PTAB

IPR2013-00012

Apotex Inc v. Alcon PharmaceuTicals Ltd

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1. Case Identification

2. Patent Overview

  • Title: Ophthalmic Antibiotic Compositions Containing Moxifloxacin
  • Brief Description: The ’830 patent is directed to topical ophthalmic, otic, and nasal pharmaceutical compositions containing the fluoroquinolone moxifloxacin. Claim 1 recites a topical ophthalmic composition comprising 0.1 to 1.0 wt% moxifloxacin and a pharmaceutically acceptable vehicle.

3. Grounds for Unpatentability

Ground 1: Anticipation - Claim 1 is anticipated by the ’942 patent under 35 U.S.C. §102.

  • Prior Art Relied Upon: Petersen (Patent 5,607,942).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Petersen (the ’942 patent) discloses every element of claim 1. The ’942 patent explicitly claims the compound moxifloxacin and discloses its use in "ophthalmological...formulations [like] eye ointments" for "local therapy," which Petitioner asserted is a topical ophthalmic composition. Crucially, the ’942 patent discloses that moxifloxacin should be present in a concentration of "about 0.1 to 99.5% by weight." Petitioner contended that the ’830 patent's claimed range of 0.1 to 1.0 wt% is entirely subsumed by the broader range disclosed in the ’942 patent. Because the patent owner never established that the narrower range was critical or produced a considerable difference in properties, the disclosure of the broader range anticipates the claim. The ’942 patent also inherently discloses a pharmaceutically acceptable vehicle by describing formulations like emulsions, ointments, and drops.

Ground 2: Obviousness over ’942 patent and OCUFLOX® - Claim 1 is obvious over the ’942 patent in view of OCUFLOX® PDR.

  • Prior Art Relied Upon: Petersen (’942 patent) and OCUFLOX® PDR (a 1996 Physician's Desk Reference entry).
  • Core Argument for this Ground:
    • Prior Art Mapping: The ’942 patent taught using moxifloxacin in ophthalmic formulations across a broad concentration range. The OCUFLOX® PDR described a successful, commercially available topical ophthalmic product containing 0.3% ofloxacin, a fluoroquinolone from the same class as moxifloxacin, in a sterile solution with a pharmaceutically acceptable vehicle.
    • Motivation to Combine: A person of ordinary skill in the art (POSA), knowing of moxifloxacin's broad-spectrum antibacterial properties from the ’942 patent, would combine it with a known and proven formulation for topical ophthalmic delivery. The OCUFLOX® PDR provided a direct template and motivation for such a formulation, including a specific concentration (0.3%) that falls squarely within the claimed range of the ’830 patent. The goal would be to create an effective topical antibacterial product using the known compound from the ’942 patent.
    • Expectation of Success: A POSA would have a reasonable expectation of success because formulating topical ophthalmic solutions was a well-understood and routine practice, as evidenced by existing products like OCUFLOX®. Since moxifloxacin and ofloxacin are structurally and functionally similar, a POSA would expect moxifloxacin to be safe and effective when formulated in a similar vehicle.

Ground 3: Obviousness over Dalhoff, OCUFLOX®, and Petersen Abstract - Claim 1 is obvious over Dalhoff in view of OCUFLOX® PDR and the Petersen Abstract.

  • Prior Art Relied Upon: Dalhoff (a 1996 journal article), OCUFLOX® PDR, and Petersen Abstract (a 1996 conference abstract).
  • Core Argument for this Ground:
    • Prior Art Mapping: Dalhoff disclosed that moxifloxacin is an excellent broad-spectrum antibiotic with antibacterial activity generally 10-fold greater than that of ciprofloxacin against gram-positive bacteria like S. aureus. OCUFLOX® PDR provided the template for a 0.3% topical ophthalmic solution. The Petersen Abstract disclosed that moxifloxacin has a high aqueous solubility of 24 mg/mL (equivalent to 2.4 wt%), which is significantly higher than the claimed range's upper limit of 1.0 wt%.
    • Motivation to Combine: Dalhoff’s disclosure of moxifloxacin's superior antibacterial potency would strongly motivate a POSA to develop it as an alternative and improved therapy to existing ophthalmic antibiotics. A POSA would turn to established formulations, like that of OCUFLOX®, as a starting point. The 0.3% concentration used in OCUFLOX® provided a logical and proven concentration to use for moxifloxacin.
    • Expectation of Success: The Petersen Abstract's disclosure of high aqueous solubility would provide a strong expectation that moxifloxacin could be successfully formulated into a stable and effective topical solution at concentrations within the 0.1 to 1.0 wt% range without difficulty. Combined with the known safety and efficacy of the OCUFLOX® formulation, a POSA would reasonably expect the resulting moxifloxacin composition to be a safe and effective treatment for eye infections.
  • Additional Grounds: Petitioner asserted additional obviousness challenges, including combinations substituting CILOXAN® PDR (containing the fluoroquinolone ciprofloxacin) for OCUFLOX® PDR and incrementally adding the Petersen Abstract to other combinations. These grounds relied on similar theories of using known commercial products as formulation templates and motivation for developing a moxifloxacin-based therapy.

4. Key Technical Contentions (Beyond Claim Construction)

  • Rebuttal of "Teaching Away" Arguments: Petitioner dedicated significant argument to preemptively rebutting potential assertions that the prior art taught away from the invention. Petitioner argued that prior art concerns over fluoroquinolone toxicity were related to systemic administration, not the much smaller dosages used in topical ophthalmic treatments, which were known to be safe. Further, Petitioner contended that while moxifloxacin may have been less active against P. aeruginosa than other drugs, its high aqueous solubility allowed it to be formulated at concentrations sufficient for treatment. Finally, Petitioner asserted the art showed moxifloxacin was less likely to cause bacterial resistance than ciprofloxacin, directly contradicting any potential teaching away argument.

5. Relief Requested

  • Petitioner requests institution of IPR and cancellation of claim 1 of the ’830 patent as unpatentable under 35 U.S.C. §§ 102 and 103.