moxifloxacin / 1,340,114 – 2,342,211 – 2,192,418 / VIGAMOX
Previous posts have discussed the issues raised by the 114 patent. The issues raised by the 211 and 418 patents turned largely on the facts.
The 211 patent claimed the use of a specified concentration of moxifloxacin for use in the treatment and prevention of ophthalmic infections. The prior art, in particular the US 942 and 517 patents (full patent number not provided), disclosed the uses of a large class of compounds, including moxifloxacin, for the treatment of an extensive list of diseases, and disclosed a broad dosage range. Alcon in effect argued that the 211 patent was a selection patent over the 942 prior art . The problem for Alcon was that a selection patent must disclose some special advantage over that which would be expected from mere membership in the class. Alcon appealed to reduced toxicity , and effectiveness against P aerugionosa, a particularly nasty eye pathogen , but on the facts, the lack of toxicity was not surprising , and special effectiveness against P aerugionosa was not disclosed . Consequently, the invention was obvious . It was what the Europeans would call an arbitrary selection: T 0939/92 Triazole / AgrEvo ¶ 2.5.3. While not framed as such, moxifloxacin (NOC) is an example of the obviousness requirement being used to police selection inventions.
The 418 patent claimed the monohydrate form of moxifloxacin (Claim 1) and the monohydrate in a specific crystalline form (Claim 2), which was said to have superior storage and manufacturability properties. The Cobalt product was in solution, not a solid form, so it was conceded that the product itself did not infringe, and the question was whether Cobalt’s process for making the product infringed . Alcon’s infringement case failed for lack of evidence.
Phelan J held
 I agree with Cobalt’s submission that based on Justice McGillis’ decision in SmithKline, where the allegation is that a form of crystal will be present at some point in the manufacturing process, it must be proven that this actually occurs rather than merely raising it as a possibility.
 A possibility of infringement is not enough to rebut the presumption of truth of the allegations contained in an NOA (Pfizer Canada Inc v Novapharm Ltd, 2005 FCA 270, 341 NR 330).
In the result, Alcon simply failed to meet its burden of proof of establishing infringement .