First-in-human study of 23ME-00610, an antagonistic antibody for genetically validated CD200R1 immune checkpoint, in participants with advanced solid malignancies.

Purpose: In this Phase 1 portion of a first-in-human Phase 1/2a study (NCT05199272), 23ME-00610 was evaluated in participants with advanced solid malignancies to determine its safety, tolerability, pharmacokinetics, and pharmacodynamics. Exploratory biomarkers were evaluated to examine potential correlates of efficacy and safety.

Patients And Methods: Eligible participants (≥18 years) were administered 23ME-00610 intravenously every 3 weeks using an accelerated titration design followed by a traditional 3+3 design, with an initial dose level of 2 mg.

An LC-MS/MS method for determination of tenofovir (TFV) in human plasma following tenofovir alafenamide (TAF) administration: Development, validation, cross-validation, and use of formic acid as plasma TFV stabilizer.

Tenofovir disoproxil fumarate (TDF) and tenofovir alafenamide (TAF) are both tenofovir (TFV) prodrugs, with the same active intracellular metabolite, TFV-diphosphate (TFV-DP). TAF delivers TFV-DP to target cells more efficiently and at lower doses than TDF, thereby substantially reducing systemic exposure to TFV, which results in improved bone and renal safety relative to TDF. As such, the method developed for the determination of TFV following TAF administration involved two key differences from determination of TFV following TDF administration.

Confirmation of the drug-drug interaction potential between cobicistat-boosted antiretroviral regimens and hormonal contraceptives.

Background: Cobicistat (COBI), a CYP3A inhibitor, is a pharmacokinetic enhancer that increases exposures of the HIV protease inhibitors (PIs) atazanavir (ATV) and darunavir (DRV). The potential drug interaction between COBI-boosted PIs and hormonal contraceptives, which are substrates of intestinal efflux transporters and extensively metabolized by CYP enzymes, glucuronidation and sulfation, was evaluated.

Methods: This was a Phase I, open-label, two cohort (n=18/cohort), fixed-sequence study in healthy females that evaluated the drug-drug interaction (DDI) between multiple-dose ATV+COBI or DRV+COBI and single-dose drospirenone/ethinyl estradiol (EE).

The determination of human peripheral blood mononuclear cell counts using a genomic DNA standard and application in tenofovir diphosphate quantitation.

A fluorescent quantitation method to determine PBMC-derived DNA amounts using purified human genomic DNA (gDNA) as the reference standard was developed and validated. gDNA was measured in a fluorescence-based assay using a DNA intercalant, SYBR green. The fluorescence signal was proportional to the amount (mass) of DNA in the sample.

Safety of elvitegravir, cobicistat, emtricitabine, and tenofovir alafenamide in HIV-1-infected adults with end-stage renal disease on chronic haemodialysis: an open-label, single-arm, multicentre, phase 3b trial.

Background: Current treatment for HIV-infected individuals with renal failure on haemodialysis frequently requires complex regimens with multiple pills. A daily single-tablet regimen of coformulated elvitegravir, cobicistat, emtricitabine, and tenofovir alafenamide is approved in Europe, the USA, and in other regions for use in HIV-1-infected individuals with mild-to-moderate chronic kidney disease (creatinine clearance 30-69 mL/min). We aimed to assess the safety, efficacy, and pharmacokinetics of this regimen in HIV-infected adults with end-stage renal disease on chronic haemodialysis.

Quantitation of intracellular triphosphate metabolites of antiretroviral agents in peripheral blood mononuclear cells (PBMCs) and corresponding cell count determinations: review of current methods and challenges.

Peripheral blood mononuclear cells (PBMCs) are a critical component of the immune system and the target cells for human immunodeficiency virus, type 1 (HIV-1) infection. Nucleoside/nucleotide analogs for the treatment of HIV infection are prodrugs that require cellular activation to triphosphate (TP) metabolites for antiviral activity. A reliable method of PBMC isolation and subsequent cell counting, as well as an accurate bioanalytical determination of the TPs in PBMCs are important for understanding the intracellular pharmacokinetic (PK) of the TPs and its correlation with plasma PK, the drug effect, and dose determination.

Clathrin light chains' role in selective endocytosis influences antibody isotype switching.

Clathrin, a cytosolic protein composed of heavy and light chain subunits, assembles into a vesicle coat, controlling receptor-mediated endocytosis. To establish clathrin light chain (CLC) function in vivo, we engineered mice lacking CLCa, the major CLC isoform in B lymphocytes, generating animals with CLC-deficient B cells. In CLCa-null mice, the germinal centers have fewer B cells, and they are enriched for IgA-producing cells.

Clathrin light chains are required for the gyrating-clathrin recycling pathway and thereby promote cell migration.

The clathrin light chain (CLC) subunits participate in several membrane traffic pathways involving both clathrin and actin, through binding the actin-organizing huntingtin-interacting proteins (Hip). However, CLCs are dispensable for clathrin-mediated endocytosis of many cargoes. Here we observe that CLC depletion affects cell migration through Hip binding and reduces surface expression of β1-integrin by interference with recycling following normal endocytosis of inactive β1-integrin.

Clathrin promotes centrosome integrity in early mitosis through stabilization of centrosomal ch-TOG.

Clathrin depletion by ribonucleic acid interference (RNAi) impairs mitotic spindle stability and cytokinesis. Depletion of several clathrin-associated proteins affects centrosome integrity, suggesting a further cell cycle function for clathrin. In this paper, we report that RNAi depletion of CHC17 (clathrin heavy chain 17) clathrin, but not the CHC22 clathrin isoform, induced centrosome amplification and multipolar spindles.