Fujikawa v. Wattanasin
United States Court of Appeals for the Federal Circuit
93 F.3d 1559 (1996)
Yoshihiro Fujikawa (plaintiff) obtained patents in 1987 for cholesterol-lowering compounds he developed overseas, but Sompong Wattanasin (defendant) had actually begun testing the same compounds back in 1982 for his employer Sandoz, paused the project for about two years, resumed testing in January 1987, and only filed a patent application in March 1989, 17 months after resuming work. Both inventors sought a Patent Office interference proceeding to determine priority, and the Board found Wattanasin had priority for both patents despite Fujikawa filing first; Fujikawa appealed.
Whether, under a first-to-invent patent system, the first person to actually invent something retains patent priority over a later inventor who files first, so long as the first inventor did not abandon, suppress, or conceal the invention.