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Fibroblast growth factor (FGF) signaling plays critical roles in key biological processes ranging from embryogenesis to wound healing and has strong links to several hallmarks of cancer. Genetic alterations in FGF receptor (FGFR) family members are associated with increased tumor growth, metastasis, angiogenesis, and decreased survival. JNJ-42756493, erdafitinib, is an orally active small molecule with potent tyrosine kinase inhibitory activity against all four FGFR family members and selectivity versus other highly related kinases. JNJ-42756493 shows rapid uptake into the lysosomal compartment of cells in culture, which is associated with prolonged inhibition of FGFR signaling, possibly due to sustained release of the inhibitor. In xenografts from human tumor cell lines or patient-derived tumor tissue with activating FGFR alterations, JNJ-42756493 administration results in potent and dose-dependent antitumor activity accompanied by pharmacodynamic modulation of phospho-FGFR and phospho-ERK in tumors. The results of the current study provide a strong rationale for the clinical investigation of JNJ-42756493 in patients with tumors harboring FGFR pathway alterations.

Conclusions:The potent antitumor activity as a single agent in preclinical models combined with its favorable pharmacodynamic profile makes JNJ-26481585 a promising "second-generation" HDAC inhibitor. The compound is currently in clinical studies, to evaluate its potential applicability in a broad spectrum of both solid and hematologic malignancies. (Clin Cancer Res 2009;15(22):6841-51)

ABSTRACT:The aim of this study was to evaluate different physiologically based modeling strategies for the prediction of human pharmacokinetics. Plasma profiles after intravenous and oral dosing were simulated for 26 clinically tested drugs. Two mechanism-based predictions of human tissue-to-plasma partitioning (P tp ) from physicochemical input (method Vd1) were evaluated for their ability to describe human volume of distribution at steady state (V ss ). This method was compared with a strategy that combined predicted and experimentally determined in vivo rat P tp data (method Vd2). Best V ss predictions were obtained using method Vd2, providing that rat P tp input was corrected for interspecies differences in plasma protein binding (84% within 2-fold). V ss predictions from physicochemical input alone were poor (32% within 2-fold). Total body clearance (CL) was predicted as the sum of scaled rat renal clearance and hepatic clearance projected from in vitro metabolism data. Best CL predictions were obtained by disregarding both blood and microsomal or hepatocyte binding (method CL2, 74% within 2-fold), whereas strong bias was seen using both blood and microsomal or hepatocyte binding (method CL1, 53% within 2-fold). The physiologically based pharmacokinetics (PBPK) model, which combined methods Vd2 and CL2 yielded the most accurate predictions of in vivo terminal half-life (69% within 2-fold). The Gastroplus advanced compartmental absorption and transit model was used to construct an absorption-disposition model and provided accurate predictions of area under the plasma concentration-time profile, oral apparent volume of distribution, and maximum plasma concentration after oral dosing, with 74%, 70%, and 65% within 2-fold, respectively. This evaluation demonstrates that PBPK models can lead to reasonable predictions of human pharmacokinetics.In the drug discovery process considerable resources are required to assess the pharmacokinetic (PK) properties of potential drug candidates in vivo in animals. To optimize the use of such in vivo testing, there has been a growing interest in predicting the PK behavior of drug candidates (Theil et al., 2003;van de Waterbeemd and Gifford, 2003). If sufficiently reliable, such simulations could also help to select the most promising candidates for development and reject those with a low probability of success (van de Waterbeemd and Gifford, 2003).The majority of the approaches to predict human PK developed to date typically focus on the drug's behavior in individual processes of absorption, distribution, metabolism and excretion (ADME). The characterization of a drug's PK in a complex biological system is best described by assembling these processes in one global model. In this context, physiologically based pharmacokinetics (PBPK) models have been developed (Bischoff, 1986). PBPK models map the complex drug transport scheme onto a physiologically realistic compartmental structure (Fig. 1). The major structural elements of the PBPK disposition model are derived from the anato...

Recently, Brinster et al. suggested that type II fatty-acid biosynthesis (FASII) is not a suitable antibacterial target for Gram-positive pathogens because they use fatty acids directly from host serum rather than de novo synthesis. Their findings, if confirmed, are relevant for further scientific and financial investments in the development of new drugs targeting FASII. We present here in vitro and in vivo data demonstrating that their observations do not hold for Staphylococcus aureus, a major Gram-positive pathogen causing several human infections. The observed differences among Gram-positive pathogens in FASII reflects heterogeneity either in fatty-acid synthesis or in the capacity for fatty-acid uptake from the environment.