Development of Dolutegravir Single-entity and Fixed-dose Combination Formulations for Children.

BACKGROUND: The World Health Organization (WHO) 2019 antiretroviral treatment guidelines recommend use of optimal treatment regimens in all populations. Dolutegravir-based regimens are the preferred first-line and second-line treatment in infants and children with HIV 4 weeks of age and above. There is an urgent need for optimal pediatric formulations of dolutegravir as single-entity (SE) and fixed-dose combination (FDC) to ensure correct dosing and adherence for swallowing and palatability. This article outlines the chronology of dolutegravir pediatric formulation development as granules and conventional and dispersible tablets in a total of 5 pharmacokinetic studies evaluating the relative bioavailability of dolutegravir SE and FDC formulations in healthy adults. METHODS: The relative bioavailability studies were 2-part, Phase I, open-label, randomized studies in healthy adults. Dolutegravir SE study compared conventional dolutegravir 50 and 25 mg with equivalent conventional 10-mg and dispersible 5-mg tablets, respectively. Subsequently, dolutegravir FDC study compared adult FDC of abacavir/dolutegravir/lamivudine and adult FDC of dolutegravir/lamivudine with their respective pediatric FDC formulations, taken as dispersion immediately or swallowed whole. RESULTS: As observed in previous studies, dolutegravir administered as dispersion (granules/dispersible tablets) showed relatively higher bioavailability compared with conventional tablets. The bioavailability of dolutegravir dispersible tablets (both SE and FDC) was approximately 1.6-fold higher when compared with conventional tablets. In addition, the bioavailability of abacavir/lamivudine was not impacted by dispersible formulation. CONCLUSIONS: These studies demonstrate the successful development of pediatric dolutegravir-containing formulations as SE and FDC that permit pediatric dosing in line with WHO recommendations.

A double-blind, randomized, placebo-controlled study to assess the safety, antiviral activity and pharmacokinetics of GSK2336805 when given as monotherapy and in combination with peginterferon alfa-2a and ribavirin in hepatitis C virus genotype 1-infected treatment-naive subjects.

BACKGROUND & AIMS: GSK2336805 is a HCV NS5A inhibitor for chronic hepatitis C (CHC). In a prior Phase I study, GSK2336805 was well tolerated and had an antiviral and pharmacokinetic profile suitable for once-daily administration. This 28-day, double-blind, randomized, placebo-controlled study evaluated once daily GSK2336805 60 mg alone or in combination with peginterferon alfa-2a (180 µg per week) and ribavirin (1000-1200 mg daily) (PEG/RIBA) in treatment-naive genotype 1 CHC subjects. METHODS: Five centres enrolled 16 subjects in the USA and Puerto Rico who received GSK2336805 + PEG/RIBA or placebo + PEG/RIBA. RESULTS: Following a single monotherapy dose of GSK2336805 on day 1, median reduction from baseline in HCV RNA was -2.96 log10 (N = 11) vs. -0.13 log10 (N = 4) for placebo. With the addition of PEG/RIBA on day 2, subjects receiving GSK2336805 exhibited greater decreases in viral load over the 28-day treatment period as compared with placebo. At day 28, median reduction from baseline was -4.86 log10 (N = 9) in the GSK2336805 + PEG/RIBA group as compared with -1.98 log10 (N = 4) in the placebo + PEG/RIBA group. At day 28, rapid virological response (RVR) occurred in 8/11 (73%) of the GSK2336805 + PEG/RIBA subjects as compared with 1/4 (25%) of the placebo + PEG/RIBA subjects. Adverse events were consistent with those reported in clinical trials of peginterferon and ribavirin, and no unique adverse events appeared to be associated with GSK2336805. CONCLUSIONS: GSK2336805 is a potent NS5A inhibitor that showed a substantial antiviral effect as a monotherapy and in combination with peginterferon and ribavirin. ClinicalTrials.gov Identifier: NCT01439373.