Metabolism, excretion, and pharmacokinetics of oral brivanib in patients with advanced or metastatic solid tumors

Recent advances of dual FGFR inhibitors as a novel therapy for cancer

Fibroblast growth factor receptor (FGFR) includes four highly conserved transmembrane receptor tyrosine kinases (FGFR1-4). FGF and FGFR regulate many biological processes, such as angiogenesis, wound healing and tissue regeneration. The abnormal expression of FGFR is related to the tumorigenesis, tumor progression and drug resistance of anti-tumor treatments in many types of tumors. Nowadays there are many anti-cancer drugs targeting FGFR. However, traditional single-target anti-tumor drugs are easy to acquire drug resistance. The therapeutic effect can be enhanced by simultaneously inhibiting FGFR and another target (such as VEGFR, EGFR, PI3K, CSF-1R, etc.). We know drug combination can bring problems such as drug interactions. Therefore, the development of FGFR dual target inhibitors is an important direction. In this paper, we reviewed the research on dual FGFR inhibitors in recent years and made brief comments on them.

Targeting FGFR in Squamous Cell Carcinoma of the Lung

Unlike for adenocarcinomas of the lung, no molecular targeted therapies have yet been developed for squamous cell lung cancers, because targetable oncogenic aberrations are scarce in this tumor type. Recent discoveries have established that the fibroblast growth factor (FGF) signaling pathway plays a fundamental role in cancer development by supporting tumor angiogenesis and cancer cell proliferation via different mechanisms. Through comprehensive genomic studies, aberrations in the FGF pathway have been identified in various tumor types, including squamous cell lung cancer, making FGF receptor (FGFR) a potentially druggable target in this malignancy. Several multi-targeted tyrosine kinase inhibitors include FGFR in their target spectrum and a number of these compounds have been approved for clinical use in different cancers. Novel agents selectively targeting FGFRs have been developed and are currently under investigation in clinical trials, showing promising results. This article reviews FGFR aberrations and the clinical data involving selective and multikinase FGFR inhibitors in squamous cell lung cancer.

Pharmacokinetic Aspects of Vascular Endothelial Growth Factor Tyrosine Kinase Inhibitors

Scientists have identified the impact of angiogenesis on tumor growth and survival. Among other efficient drugs, several small-molecule tyrosine kinase inhibitors (TKIs) targeting the vascular endothelial growth factor receptor (VEGFR) have been developed and have already been integrated into the treatment of various advanced malignancies. This review provides a compilation of current knowledge on the pharmacokinetic aspects of all VEGFR-TKIs already approved by the US Food and Drug Administration (FDA) and the European Medicines Agency (EMA) and of those still under investigation. Additional information on substance metabolism, potential for drug-drug interactions (DDIs), and the need for dose adaptation in patients with predominant renal and/or hepatic impairment has been included. All TKIs introduced in this review were administered orally, allowing for easy drug handling for healthcare professionals and patients. For almost all substances, the maximum plasma concentrations were reached within a short period of time. The majority of the substances showed a high plasma protein binding and their excretion occurred via the feces and, to a lesser extent, via the urine. In most cases, dose adaptation in patients with mild to moderate renal or hepatic impairment is not recommended. Cytochrome P450 (CYP) 3A4 was found to play a crucial role in the drug metabolic processes of many compounds. In order to prevent unwanted DDIs, co-administration of VEGFR TKIs together with CYP3A4 inhibitors or inducers should be avoided. Throughout all TKIs, the data indicate high inter-individual variability. The causes of this are still unclear and require further research to allow for individualization of treatment regimens.

Regulatory aspects of human radiolabeled mass balance studies in oncology: concise review

Human radiolabeled mass balance studies are performed to obtain information about the absorption, distribution, metabolism, and excretion of a drug in development. The main goals are to determine the route of elimination and major metabolic pathways. This review provides an overview of the current regulatory guidelines concerning human radiolabeled mass balance studies and discusses scientific trends seen in the last decade with a focus on mass balance studies of anticancer drugs. This paper also provides an overview of mass balance studies of anticancer agents that were executed in the last 10 years.

Molecular aberrations, targeted therapy, and renal cell carcinoma: current state-of-the-art

Renal cell carcinoma (RCC) is among the most prevalent malignancies in the USA. Most RCCs are sporadic, but hereditary syndromes associated with RCC account for 2-3 % of cases and include von Hippel-Lindau, hereditary leiomyomatosis, Birt-Hogg-Dube, tuberous sclerosis, hereditary papillary RCC, and familial renal carcinoma. In the past decade, our understanding of the genetic mutations associated with sporadic forms of RCC has increased considerably, with the most common mutations in clear cell RCC seen in the VHL, PBRM1, BAP1, and SETD2 genes. Among these, BAP1 mutations are associated with aggressive disease and decreased survival. Several targeted therapies for advanced RCC have been approved and include sunitinib, sorafenib, pazopanib, axitinib (tyrosine kinase inhibitors (TKIs) with anti-vascular endothelial growth factor (VEGFR) activity), everolimus, and temsirolimus (TKIs that inhibit mTORC1, the downstream part of the PI3K/AKT/mTOR pathway). High-dose interleukin 2 (IL-2) immunotherapy and the combination of bevacizumab plus interferon-α are also approved treatments. At present, there are no predictive genetic markers to direct therapy for RCC, perhaps because the vast majority of trials have been evaluated in unselected patient populations, with advanced metastatic disease. This review will focus on our current understanding of the molecular genetics of RCC, and how this may inform therapeutics.

HPLC-MS/MS method for quantitative determination of the novel dual inhibitor of FGF and VEGF receptors E-3810 in tumor tissues from xenograft mice and human biopsies

We developed and validated a high-performance liquid chromatography-tandem mass spectrometry analytical method to measure E-3810, a novel dual inhibitor of fibroblast growth factor receptor 1 and vascular endothelial growth factor receptor 1-3 in tissues and determined the drug concentration in a biopsy of human breast cancer for the first time. The method is a modification of our previous one in plasma to study the clinical pharmacokinetics of the drug during the phase I/II trial. In view of the changes in matrix, we applied a partial validation protocol to determine recovery, sensitivity, range of linearity, precision, accuracy and stability of the method over three runs in a mouse tumor tissue and liver. The recovery of E-3810 from liver or tumor homogenate was >69%, and the lower limit of quantification was 5 ng/ml. The method was linear in the concentration range 5.0-500.0 ng/ml, as demonstrated by a determination coefficient R(2) ≥ 0.9955. The range of the calibration curve was appropriate for the analysis, as demonstrated by the accuracy, which was between 91.4% and 106.7%. Interday precision and accuracy on quality control samples at 9, 30 and 300 ng/ml were 3.1-11.2% and 98.3-111.4%, respectively. The assay was applied successfully to determine the intratumor concentration of E-3810 in different mouse xenograft tumor models and in a biopsy of a patient with breast cancer included in the phase I/II trial of the drug. In mouse tumors, the concentrations of E-3810 were higher than necessary to exert antitumor activity in vitro (1 µM). Even more of interest was the result obtained in a human biopsy of few milligrams, where E-3810 reached 4.9 µg/g (11 µM).

In-vitro growth inhibition of chemotherapy and molecular targeted agents in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common and challenging malignant disease. The prognosis is poor in patients with advanced disease. Although sorafenib prolongs survival in these patients, improvement remains modest. We used doxorubicin and sorafenib as controls and screened eight new agents including ixabepilone, gefitinib, cetuximab, brivanib, dasatinib, sunitinib, BMS-690514, and BMS-536924 against nine HCC cell lines and evaluated their interactions. We studied growth inhibition of 10 drugs against nine HCC cell lines. Single-agent activity was tested using an MTS assay. Combination studies were carried out in both resistant and sensitive cells to determine the combination index. The IC50 of each agent varied widely among nine cell lines. Ixabepilone was more potent than doxorubicin. HT-17 cells were more sensitive to gefitinib and cetuximab than the other eight cell lines. BMS-536924 showed good efficacy (IC50 ≤ 1 µmol/l) on all three α-fetoprotein (AFP)-producing cell lines (HepG2, Hep3B, Huh-7). Three cell lines showed moderate sensitivity to dasatinib (IC50 ≤ 1 µmol/l). Dasatinib showed the most frequent and strongest synergism with ixabepilone, gefitinib, brivanib, BMS-690514, or BMS-536924. Ixabepilone, sorafenib, brivanib, dasatinib, and BMS-536924 are active against HCC cell lines. The heterogeneity of the sensitivity of each cell line emphasizes the need for individualized treatment. The sensitivity to BMS-536924 is closely associated with the production of AFP. AFP may be a biomarker predicting response to the insulin-like growth factor-1 receptor inhibitor in HCC patients. Additional studies are warranted. The synergism between dasatinib and other agents also provides future research directions to understand drug resistance and improve outcome.

Nonsmall cell lung cancer therapy: insight into multitargeted small-molecule growth factor receptor inhibitors

To date, lung cancer is the leading cause of cancer-related death worldwide, among which nonsmall cell lung cancer (NSCLC) comprises about 85%. Taking into account the side effects of surgery, radiation, platinum-based doublet chemotherapy, and the growth self-sufficiency characteristic of cancer cells, drugs have been discovered toward growth factor receptor (GFR) to treat NSCLC. As expected, these drugs provide a greater benefit. To increase the efficacy of such growth factor receptor tyrosine kinase inhibitors (RTKIs), coinhibition of GFR signaling pathways and combination of inhibitors along with radiation or chemotherapy have drew intense insight. Although clinical trials about single-agent RTKIs or their combination strategies suggest their increase potency against cancer, they are not beyond adverse effects, and sometimes the effects are more deadly than chemotherapy. Nevertheless the hope for RTKIs may be proved true by further researches and digging deep into cancer therapeutics.

The effects of liver impairment on the pharmacokinetics of brivanib, a dual inhibitor of fibroblast growth factor receptor and vascular endothelial growth factor receptor tyrosine kinases

PURPOSE

Hepatic impairment may impede tyrosine kinase inhibitor metabolism. This phase I study compared the pharmacokinetics of brivanib in patients with hepatocellular carcinoma (HCC) and varying levels of hepatic impairment with those with non-HCC malignancies and normal liver function.

METHODS

Patients were assigned to the following groups: Groups A, B, and C (HCC plus mild, moderate, or severe hepatic impairment, respectively) and Group D (non-HCC malignancy and normal hepatic function). Brivanib alaninate (brivanib prodrug) doses were 400 mg in Groups A, B, and D and 200 mg in Group C. Brivanib exposure was determined on day 1 (single dose) and day 28 (multiple doses).

RESULTS

Twenty-four patients participated in the study. After a single brivanib alaninate dose, brivanib exposure was comparable between Groups A, B, and D. Area under the concentration-time curve was 50 % higher in Group C versus Group D. There were not enough data to draw conclusions on multiple doses. Safety profile in Groups A, B, and D was consistent with previous brivanib monotherapy experience. Tolerability could not be assessed in Group C because of dose interruptions and discontinuations, generally due to the disease natural history.

CONCLUSIONS

Brivanib exposure was similar in patients with HCC and mild or moderate hepatic impairment (Child-Pugh [CP] A or B status) and those with non-HCC malignancies and normal hepatic function, suggesting dose adjustment is unnecessary with CP A or B status. Experience with HCC and severe hepatic impairment (CP C status) is insufficient to recommend brivanib use in this population.

FGFR1 amplifications in squamous cell carcinomas of the lung: diagnostic and therapeutic implications

Fibroblast growth factor receptor 1 (FGFR1) is a type 4 receptor tyrosine kinase. The receptor and its ligands play an important role in development and physiology. However, constitutive activation of FGFR1 by gene amplification, translocation or mutation is associated with various malignancies as, for example, breast cancer or myeloproliferative diseases. We have recently reported that FGFR1 amplification occurs in 20% of pulmonary squamous cell carcinomas, and preclinical tests have shown that these alterations are therapeutically tractable. These findings make FGFR1 amplification a potential biomarker for lung cancer treatment. Squamous cell carcinomas of the lung are characterized by an uneven FGFR1 gene copy number distribution. Therefore, fluorescence in situ hybridization assays need to address focality and heterogeneity of FGFR1 in these tumors. Here, we review our proposal for a reading and evaluation strategy. Furthermore, we highlight the emerging landscape of clinical trials with selective and unselective FGFR inhibitors and provide first response data from early clinical trials.

Brivanib: a review of development

The development of new agents in oncology has focused on disrupting key pathways in oncogenesis. Both malignant angiogenesis and peptide growth factor signaling have been studied extensively and have been validated for cancer treatment. While antibody-directed therapeutics offer increased specificity, small-molecule tyrosine kinase inhibitors often have the ability to hit multiple targets. Brivanib alaninate (BMS582664) is an oral, potent selective inhibitor of both the FGF and VEGF family of receptors. It is a first-in-class FGF/VEGF inhibitor now in late-phase clinical trials. Besides its antiangiogenic activity from blocking VEGF receptor 1-3, its ability to disrupt FGF receptors 1-3 has been suggested to add additional antiangiogenic activity, overcome resistance from VEGF blockade, and block FGF-dependent tumor proliferation. In this review, we will discuss the preclinical science driving brivanib's development and the clinical data generated to date.

Antiangiogenic agents in the management of non-small cell lung cancer: where do we stand now and where are we headed?

Several therapies targeting angiogenesis are currently in development for non-small cell lung cancer (NSCLC). This review discusses results of recent clinical trials evaluating chemotherapy plus antiangiogenic therapy for NSCLC. Bevacizumab, an anti-VEGF antibody, is currently approved for the treatment of advanced NSCLC in combination with carboplatin and paclitaxel. Completed phase III trials evaluating bevacizumab plus chemotherapy have shown prolonged progression-free survival; however, not all trials showed significant improvement in overall survival (OS). Phase III trials of the tyrosine kinase inhibitors (TKIs) vandetanib and sorafenib and the vascular disrupting agent ASA404 also failed to improve OS compared with chemotherapy alone. Clinical trials are ongoing involving several new antiangiogenic therapies, including ramucirumab, aflibercept, cediranib, BIBF 1120, sunitinib, pazopanib, brivanib, ABT-869, axitinib, ABT-751, and NPI-2358; several of these agents have shown promising phase I/II results. Results from recently completed and ongoing phase III trials will determine if these newer antiangiogenic agents will be incorporated into clinical practice.

Metabolic chiral inversion of brivanib and its relevance to safety and pharmacology

Brivanib alaninate is an orally administered alanine prodrug of brivanib, a dual inhibitor of the vascular endothelial growth factor (VEGF) and fibroblast growth factor (FGF) signaling pathways. It is currently in clinical trials for the treatment of hepatocellular carcinoma and colorectal cancer. Brivanib has a single asymmetric center derived from a secondary alcohol. The potential for chiral inversion was investigated in incubations with liver subcellular fractions and in animals and humans after oral doses of brivanib alaninate. Incubations of [¹⁴C]brivanib alaninate with liver microsomes and cytosols from rats, monkeys, and humans followed by chiral chromatography resulted in two radioactive peaks, corresponding to brivanib and its enantiomer. The percentage of the enantiomeric metabolite relative to brivanib in microsomal and cytosolic incubations of different species in the presence of NADPH ranged from 11.6 to 15.8 and 0.8 to 3.1%, respectively. The proposed mechanism of inversion involves the oxidation of brivanib to a ketone metabolite, which is subsequently reduced to brivanib and its enantiomer. After oral doses of brivanib alaninate to rats and monkeys, the enantiomeric metabolite was a prominent drug-related component in plasma, with the percentages of area under the curve (AUC) at 94.7 and 39.7%, respectively, relative to brivanib. In humans, the enantiomeric metabolite was a minor circulating component, with the AUC <3% of brivanib. Pharmacological studies indicated that brivanib and its enantiomer had similar potency toward the inhibition of VEGF receptor-2 and FGF receptor-1 kinases. Because of low plasma concentration in humans, the enantiomeric metabolite was not expected to contribute significantly to target-related pharmacology of brivanib. Moreover, adequate exposure in the toxicology species suggested no specific safety concerns with respect to exposure to the enantiomeric metabolite.

Adding to the mix: fibroblast growth factor and platelet-derived growth factor receptor pathways as targets in non-small cell lung cancer

The treatment of advanced non � small cell lung cancer (NSCLC) increasingly involves the use of molecularly targeted therapy with activity against either the tumor directly, or indirectly, through activity against host-derived mechanisms of tumor support such as angiogenesis. The most well studied signaling pathway associated with angiogenesis is the vascular endothelial growth factor (VEGF) pathway, and the only antiangiogenic agent currently approved for the treatment of NSCLC is bevacizumab, an antibody targeted against VEGF. More recently, preclinical data supporting the role of fibroblast growth factor receptor (FGFR) and platelet-derived growth factor receptor (PDGFR) signaling in angiogenesis have been reported. The platelet-derived growth factor (PDGF) and fibroblast growth factor (FGF) pathways may also stimulate tumor growth directly through activation of downstream mitogenic signaling cascades. In addition, 1 or both of these pathways have been associated with resistance to agents targeting the epidermal growth factor receptor (EGFR) and VEGF. A number of agents that target FGF and/or PDGF signaling are now in development for the treatment of NSCLC. This review will summarize the potential molecular roles of PDGFR and FGFR in tumor growth and angiogenesis, as well as discuss the current clinical status of PDGFR and FGFR inhibitors in clinical development.

Bioanalytical aspects of clinical mass balance studies in oncology

Clinical mass balance studies aim to investigate the absorption, distribution, metabolism and excretion (ADME) of a(n) (often radiolabeled) drug, following a single administration to humans. They are perfectly suited to determine the disposition and major metabolic pathways of a drug, the exposure to the parent drug and its metabolites, and the rate and route of elimination. A mass balance study, however, poses interesting challenges to the analysis of parent drug and metabolites in different biological matrices. Using recent clinical mass balance studies in oncology as an example, this review focuses on the aspects of mass balance studies, from bioanalytical assay development, analysis of clinical samples to reporting of study results. Along the way, it discusses bioanalytical problems and practical solutions.

Antiangiogenic agents in the management of non-small cell lung cancer: where do we stand now and where are we headed?

Several therapies targeting angiogenesis are currently in development for non-small cell lung cancer (NSCLC). This review discusses results of recent clinical trials evaluating chemotherapy plus antiangiogenic therapy for NSCLC. Bevacizumab, an anti-VEGF antibody, is currently approved for the treatment of advanced NSCLC in combination with carboplatin and paclitaxel. Completed phase III trials evaluating bevacizumab plus chemotherapy have shown prolonged progression-free survival; however, not all trials showed significant improvement in overall survival (OS). Phase III trials of the tyrosine kinase inhibitors (TKIs) vandetanib and sorafenib and the vascular disrupting agent ASA404 also failed to improve OS compared with chemotherapy alone. Clinical trials are ongoing involving several new antiangiogenic therapies, including ramucirumab, aflibercept, cediranib, BIBF 1120, sunitinib, pazopanib, brivanib, ABT-869, axitinib, ABT-751, and NPI-2358; several of these agents have shown promising phase I/II results. Results from recently completed and ongoing phase III trials will determine if these newer antiangiogenic agents will be incorporated into clinical practice.

Phase II, open-label study of brivanib as second-line therapy in patients with advanced hepatocellular carcinoma

PURPOSE

Brivanib, a selective dual inhibitor of fibroblast growth factor and VEGF signaling, has recently been shown to have activity as first-line treatment for patients with advanced hepatocellular carcinoma (HCC). This phase II open-label study assessed brivanib as second-line therapy in patients with advanced HCC who had failed prior antiangiogenic treatment.

EXPERIMENTAL DESIGN

Brivanib was administered orally at a dose of 800 mg once daily. The primary objectives were tumor response rate, time to response, duration of response, progression-free survival, overall survival (OS), disease control rate, time to progression (TTP), and safety and tolerability.

RESULTS

Forty-six patients were treated. Best responses to treatment with brivanib (N = 46 patients) using modified World Health Organization criteria were partial responses for two patients (4.3%), stable disease for 19 patients (41.3%), and progressive disease for 19 patients (41.3%). The tumor response rate was 4.3%; the disease control rate was 45.7%. Median OS was 9.79 months. Median TTP as assessed by study investigators following second-line treatment with brivanib was 2.7 months. The most common adverse events were fatigue, decreased appetite, nausea, diarrhea, and hypertension.

CONCLUSION

Brivanib had a manageable safety profile and is one of the first agents to show promising antitumor activity in advanced HCC patients treated with prior sorafenib.

Lack of food effect on single-dose pharmacokinetics of brivanib, and safety and efficacy following multiple doses in subjects with advanced or metastatic solid tumors

PURPOSE

Brivanib alaninate, an orally available prodrug of brivanib, is currently under evaluation for the treatment of several malignancies. This study aimed to (1) investigate effects of a high-fat meal on single-dose pharmacokinetics of brivanib in subjects with advanced/metastatic solid tumors and (2) assess the safety and preliminary efficacy of single and multiple doses of brivanib alaninate in this population.

METHODS

A two-part study was conducted consisting of a single-dose phase (Part A) and a multiple-dose phase (Part B). In Part A, subjects received a single dose of brivanib alaninate (800 mg) either in a fasting state or following ingestion of a high-fat meal (approximately 951 kcal [15% protein, 33% carbohydrate, 52% fat]); serial blood samples were collected for pharmacokinetic analysis up to 48 h post-dosing. In Part B, subjects received brivanib alaninate (800 mg) once daily until discontinuation. Throughout both phases, subjects were evaluated for adverse events (AEs) and best clinical response.

RESULTS

No clinically significant differences in brivanib exposure were observed between fed and fasting subjects in Part A; C (max) was unchanged and AUC(INF) decreased marginally when administered in a fed versus fasted state. In Part A, the incidence of treatment-emergent AEs was broadly similar in a fed or fasted state. Brivanib alaninate was generally well tolerated throughout the study and showed preliminary evidence of antitumor activity.

CONCLUSIONS

Consumption of a high-fat meal had no significant effect on brivanib pharmacokinetics. The study further demonstrates the acceptable safety/tolerability profile and antitumor potential of brivanib in patients with advanced malignancies.