Anticipate This!™ | Patent and Trademark Law Blog

Abbott Laboratories, et al. v. Baxter Pharmaceutical Products, Inc., et al.

Posted in Opinion Commentary by Jake Ward on November 14, 2006

A Reference May Anticipate Even When the Relevant Properties of the Disclosure Were Not Appreciated at the Time.

(Fed. Cir. 2006, 06-1021)


Abbott appealed from a district court (N.D. Ill.) judgment of noninfringement of U.S. Patent No. 5,990,176 (“the ’176 patent”).  Baxter cross-appealed, arguing that the asserted claims are invalid.  In it’s second hearing of this case, the CAFC reversed and found the ’176 patent to be invalid as anticipated by U.S. Patent No. 5,684,211 (“the ’211 patent”).

The technology at issues is related to sevoflurane, a fast-acting, highly effective inhalation anesthetic.  Pure sevoflurane degrades in the presence of Lewis acids.  This was unknown at the time of its invention.  Abbott discovered that water mixed in with sevoflurane binds to and deactivates Lewis acids, thus protecting the sevoflurane from degradation.  A deliberate addition of water to sevoflurane ran counter to the conventional wisdom at the time of the invention.  Baxter had sought to ship its own sevoflurane product and filed an amended ANDA covering its product along with a certification of noninfringement and invalidity of the ’176 patent, prompting this suit.

The primary argument made by Baxter was that the ’211 patent disclosed a composition of water-saturated sevoflurane that met all the limitations of the ‘176 claims.  The district court had relied on Bristol-Myers Squibb Co. v. Ben Venue Labs., Inc.,246 F.3d 1368, 1376 (Fed. Cir. 2001), which stated that “[n]ewly discovered results of known processes directed to the same purpose are not patentable because such results are inherent.”  Subseqently, the lower court found the ‘176 claims novel, reasoning that since the patents’ purposes were different (the ‘211 disclosed an intermediate step in sevoflurane production), the Bristol-Myers Squibb distinction foreclosed a finding of anticipation.

In reversing, the CAFC noted that a reference may anticipate even when the relevant properties of the thing disclosed were not appreciated at the time.  The general principle that a newly-discovered property of the prior art cannot support a patent on that same art is not avoided if the patentee explicitly claims that property. “[A] prior art reference may anticipate without disclosing a feature of the claimed invention if that missing characteristic is necessarily present, or inherent, in the single anticipating reference.”

In this case, all of the steps of the ’176 patent were disclosed in the ’211 patent.  All that was contributed by the method claims of the ’176 patent was the recognition of a new property of the prior art process, i.e. the ability of water in the sevoflurane to prevent degradation. Thus, the CAFC held that “the claimed process here is not directed to a new use; it is the same use.”  Reversed.

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