Investigation of Clinical Absorption, Distribution, Metabolism, and Excretion and Pharmacokinetics of the HIV-1 Maturation Inhibitor GSK3640254 Using an Intravenous Microtracer Combined with EnteroTracker for Biliary Sampling.

GSK3640254 is a next-generation maturation inhibitor in development for HIV-1 treatment, with pharmacokinetics (PK) supporting once-daily oral dosing in human. This open-label, nonrandomized, two-period clinical mass balance and excretion study was used to investigate the excretion balance, PK, and metabolism of GSK3640254. Five healthy men received a single intravenous microtracer of 100 µg [14C]GSK3640254 with a concomitant oral nonradiolabeled 200-mg tablet followed by an oral 85-mg dose of [14C]GSK3640254 14 days later. Complementary methods, including intravenous microtracing and accelerator mass spectrometry, allowed characterization of several parameters, including fraction absorbed, fraction escaping gut metabolism, hepatic extraction ratio, and renal clearance. Intravenous PK of GSK3640254 was characterized by low plasma clearance (1.04 l/h), moderate terminal phase half-life (21.7 hours), and low volume of distribution at steady state (28.7 L). Orally dosed GSK3640254 was absorbed (fraction absorbed, 0.26), with a high fraction escaping gut metabolism (0.898) and a low hepatic extraction ratio (0.00544), all consistent with low in vitro intrinsic clearance in liver microsomes and hepatocytes. No major metabolites in human plasma required further qualification in animal studies. Both unchanged parent GSK3640254 and its oxidative and conjugative metabolites were excreted into bile, with GSK3640254 likely subject to further metabolism through enterohepatic recirculation. Renal elimination of GSK3640254 as the parent drug or its metabolites was negligible, with >94% of total recovery of oral dose and >99% of the recovered radioactivity in feces. Altogether, the data suggest that systemically available GSK3640254 was slowly eliminated almost entirely by hepatobiliary secretion, primarily as conjugative and oxidative metabolites. SIGNIFICANCE STATEMENT: The combination of an intravenous 14C microtracer with duodenal bile sampling using EnteroTracker in a human absorption, distribution, metabolism, and excretion study enabled derivation of absorption and first-pass parameters, including fraction absorbed, proportion escaping first-pass extraction through the gut wall and liver, hepatic extraction, and other conventional clinical pharmacokinetic parameters. This approach identified hepatic metabolism and biliary excretion as a major elimination pathway for absorbed drug, which would be overlooked based solely on analyses of plasma, urine, and fecal matrices.

Medium-Term Bioresorbable Scaffold Outcomes Utilising Data From an Australian Clinical Quality Registry.

BACKGROUND: Bioresorbable scaffolds (BRS) are a novel technology in coronary intervention. However, recent trials demonstrate higher rates of device failure compared to contemporary drug-eluting stents. This study sought to utilise a clinical quality registry to assess the medium-term safety of the Abbott Absorb BRS (Abbott Vascular, Santa Clara, CA, USA), in an Australian context. METHODS: A prospective, observational study of 192 BRS percutaneous coronary interventions (PCI) compared to 31,773 non-BRS PCIs entered in the Victorian Cardiac Outcomes Registry from 2013 to 2017. The main outcome measure was patient-oriented composite endpoint (POCE) events comprising all-cause mortality, any myocardial infarction (MI), and any revascularisation. RESULTS: Bioresorbable scaffolds patients (mean age 61.6±10.5 years, 79% male) were younger, had less comorbidity, less prior PCI, fewer ST elevation myocardial infarction (STEMI) presentations, lower rates of multi-lesion disease and more adjuvant devices compared to non-BRS PCI (all p<0.01). All-cause mortality was 2.1%, myocardial infarction (MI) 2.1%, scaffold thrombosis 3.1% and any revascularisation 14.1% (mean follow-up 27.4±8.9 months). POCE events occurred in 11.5% at 1 year and 16.9% at 2 years, comparable to pooled-trial data. Multivariate predictors of POCE were >1 scaffold used (odds ratio [OR] 4.6, 95% confidence interval [CI] 1.9-11.4, p<0.01) and scaffold diameter ≤2.5 mm (OR 3.3, 95% CI 1.4-7.6, p=0.02). Over 95% guideline adherence was achieved in six of eight patient selection criteria and four of six device deployment criteria. CONCLUSION: In an Australian setting, BRS were used in non-complex patients. Most guidelines for use were adhered to and outcomes were comparable to pooled trial data. Clinical quality registries are effective in assessing novel treatments and technologies when potential safety concerns develop.