Background: A clinical drug-drug interaction (DDI) study was designed to evaluate the effect of multiple doses of modafinil, a moderate CYP3A4 inducer at a 400 mg QD dose, on the multiple oral dose pharmacokinetics (PK) of encorafenib and its metabolite, LHY746 and binimetinib and its metabolite, AR00426032.
Methods: This study was conducted in patients with BRAF V600-mutant advanced solid tumors. Treatment of 400 mg QD modafinil was given on Day 15 through Day 21.
Background And Objectives: Encorafenib is a kinase inhibitor indicated for the treatment of patients with unresectable or metastatic melanoma or metastatic colorectal cancer, respectively, with selected BRAF V600 mutations. A clinical drug-drug interaction (DDI) study was designed to evaluate the effect of encorafenib on rosuvastatin, a sensitive substrate of OATP1B1/3 and breast cancer resistance protein (BCRP), and bupropion, a sensitive CYP2B6 substrate. Coproporphyrin I (CP-I), an endogenous substrate for OATP1B1, was measured in a separate study to deconvolute the mechanism of transporter DDI.
View Article and Find Full Text PDFEncorafenib is a potent and selective ATP competitive inhibitor of BRAF V600-mutant kinase approved for patients with BRAF-mutant melanoma and colorectal cancer. Encorafenib is mainly metabolized by cytochrome P450 (CYP) 3A4 in vitro and may be susceptible to drug-drug interactions when co-administered with CYP3A inhibitors or inducers. The primary objective was to assess the impact of the strong CYP3A inhibitor posaconazole (part 1) and the moderate CYP3A and P-gp inhibitor diltiazem (part 2) on encorafenib pharmacokinetics in healthy volunteers following a single 50-mg dose.
View Article and Find Full Text PDFEncorafenib is a novel kinase inhibitor of BRAF V600E as well as wild-type BRAF and CRAF and has received approval, in combination with binimetinib, to treat BRAF V600E or V600K mutation-positive unresectable or metastatic melanoma or in combination with cetuximab to treat BRAF V600E mutation-positive colorectal cancer. The absorption, distribution, metabolism and excretion (ADME) of encorafenib was studied by administering [ C] encorafenib (100 mg containing 90 μCi of radiolabeled material) to 4 healthy male subjects (NCT01436656). Following a single oral 100-mg dose of [ C] encorafenib to healthy male subjects, the overall recovery of radioactivity in the excreta was ≥93.
View Article and Find Full Text PDFEncorafenib is a kinase inhibitor indicated for the treatment of patients with BRAF mutant melanoma and BRAF mutant metastatic colorectal cancer. To understand the effect of food and coadministration with a proton-pump inhibitor (PPI), , , and data were generated to optimize the clinical dose, evaluate safety, and better understand the oral absorption process under these conditions. Study 1 evaluated the effect of food on the plasma pharmacokinetics, safety, and tolerability after a single oral dose of encorafenib 100 mg.
View Article and Find Full Text PDFPurpose: This open-label, dose-finding phase Ib/II study reports the safety and activity of the first combination use with BRAF inhibitor (BRAFi) encorafenib plus MEK inhibitor (MEKi) binimetinib in patients with V600E-mutant solid tumors.
Patients And Methods: In phase I, the recommended phase 2 doses (RP2D) were established (primary objective). In phase II, the clinical activity of the combination at the RP2D was assessed (primary objective) in patients with -mutant metastatic colorectal cancer (mCRC), BRAFi-treated -mutant melanoma, and BRAFi-naïve BRAF-mutant melanoma.
Capping off an era marred by drug development failures and punctuated by waning interest and presumed intractability toward direct targeting of KRAS, new technologies and strategies are aiding in the target's resurgence. As previously reported, the tetrahydropyridopyrimidines were identified as irreversible covalent inhibitors of KRAS that bind in the switch-II pocket of KRAS and make a covalent bond to cysteine 12. Using structure-based drug design in conjunction with a focused in vitro absorption, distribution, metabolism and excretion screening approach, analogues were synthesized to increase the potency and reduce metabolic liabilities of this series.
View Article and Find Full Text PDFLarotrectinib, a selective TRK tyrosine kinase inhibitor (TKI), has demonstrated histology-agnostic efficacy in patients with TRK fusion-positive cancers. Although responses to TRK inhibition can be dramatic and durable, duration of response may eventually be limited by acquired resistance. LOXO-195 is a selective TRK TKI designed to overcome acquired resistance mediated by recurrent kinase domain (solvent front and xDFG) mutations identified in multiple patients who have developed resistance to TRK TKIs.
View Article and Find Full Text PDFMyelodysplastic syndromes (MDS) and acute myeloid leukemia (AML) suppress normal hematopoietic activity in part by enabling a pathogenic inflammatory milieu in the bone marrow. In this report, we show that elevation of angiopoietin-1 in myelodysplastic CD34(+) stem-like cells is associated with higher risk disease and reduced overall survival in MDS and AML patients. Increased angiopoietin-1 expression was associated with a transcriptomic signature similar to known MDS/AML stem-like cell profiles.
View Article and Find Full Text PDFCytochrome P450 (P450) protein-protein interactions have been shown to alter their catalytic activity. Furthermore, these interactions are isoform specific and can elicit activation, inhibition, or no effect on enzymatic activity. Studies show that these effects are also dependent on the protein partner cytochrome P450 reductase (CPR) and the order of protein addition to purified reconstituted enzyme systems.
View Article and Find Full Text PDFBackground: Pexmetinib (ARRY-614) is a dual inhibitor of p38 mitogen-activated protein kinase and Tie2 signaling pathways implicated in the pathogenesis of myelodysplastic syndromes. Previous clinical experience in a Phase I dose-escalation study of myelodysplastic syndrome patients using pexmetinib administered as neat powder-in-capsule (PIC) exhibited high variability in pharmacokinetics and excessive pill burden, prompting an effort to improve the formulation of pexmetinib.
Methods: A relative bioavailability assessment encompassed three parallel treatment cohorts of unique subjects comparing the two new formulations (12 subjects per cohort), a liquid oral suspension (LOS) and liquid-filled capsule (LFC) and the current clinical PIC formulation (six subjects) in a fasted state.
Cytochrome P450 enzymes play a key role in the metabolism of pharmaceutical agents. To determine metabolite toxicity, it is necessary to obtain P450 metabolites from various pharmaceutical agents. Here, we describe a bioreactor that is made by immobilizing cytochrome P450 2C9 (CYP2C9) to a poly(methyl methacrylate) surface and, as an alternative to traditional chemical synthesis, can be used to biosynthesize P450 metabolites in a plug flow bioreactor.
View Article and Find Full Text PDFElectron transfer in cytochrome P450 enzymes is a fundamental process for activity. It is difficult to measure electron transfer in these enzymes because under the conditions typically used they exist in a variety of states. Using nanotechnology-based techniques, gold conducting nanopillars were constructed in an indexed array.
View Article and Find Full Text PDFMonte Carlo simulations (MCS) present a powerful tool to evaluate candidate regimens by determining the probability of target attainment. Although these assessments have traditionally incorporated variability in pharmacokinetic (PK) parameters and MICs, consideration of interstrain pharmacodynamic (PD) variability has been neglected. A population PK/PD model was developed for doripenem using murine thigh infection data based on 20 bacterial strains.
View Article and Find Full Text PDFThis work describes an original and simple technique for protein immobilization into nanowells, fabricated using nanopatterned array fabrication methods, while ensuring the protein retains normal biological activity. Nanosphere lithography was used to fabricate a nanowell array with nanowells 100 nm in diameter with a periodicity of 500 nm. The base of the nanowells was gold and the surrounding material was silicon dioxide.
View Article and Find Full Text PDFThe antiepileptic, carbamazepine, is extensively metabolized via hepatic enzymes in the cytochrome P450 family and is therefore subject to a myriad of drug interactions. Concomitant administration with phenytoin enhances carbamazepine metabolism thus reducing serum concentrations and necessitating the use of a higher maintenance dose. Removal of phenytoin therapy in the absence of anticipatory dose adjustments and careful monitoring of serum concentrations may result in catastrophic outcomes.
View Article and Find Full Text PDFIn this paper, Mn(12)-based ordered honeycomb structures were successfully constructed from a simple solution casting process at high relative humidity through the modification of fatty acids to Mn(12) clusters. Mn(12)-fatty acid complexes maintain typical features of a single-molecule magnet as confirmed by IR spectra and magnetization hysteresis studies. Investigation of the effects of concentration, velocity of humid airflow, solvent, substrate, and alkyl chain length of the Mn(12) complex on the morphology of the honeycomb structures demonstrated wide generality and high reproducibility of the formation of Mn(12)-based self-organized honeycomb-patterned films.
View Article and Find Full Text PDFSpecies and tissue differences in the activity of three major classes of esterases, carboxylesterase (CE), butyrylcholinesterase (BChE) and paraoxonase (PON), were studied. Substantial species differences in activity of these esterases were observed between the mouse, rat, dog monkey and human. Such species differences must be considered when using these preclinical species to optimize the pharmacokinetic properties of ester compounds intended for human use.
View Article and Find Full Text PDFCytochrome P450 (P450) enzymes typically require the presence of at least cytochrome P450 reductase (CPR) and NADPH to carry out the metabolism of xenobiotics. To address whether the need for redox transfer proteins and the NADPH cofactor protein could be obviated, CYP2C9 was bonded to a gold electrode through an 11-mercaptoundecanoic acid and octanethiol self-assembled monolayer (SAM) through which a current could be applied. Cyclic voltammetry demonstrated direct electrochemistry of the CYP2C9 enzyme bonded to the electrode and fast electron transfer between the heme iron and the gold electrode.
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