Phase II study of everolimus in patients with locally advanced or metastatic transitional cell carcinoma of the urothelial tract: clinical activity, molecular response, and biomarkers

BACKGROUND

This phase II study assessed the safety and efficacy of everolimus, an oral mammalian target of rapamycin inhibitor in advanced transitional carcinoma cell (TCC) after failure of platinum-based therapy.

PATIENTS AND METHODS

Thirty-seven patients with advanced TCC received everolimus 10 mg/day until progressive disease (PD) or unacceptable toxicity. The primary end point was the disease control rate (DCR), defined as either stable disease (SD), partial response (PR), or complete response at 8 weeks. Angiogenesis-related proteins were detected in plasma and changes during everolimus treatment were analyzed. PTEN expression and PIK3CA mutations were correlated to disease control.

RESULTS

Two confirmed PR and eight SD were observed, resulting in a DCR of 27% at 8 weeks. Everolimus was well tolerated. Compared with patients with noncontrolled disease, we observed in patients with controlled disease a significant higher baseline level of angiopoietin-1 and a significant early plasma decrease in angiopoietin-1, endoglin, and platelet-derived growth factor-AB. PTEN loss was observed only in patients with PD.

CONCLUSIONS

Everolimus showed clinical activity in advanced TCC. The profile of the plasma angiogenesis-related proteins suggested a role of the everolimus antiangiogenic properties in disease control. PTEN loss might be associated with everolimus resistance.

Angiogenesis as a therapeutic target in urothelial carcinoma

In the last few years, angiogenesis has confirmed its critical role in the development of malignant neoplasms. Antiangiogenic drugs, mainly bevacizumab, sorafenib, or sunitinib, are currently approved in a wide number of tumor types, such as breast, colorectal, liver, or kidney cancer, and have changed dramatically the evolution of our patients. Unfortunately, in urothelial carcinoma, which is a very common neoplasm, antiangiogenic agents are still in a very preliminary phase of clinical research. In this study, we focus on the biological basis of angiogenesis in urothelial tumors, its influence in the prognosis of these malignancies, and the available evidence about the use of antiangiogenic drugs in urothelial carcinoma.

Systemic therapy of metastatic bladder cancer in the molecular era: current status and future promise

IMPORTANCE OF THE FIELD

Platinum-based chemotherapy is considered the standard-of-care first-line therapy for metastatic bladder cancer. Despite the initial high response rate, the vast majority of patients eventually progress and succumb to their disease, urging the need for development of novel therapies.

AREAS COVERED IN THIS REVIEW

This article discusses the main signaling pathways implicated in the pathogenesis of bladder carcinomas, reviews recently completed and ongoing clinical trials, and anticipates the future direction of molecularly targeted agents.

WHAT THE READER WILL GAIN

This manuscript presents the current status of conventional chemotherapy in advanced bladder cancer, and provides a comprehensive review of molecular targeted agents currently in clinical development for this disease.

TAKE HOME MESSAGE

Improved understanding of the biology of urothelial carcinogenesis has paved the way for the development of novel molecularly targeted therapies, several of which are currently tested in clinical trials. In this regard, VEGF and EGFR pathways are emerging as important therapeutic targets for metastatic bladder cancer, either alone or in combination with conventional chemotherapeutics. Other therapies, including aurora kinase inhibitors, endothelin receptor antagonists, RAS/MAPK pathway inhibitors and novel immunologic strategies, may also prove helpful in the treatment of this disease.