PTAB

PGR2025-00043

Intas Pharmaceuticals Ltd v. Atossa Therapeutics Inc

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Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Methods for Making and Using Endoxifen
  • Brief Description: The ’391 patent is directed to pharmaceutical compositions comprising a compound of at least 90% by weight (Z)-endoxifen, or a salt thereof, and an enteric material. The patent also claims methods of administering these compositions.

3. Grounds for Unpatentability

Ground 1: Anticipation by Ahmad - Claims 1-2, 4-6, 8-9, 11-15, 20, 23, 26-37, and 40-44 are anticipated by Ahmad.

  • Prior Art Relied Upon: Ahmad (Patent 9,333,190).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Ahmad expressly teaches every element of the independent claims. Ahmad discloses compositions containing endoxifen, including the Z-isomer at purities of "at least 90%." It further teaches that these compositions can be in the form of a pharmaceutically acceptable salt and can be encapsulated in enteric-coated capsules or tablets to protect the active ingredient from stomach acid. Petitioner contended that Ahmad’s disclosure of an enteric-coated capsule containing a composition of at least 90% (Z)-endoxifen anticipates the independent claims, which recite an "enteric material." For the method claims, Ahmad discloses administering these compositions to treat breast cancer. Petitioner also asserted that many challenged claims present "identical issues of patentability" to claims in the grandparent ’334 patent, which were previously found unpatentable over Ahmad in a Final Written Decision (FWD).

Ground 2: Obviousness over Ahmad and Clinical Data - Claims 26-29, 33-37, 40, and 41 are obvious over Ahmad in view of Ahmad 2010/2012.

  • Prior Art Relied Upon: Ahmad (Patent 9,333,190), Ahmad 2010 (a clinical pharmacology journal article), and Ahmad 2012 (an ASCO meeting abstract).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground targeted claims reciting specific dosage ranges and pharmacokinetic (PK) parameters. Petitioner asserted that while Ahmad teaches a 1-10 mg/day dose of (Z)-endoxifen, the Ahmad 2010 and Ahmad 2012 references provide safety and PK data for doses of 4 mg and 4.0-8.0 mg, respectively. These references suggested that such doses would result in exposures sufficient for effective therapy and fall within the claimed ranges. The resulting PK parameters (e.g., steady-state plasma concentration, AUC, Cmax) were argued to be inherent or predictable properties arising from administering Ahmad's formulation at dosages suggested by the later clinical data.
    • Motivation to Combine: A Person of Ordinary Skill in the Art (POSA) would look to available clinical data, like Ahmad 2010 and Ahmad 2012, to optimize the formulation taught in the primary Ahmad reference and determine a proper, safe, and effective dosage for treating breast cancer.
    • Expectation of Success: The clinical data provided specific dosage levels and resulting PK values, giving a POSA a high expectation of success in achieving the claimed dosage forms and PK profiles through routine experimentation.

Ground 3: Obviousness over Ahmad and Benameur - Claim 7 is obvious over Ahmad in view of Benameur.

  • Prior Art Relied Upon: Ahmad (Patent 9,333,190) and Benameur (a 2015 article in Drug Development & Delivery).

  • Core Argument for this Ground:

    • Prior Art Mapping: This ground specifically addressed claim 7, which requires the composition to be "uncoated." Ahmad teaches an enteric coated capsule. Benameur discloses an "intrinsically enteric capsule" technology that provides enteric protection "without the use of coatings."
    • Motivation to Combine: A POSA would combine Benameur's uncoated enteric capsule with Ahmad's (Z)-endoxifen formulation as a routine design choice. The motivation would be to gain the known benefits of uncoated enteric capsules, such as avoiding a heat-intensive coating step that could degrade the active ingredient and simplifying the manufacturing process.
    • Expectation of Success: Both endoxifen formulations and intrinsic enteric capsules were well-known technologies, making their combination straightforward and predictable.

  • Additional Grounds: Petitioner asserted additional challenges, including that claims 1-6, 8-9, 11-16, 20, 23, 26-37, and 40-44 are obvious over Ahmad in view of the general knowledge of a POSA. Further obviousness grounds relied on combining Ahmad with de Villiers/Gandhi for syrup/elixir suspensions (claims 10, 12-15, 30, 31), Stegemann/HPE for common excipients like fillers and lubricants (claims 21-25), and Cole for specific dissolution properties (claims 17-19, 38, 39). Finally, Petitioner argued in the alternative that claims 10, 12-15, and 30 lack written description and enablement under 35 U.S.C. §112.

4. Arguments Regarding Discretionary Denial

  • Petitioner argued that discretionary denial under 35 U.S.C. §325(d) was inappropriate. The Examiner did not issue any art-based rejections during prosecution of the ’391 patent. Although some references (Ahmad, Liu, Ahmad 2010/2012) were cited by the Examiner, Petitioner contended they were not substantively considered or used as the basis for a rejection. Petitioner argued the Examiner materially erred by failing to appreciate the strength of these references, particularly Ahmad, which allegedly discloses all limitations of the independent claims. The fact that nearly identical claims in a grandparent patent were found unpatentable over the same art in a prior post grant review (PGR) was presented as strong evidence of the Examiner's error.

5. Relief Requested

  • Petitioner requests institution of post grant review and cancellation of claims 1-44 of the ’391 patent as unpatentable.