In the USA, Harvard’s OncoMouse has gone into the public domain

Harvard's patented OncoMouse not only made the headlines in its early days; the invention has proven to be a blockbuster for cancer research.  In the mid 1980s Harvard researchers inserted a heritable cancer-causing gene into a mouse, and created a great model system for studies of drugs against cancer. Patent applications on the OncoMouse were filed back in the mid-1980s in numerous countries. Harvard exlusively licensed its OncoMouse patents to DuPont.  In the U.S., important aspects of the OncoMouse invention are covered under U.S. Patent No. 5,925,803, which is supposed to last until 2016... wait, except that the USPTO has ruled that the 5,925,803 patent has expired.  It turns out that a terminal dislaimer was filed in a parent patent application (for U.S. Patent No. 5,087,571), in which the patentee agreed to disclaim the term of the parent patent as well as any patent claiming benefit of the patent under 35 U.S.C. §120.  In a recent reexamination request, the USPTO has interpreted the disclaimer to effectively limit the term of patent 5,925,803 to 2005.  Of course, hurt DuPont has now filed a civil suit in Virginia requesting that the court overturn the USPTO decision.  Stay tuned.