From The Field

January 31, 2022

The Federal Circuit recently held in Novartis Pharmaceuticals Corp. v. HEC Pharm Co., Ltd, (Jan. 3, 2022), over a vigorous dissent, that the written description requirement may be met by the trial testimony of expert witnesses even though the specification is silent on the claim limitation at issue.  This decision is important for patent prosecutors and litigators. 

The patent claims at issue in Novartis covered a method for administering a multiple sclerosis drug.  The claims required a particular daily dosage for the drug along with a negative claim limitation.  Specifically, the claims stated that the required dose should be administered “absent an immediately preceding loading requirement.”  The applicant added this limitation during prosecution to overcome prior art.  

A “loading dose” of a drug is a higher-than-therapeutic dose given before actually administering the required dose.  The purpose of a loading dose is to allow a drug to achieve therapeutic effect in a patient more quickly.  A loading dose is generally recommended for many drugs, including some multiple sclerosis drugs. 

The specification for the patent at issue never expressly stated anything about a loading dose, such as whether it should be administered initially or not.  The specification did contain working examples for the doses of the drug to be administered.  And these examples did not mention any loading dose, which could suggest that no loading dose was given.  But the relevant examples did not expressly state that no loading dose was administered.  They said nothing on the subject.    

The Defendants argued that the specification’s failure to say that a loading dose should not be administered rendered the claims invalid for failing the written description requirement.  The District Court disagreed.  After a four-day bench trial, which included testimony from several experts, the District Judge found that the Defendants had not met their burden of showing an insufficient written description.  The Defendants appealed and a split Federal Circuit panel affirmed. 

According to the majority, which consisted of Judges O’Malley and Linn, the touchstone of the written description requirement is “that it is how a skilled artisan reads a disclosure that matters.  Written description may take any form, so long as a skilled artisan would read the disclosure as describing the claimed limitation.”  (Maj. Op. at 17.)  “What is critical is how a person of skill in the art would read the disclosure – not the exact words used.”  (Id. at 18.)      

With this framing, the majority credited the testimony from four experts, including one of Defendants’ experts, and found no clear error in the District Court’s analysis or conclusions.  One expert stated that “there were two perfectly logical places [in the specification] that if there was going to be a loading does, it would have been stated.”  (Id. at 19.)  Another expert testified that “[o]ne would expect in a patent that if there was going to be a loading dose, it would be specified.”  (Id. at 20.)  This expert emphasized that “information of having a loading dose is not there, and what’s instead there is examples of daily dose, daily dose, daily dose.”  (Id.) 

In light of this and other testimony, the majority agreed with the District Court’s finding that, “if a loading dose were directed, the patent would say it ‘should be administered initially.’”  (Id. at 7.)  On this record, the patent’s failure to state that a loading dose was administered “provides sufficient written description of the negative limitation.”  (Id. at 8; see also id. at 20-21.) 

The dissent, authored by Chief Judge Moore, criticized the majority and argued that there was no support in the patent’s written description for the negative claim limitation.  Chief Judge Moore pointedly stated that “[s]ilence is not disclosure” (Dissent at 2), and that, “[i]f silence were sufficient[,] then every later-added negative limitation would be supported as long as the patent makes no mention of it.”  (Id. at 5.)  This, according to Chief Judge Moore, “is a fundamental error of law.”  (Id.)     

The dissent would require the specification to provide a “reason to exclude the relevant limitation, such as by listing the disadvantages of some embodiment.”  (Id. at 3 (internal quotation marks omitted).)  However, Chief Judge Moore lamented that “[n]owhere in the patent does it say a loading dose should not be administered.  Nowhere does it discuss alternatives (including or not including a loading dose).  Nowhere does it give advantages or disadvantages of including a loading dose.  Indeed, it provides no reason to exclude a loading dose.”  (Id. at 4.)  Given that record, Chief Judge Moore concluded that the patent “provides nothing to signal to the public that the inventors possessed a treatment excluding a loading dose” as their claims required.  (Id. at 5.)  She believed that the majority had relegated the written description requirement “to the backseat of an expert’s post- hoc rationalization.”  (Id. at 8.)

Whether the ruling in Novartis expands and broadens what a patent now can cover (as the dissent proclaims) is up for debate.  At a minimum, however, Novartis underscores the importance of obtaining well-grounded expert testimony.  Many patent cases boil down to the testimony of experts and written description disputes now will often hinge on such testimony.

The holding provides some ammunition for patent applicants trying to add negative limitations during prosecution to overcome specific prior art references.  Examiners sometimes refuse to allow such limitations if the absence of the thing in question is not explicitly stated in the specification.  However, if one skilled in the art would expect a particular thing to be explicitly mentioned if it were indeed present in the embodiment, Novartis supports the applicant’s written description case for adding such a limitation during prosecution based on the specification’s silence.      

Author: Rory Radding