Purpose: The PI3K/mTOR pathway is frequently aberrated in cancer. LY3023414 is a potent and selective ATP-competitive inhibitor of class I PI3K isoforms, mTOR, and DNA-PK. Here we report the dose-escalation results of the first-in-human phase I study of LY3023414.Experimental Design: A 3þ3 dose escalation for once-daily and twice-daily oral dosing of LY3023414 was followed by an expansion cohort for CYP3A4 drug-drug interaction (DDI) assessment. The primary objective was to determine the recommended phase 2 dose (RP2D). Additional objectives included safety, pharmacokinetics/pharmacodynamics, and antitumor activity.Results: Forty-seven patients with solid tumors received LY3023414 at once-daily (20-450 mg) or twice-daily dosing (150-250 mg). Dose-limiting toxicities were observed at 450 mg once-daily (thrombocytopenia, hypotension, hyperkalemia) in three of three patients, 250-mg twice-daily dosing (hypophosphatemia, fatigue, mucositis) in three of four patients, and in one of 15 patients at 200 mg twice-daily (nausea). Common related AEs included nausea (38%), fatigue (34%), and vomiting (32%) and were mostly mild or moderate. LY3023414 pharmacokinetics demonstrated dose-dependent increase in exposure with ! 90% target inhibition at doses !150 mg. DDI analysis demonstrated LY3023414 to be a weak inhibitor of CYP3A4. Durable partial response was observed in a patient with endometrial cancer harboring PIK3R1 and PTEN truncating mutations, and 13 additional patients (28%) had a decrease in their target lesions by up to 30%.Conclusions: LY3023414 has a tolerable safety profile and single-agent activity in patients with advanced cancers. The RP2D of LY3023414 monotherapy is 200 mg twice daily based on safety, tolerability, and pharmacokinetic/pharmacodynamic data. Clin Cancer Res; 1-10. Ó2018 AACR.
Gemcitabine triphosphate (dFdCTP) is a highly active metabolite of gemcitabine. It is formed intra-cellularly via the phosphorylation of gemcitabine by deoxycytidine kinase. The monitoring of dFdCTP in human peripheral blood mononuclear cells (PBMCs), in addition to plasma concentrations of gemcitabine and its metabolite 2',2'-difluorodeoxyuridine, is considered very useful in determining pharmacokinetic-pharmacodynamic relationships. We describe a novel sensitive assay for the quantification of dFdCTP in human PBMCs. The method is based on weak anion-exchange liquid chromatography and detection with tandem mass spectrometry (LC-MS/MS). The assay has been validated from 1 ng/ml (lower limit of quantification, LLOQ) to 25 ng/ml (upper limit of quantification, ULOQ) using 180 microl aliquots of PBMC extracts containing approximately 0.648 mg protein or 3.8 x 10(6) lysed PBMCs. The LLOQ is equivalent to 94 fmol/10(6) cells (1 ng/ml = 0.18 ng/180 microl or 0.18 ng/0.648 mg protein = 0.047 ng/10(6) cells or 94 fmol/10(6) cells). This highly sensitive assay is capable of quantifying about 200-fold lower concentrations of dFdCTP in human PBMCs than currently available methods.
The 2015 9th Workshop on Recent Issues in Bioanalysis (9th WRIB) took place in Miami, Florida with participation of over 600 professionals from pharmaceutical and biopharmaceutical companies, biotechnology companies, contract research organizations and regulatory agencies worldwide. It is once again a 5-day week long event - a full immersion bioanalytical week - specifically designed to facilitate sharing, reviewing, discussing and agreeing on approaches to address the most current issues of interest in bioanalysis. The topics covered included both small and large molecules, and involved LCMS, hybrid LBA/LCMS, LBA approaches including the focus on biomarkers and immunogenicity. This 2015 White Paper encompasses recommendations that emerged from the extensive discussions held during the workshop, and is aimed to provide the bioanalytical community with key information and practical solutions on topics and issues addressed, in an effort to advance scientific excellence, improve quality and deliver better regulatory compliance. Due to its length, the 2015 edition of this comprehensive White Paper has been divided into three parts. Part 1 covers the recommendations for small molecule bioanalysis using LCMS. Part 2 (hybrid LBA/LCMS and regulatory agencies' inputs) and Part 3 (large molecule bioanalysis using LBA, biomarkers and immunogenicity) will also be published in volume 7 of Bioanalysis, issues 23 and 24, respectively.
Although traditionally reserved for proteomic analysis, nanoESI has found increased use for small molecule applications related to drug metabolism/pharmacokinetics (DMPK). NanoESI, which refers to ESI performed at flow rates in the range of 200 to 1000 nL/min using smaller diameter emitters (10 to 100 microm id), produces smaller droplets than conventional ESI resulting in more efficient ionization. Benefits include greater sensitivity, enhanced dynamic range, and a reduced competition for ionization. These advantages may now be harnessed largely due to the introduction of a commercial system for automated nanoESI infusion. This development in turn has allowed ADME (absorption, distribution, metabolism, and excretion) scientists to consider novel approaches to mass spectrometric analysis without direct LC interfacing. While it is freely acknowledged that nanoESI infusion is not likely to supplant LC-MS as the primary analytical platform for ADME, nanoESI infusion has been successfully applied to both quantitative (bioanalysis) and qualitative (metabolite identification) applications. This review summarizes published applications of this technology and offers a perspective on where it fits best into the DMPK laboratory.
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