Effects of Food and Calcium Carbonate on the Pharmacokinetics of Lusutrombopag, a Novel Thrombopoietin Receptor Agonist.

Purpose: Lusutrombopag is a novel, orally active thrombopoietin receptor agonist. This report describes 3 studies aimed at assessing the effects of food and calcium carbonate on the pharmacokinetic parameters of lusutrombopag in healthy subjects.

Methods: Three single-dose, open-label crossover studies were conducted. In study 1, eighteen healthy subjects were administered a single 2-mg dose of lusutrombopag as a single tablet in the fasted or fed state or as a 2-mg solution in the fasted state. In study 2, fifteen healthy subjects were administered a single 0.75-mg dose of lusutrombopag as three 0.25-mg tablets in the fasted or fed state, or in the fasted state with coadministration of 4000-mg calcium carbonate. In study 3, fifteen healthy subjects were administered 4-mg lusutrombopag as a single tablet in the fasted or fed state. Pharmacokinetic parameters were estimated from plasma lusutrombopag concentrations.

Findings: Mean fed versus fasted state ratios (90% CIs) of C and AUC, respectively, were: 0.904 (0.864-0.945) and 0.920 (0.886-0.956) (study 1); 0.972 (0.864-1.09) and 1.02 (0.945-1.11) (study 2); and 0.917 (0.842-0.999) and 0.908 (0.855-0.964) (study 3). The respective ratios for calcium carbonate versus no calcium carbonate (fasted state) were 1.08 (0.959-1.21) and 0.989 (0.913-1.07) (study 2). Lusutrombopag exposure remained unaffected, except for a slight decrease in exposure with food. Lusutrombopag exposure did not change with the coadministration of calcium carbonate. These findings suggest that there was no clinically significant effect of food or calcium carbonate on the bioavailability of lusutrombopag. Each treatment regimen was well tolerated.

Implications: According to the present findings, no specific restrictions are required for lusutrombopag administration with regard to meals (including those with dairy products), mineral supplements, or coadministration of antacids.

Clinical Trial Registration: JapicCTI-No.: JapicCTI-194690, JapicCTI-194689. ClinicalTrials.gov identifier: NCT03897413.