Under unusual circumstances, CAFC re-affirms that conception does not require understanding how or why an invention works

Ryan Chirnomas | December 21, 2011

Teva Pharmaceutical Industries v. AstraZeneca Pharmaceuticals and IPR Pharmaceuticals

CAFC, December 1, 2011

Panel: Rader, Linn and Dyk.  Opinion by Linn.


The CAFC has re-affirmed that in order to establish conception of one’s invention, it is only necessary for the inventor to appreciate what the invention is, not how or why the invention works.  In this case, it was only required that the inventor understand the contents of a drug formulation, and it was not necessary to understand the stabilizing function of one compound of the formulation.  This principle is relatively non-controversial, but is presented in the context of the unusual strategy of conceding infringement even though the accused product did not meet one claim limitation, in order to attack the patent on §102(g) grounds.


Statins are a class of drugs, which are useful for treatment of a variety of conditions, such as high cholesterol, also known as dyslipidemia.  However, statins are unstable, and have to be paired with a stabilizer in order to be an effective medicine.  In mid-1999, AstraZeneca produced a small batch of a drug formulation containing (i) an active statin ingredient called rosuvastatin calcium, (ii) an amido-group containing polymeric compound (“AGCP compound”) called crospovidone, which AstraZeneca thought was a disintegrant but not a stabilizer, and (iii) a stabilizer called tribasic calcium phosphate, which is not an AGCP compound.  This formulation later became the drug Crestor.  In summer and fall of 1999, AstraZeneca made additional batches of the drug formulation.  AstraZeneca filed a UK patent application in January 2000.

Meanwhile, Teva was working on a similar drug.  Teva discovered that the AGCP compound actually was a stabilizer, and that no other type of stabilizer was needed.  On December 1, 1999, Teva reduced to practice a drug formulation including a statin and an AGCP compound as a stabilizer, without any additional stabilizers.  On April 10, 2000, Teva filed a provisional application to this subject matter.  A patent was granted, which was eventually reissued as RE 39,502.  Representative claim 1 recites (emphasis added by the court):

1.  A stabilized pharmaceutical composition for the treatment of dyslipidemia, comprising

an active component consisting essentially of one or more compounds selected from the group consisting of (i) an HMG-CoA reductase inhibiting ring-opened 7-substituted-3,5-dihydroxyheptafloic acid or a pharmaceutically acceptable acid salt thereof, and (ii) an HMG-CoA reductase inhibiting ring-opened 7-substituted-3,5-dihydroxyheptenoic acid or a pharmaceutically acceptable acid salt thereof, and

a stabilizing effective amount of at least one amido-group containing polymeric compound or at least one amino-group containing polymeric compound, or combination thereof, wherein said stabilized pharmaceutical composition does not contain a stabilizing effective amount of another stabilizer or a combination of other stabilizers.

In October 2008, Teva sued AstraZeneca for infringement of the ‘502 patent based on its sale of Crestor.  Teva accused AstraZeneca for infringement even though Crestor was arguably outside of the scope of the claims due to not meeting the negative limitation—an AGCP compound as a stabilizer, to the exclusion of other kinds of stabilizers.  Note that AstraZeneca’s formulation included an AGCP stabilizer and a non-AGCP stabilizer.  There was no dispute between the parties regarding the facts outlined above.

AstraZeneca moved for summary judgment on the basis that the claims were invalid under 35 U.S.C. §102(g)(2), since AstraZeneca conceived and reduced to practice the invention before Teva did.  35 U.S.C. §102(g)(2) states:

A person shall be entitled to a patent unless…(g)…(2) before such person’s invention thereof, the invention was made in this country by another inventor who had not abandoned, suppressed, or concealed it. In determining priority of invention under this subsection, there shall be considered not only the respective dates of conception and reduction to practice of the invention, but also the reasonable diligence of one who was first to conceive and last to reduce to practice, from a time prior to conception by the other.

In conjunction with this strategy, AstraZeneca conceded infringement for the purposes of their summary judgment motion.  The district court granted the summary judgment motion, stating that “an appreciation of the stabilizing effect of crospovidone by AstraZeneca, as opposed to its appreciation of the stabilization of its overall pharmaceutical composition that included crospovidone, was not required.”  As such, the district court held that the claims were invalid.


At the CAFC, Teva argued that the district court erred in granting the summary judgment motion, because they should have required AstraZeneca to show recognition of the stabilizing effect of the AGCP compound.  In failing to require this of AstraZeneca, Teva argued that the district court basically ignored the negative limitation in the claim.

In response, AstraZeneca urged that any argument regarding claim construction (whether or not the district court ignored the negative limitation) is irrelevant.  Since Teva accused AstraZeneca of infringement of the claim, and AstraZeneca conceded, there was no issue in question about whether the formulation fit into the scope of the claims.  Furthermore, AstraZeneca argues that §102(g)(2) does not require that the inventor appreciate how the invention works, but just what the invention is.

The CAFC agreed with AstraZeneca on all points.  Since AstraZeneca conceded infringement, the CAFC did not need to interpret claim scope, but just whether §102(g)(2) requires comprehension of the stabilizing effect of the AGCP compound in order show earlier invention.

The CAFC cited a string of cases, Dow Chemical v. Astro-Valcour, Mycogen Plant Sciences v. Monstano, and Invitrogen v. Clontech Labs to support the position that an inventor merely needs to appreciate what the invention is and how it is applied, in order to be regarded as “conceiving” the invention.   In Dow, the inventors appreciated the ingredients used, that they were significant and that the result was useful foam.  In Mycogen, the earlier inventors were regarded as having conceived of the invention, even though they defined it in different terms (nucleotides vs. codons) than the later party.

On the other hand, in Invitrogen, the inventors created 100 random variants of a gene, two of which were later claimed.  However, the inventors did not realize that two of the variants coded for a useful enzyme.  Thus, this case was categorized as “unrecognized, accidental duplication.”

The CAFC clarifies that conception requires that the inventor appreciate what they made, but does not need to explain how or why it works.  The inventor also does not need to define the invention in the same terms as another party.  The court cites to William Shakespeare to illustrate this point:  “[T]hat which we call a rose [b]y any other name would smell as sweet.”

The court goes on to explain that AstraZeneca’s product had “stabilizing effective amount” of the AGCP compound, and that this was appreciated by AstraZeneca.  AstraZeneca knew that ingredients of the formulation included some amount of an AGCP compound, the creation of the formulation was not accidental, and the formulation was stable.   However, AstraZeneca did not need to know which ingredient was responsible for the stabilization, as that would be requiring the inventor to know how or why the invention works.  The court states that Teva’s arguments are essentially asking “this court to fault AstraZeneca for not first conceiving of its drug in the same words in which Teva later chose to claim it.”  The CAFC refuses to do so, and the district court’s decision is AFFIRMED.


Although the decision is consistent with previous case law, the outcome of this case is rather strange:  AstraZeneca is given credit for earlier invention of a drug formulation (containing only the AGCP stabilizer and no other stabilizers) that was never conceived of or produced by them.  However, this legal fiction is a by-product of Teva asserting the claims against AstraZeneca, perhaps overzealously.

Additionally, this case turned on what was considered the “invention”:  A drug formulation including an AGCP compound as a stabilizer, or the use of an AGCP as a stabilizer.   Since the claim recites a pharmaceutical composition, the court viewed the “invention” as the formulation itself.  Consistent with this, a later inventor cannot obtain a patent due to their discovery of how a composition works, if they did not invent the composition in the first place.   In this case, Teva was left with nothing to show for their technical contribution:  the discovery of the stabilizing properties of an AGCP compound.  However, patents are granted for inventions, not discoveries.

It is unclear why Teva asserted the claim against AstraZeneca.  It seems that AstraZeneca made a strategic decision to concede infringement, even though they most likely would not have infringed the claims under traditional claim construction.  Here, it seems that Teva was overly aggressive, and as a result, their claims were invalidated.

Finally, readers may note that although the AIA eliminates §102(g), because applications filed on or before March 15, 2013 are subject to the “old” §102, cases such as this may arise in the future in the same way that interferences will cast a long shadow over the U.S.P.T.O. for a decade or more.

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