What more can a patentee do? Baxter International won a patent infringement suit against rival Fresenius USA, convinced the Federal Circuit to uphold that verdict and on March 16, obtained a final judgment for more than $23.5 million dollars. Baxter’s legal battle, one might think, is over.
It’s not. Baxter is at risk of losing its hard-fought judicial victory because in an ex parte re-examination, the U.S. Patent and Trademark Office (PTO) found Baxter’s invention was obvious and voided its patent.
The legal battle began in 1991, when Baxter filed for patents on a hemodialysis machine with a touchscreen interface. Baxter subsequently obtained three patents on this machine, which became a commercial success.
In re Baxter isn’t the first time the Federal Circuit has declared that even after the courts have rejected an obviousness challenge to a patent, the PTO can nullify a patent for obviousness (see “Drawing Distinctions”). But this interpretation of the law seems far from settled.