PTAB

IPR2013-00015

Apotex Inc v. Alcon

Log In

1. Case Identification

2. Patent Overview

  • Title: Method of Treating Ophthalmic Infections with Moxifloxacin Compositions
  • Brief Description: The ’070 patent discloses methods for treating ophthalmic, otic, and nasal infections by topically applying pharmaceutical compositions containing the fluoroquinolone antibiotic moxifloxacin.

3. Grounds for Unpatentability

Ground 1: Anticipation over the ’942 Patent - Claims 1, 15, and 17-19 are anticipated by Patent 5,607,942.

  • Prior Art Relied Upon: Patent 5,607,942 (“’942 patent”).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that the ’942 patent, which issued before the ’070 patent’s priority date, expressly and inherently disclosed every element of the challenged claims. The ’942 patent teaches using moxifloxacin in ophthalmic formulations (e.g., eye ointments, drops) for treating eye infections caused by a broad spectrum of bacteria. It discloses a moxifloxacin concentration range of "about 0.1 to 99.5% by weight," which entirely subsumes the ’070 patent’s claimed range of 0.1 to 1.0 wt. % (claim 1) and the specific concentration of about 0.35 wt. % (claim 17). Petitioner contended that the treatment of conjunctivitis (claims 15, 18-19) is inherently disclosed because the ’942 patent teaches treating eye infections caused by pathogens known to cause conjunctivitis, such as S. aureus and S. pneumoniae.

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

  • Prior Art Relied Upon: ’942 patent and OCUFLOX® PDR (product information for Ofloxacin ophthalmic solution 0.3% from the 1996 Physician’s Desk Reference).
  • Core Argument for this Ground:
    • Prior Art Mapping: The ’942 patent provided the foundational teaching of using moxifloxacin, a potent fluoroquinolone, in topical ophthalmic formulations to treat eye infections. The OCUFLOX® PDR described a commercially successful and widely used sterile ophthalmic solution containing ofloxacin, a fluoroquinolone from the same class as moxifloxacin, at a concentration of 0.3%. This concentration falls squarely within the range claimed in the ’070 patent.
    • Motivation to Combine: A Person of Ordinary Skill in the Art (POSA) would combine the teachings to develop an improved or alternative treatment for ophthalmic infections. A POSA would have been motivated to formulate the potent antibacterial moxifloxacin (disclosed in the ’942 patent) using the established, safe, and effective concentration and formulation parameters of a similar, commercially available product like OCUFLOX®. The 0.3% concentration in OCUFLOX® PDR would have specifically suggested a concentration within the claimed range.
    • Expectation of Success: A POSA would have had a high expectation of success because moxifloxacin was known to be a safe and effective antibacterial agent for ophthalmic use, and OCUFLOX® provided a proven template for a successful topical ophthalmic formulation of a similar compound.

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

  • Prior Art Relied Upon: Dalhoff (a 1996 journal article on moxifloxacin’s in vitro activity), OCUFLOX® PDR, and Petersen Abstract (a 1996 abstract on moxifloxacin’s high aqueous solubility).
  • Core Argument for this Ground:
    • Prior Art Mapping: This combination of references provided all necessary elements for the claimed invention. Dalhoff established moxifloxacin as an excellent broad-spectrum antibiotic with antibacterial activity superior to existing drugs like ciprofloxacin, particularly against gram-positive bacteria such as S. aureus. OCUFLOX® PDR again provided the template for a 0.3% topical ophthalmic formulation. The Petersen Abstract reinforced the feasibility by teaching that moxifloxacin has high aqueous solubility, allowing it to be formulated at high concentrations for effective topical delivery.
    • Motivation to Combine: A POSA would combine these references to create a more effective ophthalmic therapy. Dalhoff’s disclosure of moxifloxacin’s superior potency would motivate a POSA to use it as an alternative to existing therapies. OCUFLOX® PDR provided a known and safe formulation approach, while Petersen confirmed that achieving the necessary concentration would not be an obstacle.
    • Expectation of Success: The combined knowledge of moxifloxacin's superior potency (Dalhoff), high solubility (Petersen), and the existence of a successful formulation for a similar drug (OCUFLOX® PDR) would have provided a POSA with a strong and reasonable expectation of success in creating a safe and effective topical treatment for eye infections as claimed.
  • Dependent Claims: Petitioner argued that the additional limitations in the dependent claims were also obvious over the asserted prior art combinations. For example, treating conjunctivitis was a known indication for OCUFLOX® and CILOXAN®, and formulation details like pH, preservatives, and tonicity agents were all disclosed in these commercial product descriptions as standard practice for ophthalmic solutions.
  • Additional Grounds: Petitioner asserted additional obviousness challenges based on the '942 patent or Dalhoff combined with CILOXAN® PDR and/or Petersen Abstract, relying on similar motivations to create an alternative or improved ophthalmic therapy.

4. Key Technical Contentions (Beyond Claim Construction)

  • Secondary Considerations Rebuttal: Petitioner dedicated significant argument to preemptively rebutting Patent Owner's likely reliance on secondary considerations of non-obviousness. Petitioner contended that any alleged "unexpected results" of moxifloxacin were, in fact, entirely expected by a POSA. The superior performance of moxifloxacin was a direct and foreseeable consequence of its known properties, including superior MIC values against certain bacteria and higher aqueous solubility compared to prior art compounds like ciprofloxacin, which were documented in references like Dalhoff and Petersen.
  • No Teaching Away: Petitioner argued that the prior art did not teach away from the invention. Patent Owner's prior arguments regarding the toxicity of fluoroquinolones were misplaced, as they relied on data from systemic administration, not the much smaller and safer doses used in topical ophthalmic treatments. Further, while moxifloxacin may have been less active against P. aeruginosa than ciprofloxacin, its known superior activity against gram-positive pathogens like S. aureus provided a compelling reason for its development as an ophthalmic treatment.

5. Relief Requested

  • Petitioner requests institution of an inter partes review (IPR) and cancellation of claims 1, 15, 17-20, 22-32, and 34-41 of the ’070 patent as unpatentable.