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.