KHK-4323

Part 1: To investigate the safety and tolerability of intravenous (IV) or subcutaneous (SC) administration of a single dose of KHK4323 to Japanese or Caucasian healthy adult males in a double-blind, placebo-controlled study.
Part 2: To investigate the safety and tolerability of intravenous (IV) administration of repeated doses of KHK4323 to atopic dermatitis patients in a double-blind, placebo-controlled study.