Pharma in brief - Federal Court dismisses prohibition application for non-infringement

Case:                                     Meda AB v Pharmascience Inc, 2016 FC 1362 (T-200-15)

Drug:                                     SUBLINOX® (zolpidem tartrate sublingual orally disintegrating tablets)

Nature of case:                   Prohibition application pursuant to section 6 of the Patented Medicines (Notice of Compliance) Regulations, SOR/93-133 (the Regulations)

Successful party:               Pharmascience Inc. (Pharmascience)

Date of decision:                December 9, 2016

 

Summary

Valeant Canada LP/Valeant Canada S.E.C. markets SUBLINOX® (zolpidem tartrate sublingual orally disintegrating tablets) in Canada for the treatment of insomnia.

Pharmascience sought approval for a generic version of SUBLINOX® and was opposed by Valeant, which asserted Canadian Patent No. 2,629,988 (the 988 Patent) under section 6 of the Regulations. The court found in favour of Valeant on the validity of all but one of the claims in issue, but held that Valeant failed to rebut Pharmascience’s non-infringement allegations. As a result, the court dismissed the application.

Background

The 988 Patent claims rapid-onset sublingual pharmaceutical compositions for treating the acute disorder insomnia, involving ordered mixtures and bio/mucoadhesives, a method for making such compositions, and their use in the manufacture of a medicament. Pharmascience alleged that the patent was invalid for anticipation, inutility, obviousness, and overbreadth and that its proposed generic product, PMS-zolpidem, will not infringe the patent.

File history inadmissible

The court relied upon the experts for the construction of “bio/mucoadhesive promoting agent” and “ordered mixtures,” both essential elements of all the claims. In reaching its construction, the court rejected Pharmascience’s argument that statements made in the prosecution of a corresponding European patent application regarding the meaning of one of these terms should be taken as an admission against interest in this case. The court held that the file history of the Canadian patent, and any corresponding foreign patent, is inadmissible for purposes of construction or as part of the common general knowledge.

Validity

  1. Anticipation. Pharmascience argued that the claims of the 988 Patent were anticipated by EPO 324,725 (the 725 Patent), which relates to pharmaceutical carrier substances. The 725 Patent includes an example of a formulation containing Ac-Di-Sol, which is disclosed to be a bio/mucoadhesive in the 988 Patent. However, Manson J agreed with Valeant that the 725 Patent taught the use of this compound as a disintegrant, not a bio/mucoadhesive. Since this is an essential element of the claims of the 988 Patent, the court rejected Pharmascience’s allegation.
  2. Obviousness. Pharmascience also argued that the 725 Patent, together with the common general knowledge on bio/mucoadhesive formulations, rendered the 988 Patent obvious. In dismissing this argument, Manson J emphasized the importance of the climate in the relevant field at the time of the invention and the motivation at the time to solve a recognized problem. He accepted that the question of whether one could make a rapidly dissolving sublingual dosage form with a bio/mucoadhesive was not being asked in the field and, what is more, the prior art taught away from it.
  3. Overbreadth. Claim 1 of the 988 Patent lacked two key limitations that were discussed in the description of the 988 Patent. Justice Manson held that one of these limitations was an implied requirement of claim 1. However, the other limitation was present in claim 2 (and claims depending therefrom). Justice Manson agreed with Pharmascience that since it was present in a dependent claim, it could not be implied into claim 1. He also agreed that claim 1 was thus invalid for failure to claim a feature necessary for the invention to work.
  4. Inutility. Justice Manson agreed with Valeant that the promised utility of the claims of the 988 Patent was demonstrated by two examples in the 988 Patent or, if not, it was soundly predicted when they were taken together with the common general knowledge. Pharmascience’s experts demanded a level of proof required for regulatory approval but beyond what was mandated by patent law. Justice Manson also rejected the argument that the claims lacked utility because one of the compounds listed as a bio/mucoadhesive in the description does not perform this function: he held that a skilled person would not have been confused by this error.

Non-infringement

Pharmascience argued that PMS-zolpidem contains neither an ordered mixture nor a bio/mucoadhesive component. Relying upon an analysis that was largely redacted in the public reasons for judgment, the court held that PMS-zolpidem did not contain an ordered mixture.

Link:

Meda AB v Pharmascience Inc.,2016 FC 1362

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