The tyrosine kinase inhibitor E-3810 combined with paclitaxel inhibits the growth of advanced-stage triple-negative breast cancer xenografts.

E-3810 is a novel small molecule that inhibits VEGF receptor-1, -2, and -3 and fibroblast growth factor receptor-1 tyrosine kinases at nmol/L concentrations currently in phase clinical II. In preclinical studies, it had a broad spectrum of antitumor activity when used as monotherapy in a variety of human xenografts. We here investigated the activity of E-3810 combined with different cytotoxic agents in a MDA-MB-231 triple-negative breast cancer xenograft model. The molecule could be safely administered with 5-fluorouracil, cisplatin, and paclitaxel. The E-3810-paclitaxel combination showed a striking activity with complete, lasting tumor regressions; the antitumor activity of the combination was also confirmed in another triple-negative breast xenograft, MX-1. The activity was superior to that of the combinations paclitaxel+brivanib and paclitaxel+sunitinib. Pharmacokinetics studies suggest that the extra antitumor activity of the combination is not due to higher paclitaxel tumor levels, which in fact were lower in mice pretreated with all three kinase inhibitors, and the paclitaxel plasma levels excluded reduced drug availability. Pharmacodynamic studies showed that E-3810, brivanib, and sunitinib given as single agents or in combination with paclitaxel reduced the number of vessels, but did not modify vessel maturation. Reduced tumor collagen IV and increased plasma collagen IV, associated with increased matrix metalloproteinases (MMP), particularly host MMP-9, indicate a proteolytic remodeling of the extracellular matrix caused by E-3810 that in conjunction with the cytotoxic effect of paclitaxel on the tumor cells (caspase-3/7 activity) may contribute to the striking activity of their combination. These data support the therapeutic potential of combining E-3810 with conventional chemotherapy.

E-3810 is a potent dual inhibitor of VEGFR and FGFR that exerts antitumor activity in multiple preclinical models.

Tumor angiogenesis is a degenerate process regulated by a complex network of proangiogenic factors. Existing antiangiogenic drugs used in clinic are characterized by selectivity for specific factors. Antiangiogenic properties might be improved in drugs that target multiple factors and thereby address the inherent mechanistic degeneracy in angiogenesis. Vascular endothelial growth factor (VEGF) and fibroblast growth factor (FGF) family members and their cognate receptors are key players in promoting tumor angiogenesis. Here we report the pharmacologic profile of E-3810, a novel dual inhibitor of the VEGF and FGF receptors. E-3810 potently and selectively inhibited VEGF receptor (VEGFR)-1, -2, and -3 and FGF receptor (FGFR)-1 and -2 kinases in the nanomolar range. Ligand-dependent phosphorylation of VEGFR-2 and FGFR-1 was suppressed along with human vascular endothelial cell growth at nanomolar concentrations. In contrast, E-3810 lacked cytotoxic effects on cancer cell lines under millimolar concentrations. In a variety of tumor xenograft models, including early- or late-stage subcutaneous and orthotopic models, E-3810 exhibited striking antitumor properties at well-tolerated oral doses administered daily. We found that E-3810 remained active in tumors rendered nonresponsive to the general kinase inhibitor sunitinib resulting from a previous cycle of sunitinib treatment. In Matrigel plug assays performed in nude mice, E-3810 inhibited basic FGF-induced angiogenesis and reduced blood vessel density as assessed by histologic analysis. Dynamic contrast-enhanced magnetic resonance imaging analysis confirmed that E-3810 reduced the distribution of angiogenesis-sensitive contrast agents after only 5 days of treatment. Taken together, our findings identify E-3810 as a potent antiangiogenic small molecule with a favorable pharmacokinetic profile and broad spectrum antitumor activity, providing a strong rationale for its clinical evaluation.

A work in progress: the clinical development of histone deacetylase inhibitors.

It has been widely recognized that histone deacetylases (HDAC) are promising targets in the field of oncology. An impressive body of preclinical research points to the ability of HDAC inhibitors (HDACIs) to modulate a wide variety of cellular functions, including cell differentiation, cell cycle progression, apoptosis, cytoskeletal modifications and angiogenesis. Originally developed as epigenetic drugs because of their ability to inhibit histones deacetylation, HDACIs are now being considered also because of their effects on other acetylation-regulated proteins with pivotal roles in transformed cells. This review will highlight the clinical development of HDACIs in oncology and will try to discuss the several major open clinical issues challenging the successful clinical development of HDACIs, with a particular emphasis on the spectrum of activity of these agents, the best development strategy in solid tumors, the cardiac side effects and bio-markers to be used in clinical trials.

A phase I study of the trinuclear platinum compound, BBR 3464, in combination with protracted venous infusional 5-fluorouracil in patients with advanced cancer.

PURPOSE: BBR 3464 is a novel trinuclear platinum anticancer agent with a broad spectrum of preclinical antitumour activity. A phase I, open-label dose-escalating study was performed to determine the maximum tolerated dose (MTD) of BBR 3464 administered in combination with protracted venous infusional (PVI) 5-fluorouracil (5-FU) for up to six courses in patients with locally advanced and/or metastatic cancer. METHODS: Dose escalation was based on observation of toxicity at each dose level. BBR 3464 (0.6 mg/m(2) escalated to 0.75 mg/m(2)) was studied in combination with PVI 5-FU (200 mg/m(2) per day). RESULTS: Entered into the study were 14 patients. The most frequent toxicities were nausea, neutropenia, fatigue and diarrhoea. The protocol-defined MTD was not determined as 11/14 patients experienced grade 3 or 4 neutropenia that interrupted the planned administration of PVI 5-FU on day 15 (of 21). Although these events were not dose-limiting, as defined in the protocol, they imposed limitations on the dose of PVI 5-FU administered. Antitumour activity was observed: a partial response in one patient (7%) with invasive breast cancer. Stable disease was confirmed in three patients (21%). These four patients all completed the planned six courses of combined therapy. CONCLUSIONS: In light of the lack of septic events associated with the recorded neutropenia, it may be possible to safely continue PVI 5-FU despite the grade 3 or 4 neutropenia or modify the PVI schedule and administer therapy on days 1-15 of the 21-day cycle, but these modifications were not considered in this study.

Phase-II study of the new aza-anthracenedione, BBR 2778, in patients with relapsed aggressive non-Hodgkin's lymphomas.

BACKGROUND AND OBJECTIVES: BBR 2778 is a new aza-anthracenedione. Its activity against hematologic neoplasias in a mouse model is greater than that of doxorubicin or mitoxantrone. A phase-I study in patients with non-Hodgkin's lymphoma (NHL) showed that the drug has promising anti-tumor activity. Therefore, a phase-II study in patients with relapsed aggressive NHL was initiated. DESIGN AND METHODS: The primary objective was to determine the efficacy of 85 mg/m2 BBR 2278 for a q1w x3 treatment schedule (repeat day 29). Secondary objectives included the evaluation of response duration and safety in this open-label, non-randomized, multicenter trial. Patients with relapsed aggressive NHL according to the REAL-classification were included. RESULTS: Eight centers enrolled a total of 33 patients. The median age of these patients was 66 years (range 24-81). The majority of patients had diffuse large B-cell lymphoma (n=24) or mantle-cell lymphoma (n=7), pretreated with a median of 2 regimens. Confirmed responses included 5 complete and 4 partial remissions, with the period between the first appearance of response and any signs or symptoms of progression being up to 17+ months. The main toxicity was neutropenia. INTERPRETATIONS AND CONCLUSIONS: These results indicate that 85 mg/m2 BBR 2778 in a q1w x 3 schedule is active in elderly and pretreated patients with relapsed aggressive NHL and was generally well tolerated. Thus, we recommend further clinical evaluation of this new compound in phase-III studies for the treatment of NHL.