TV-1106 is a human serum albumin genetically fused to recombinant human growth hormone, designed to provide a long-acting alternative to daily GH injections in patients with GH deficiency. This study investigated the pharmacokinetics, pharmacodynamics and safety of single subcutaneous doses of TV-1106 (7.5, 15, 50 and 100mg) in Japanese (n = 44) and Caucasian (n = 44) healthy subjects. TV-1106 pharmacokinetics and pharmacodynamics were comparable in Japanese and Caucasian populations. TV-1106 demonstrated relatively slow absorption (median tmax 10-30 hours) and mean elimination half-life of 26-36 hours. Apparent clearance and volume of distribution decreased with increasing TV-1106 doses in both populations and appeared to increase more than dose proportionality across the tested doses. Insulin-like growth factor-1 (IGF-1) and IGF binding protein-3 (IGFBP-3) increased in a dose-related manner with maximum responses observed at 33-96 hours and 42-109 hours, respectively. IGF-1 and IGFBP-3 returned to baseline values at 168 hours following 7.5 and 15 mg TV-1106, and 336 hours following 50 and 100mg TV-1106. TV-1106 appeared safe in both populations. There was no evidence of differences in pharmacokinetics, pharmacodynamics or safety of TV-1106 between Japanese and Caucasian populations. The data also demonstrate long-acting growth hormone properties of TV-1106 and support its potential for once-weekly dosing. This article is protected by copyright. All rights reserved.