Bioequivalence Study of Two Imatinib Formulations after Single-dose Administration in Healthy Korean Male Volunteers

Imatinib mesylate is effective for chronic myeloid leukaemia and gastrointestinal tumours. We aimed to evaluate the pharmacokinetics of a 200-mg imatinib tablet compared to 2×100-mg imatinib tablets in order to meet the regulatory requirements for marketing in Korea. An open-label, randomized, single-dose, 2-period, 2-treatment cross-over study was conducted in 28 healthy Korean male volunteers. Subjects were administered a 200-mg imatinib tablet and 2×100-mg imatinib tablets under a fasting state according to a randomly assigned order with a 2-week wash-out period. Serial blood samples were collected up to 72 h post-dose. The pharmacokinetic parameters were calculated using non-compartmental methods. A total of 28 subjects were enrolled and 23 subjects completed the study. There were no serious adverse events during the study. 23 mild to moderate adverse events were reported (11 events with 200-mg imatinib vs. 12 events with 2×100-mg imatinib) and subjects recovered without sequelae. The C max value was 922.8±318.8 μg/L at 3.15 h for 200-mg imatinib tablet, and 986.3±266.0 μg/L at 2.91 h for the 2×100-mg imatinib tablet. The AUC last of 200-mg and 2×100-mg tablets were 13 084.3±39.1 and 14 131.7±3 826.2 h · μg/L, respectively. The geometric mean ratios (90% confidence intervals) for C max and AUC last were 0.9121 (0.8188, 1.0161) and 0.9558 (0.8685, 1.0519), respectively. A newly developed 200-mg imatinib tablet was bioequivalent to 2×100-mg imatinib tablets in healthy Korean subjects. A single-dose of either of the 2 formulations was generally well tolerated.