Food Effect and Pharmacokinetic Bridging of Avacopan in Caucasian and Japanese Healthy Participants

Avacopan 30 mg twice daily (BID) is approved for the treatment of severe active antineutrophil cytoplasmic autoantibody–associated vasculitis (granulomatosis with polyangiitis and microscopic polyangiitis). Food effect on avacopan pharmacokinetics (PKs) and PK bridging in Japanese participants were examined through 2 phase 1 studies involving healthy adult participants. In Study 1, an open-label, crossover trial, participants received oral administration of a single 30-mg dose of avacopan under fasted and fed conditions. Study 2 was a randomized, single-blind, placebo-controlled trial in Caucasian and Japanese participants: Part A investigated single doses of 10 and 30 mg of avacopan under fasted and fed conditions and Part B investigated 30 and 50 mg BID avacopan. The PKs of single-dose administrations of 10 and 30 mg in Japanese participants was compared with that in Caucasian participants under fasted conditions. Food substantially increased plasma avacopan area under the plasma concentration-time curve from time 0 to time infinity (AUC_0-inf) by 1.72-fold, supporting the recommendation of taking avacopan with food. Maximum plasma concentration (C_max) remained relatively unchanged. The median time to reach C_max (t_max) was delayed by 3 hours. No significant food effect was observed on the active metabolite CCX168-M1 (M1) AUC. Avacopan and M1 exposures were <1.5-fold higher in Japanese participants than in Caucasian participants following multiple-dose administration of avacopan.