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Federal Circuit Affirms Invalidity of Concerta Patent for Lack of Enablement

By Aaron Barkoff

ALZA Corp. v. Andrx Pharms., No. 2009-1350 (Fed. Cir. 2010)

Earlier this week, the Federal Circuit affirmed a district court decision finding ALZA's U.S. Patent No. 6,919,373 invalid for lack of enablement.  The '373 patent claims methods for treating Attention Deficit and Hyperactivity Disorder ("ADHD") and is listed in the Orange Book for Concerta, an extended-release formulation of methylphenidate.

Last year, following a bench trial held in late 2007, the U.S. District Court for the District of Delaware found the '373 patent not invalid for obviousness, but invalid for lack of enablement and also not infringed by Andrx's ANDA for a generic version of Concerta.  The Federal Circuit affirmed the lack-of-enablement finding, and therefore did not address the other issues.

Claim 1 of the '373 patent reads:

A method for treating ADD or ADHD comprising administering a dosage form comprising methylphenidate that provides a release of methylphenidate at an ascending release rate over an extended period of time.

According to the Federal Circuit opinion, the specification of the '373 patent "focuses on how osmotic systems can be adapted to create an ascending release dosage form to treat ADHD.  The specification also mentions non-osmotic dosage forms."  Both Concerta and Andrx's product are non-osmotic dosage forms that contain an outer immediate-release coating around a sustained-release inner core.

On appeal, ALZA argued that the district court erred in finding claim 1 invalid for lack of enablement on the grounds that the specification does not enable the full scope of claim 1, which covers both osmotic and non-osmotic dosage forms.  The parties agreed that osmotic dosage forms are enabled, but disputed whether the specification would have enabled a person of ordinary skill in the art to create non-osmotic oral dosage forms--namely, tablets and capsules--with ascending release rates without undue experimentation.

The test of enablement is whether the specification would have taught someone having ordinary skill in the art, at the time of invention, how to make and use the full scope of the claimed invention without undue experimentation.  In the Wands case, the Federal Circuit set forth eight factors (the "Wands factors") that a court may consider when determining whether undue experimentation would have been required:

(1) the quantity of experimentation necessary, (2) the amount of direction or guidance presented, (3) the presence or absence of working examples, (4) the nature of the invention, (5) the state of the prior art, (6) the relative skill of those in the art, (7) the predictability or unpredictability of the art, and (8) the breadth of the claims.

ALZA asserted that creating non-osmotic dosage forms and manipulating their release rates were well known to a person of ordinary skill in the art at the time of invention.  In addition, ALZA argued that the specification provides sufficient guidance regarding non-osmotic dosage forms because "it identifies a variety of suitable non-osmotic dosage forms and cites to a portion of a standard text to explain how to make and use such non-osmotic, sustained-release dosage forms" with mere routine experimentation.

Andrx disputed ALZA's contention that enablement can be satisfied by referring to what persons of ordinary skill in the art 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 non-osmotic dosage forms exhibiting ascending release rates."  In addition, Andrx pointed to three Wands factors in particular--the sparse guidance provided by the specification, the absence of working embodiments, and the breadth of the claims--in support of its argument that creating non-osmotic dosage forms with ascending release rates would have required undue experimentation.

The Federal Circuit rejected ALZA's first argument:

To the extent that ALZA argues that the knowledge of a person of ordinary skill in the art satisfies the enablement requirement, we disagree.  As this court has repeatedly stated, "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."  Auto. Tech., 501 F.3d at 1282.

The Federal Circuit next addressed ALZA's argument that the disclosure in the '373 patent specification enables a person of ordinary skill to make and use the claimed dosage forms.  According to the court, ALZA pointed to "ten lines of the specification, which mention non-osmotics and refer to a textbook discussing how to make and use various types of non-osmotic sustained-release dosage forms."  The court agreed with the district court that "this disclosure provides no guidance as to how to achieve ascending release with non-osmotic oral dosage forms."  The court again quoted the Auto. Tech. case:

The omission of minor details does not cause a specification to fail to meet the enablement requirement.  However, when there is no disclosure of any specific starting material or of any of the conditions under which a process can be carried out, undue experimentation is required.

The Federal Circuit concluded with a statement akin to "you've made your bed, now lie in it":

As we stated in Liebel-Flarsheim . . ., "The irony of this situation is that Liebel successfully pressed to have its claims include a jacketless system, but, having won that battle, it then had to show that such a claim was fully enabled, a challenge it could not meet."  In this case, ALZA successfully argued to the district court that the claims encompassed both osmotic and non-osmotic dosage forms.  However, ALZA's patent specification does not enable the full scope of the claims, namely non-osmotic oral dosage forms with ascending release rates.

ADDITIONAL READING:

• AP story
• J&J (ALZA) press release
• Watson (Andrx) press release

Full post as published by Orange Book Blog: At the Intersection of Patent Law and FDA Law on April 29, 2010 (boomark / email).