PF-06480605, a fully human IgG1 monoclonal antibody targeting tumor necrosis factor α-like ligand 1A (TL1A), has demonstrated acceptable safety and the potential as an effective treatment for inflammatory bowel disease in phase 1/2a studies. To facilitate future clinical development in Japan and China, a Japan local phase 1 study was designed in consultation with the Japan regulatory authority. In addition to fulfilling Japan regulatory requirements, this study will bring operational efficiency and speed to global and China development by evaluating PF-06480605 in Japanese healthy adults prior to a China local phase 1 study as required by the China regulatory authority. This phase 1, randomized, double-blind, placebo-controlled, single-dose escalating study investigated the safety, tolerability, immunogenicity, pharmacokinetics (PK), and pharmacodynamics of PF-06480605 in Japanese healthy adults assigned to receive a single subcutaneous (SC) dose of PF-06480605 150 mg (N = 6), 450 mg (first-in-human dose level, N = 6), or placebo (N = 4). PF-06480605 was well tolerated and absorbed slowly with a median T