PTAB

IPR2018-00173

Mylan Technologies Inc v. Noven Pharmaceuticals Inc

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Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Monolithic Transdermal Estradiol Delivery System
  • Brief Description: The ’310 patent is directed to a monolithic (single drug-containing layer) transdermal patch for the administration of estradiol. The claims specify a system with particular parameters for coat weight, estradiol dose per-unit-area, and the resulting estradiol flux.

3. Grounds for Unpatentability

Ground 1: Anticipation by Mueller - Claims 1-2, 8, and 10-15 are anticipated under 35 U.S.C. §102 by Mueller.

  • Prior Art Relied Upon: Mueller (Application # US2003/0099695).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Example 3 of Mueller explicitly discloses a single embodiment that meets every limitation of the challenged claims. Mueller’s patch is a monolithic transdermal system for estradiol comprising a backing layer, a single adhesive polymer matrix, and a release liner. The formulation in Example 3 results in a coat weight of 11.5 mg/cm² (meeting the “greater than about 10 mg/cm²” limitation) and an estradiol dose per-unit-area of 0.1725 mg/cm² (meeting the “greater than 0.156 mg/cm²” limitation). Furthermore, flux calculations from Mueller’s data show values of 0.015 mg/cm²/day and 0.014 mg/cm²/day, which fall squarely within the claimed range of “about 0.0125 to about 0.05 mg/cm²/day.” Petitioner contended that Mueller also meets the dependent claim limitations, including the specific polymer blend of claim 2, the delivery period of claim 8, the specific flux values of claims 10-14, and the estradiol weight percentage of claim 15, particularly when applying the patent’s own definition of “about.”

Ground 2: Obviousness over Mueller, Vivelle-Dot, and Kanios - Claims 3-7 are obvious over Mueller in view of Vivelle-Dot® Label and Kanios.

  • Prior Art Relied Upon: Mueller (Application # US2003/0099695), Vivelle-Dot® Label, and Kanios (Application # US2006/0078602).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner asserted that while Mueller discloses the basic patch formulation, the specific component percentages recited in claims 3-7 would have been an obvious modification based on the teachings of Kanios. Mueller’s Example 3 teaches a patch with 6.58% polyacrylate and 79.52% silicone adhesive. Kanios teaches similar patches but with higher concentrations of hydrophile polymers (polyacrylate and PVP) to achieve a higher flux. Modifying Mueller’s patch to incorporate the higher hydrophile content taught by Kanios would result in a composition with percentages of acrylic adhesive, silicone adhesive, PVP, penetration enhancer, and estradiol falling within the ranges claimed in claims 3-7.
    • Motivation to Combine: A person of ordinary skill in the art (POSITA) would combine these references to achieve a well-known goal: increasing drug flux to permit a smaller, more desirable patch size. Mueller itself teaches that increasing hydrophile content increases flux. Kanios provides a specific example of doing so in a similar system to achieve higher flux values. A POSITA would have been motivated to modify Mueller’s formulation by increasing its hydrophile content as taught by Kanios, which would necessitate decreasing the silicone adhesive content to accommodate the change, resulting in the claimed composition.
    • Expectation of Success: Because Kanios demonstrated that increasing the proportion of hydrophile polymers in a similar estradiol patch successfully and predictably increased flux, a POSITA would have had a reasonable expectation of success.

Ground 3: Obviousness over Mueller, Vivelle-Dot, Kanios, and Chien - Claims 1-15 are obvious over Mueller in view of Vivelle-Dot® Label, Kanios, and Chien.

  • Prior Art Relied Upon: Mueller (Application # US2003/0099695), Vivelle-Dot® Label, Kanios (Application # US2006/0078602), and Chien (Patent 5,145,682).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground builds on the previous combinations and adds Chien to directly rebut the patent owner’s argument of "unexpected results" made during prosecution. The patent owner had argued it was "surprising and unexpected" that increasing the coat weight of the matrix would increase drug flux. Chien, however, explicitly teaches this exact principle. Figure 5 of Chien demonstrates a direct, positive correlation between the coating thickness (i.e., coat weight) of a monolithic estradiol patch and its resulting flux.
    • Motivation to Combine: The motivation to combine Mueller, Vivelle-Dot, and Kanios is to create an improved estradiol patch with higher flux. The motivation to further apply the teachings of Chien was to use a known, simple method—increasing the coat weight—to further increase the flux of that patch. This was a routine optimization strategy, not an unexpected discovery.
    • Expectation of Success: Chien’s data provides clear empirical evidence that increasing coat weight increases flux, giving a POSITA a very high expectation of success. This combination renders all claims obvious and undermines the patent’s patentability argument.
  • Additional Grounds: Petitioner asserted an additional obviousness challenge (Ground 2) for claims 1-2 and 8-15 over Mueller in view of the Vivelle-Dot® Label, arguing it would have been obvious to use Mueller's higher-flux patch to deliver the standard, well-known estradiol doses taught by the Vivelle-Dot® Label.

4. Key Claim Construction Positions

  • "About": Petitioner argued this term should be construed as "up to plus or minus 10% of the particular term," based on an explicit definition in the ’310 patent’s specification. This construction was critical to demonstrating that the numerical values disclosed in the prior art, such as the flux and estradiol percentage in Mueller, fell within the scope of the claims.
  • "Coat weight": Petitioner argued this term refers to the dry weight per-unit-area of the drug-containing adhesive layer. This construction was important for linking the explicit teachings in prior art like Chien regarding coating "thickness" to the claimed "coat weight" limitation, as the two were treated as proxies for one another in the art and during prosecution.

5. Key Technical Contentions (Beyond Claim Construction)

  • Petitioner’s central technical contention was that the positive relationship between increased coat weight and increased drug flux in monolithic patches was a well-established and predictable principle in the art, not a "surprising and unexpected" discovery. Petitioner cited Chien and other references not before the examiner to prove that this was a routine and obvious strategy for a POSITA seeking to enhance drug delivery. This argument directly targeted the basis upon which the patent owner secured allowance of the claims.

6. Arguments Regarding Discretionary Denial

  • Petitioner argued that institution was proper and that deference should not be given to the Examiner's decision because critical prior art was not considered during prosecution. Specifically, references like Chien, which directly teach that increasing coat weight increases flux, were not of record. Therefore, the patent owner’s allowance—secured by arguing that this very effect was "unexpected"—was based on a flawed premise and an incomplete record, warranting review by the Board.

7. Relief Requested

  • Petitioner requested the institution of an inter partes review and the cancellation of claims 1-15 of Patent 9,724,310 as unpatentable.