Tolerability and pharmacokinetics of a new P-glycoprotein inhibitor, HM30181, in healthy Korean male volunteers: single- and multiple-dose randomized, placebo-controlled studies.

BACKGROUND

HM30181 is an oral P-glycoprotein (P-gp) inhibitor developed to enhance the oral bioavailability of P-gp substrate drugs.

OBJECTIVE

The objective of this study was to investigate the tolerability and pharmacokinetic properties of HM30181 after single and multiple oral administrations to healthy Korean male volunteers. The study was performed to meet regulatory criteria for marketing the test product in South Korea.

METHODS

A dose-block-randomized, double-blind, placebo-controlled, dose-escalation study was performed in 180-, 360-, 600-, and 900-mg single-dose groups and 60-, 180-, and 360-mg multiple-dose groups with 10 subjects (8 active; 2 placebo) per group. In the single-dose study, blood and urine samples were collected for up to 120 hours after drug administration. In the multiple-dose study, subjects received the study drug or placebo orally once daily for 5 days. Blood samples were collected up to 624 hours after the last dose, and up to 24 hours after the first dose to evaluate the accumulation index. Urine samples were collected up to 120 hours after the last dose. Pharmacokinetic analysis was performed using noncompartmental methods. Adverse events were collected by the spontaneous reporting of the subjects or when subjects were asked general health-related questions.

RESULTS

Thirty and 70 healthy male volunteers completed the single- and multiple-dose studies, respectively. Mean (SD) age and body weight of subjects in the single administration group were 24.0 (1.8) years and 68.8 (7.4) kg, respectively, and those of the multiple administration group were 24.5 (2.6) years and 67.6 (7.7) kg, respectively. The plasma concentrations peaked at 14 to 42 hours and declined with t(½) of 75.7 to 169.3 hours after single administration, and peaked at 5.5 to 8.0 hours and declined with t(½) of 153.5 to 215.2 hours after multiple administrations. C(max) and area under the concentration curve within dosing intervals (AUC(τ)) increased dose dependently after single administration; however, dose-dependent increases in C(max) and AUC(τ) were not observed after multiple administrations. The fraction of drug excreted unchanged in urine was minimal, with values <0.01% in all dose groups. HM30181 accumulated after multiple administrations with an accumulation index of 4.0 to 7.4. All adverse events reported were mild in intensity; there were no serious adverse events reported. The most frequently reported adverse event was gastrointestinal disorder.

CONCLUSIONS

HM30181 was well tolerated after oral administration within the dose range evaluated, with the exception of the repeated administration of 360 mg, for which gastrointestinal disorders were frequently reported. The systemic exposure of HM30181 was relatively low, and dose proportional properties of HM30181 were not observed.