PTAB

IPR2015-01495

Pharmacosmos A/S v. Luitpold Pharmaceuticals, Inc.

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1. Case Identification

2. Patent Overview

  • Title: Methods and Compositions for Administration of Iron
  • Brief Description: The ’612 patent describes methods for treating iron deficiency anemia by administering an iron carbohydrate complex. The invention purports to allow for a single, high dose (e.g., 0.6 grams or more) of parenteral iron to be administered rapidly (e.g., in 15 minutes or less) with a low risk of anaphylactoid or hypersensitivity reactions.

3. Grounds for Unpatentability

Ground 1: Anticipation of Claims 1-5, 15, and 16 under §102(b) by Groman

  • Prior Art Relied Upon: Groman (Application # 2003/0232084).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Groman discloses every limitation of independent claim 1 and its dependent claims. Groman teaches methods of treating anemia with iron carbohydrate complexes, specifically disclosing a complex it calls “carboxymethyl reduced dextran” (CMRD), which Petitioner asserted is the same as the "iron polyglucose sorbitol carboxymethyl ether complex" recited in claim 1. Groman allegedly discloses administering single doses up to 600 mg (0.6 g) of elemental iron in a time interval that includes 15 minutes or less. Furthermore, Groman describes its complexes as "immunosilent" with a "minimal incidence of anaphylaxis," which Petitioner contended meets the claim limitation of having a "substantially non-immunogenic carbohydrate component." Groman’s disclosure of particle sizes less than 35 nm (e.g., 21 nm) and parenteral administration were argued to anticipate claims 15 and 16, respectively.

Ground 2: Anticipation of Claim 20 under §102(b) by Marchasin

  • Prior Art Relied Upon: Marchasin (1964, Blood 23:354-358).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground targets claim 20, which depends from claim 1 and specifies that the iron carbohydrate complex is an "iron polyisomaltose complex." Central to this argument is Petitioner's construction that "iron polyisomaltose" is synonymous with "iron dextran," based on the ’612 patent’s specification. Marchasin describes a study treating iron-deficiency anemia with intravenous iron dextran (Imferon®) in single high doses of 1000-3000 mg (1.0-3.0 g), which meets the "at least about 0.6 g" limitation. The doses were administered by injection over a 4-10 minute period, satisfying the "about 15 minutes or less" limitation. Petitioner contended that Marchasin’s report of "no untoward local reactions" and its conclusion that iron dextran is a "safe and well-tolerated" preparation meets the requirement for a "substantially non-immunogenic carbohydrate component," particularly under a broad interpretation.

Ground 3: Obviousness of Claims 7, 11, and 12 under §103 over Groman in view of Geisser

  • Prior Art Relied Upon: Groman (Application # 2003/0232084) and Geisser (WO 2004037865).

  • Core Argument for this Ground:

    • Prior Art Mapping: This ground addresses claims requiring a higher dose (claim 7: ≥1.0 g) and specifying an "iron carboxymaltose complex" (claims 11 and 12). Petitioner asserted that Groman teaches rapid administration (≤15 minutes) of up to 0.6 g of an iron complex, while Geisser discloses administering higher single doses (500-1000 mg) of iron carboxymaltose, a complex noted for high stability and low toxicity. Claim 12’s specific chemical formula for iron carboxymaltose is also explicitly taught by Geisser. The combination of Groman's rapid administration method with Geisser's stable, high-dose iron carboxymaltose was argued to render the claims obvious.
    • Motivation to Combine: A person of ordinary skill in the art (POSITA) would combine these references because they address the same problem (parenteral iron administration) with structurally analogous iron carbohydrate complexes. A POSITA would have been motivated to apply the rapid administration rates taught by Groman to the stable, high-dose iron carboxymaltose complex taught by Geisser to achieve a more efficient treatment regimen.
    • Expectation of Success: The structural similarities between the complexes and Geisser's teachings of high stability and reduced toxicity would give a POSITA a reasonable expectation of success in administering Geisser's higher doses at Groman's rapid rates without adverse effects.

  • Additional Grounds: Petitioner asserted additional challenges, including that claim 20 is anticipated by Groman under an alternative claim construction (Ground 3), and that claims 8 and 17 (reciting doses ≥1.5 g) are obvious over Groman in view of van Zyl-Smit, which taught total dose infusions up to 3,200 mg (Ground 5).

4. Key Claim Construction Positions

  • "Iron Polyisomaltose Complex": Petitioner argued this term must be construed as a synonym for "iron dextran." This position is based on the patent's own specification, which explicitly states, "[e]xamples of iron carbohydrate complexes include... iron polyisomaltose (iron dextran)." This construction is critical to Ground 2, which relies on the Marchasin reference teaching administration of iron dextran.
  • "Substantially Non-Immunogenic Carbohydrate Component": Petitioner proposed this term should be construed broadly to mean a carbohydrate that results in a "low risk of anaphylactoid/hypersensitivity reactions." This interpretation would allow prior art complexes described as "safe and well-tolerated," even if known to cause some reactions in a larger population, to meet the claim limitation.
  • "Iron Carboxymaltose Complex": Petitioner argued this term should be construed to include the complexes made by oxidizing maltodextrins as described in the Geisser reference. This is supported by the fact that the ’612 patent's description of preparing iron carboxymaltose closely tracks the language in Geisser.

5. Relief Requested

  • Petitioner requested the institution of an inter partes review and the cancellation of claims 1-5, 7, 8, 11, 12, 15, 16, 17, and 20 of the ’612 patent as unpatentable.