Pharmascience Sleeping Like A Baby After Sublinox Patent Win

On December 9, 2016 Justice Manson released his Public Judgement and Reasons dismissing Meda’s application for a prohibition order regarding Pharmascience’s zolpidem product and Canadian Patent No. 2,629,988. Zolpidem is used for the treatment of insomnia and is marketed under the trade name SUBLINOX. The 988 Patent is generally directed to pharmaceutical compositions of zolpidem comprising ordered mixtures of microparticles of zolpidem, water-soluble carrier particles and bio/mucoadhesives.

Overbreadth

Pharmascience had alleged that all claims of the 988 Patent are overly broad because they are missing the essential limitation that the formulation be essentially free from water. Justice Manson found that the skilled person would know that the formulation would have to be essentially free from water to work. In other words, being essentially free from water was implicit in the claims and therefore the claims were not overly broad.

Pharmascience also argued that claim 1 is overly broad for missing another essential limitation requiring that the bio/mucoadhesive agent be positioned on the surface of the carrier particles. Justice Manson, relying on the principles of claim redundancy, held that claim 1 was overly broad for omitting this essential limitation:

[168] I agree that a POSITA, reading claim 1 in light of the specification as a whole, with a mind willing to understand, would know that the formulation would have to be essentially free from water to work. However, because the limitation of the bio/mucoadhesion agent being adhered to the surface of the carrier particles is provided in claims 2 and following, the presumption against redundancy precludes the limitation from being implied into claim 1 (see Patent Rules, SOR/96-423, s 87; Bridgeview at paras 27; Eli Lilly at paras 90, 122). Since this limitation is an essential feature of the invention and necessary for the invention to work, claim 1 is broader than the invention made or disclosed.

Apart from claim 1 being overly broad, Justice Manson held that Pharmascience’s remaining invalidity allegations were not justified. Justice Manson found that the utility of rapid release and absorption resulting from sufficient bio/mucoadhesion had been demonstrated and that the prior art cited by Pharmacscience failed to disclose or enable any claims of the 988 Patent. Justice Manson also rejected Pharmascience’s obviousness allegation, in light of  Pharmascience’s own expert conceding that the invention was an unusual approach and very different from all formulations he had read:

[151] The Applicants relied on Pharmascience’s own expert’s evidence, that of Dr. Smart, who on cross-examination admitted that, in his 2004 review article “Recent Developments in the Use of Bioadhesive Systems for Delivery of Drugs to the Oral Cavity”, the ‘988 invention was “an unusual approach” and “very different from all the formulations that [he’d] read. So [he] thought it was worth reporting…this was not like everything else [he] was looking at”.

Non-Infringement

Pharmascience argued that PMS-Zolpidem does not have an ordered mixture or a bio/mucoadhesive component and therefore does not infringe any claim of the 988 Patent. While key portions of Justice Manson’s reasons regarding infringement are redacted, his finding of non-infringement appears to be based on the facts.

Sufficiency of the NOA

Meda took issue with documents listed but not discussed in Pharmascience’s NOA as well as several instances where it alleged Pharmascience’s experts cited documents for propositions differing from those set out in the NOA. Meda argued that this evidence should be struck as it would allow Pharmascience to improperly stray from its NOA and that since many of the documents were not discussed in the NOA they were denied proper notice of the case to be met.

After carefully reviewing the NOA Justice Manson declined to strike any of the impugned evidence but noted that any expert evidence raising facts broader than the NOA was given no weight as was evidence used for a purpose not set out in the NOA. In doing so, Justice Manson reiterated that the prohibition against raising new facts does not mean that experts cannot rely on documents not discussed in the NOA to support facts clearly set out in the NOA:

[38] … However, as stated above, the prohibition against raising new facts does not mean that experts cannot rely upon documents not discussed in the NOA to support facts clearly in the NOA.

Pharmascience received its NOC for its PMS-zolpidem product on December 7, 2016.

A copy of Justice Manson’s Public Judgment and Reasons can be found here.