The Federal Court has dismissed two infringement actions brought against defendants under subsection 6(1) of the Patented Medicines (Notice of Compliance) Regulations (Regulations), following a common trial on the validity of Canadian Patent No. 2,562,277 (277 Patent). The Court found that all the asserted claims – to uses for treating multiple sclerosis (MS) – were obvious and that some were anticipated. This is the third decision on the merits of an action under the Regulations since they were amended in September 2017. We previously reported on the first and second trial judgments.

The actions. The defendants, Taro and Pharmascience, are both seeking to market their own generic version of Biogen’s FAMPYRA® (fampridine). Both defendants denied infringement and alleged that the 277 Patent was invalid for anticipation, obviousness, and lack of patentable subject matter. The Court heard the invalidity allegations concurrently for both actions, with the two defendants relying on the same evidence, along with the infringement allegations against Taro.

Claim Construction. The Court found that the asserted claims all related to a particular treatment regimen: twice daily (bid) use of a fixed dose of 10 mg of a sustained release fampridine composition (fampridine SR) for improving walking (or increasing walking speed) in MS subjects with a walking disability, for a period of at least two weeks. The improvement must be quantitatively measured and statistically significant given the variability of symptoms and the prevalence of placebo effects in MS treatment. Dependent claims contained further limitations related to the pharmacokinetics or the administration of fampridine SR.

Anticipation. The Court found that four independent claims (without pharmacokinetic and administration limitations) were anticipated by a prior art document (Acorda S-1), which the patentee had publicly filed with the US Securities and Exchange Commission. Acorda S-1 describes two clinical studies (MS-F201, MS-F202) of fampridine SR for treating symptoms of MS. The Court found that Acorda S-1 met the disclosure and enablement requirements of anticipation for the four independent claims:

  • The disclosure requirement was met as: 1) Performing the MS-F202 study protocol described in Acorda S-1 would necessarily result in infringement; and 2) results from the MS-F201 study, which would have been understood by the skilled person as showing that 10 mg bid of fampridine SR was associated with a statistically-significant increase in walking speed. Since both the MS-F202 protocol and MS-F201 results were disclosed in the single Acorda S-1 document, the disclosure requirement had been met.
  • The enablement requirement was met even though performing the MS-F202 study protocol would have failed to achieve the study’s pre-defined endpoint (increased average walking speed). The Court emphasized that at the enablement stage of the analysis, the skilled person is willing to conduct routine trial-and-error experiments to get the invention to work. The skilled person would have been able to conduct a post hoc analysis of the data obtained from the MS-F202 study and determine that a subgroup of subjects had a statistically-significant increase in walking speed.

Obviousness. The Court found that all of the asserted claims were obvious. The difference between the prior art and the inventive concept was that fampridine SR, taken in fixed doses of 10 mg bid for at least two weeks, provides a statistically-significant improvement in walking (or walking speed) in MS patients with a walking disability. Bridging this gap would have been obvious to try:

  • Self-evident – It was more-or-less self-evident that trying a low dose of fampridine SR bid would work based on the prior art, including Acorda S-1, which reported statistically-significant increases in walking speed using pooled data with doses from 10 to 25 mg bid. Based on the results of MS-F201 and the MS-F202 study protocol in Acorda S-1, the skilled person would have focused on fixed doses of 10, 15, and 20 mg bid, and would have only needed to conduct a small trial comparing these doses over a time period longer than two weeks to confirm efficacy of the 10 mg fixed dose.
  • Extent of Effort – The skilled person could have arrived at the claimed invention by carrying out routine trials. The MS-F201 results and the MS-F202 study protocol provide the skilled person with a clear direction to pursue, and carrying out a similar study would have led to the invention.
  • Motive – The skilled person would have been motivated to pursue low doses of fampridine SR bid to improve walking in MS patients, as the prior art suggested that this treatment regimen would be effective.

The Court also found that the pharmacokinetic properties in the dependent claims added nothing inventive, as these were merely inherent properties of fampridine SR when dosed at 10 mg bid.  In addition, a prior art publication taught the pharmacokinetic properties of 10 mg bid fampridine SR and the skilled person would have combined this teaching with the teachings from Accord S-1.

Patentable subject matter.  The Court found that the asserted claims were not invalid as methods of medical treatment, as all the claims were limited to fixed dosages and intervals of administration.  The Court also found that Swiss-type claims, which claim the use of fampridine SR in the manufacture of a medicament, would not constrain the exercise of skill and judgment by medical professionals.

Biogen Canada Inc. v. Taro Pharmaceuticals Inc., 2020 FC 621