PTAB

IPR2017-01101

Actavis LLC v. Abraxis Bioscience LLC

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Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Compositions and Methods of Delivery of Pharmacological Agents
  • Brief Description: The ’788 patent describes injectable pharmaceutical compositions comprising nanoparticles of the anticancer drug paclitaxel and the carrier protein albumin. The claims are directed to specific formulations where the nanoparticles have a size of less than about 200 nm and the weight ratio of albumin to paclitaxel is within a specified range, such as about 1:1 to about 9:1.

3. Grounds for Unpatentability

Ground 1: Anticipation under 35 U.S.C. §102 - Claims 1-9 and 11-12 are anticipated by Desai.

  • Prior Art Relied Upon: Desai (WO 1999/000113).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Desai, an international application from the same inventors, discloses every limitation of the challenged claims. Specifically, Example 1 of Desai teaches a process for making an injectable albumin-paclitaxel composition by combining 30 mg of paclitaxel with 270 mg of human serum albumin. Petitioner asserted this inherently discloses the claimed weight ratio of exactly 9:1. Desai further discloses that this process produces nanoparticles with a typical diameter of 160-220 nm, which satisfies the claim limitation of "less than about 200 nm." Desai also teaches that the resulting composition is lyophilized for intravenous administration and is free of Cremophor, anticipating limitations in dependent claims.
    • Key Aspects: The core of the anticipation argument rested on the assertion that the ratio of starting materials in Desai's Example 1 (270 mg albumin to 30 mg paclitaxel) constitutes an express or inherent disclosure of the claimed 9:1 ratio, and that the resulting particle size range overlaps with the claimed size.

Ground 2: Obviousness over Desai - Claims 1-12 are obvious over Desai.

  • Prior Art Relied Upon: Desai (WO 1999/000113).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that, even if not anticipating, Desai renders the claims obvious. Desai discloses albumin-paclitaxel nanoparticle compositions for injection with particle sizes under 200 nm. It also discloses a range of albumin-paclitaxel ratios, including a 13.3:1 ratio in its preferred "Capxol™" embodiment and other examples with ratios of 9.8:1 and 12.9:1. Petitioner asserted that the claimed 9:1 ratio falls within a range disclosed and suggested by Desai.
    • Motivation to Combine (for §103 grounds): Petitioner asserted a POSITA would be motivated to optimize Desai’s formulation by lowering the albumin-paclitaxel ratio from 13.3:1 toward the claimed 9:1. Desai itself provided the motivation, teaching that it is desirable to develop formulations with higher paclitaxel concentrations to reduce infusion times, minimize patient discomfort from large fluid volumes, and achieve a higher drug response rate. This would lead a POSITA to reduce the amount of the albumin excipient relative to the paclitaxel active ingredient.
    • Expectation of Success (for §103 grounds): A POSITA would have reasonably expected success in creating a stable formulation. Desai teaches that its albumin-based formulations possess "inherent stability" and provides working examples of stable compositions (including the 9:1 ratio in Example 1). Therefore, a modest reduction from the 13.3:1 ratio would not have been expected to cause instability.

Ground 3: Obviousness over Combination - Claims 1-12 are obvious over Desai in view of Kadima and Liversidge.

  • Prior Art Relied Upon: Desai (WO 1999/000113), Kadima (WO 2000/006152), and Liversidge (Patent 5,399,363).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued this combination strengthens the obviousness case. Desai provides the base formulation of albumin-paclitaxel nanoparticles. Kadima and Liversidge provide additional teachings that make the claimed ratio obvious. Kadima explicitly discloses an albumin-paclitaxel ratio range of about 0.5:1 to 10:1, which entirely encompasses the ’788 patent's claimed range of about 1:1 to 9:1. Liversidge, directed to surface-modified drug nanoparticles, discloses ratios up to 9:1.
    • Motivation to Combine (for §103 grounds): A POSITA would combine these teachings for clear economic and clinical reasons. Kadima explicitly teaches that albumin is an "expensive ingredient" and a "cost-limiting component," motivating a formulator to reduce the albumin ratio to create a more commercially viable product. The overlapping and encompassing ranges disclosed in Kadima and Liversidge would have made it obvious to a POSITA to select a ratio within the claimed range for Desai’s nanoparticle platform.
    • Key Aspects: Petitioner contended that the existence of overlapping and encompassing ranges in the prior art created a strong prima facie case of obviousness, shifting the burden to the Patent Owner to show the criticality of the specific 9:1 ratio.

4. Key Claim Construction Positions

  • "the weight ratio of albumin to paclitaxel...": Petitioner argued for a broad construction where the ratio is determined by the amounts of the starting ingredients used to make the composition. This interpretation was supported by examples in the ’788 patent itself, which calculate the ratio based on initial component amounts.
  • "a particle size of less than about 200 nm": Petitioner argued this term should be construed to mean a particle size of 220 nm or less. This was based on examples in the ’788 patent that describe a "typical average diameter" range of 50-220 nm and the common understanding that "about" allows for a 10% variance in this technical context.

5. Relief Requested

  • Petitioner requests institution of IPR and cancellation of claims 1-12 of the ’788 patent as unpatentable.