cancer, and warrants further study in this setting. Particular attention should be paid to patients with bulky tumour masses adjacent to viscera because fistulisation is probably related to the response to pazopanib and is the most frequent serious adverse event.

FUNDING

Fondazione IRCCS Istituto Nazionale dei Tumori provided the grant. GlaxoSmithKline provided the study drug and provided funding for the independent radiological review.

Opportunities and challenges in tumor angiogenesis research: back and forth between bench and bed

Angiogenesis is essential for tumor growth and metastasis. Many signaling pathways are involved in regulating tumor angiogenesis, with the vascular endothelial growth factor pathway being of particular interest. The recognition of the heterogeneity in tumor vasculature has led to better predictions of prognosis through differential analyses of the vasculature. However, the clinical benefits from antiangiogenic therapy are limited, because many antiangiogenic agents cannot provide long-term survival benefits, suggesting the development of drug resistance. Activation of the hypoxia and c-Met pathways, as well as other proangiogenic factors, has been shown to be responsible for such resistance. Vessel co-option could be another important mechanism. For future development, research to improve the efficacy of antiangiogenic therapy includes (a) using tumor-derived endothelial cells for drug screening; (b) developing the drugs focusing on specific tumor types; (c) developing a better preclinical model for drug study; (d) developing more accurate biomarkers for patient selection; (e) targeting the c-Met pathway or other pathways; and (f) optimizing the dose and schedule of antiangiogenic therapy. In summary, the future of antiangiogenic therapy for cancer patients depends on our efforts to develop the right drugs, select the right patients, and optimize the treatment conditions.

Variability of sorafenib toxicity and exposure over time: a pharmacokinetic/pharmacodynamic analysis

BACKGROUND

Sorafenib displays major interpatient pharmacokinetic variability. It is unknown whether the pharmacokinetics of sorafenib influence its toxicity.

METHODS

We analyzed the severity and kinetics of sorafenib-induced toxicities in unselected consecutive patients with cancer, as well as their relationship with biological, clinical, and pharmacokinetic parameters. Toxicity was recorded bimonthly. Sorafenib plasma concentrations were assessed by liquid chromatography.

RESULTS

For 83 patients (median age, 62 years; range, 21-84 years), median sorafenib 12-hour area under the curve (AUC(0-12)) was 52.8 mg · h/L (range: 11.8-199.6). A total of 51 patients (61%) experienced grade 3-4 toxicities, including hand-foot skin reactions (23%), asthenia (18%), and diarrhea (11%). Sorafenib AUC(0-12) preceding grade 3-4 toxicities was significantly higher than that observed in the remaining population (61.9 mg · h/L vs. 53 mg · h/L). In 25 patients treated with fixed doses of sorafenib for the first 4 months, median dose-normalized AUC(0-12) on day 120 was significantly lower than on day 15 (63 vs. 102 mg · h/L). The incidence of hypertension and hand-foot skin reactions significantly decreased over time.

CONCLUSION

Sorafenib AUC(0-12) decreases over time, similarly to the incidence of hypertension and hand-foot skin reactions. Monitoring of sorafenib plasma concentrations may help to prevent acute severe toxicities and detect patients with suboptimal exposure at disease progression.

Novel molecular targets for the therapy of urothelial carcinoma

INTRODUCTION

First-line platinum-based combinations are active in locally advanced and metastatic urothelial carcinoma; however, long-term outcomes including disease-specific and overall survival remain suboptimal. In addition, approximately 40 - 50% of patients with advanced urothelial carcinoma have coexisting medical issues that preclude the use of cisplatin-based therapy. Improvements in our understanding of the molecular mechanisms of urothelial tumorigenesis have led to first-generation clinical trials evaluating novel agents targeting molecular pathways. These are particularly relevant in regard to subpopulations. Novel trial designs warrant consideration to accelerate accrual.

AREAS COVERED

In this review, novel molecular targets for the therapy of urothelial carcinoma, as well as recently completed and ongoing clinical trials utilizing novel targeted agents, are discussed. A Medline search with key words, abstracts reported at national conferences on urothelial carcinoma and NCI clinical trial identifiers was used for this review.

EXPERT OPINION

Improved understanding of molecular biology has identified a number of new molecular targets, but there is a seeming absence of one dominant molecular driver for urothelial cancer. An adaptive and biomarker-derived strategy may be warranted. Clinical trials utilizing targeted agents are ongoing and results are awaited.