In re Baxter Intl., Inc.

Because of the lower standard of proof used in PTO reexaminations, the PTO is not bound by validity decisions of the courts on the same patent claims, especially when the PTO considers evidence not presented to the court when it reached its decision.

Opinion (Lourie): Baxter International, Inc. (Baxter) owns patent no. 5,247,434 (’434), which describes a machine for performing kidney dialysis. In a prior lawsuit, Baxter successfully defended the validity of its patent. However, during that lawsuit the Patent and Trademark Office (PTO) began a reinvestigation of the ’434 patent that ultimately determined claims 26-31, the claims at issue in the prior suit, were obvious. Baxter appealed to the Board. The Board upheld the examiner’s determination, finding that the lower standard of proof necessary to invalidate a patent at the PTO, and the lack of a presumption of validity, meant that it was not bound by prior determinations of the courts, which apply a higher standard of proof. Baxter appealed to the Federal Circuit, which held that because of the different standards applied by the PTO, the PTO was not bound to follow the decisions of the courts. It expressed its belief, however, that the PTO and the courts should reach the same conclusion when confronted with the same questions unless the PTO’s process considers evidence that was not before the court. The Federal Circuit found that the patent examiner had relied on prior art not considered in the prior suit, which constituted substantial evidence sufficient to meet the preponderance standard applied by the PTO. With the addition of this factual determination, the court AFFIRMED the Board’s determination that the disputed claims were obvious.