Population pharmacokinetic modeling of dolutegravir/lamivudine to support a once-daily fixed-dose combination regimen in virologically suppressed adults living with HIV-1.

A fixed-dose combination (FDC) of 50 mg dolutegravir and 300 mg lamivudine is indicated for the treatment of HIV-1 infection. This analysis aimed to characterize the population pharmacokinetics (PK) of dolutegravir and lamivudine based on data from a phase 3 study (TANGO) in virologically suppressed adults living with HIV-1 switching to dolutegravir/lamivudine FDC. These analyses included 362 participants who contributed 2,629 dolutegravir and 2,611 lamivudine samples collected over 48 weeks.

Phase IIa Proof-of-Concept Evaluation of the Antiviral Efficacy, Safety, Tolerability, and Pharmacokinetics of the Next-Generation Maturation Inhibitor GSK3640254.

Background: GSK3640254 (GSK'254) is a next-generation human immunodeficiency virus type 1 (HIV-1) maturation inhibitor with pharmacokinetics (PK) supporting once-daily therapy.

Methods: This phase IIa double-blind (sponsor-unblinded), randomized, placebo-controlled, adaptive study evaluated antiviral effect, safety, tolerability, and PK of once-daily GSK'254 monotherapy administered with food (moderate-fat meal) in HIV-1-positive, treatment-naive adults. In part 1, participants received GSK'254 10 or 200 mg for 10 days.

Relative Bioavailability and Food Effect of GSK3640254 Tablet and Capsule Formulations in Healthy Participants.

GSK3640254 is a next-generation maturation inhibitor with demonstrated potency across HIV-1 subtypes and a high barrier to emergent resistance. This phase I, 2-part, randomized, open-label study (ClinicalTrials.gov identifier, NCT04263142) in healthy participants assessed the relative bioavailability of a single dose of GSK3640254 200 mg in tablet and capsule formulations (part 1) and the effect of food on the pharmacokinetic profile of the tablet formulation (part 2).

Lack of pharmacokinetic interaction between the HIV-1 maturation inhibitor GSK3640254 and combination oral contraceptives in healthy women.

Aims: GSK3640254 is a next-generation maturation inhibitor likely to be coadministered with combined oral contraceptives in HIV-positive women.

Methods: This phase I, open-label, 1-way study assessed pharmacokinetic and pharmacodynamic interactions of GSK3640254 200 mg and ethinyl oestradiol 0.03 mg/levonorgestrel 0.

A Phase I Evaluation of the Pharmacokinetics and Tolerability of the HIV-1 Maturation Inhibitor GSK3640254 and Tenofovir Alafenamide/Emtricitabine in Healthy Participants.

GSK3640254 is a next-generation maturation inhibitor that would likely be combined with standard antiretroviral agents to form a regimen of ≥2 fully active classes. This phase I, open-label, 2-period, 1-way study assessed potential pharmacokinetic (PK) interactions between GSK3640254 and tenofovir alafenamide/emtricitabine (TAF/FTC; including the metabolite tenofovir [TFV]) in healthy volunteers. Eligible participants received TAF/FTC 25/200 mg once daily (QD) on days 1 through 21 with a moderate-fat meal; GSK3640254 200 mg QD was added on days 15 through 21.

Phase I evaluation of pharmacokinetics and tolerability of the HIV-1 maturation inhibitor GSK3640254 and dolutegravir in healthy adults.

Aims: GSK3640254, a novel, next-generation maturation inhibitor effective against a range of HIV polymorphisms with no cross-resistance to current antiretroviral therapy, could potentially be coadministered with dolutegravir as a 2-drug regimen. In this phase I study, pharmacokinetics and tolerability of GSK3640254 plus dolutegravir were assessed.

Methods: Healthy participants received dolutegravir 50 mg once daily (QD) on Days 1-5 in period 1, GSK3640254 200 mg QD on Days 1-7 in period 2, and dolutegravir 50 mg plus GSK3640254 200 mg QD on Days 1-7 in period 3.

Bioequivalence and Food Effect Assessment of 2 Fixed-Dose Combination Formulations of Dolutegravir and Lamivudine.

This single-dose study evaluated the bioequivalence, food effect, and safety of 2 experimental, 2-drug, fixed-dose formulations of 50 mg dolutegravir and 300 mg lamivudine (formulation AH and formulation AK) as compared with coadministration of single-entity tablets of 50 mg dolutegravir and 300 mg lamivudine (reference). In fasted subjects, formulation AH lamivudine exposure was similar to the reference; however, dolutegravir exposure was consistently higher in formulation AH, with area under the concentration-time curve (AUC) and maximum concentration (C ) approximately 27% to 28% greater than reference. Formulation AK met bioequivalence standards to the reference for dolutegravir (AUC and C ) and lamivudine (AUC and AUC ) exposure; however, dolutegravir AUC and lamivudine C were approximately 16% and 32% higher than the reference, respectively.

Safety, efficacy, and dose response of the maturation inhibitor GSK3532795 (formerly known as BMS-955176) plus tenofovir/emtricitabine once daily in treatment-naive HIV-1-infected adults: Week 24 primary analysis from a randomized Phase IIb trial.

GSK3532795 (formerly known as BMS-955176) is a second-generation maturation inhibitor targeting a specific Gag cleavage site between capsid p24 and spacer peptide 1 of HIV-1. Study 205891 (previously AI468038) investigated the efficacy, safety, and dose response of GSK3532795 in treatment-naive, HIV-1-infected participants. Study 205891 (NCT02415595) was a Phase IIb, randomized, active-controlled, double-blind, international trial.

Population Pharmacokinetics and Pharmacodynamics Modelling of Dilmapimod in Severe Trauma Subjects at Risk for Acute Respiratory Distress Syndrome.

Introduction: Dilmapimod is a potent p38 mitogen-activated protein kinase (MAPK) inhibitor and was investigated in a study (NCT00996840) for its anti-inflammatory effect in non-head injury trauma patients at risk for developing acute respiratory distress syndrome (ARDS). The purpose of this paper is to present the details of the development of a population pharmacokinetic (PK) model, an empirical population placebo response model, and the exploration of a PK/pharmacodynamic (PD) model of dilmapimod.

Methods: A population PK model was developed to characterise the PK profile of dilmapimod in this patient population; the potential effect of available covariates on the PK of dilmapimod was evaluated.

Pharmacometrics-guided drug development of antihyperhidrosis agents.

The objective of the present work was to use modeling and simulation to inform trial design of a proof-of-concept study for agents used in the treatment of hyperhidrosis. Data were available from 36 subjects who received the vehicle, 2% or 4% topical glycopyrrolate wipes daily for 4 weeks, with response (hyperhidrosis disease severity scale [HDSS] and sweat production [SP]) measured weekly. The HDSS and SP time courses were best described using a longitudinal model with maximum response achieved by 1 week.

HIV-1 Nef interaction influences the ATP-binding site of the Src-family kinase, Hck.

Background: Nef is an HIV-1 accessory protein essential for viral replication and AIDS progression. Nef interacts with a multitude of host cell signaling partners, including members of the Src kinase family. Nef preferentially activates Hck, a Src-family kinase (SFK) strongly expressed in macrophages and other HIV target cells, by binding to its regulatory SH3 domain.

Expression of a Src family kinase in chronic myelogenous leukemia cells induces resistance to imatinib in a kinase-dependent manner.

The Bcr-Abl kinase inhibitor imatinib is remarkably effective in chronic myelogenous leukemia (CML), although drug resistance is an emerging problem. Myeloid Src family kinases such as Hck and Lyn are often overexpressed in imatinib-resistant CML cells that lack Bcr-Abl mutations. Here we tested whether Hck overexpression is sufficient to induce imatinib resistance using both wild-type Hck and a mutant (Hck-T338A) that is uniquely sensitive to the pyrazolo-pyrimidine inhibitor, NaPP1.

Conformational disturbance in Abl kinase upon mutation and deregulation.

Protein dynamics are inextricably linked to protein function but there are few techniques that allow protein dynamics to be conveniently interrogated. For example, mutations and translocations give rise to aberrant proteins such as Bcr-Abl where changes in protein conformation and dynamics are believed to result in deregulated kinase activity that provides the oncogenic signal in chronic myelogeous leukemia. Although crystal structures of the down-regulated c-Abl kinase core have been reported, the conformational impact of mutations that render Abl resistant to small-molecule kinase inhibitors are largely unknown as is the allosteric interplay of the various regulatory elements of the protein.

Abl N-terminal cap stabilization of SH3 domain dynamics.

Crystal structures and other biochemical data indicate that the N-terminal cap (NCap) region of the Abelson tyrosine kinase (c-Abl) is important for maintaining the downregulated conformation of the kinase domain. The exact contributions that the NCap makes in stabilizing the various intramolecular interactions within c-Abl are less clear. While the NCap appears to be important for locking the SH3 and SH2 domains to the back of the kinase domain, there may be other more subtle elements of regulation.

SRC family kinase activity is required for murine embryonic stem cell growth and differentiation.

Self-renewal and differentiation of embryonic stem (ES) cells are regulated by cytokines and growth factors through tyrosine kinase-dependent signaling pathways. In murine ES cells, signals for self-renewal are generated by the leukemia inhibitory factor (LIF). LIF and other growth factors are linked to the activation of the Src family of cytoplasmic protein-tyrosine kinases (SFKs), which consists of eight members having shared structural architecture.

Small molecule modulators of endogenous and co-chaperone-stimulated Hsp70 ATPase activity.

The molecular chaperone and cytoprotective activities of the Hsp70 and Hsp40 chaperones represent therapeutic targets for human diseases such as cancer and those that arise from defects in protein folding; however, very few Hsp70 and no Hsp40 modulators have been described. Using an assay for ATP hydrolysis, we identified and screened small molecules with structural similarity to 15-deoxyspergualin and NSC 630668-R/1 for their effects on endogenous and Hsp40-stimulated Hsp70 ATPase activity. Several of these compounds modulated Hsp70 ATPase activity, consistent with the action of NSC 630668-R/1 observed previously (Fewell, S.

The FEAR Before MEN: networks of mitotic exit.

Variations in the normal regulation of the mitotic cell cycle can lead to such global cellular changes as differential development or malignant transformation. Studies on the control of mitosis are particularly important to discover the details of the basic mechanisms responsible for normal cell division, as well as to learn about strategies employed by cancerous cells to indefinitely proliferate. The past years have brought noteworthy progress in elucidating the molecular pathways that regulate crucial events during mitosis such as: chromosome condensation, formation of the mitotic spindle, chromosome segregation, cytokinesis, and disassembly of the mitotic spindle.