Schering Corp. v. Geneva Pharmaceuticals, Inc

Brief Fact Summary. Schering Corp. (Plaintiff) owns two patents on antihistamines.  The first patent’s claims expired and the second patent’s claims were close to expiring.  Geneva Pharmaceuticals, Inc. (Defendant) started marketing a generic antihistamine, which Plaintiff claimed was an infringement on their second patent’s claims.  The District Court determined by summary judgment that two of the second patent’s claims were invalid because they were anticipated by the first patent.

Synopsis of Rule of Law. If a single prior invention reference reveals or enables a later claim, a patent claim is anticipated.

Facts. Plaintiff owned the ‘233 patent and the ‘716 patent on antihistamines.  The ‘233 patent was marketed as a non-drowsy antihistamine loratadine known as Claritin.  When a patient takes Claritin, that patient forms the metabolite DCL, which is the subject matter of Claims 1 and 3 of the ‘716 patent.  The ‘233 patent is a prior invention to the ‘716 patent because the ‘233 patent issued on August 4, 1981 and the earliest priority date of the ‘716 patent was February 15, 1984.  The ‘233 patent does not specifically reveal DCL or metabolites of loratadine.  When the ‘233 patent expired, Defendant and other manufacturers began marketing generic loratadine.  Plaintiff filed a lawsuit claiming patent infringement of ‘716 because the ‘716 patent would not expire until 2004.  Defendant was granted summary judgment by the District Court when they determined patent ‘233 anticipated claims 1 and 3 of the ‘716 patent.

Issue. If a single prior invention reference reveals or enables a later claim, is a patent claim anticipated?

Held. (Rader, J.)  Yes.  A patent claim is anticipated if a single prior art reference reveals or enables a later claim.  Anticipation invalidates a patent if each limitation of the claimed invention is revealed in a single prior art reference.  Even if a feature is not specifically disclosed, the claim is anticipated if the feature is inherent in the reference.  This Court holds that a person of ordinary skill in the art at the time would not have had to recognize or reproduce the inherent feature for the claim to be anticipated.  Plaintiff’s reliance on Continental Can Co. v. Monsanto Co., 948 F.2d 1264 (Fed. Cir. 1991) is misplaced because that case did not consider whether the inherent feature was recognized before or after the patent in the present case.  The other cited cases also do not stand for the proposition that inherency requires recognition.  The instant case does not even involve accidental anticipation because DCL inevitably forms when loratadine is ingested.  This may be a case of first impression since the ‘233 patent does not disclose DCL.  The prior art reference can be either express or inherent.  If the public could not practice the prior art without infringing on the new claim, then the new claim is entirely anticipated.  Here, Defendant’s use of loratadine (the prior art) infringes upon claims 1 and 3 of the ‘716 patent (the new claim) because all loratadine metabolizes into DCL.  Therefore, the prior art of loratadine, patent ‘233, anticipates claims 1 and 3 of patent ‘716.  Plaintiff next argues that loratadine tests were secret and that DCL was not in public domain prior to the critical date of February 15, 1983.  However, anticipation does not require actual disclosure or creation if one skilled in the prior art is able to create based on the express or inherent reference.  Metabolites are capable of patent protection.  For example, protection can be given to a more pure version of a naturally occurring metabolite.  Compound claims, such as this one, are not eligible for patent.  Affirmed

Dissent. (Newman, J.)  Although DCL  did not exist previously and was not known to the prior art, the Court today holds that it was anticipated.  The issue in the suit was infringement, not validity.  The Court was correct to hold no liability for infringement, but was unnecessarily strained to find the patent claims invalid.  An unknown product that existed previously is eligible for patent.  In this case, the panel wanted to overturn precedent that analyzes inherency as applied to subject matter not taught in the single prior art reference.  The panel held that since no one knew of the existence of DCL, that no person of ordinary skill in the prior art could have known that ingesting loratadine would result in DCL.  The Court en banc should have heard the case to rule on the inherency issue.

Discussion. (Newman, J.)  Although DCL  did not exist previously and was not known to the prior art, the Court today holds that it was anticipated.  The issue in the suit was infringement, not validity.  The Court was correct to hold no liability for infringement, but was unnecessarily strained to find the patent claims invalid.  An unknown product that existed previously is eligible for patent.  In this case, the panel wanted to overturn precedent that analyzes inherency as applied to subject matter not taught in the single prior art reference.  The panel held that since no one knew of the existence of DCL, that no person of ordinary skill in the prior art could have known that ingesting loratadine would result in DCL.  The Court en banc should have heard the case to rule on the inherency issue.