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Ordinary Skill Cannot Substitute for Disclosure of an Invention’s Novel Aspects to Satisfy the Enablement Requirement

April 26, 2010

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Last Month at the Federal Circuit - May 2010

Judges: Dyk, Schall, Prost (author)

[Appealed from: D. Del., Judge Farnan]

In ALZA Corp. v. Andrx Pharmaceuticals, LLC, No. 09-1350 (Fed. Cir. Apr. 26, 2010), the Federal Circuit affirmed the district court’s ruling that the asserted claims of U.S. Patent No. 6,919,373 (“the ’373 patent”) were invalid for lack of enablement. 

The ’373 patent claims methods for treating primarily Attention Deficit and Hyperactivity Disorder (“ADHD”) through a methylphenidate (“MPH”) drug dosage form that has an ascending release rate over an extended period of time.  Before the claimed invention, ADHD had been treated with other oral drugs that were immediate-release (“IR”) formulations of MPH.  At the time of the invention, it was well known how to develop sustained-release dosage forms that could exhibit descending or ascending release rates. 

ALZA Corporation (“ALZA”) developed safe and effective once-a-day extended release oral dosage forms that could deliver MPH with an ascending release pattern.  The bulk of ALZA’s efforts went into developing an osmotic dosage form, which used a compartment containing drug and various osmotic excipients.  Claim 1, the only independent claim implicated on appeal, recites administering a dosage form that provides a release of MPH at “an ascending release rate over an extended period of time.”  The specification focuses on how osmotic systems can be adapted to create an ascending release dosage form to treat ADHD.  The specification also mentions nonosmotic dosage forms.

ALZA markets and sells a product called CONCERTA®, which embodies the claimed invention; upon ingestion, it releases the drug at an ascending rate for an extended period of time, as required by claim 1.  ALZA’s competitors, Andrx Pharmaceuticals, LLC and Andrx Corporation (collectively “Andrx”), produce a product pursuant to an approved ANDA.  Like CONCERTA®, Andrx’s product has an outer IR coating around a sustained-release inner core.

ALZA sued Andrx, alleging infringement of the ’373 patent.  Andrx denied infringement and asserted affirmative defenses, including invalidity for lack of enablement.  The district court construed the claim to include nonosmotic as well as osmotic dosage forms, as ALZA requested.  The asserted claims were held nonobvious but not infringed and invalid for lack of enablement because the specification does not enable the full scope of claim 1. 

On appeal, ALZA argued that the district court erred in finding claim 1 invalid for lack of enablement.  The parties agreed that the claim construction adopted by the district court required the enablement of both osmotic and nonosmotic dosage forms, and that osmotic dosage forms were enabled.  The dispute was whether the specification would have enabled a person of ordinary skill in the art to create nonosmotic oral dosage forms (e.g., tablets and capsules) with ascending release rates without undue experimentation.

ALZA asserted that creating nonosmotic dosage forms and manipulating their release rates were well known to a person of ordinary skill in the art at the time the ’373 patent application was filed.  In addition, ALZA argued that the specification provides sufficient guidance regarding nonosmotic dosage forms because it identifies a variety of suitable nonosmotic dosage forms and cites to a portion of a standard text to explain how to make and use such nonosmotic, sustained-release dosage forms with experimentation.  ALZA conceded that even with the guidance provided in the specification, a person of ordinary skill in the art would be required to engage in an iterative, trial-and-error process to practice the claimed invention.  However, it disputed that the amount of experimentation required was undue.  Instead, ALZA argued that nonosmotic dosage forms with ascending release rates could be made with only routine effort by those skilled in the art, because the methods and materials used to produce dosage forms with constant, descending, or ascending release rate profiles were essentially the same and well known.

Andrx disputed ALZA’s contention that enablement can be satisfied by referring to what persons of ordinary skill would know because what one of the proper skill in the art knows cannot substitute for disclosure of novel aspects of the invention, i.e., the nonosmotic dosage forms exhibiting ascending release rates.  Further, Andrx argued that the evidence presented at trial indicated that even one skilled in the art would find it difficult to develop a nonosmotic dosage form exhibiting an ascending release rate, particularly in light of the sparse guidance provided in the specification.  Andrx pointed to three Wands factors in particular—the guidance provided by the specification, the presence or absence of working embodiments, and the breadth of the claims—and submitted that they strongly weigh in favor of a finding that creating nonosmotic dosage forms with ascending release rates requires undue experimentation.

The Federal Circuit held that the asserted claims were not enabled, and that there was no clear error in the district court’s finding that seven of the eight Wands factors weighed in favor of a finding that undue experimentation would be required to enable the full scope of the claims.  First, the Court explained, the specification of the ’373 patent only describes osmotic dosage forms and does not provide sufficient guidance for a person of ordinary skill in the art to make the nonosmotic dosage forms as claimed.  The rule that a specification need not disclose what is well known in the art is merely a rule of supplementation, not a substitute for a basic enabling disclosure.  “To satisfy the plain language of § 112, ¶ 1, ALZA was required to provide an adequate enabling disclosure in the specification; it cannot simply rely on the knowledge of a person of ordinary skill to serve as a substitute for the missing information in the specification.”  Slip op. at 10.

In arguing that the disclosure in the ’373 patent specification does enable a person of ordinary skill to make and use the claimed dosage forms, ALZA directed the Court to ten lines of the specification, which mention nonosmotics and refer to a textbook discussing how to make and use various types of nonosmotic sustained-release dosage forms.  However, the Court concluded that this disclosure provided no guidance as to how to achieve ascending release with nonosmotic oral dosage forms, and that undue experimentation was required because there was no disclosure of any specific starting material or any condition under which a process can be carried out.

The Federal Circuit noted that ALZA even conceded that a person of ordinary skill in the art would have been required to engage in an iterative, trial-and-error process to practice the claimed invention, even with the help of the specification.  Furthermore, because the field of ascending release dosage forms was not mature at the time the ’373 patent was filed and was a “breakaway” from the prior art, the preparation of such dosage forms was not routine.

ALZA relied heavily on the testimony of its expert witness, who explained that the experimentation required here was merely routine.  The Court noted that less weight was given to this testimony because it was based on a higher level of skill than the one the district court adopted.  The expert did not contend that the specification would enable a person at the level of skill that the district court adopted.  There was also contradictory testimony from two of ALZA’s own employees, who explained that despite its efforts, ALZA had been unable to develop these purported “routine” nonosmotic dosage forms with ascending release rates, and that even development of the osmotic form had been difficult. 

The Federal Circuit noted the irony that ALZA argued to the district court that the claims encompassed both osmotic and nonosmotic dosage forms, when the specification does not enable that full scope.  The Court did not address ALZA’s argument that the district court erred in its claim construction of a separate term, because the claims would be invalid under any reasonable construction.  The Court also did not reach Andrx’s argument that, in the alternative, the claims were invalid as obvious under 35 U.S.C. § 103.


Summary authored by Adam M. Breier, Ph.D., student associate at Finnegan.