Odanacatib Pharmacokinetics Comparison Between Chinese and Non‐Chinese Postmenopausal Women

Odanacatib (ODN), an oral selective inhibitor of cathepsin K, was an investigational agent previously in development for the treatment of osteoporosis. In this phase 1 open‐label study, 12 healthy Chinese postmenopausal women received single‐dose ODN 50 mg on day 1 and multiple‐dose ODN 50 mg once weekly on days 15, 22, 29, and 36 under fasted conditions. Pharmacokinetic (PK) parameters were evaluated on days 1 and 36. Multiple‐dose area under the concentration–time profile (AUC0–168h) and maximum plasma concentration (Cmax) were compared with historical data from 9 non‐Chinese postmenopausal women who also received ODN 50 mg once weekly for 4 weeks. Median time to Cmax (tmax) was 3 and 4 hours following single‐ and multiple‐dose administration, respectively. The arithmetic mean ± SD terminal half‐life was 81.0 ± 14.0 and 106.7 ± 14.4 hours following single‐ and multiple‐dose administration, respectively. Comparison of multiple‐dose PK parameters showed that the geometric mean ratios (Chinese/non‐Chinese) and 95%CIs for AUC0–168h and Cmax were 0.81 (0.55‒1.19) and 0.87 (0.69‒1.11), respectively. All adverse events were mild, none were serious, and none led to discontinuation. Single‐ and multiple‐dose PKs of ODN 50 mg in Chinese postmenopausal women were generally similar to those previously reported in non‐Chinese postmenopausal women.