Current regulatory guidelines on drug-food interactions recommend an early assessment of food effect to inform clinical dosing instructions, as well as a pivotal food effect study on the to-be-marketed formulation if different from that used in earlier trials. Study waivers are currently only granted for BCS class 1 drugs. Thus, repeated food effect studies are prevalent in clinical development, with the initial evaluation conducted as early as the first-in-human studies.
View Article and Find Full Text PDFOral drug absorption is a complex process depending on many factors, including the physicochemical properties of the drug, formulation characteristics and their interplay with gastrointestinal physiology and biology. Physiological-based pharmacokinetic (PBPK) models integrate all available information on gastro-intestinal system with drug and formulation data to predict oral drug absorption. The latter together with in vitro-in vivo extrapolation and other preclinical data on drug disposition can be used to predict plasma concentration-time profiles in silico.
View Article and Find Full Text PDFSPRYCEL (Dasatinib) is a Biopharmaceutical Classification System II weakly basic drug that exhibits strong pH-dependent solubility. Dasatinib is currently presented in 2 drug product formulations as an adult immediate release tablet and a pediatric powder for oral suspension. A bioequivalence study comparing the formulations in adult healthy subjects found that overall exposure (AUC) from suspension treatments was ∼9% to 13% lower, Cmax was similar, and median Tmax from powder for oral suspension was ∼30 min earlier.
View Article and Find Full Text PDFMelanoma has a high propensity to metastasize to the brain, and patients with melanoma brain metastases (MBM) have an extremely poor prognosis. The recent approval of several molecularly-targeted agents (e.g.
View Article and Find Full Text PDFBrain metastases are a major cause of morbidity and mortality in patients with advanced melanoma. Recent approval of several molecularly-targeted agents and biologics has brought hope to patients with this previously untreatable disease. However, patients with symptomatic melanoma brain metastases have often been excluded from pivotal clinical trials.
View Article and Find Full Text PDFSmall molecule inhibitors targeting the mitogen-activated protein kinase pathway (Braf/mitogen-activated protein kinase kinase/extracellular signal-regulated kinase) have had success in extending survival for patients with metastatic melanoma. Unfortunately, resistance may occur via cross-activation of alternate signaling pathways. One approach to overcome resistance is to simultaneously target the phosphoinositide 3-kinase/mammalian target of rapamycin signaling pathway.
View Article and Find Full Text PDFBrain metastases are a major cause of mortality in patients with advanced melanoma. Adequate brain distribution of targeted agents for melanoma will be critical for treatment success. Recently, improvement in overall survival led to US Food and Drug Administration (FDA) approval of the v-raf murine sarcoma viral oncogene homolog B (BRAF) inhibitors, vemurafenib and dabrafenib, and the mitogen-activated protein kinase kinase-1 (MEK)-1/2 inhibitor, trametinib.
View Article and Find Full Text PDFBrain metastases are a common cause of death in stage IV metastatic melanoma. Dabrafenib is a BRAF (gene encoding serine/threonine-protein kinase B-Raf) inhibitor that has been developed to selectively target the valine 600 to glutamic acid substitution (BRAF(V600E)), which is commonly found in metastatic melanoma. Clinical trials with dabrafenib have shown encouraging results; however, the central nervous system distribution of dabrafenib remains unknown.
View Article and Find Full Text PDFVemurafenib [N-(3-{[5-(4-chlorophenyl)-1H-pyrrolo[2,3-b]pyridin-3-yl]carbonyl}-2,4-difluorophenyl)propane-1-sulfonamide(PLX4032)] is a novel small-molecule BRAF inhibitor, recently approved by the Food and Drug Administration for the treatment of patients with metastatic melanoma with a BRAF(V600E) mutation. The objective of this study was to investigate the role of P-glycoprotein (P-gp) and breast cancer resistance protein (BCRP) in the distribution of vemurafenib to the central nervous system. In vitro studies conducted in transfected Madin-Darby canine kidney II cells show that the intracellular accumulation of vemurafenib is significantly restricted because of active efflux by P-gp and BCRP.
View Article and Find Full Text PDFFetal pharmacotherapy generally relies on nonspecific biodistribution of therapeutic agents to the unborn child following drug administration into the maternal circulation system. Physiologically, transfer of polar, high-molecular weight solutes across the placenta is facilitated by a specialized, vesicular transport mechanism termed transcytosis. To develop biotechnology-based drugs such as proteins, DNA, and siRNA as clinically effective therapeutics, transcytosis systems have been evaluated as a promising strategy to augment drug transfer across endothelial and epithelial barriers.
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