Sunitinib combined with pemetrexed and carboplatin in patients with advanced solid malignancies--results of a phase I dose-escalation study

A Phase I, Dose-Escalation Trial of Pazopanib in Combination with Cisplatin in Patients with Advanced Solid Tumors: A UNICANCER Study

Introduction

To determine the feasibility, maximum-tolerated dose (MTD), and dose-limiting toxicities (DLT) of pazopanib in combination with cisplatin.

Methods

Patients with advanced malignancies were included in a 3 + 3 dose-escalation phase I study. Pazopanib administration started 8 days before the first infusion of cisplatin; some patients were treated according to a reverse sequence (cisplatin first). Five dose levels (DLs) were planned. MTD was based on DLT observed during cycles 1 and 2.

Results

Thirty-five patients were enrolled. The MTD was reached at the first DL, (pazopanib 400 mg daily + cisplatin 75 mg/m² every 21 days). Main DLTs were pulmonary embolism, neutropenia, thrombocytopenia, and elevation of liver enzymes. Overall, most common adverse events were anemia (83%), fatigue (80%), thrombocytopenia (80%), neutropenia (73%), hypertension (59%), neurotoxicity (56%), and anorexia (53%). Sixteen patients (46%) discontinued the study due to toxicity. One patient (sarcoma) had a complete response, and three patients (one with breast cancer and two with ovarian cancers) had a partial response. Pharmacokinetic (PK) analyses showed interactions with aprepitant, resulting in increased exposure to pazopanib, which might explain partly the poor tolerance of the combination.

Conclusion

Cisplatin and pazopanib could not be administered at their single agent full doses, partly due to a PK interaction between pazopanib and aprepitant.

Funding

This work was funded by GlaxoSmithKline and by the charity Ligue Nationale de Lutte Contre le Cancer.

Trial registered

ClinicalTrials.gov identifier, NCT01165385.

Targeted antiangiogenic agents in combination with cytotoxic chemotherapy in preclinical and clinical studies in sarcoma

Sarcomas are a heterogeneous group of mesenchymal malignancies. In recent years, studies have demonstrated that inhibition of angiogenic pathways or disruption of established vasculature can attenuate the growth of sarcomas. However, when used as monotherapy in the clinical setting, these targeted antiangiogenic agents have only provided modest survival benefits in some sarcoma subtypes, and have not been efficacious in others. Preclinical and early clinical data suggest that the addition of conventional chemotherapy to antiangiogenic agents may lead to more effective therapies for patients with these tumors. In the current review, the authors summarize the available evidence and possible mechanisms supporting this approach.

Sunitinib reduces tumor hypoxia and angiogenesis, and radiosensitizes prostate cancer stem-like cells

INTRODUCTION

The need for new treatments for advanced prostate cancer has fostered the experimental use of targeted therapies. Sunitinib is a multi-tyrosine kinase inhibitor that mainly targets membrane-bound receptors of cells within the tumor microenvironment, such as endothelial cells and pericytes. However, recent studies suggest a direct effect on tumor cells. In the present study, we have evaluated both direct and indirect effects of Sunitinib in prostate cancer and how this drug regulates hypoxia, using in vitro and in vivo models.

METHODS

We have used both in vitro (PC-3, DU145, and LNCaP cells) and in vivo (PC-3 xenografts) models to study the effect of Sunitinib in prostate cancer. Analysis of hypoxia based on HIF-1α expression and FMISO uptake was conducted. ALDH activity was used to analyze cancer stem cells (CSC).

RESULTS

Sunitinib strongly reduced proliferation of PC-3 and DU-145 cells in a dose dependent manner, and decreased levels of p-Akt, p-Erk1/2, and Id-1, compared to untreated cells. A 3-fold reduction in tumor growth was also observed (P < 0.001 with respect to controls). Depletion of Hif-1α levels in vitro and a decrease in FMISO uptake in vivo showed that Sunitinib inhibits tumor hypoxia. When combined with radiotherapy, this drug enhanced cell death in vitro and in vivo, and significantly decreased CD-31, PDGFRβ, Hif-1α, Id1, and PCNA protein levels (whereas apoptosis was increased) in tumors as compared to controls or single-therapy treated mice. Moreover, Sunitinib reduced the number of ALDH + cancer stem-like cells and sensitized these cells to radiation-mediated loss of clonogenicity.

DISCUSION

Our results support the use of Sunitinib in prostate cancer and shows that both hypoxia and cancer stem cells are involved in the effect elicited by this drug. Combination of Sunitinib with radiotherapy warrants further consideration to reduce prostate cancer burden.