Long-acting cabotegravir (CAB) extends antiretroviral drug (ARV) administration from daily to monthly. However, dosing volumes, injection site reactions, and health care oversight are obstacles towards broad usage. The creation of poloxamer-coated hydrophobic and lipophilic CAB prodrugs with controlled hydrolysis and tissue penetrance can overcome these obstacles. To such ends, fatty acid ester CAB nanocrystal prodrugs with 14, 18, and 22 added carbon chains were encased in biocompatible surfactants named NMCAB, NM2CAB, and NM3CAB and tested for drug release, activation, cytotoxicity, antiretroviral activities, pharmacokinetics (PK), and biodistribution. PK studies, performed in mice and rhesus macaques, with the lead 18-carbon ester chain NM2CAB, showed plasma CAB levels above the protein-adjusted 90% inhibitory concentration for up to a year. The NM2CAB, compared to NMCAB and NM3CAB, demonstrated prolonged drug release, plasma circulation time and tissue drug concentrations after a single 45 mg/kg intramuscular injection. These prodrug modifications could significantly improve CAB’s effectiveness.

An enantioselective synthesis of INCB018424 via organocatalytic asymmetric aza-Michael addition of pyrazoles (16 or 20) to (E)-3-cyclopentylacrylaldehyde (23) using diarylprolinol silyl ether as the catalyst was developed. Michael adducts (R)-24 and (R)-27 were isolated in good yield and high ee and were readily converted to INCB018424.

ABSTRACT:The metabolism, excretion, and pharmacokinetics of 3-(4-(7H-pyrrolo[2,3-d]pyrimidin-4-yl)-1H-pyrazol-1-yl)-3-cyclopentylpropanenitrile (INCB018424), a potent, selective inhibitor of Janus tyrosine kinase1/2 and the first investigational drug of its class in phase III studies for the treatment of myelofibrosis, were investigated in healthy human subjects given a single oral 25-mg dose of [ 14 C]INCB018424 as an oral solution. INCB018424 and total radioactivity were absorbed rapidly (mean time to reach the maximal drug concentration <1 h), declining in a monophasic or biphasic fashion (mean t 1/2 of 2.32 and 5.81 h, respectively). Recovery of administered radioactivity was fairly rapid (>70% within 24 h postdose) with 74 and 22% recovered in urine and feces, respectively. Parent compound was the predominant entity in the circulation, representing 58 to 74% of the total radioactivity up to 6 h postdose, indicating that the overall circulating metabolite burden was low (<50% of parent). Two metabolite peaks in plasma (M18 and a peak containing M16/M27, both hydroxylations on the cyclopentyl moiety) were identified as major (30 and 14% of parent based on area under the curve from 0 to 24 h). The exposures of other circulating INCB018424-related peaks were <10% of parent, consisting of mono-and dihydroxylated metabolites. The profiles in urine and feces consisted of hydroxyl and oxo metabolites and subsequent glucuronide conjugates with parent drug accounting for <1% of the excreted dose, strongly suggesting that after an oral dose, INCB018424 was >95% absorbed. In healthy subjects administered daily oral doses of unlabeled INCB018424, there were minimal differences in parent and metabolite concentrations between day 1 and day 10, indicating a lack of accumulation of parent or metabolites between single and multiple dosing.