Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of Atacicept in a Randomized Trial in Healthy Caucasian and Japanese Subjects.

BACKGROUND AND

objectiveAtacicept is an inhibitor of the B lymphocyte stimulator (BLyS) and a proliferation-inducing ligand (APRIL), and is being studied in relation to immunological disease. Currently, limited data on atacicept are available in non-Caucasian subjects. Pharmacokinetic data from earlier studies of atacicept were derived using an enzyme-linked immunosorbent assay (ELISA), which was subsequently found to have inadequacies. Hence, a new bioanalytical ELISA for total atacicept was developed and validated. We conducted this randomized, double-blind, placebo-controlled phase I study to compare the safety, tolerability, pharmacokinetics, and pharmacodynamics of atacicept in healthy Japanese and Caucasian subjects while generating pharmacokinetic data using the new ELISA.

methodsJapanese subjects aged ≥ 18 to ≤ 55 years (n  = 24) were randomized (1:1:1:1) to a single subcutaneous dose of atacicept 25, 75, or 150 mg or placebo. Caucasian subjects were then enrolled to match the Japanese subjects' gender, body weight (± 20%), and height (± 15%).

resultsAtacicept was well tolerated and there were no clinically significant differences in treatment-emergent adverse events (TEAEs), vital signs, or laboratory parameters between the Japanese and Caucasian subjects. Most (90%) TEAEs were mild; no severe or serious TEAEs or deaths occurred. Weight-adjusted atacicept exposure was comparable between ethnicities and across doses: the Japanese/Caucasian ratio of the area under the serum concentration-time curve from time zero to the last sampling point (AUC

conclusionThe safety, pharmacokinetic, and pharmacodynamic profiles of atacicept in healthy Japanese subjects were comparable to those in healthy Caucasian subjects. EudraCT-ID: 2013-002703-34.