June 9, 2020
In Biogen v Taro, 2020 FC 621, the Federal Court dismissed two actions by the plaintiffs, Biogen Canada Inc., Biogen International GmBH and Acorda Therapeutics Inc. (collectively “Biogen”), brought pursuant to subsection 6(1) of the PM(NOC) Regulations for a declaration that Taro Pharmaceuticals Inc. (“Taro”) and Pharmascience Inc. (“Pharmascience”) would infringe certain claims of Canadian Letters Patent No. 2,562,277 (the “277 Patent”).
The 277 Patent is listed on the Patent Register in respect of Biogen’s drug FAMPYRA, which is indicated for use in adult multiple sclerosis patients with a walking disability.
While the Court addressed other issues, this article focuses on anticipation and obviousness.
Asserted Claims of the 277 Patent
The 277 Patent is titled “Methods of Using Sustained Release Aminopyridine Compositions”. The invention claimed in the 277 Patent relates to using sustained release (“SR”) compositions of aminopyridines for the treatment of various diseases, including multiple sclerosis.
One embodiment relates to a method of selecting individuals based on responsiveness to a treatment (the “responder” or “post hoc” analysis). This method is not part of the invention as claimed in the 277 Patent, even though the disclosure refers to a method for selecting individuals.
The subject matter of the asserted claims relates to the twice daily (“bid”) use of 10 mg of a fampridine SR composition for improving walking (or increasing walking speed) in a subject with multiple sclerosis in need thereof for a period of at least two weeks.
Expert Opinion Evidence
The Court noted that both parties’ main expert witnesses engaged in improper advocacy and took unreasonable positions, resulting in their evidence being given little weight.
For example, Dr. Leist, one of Biogen’s experts, approached much of the prior art with an apparent mind unwilling to understand, and his approach seemed focused on disparaging the cited art that was unfavourable to Biogen to the point that, in his opinion, the skilled person would not have learned anything from these prior art references.
Dr. Ebers, one of the Defendants’ experts, disparaged virtually every study put forward as prior art, labelling them as speculative, poorly designed and limited by the small number of patients tested. In addition, approximately one hundred paragraphs of Dr. Ebers’ report were copied nearly verbatim from Taro’s Notice of Allegation (“NOA”), which Dr. Ebers acknowledged he had never reviewed. The Court was of the view that this type of conduct, where the expert accepts large portions of a NOA prepared by legal counsel which the expert has not seen or reviewed, puts into real doubt the impartiality and independence of the expert.
The Court considered whether the subject matter of the asserted claims of the 277 Patent was anticipated by the Acorda S-1 reference, which was the registration statement submitted to the US Securities and Exchange Commission as part of Acorda’s process of going public (“Acorda S-1”).
Acorda S-1 described the MS-F201 and MS-F202 studies, stating that MS-F201 was completed in 2001, and MS-F202 was initiated in early 2003, with results anticipated by the end of March 2004.
The MS-F201 results disclosed that the use of a fampridine SR composition at unit doses of 10 to 25 mg bid for treating a subject with multiple sclerosis was associated with a statistically significant improvement in walking.
The MS-F202 study protocol, as included in Acorda S-1, disclosed the use of a fampridine SR composition at a unit dose of 10 mg bid for treating a subject with multiple sclerosis for a period of twelve weeks where the primary study endpoint was improvement in walking speed. There were no results included. Therefore, the skilled person would not have known whether using fixed doses of 10 mg bid resulted in a statistically significant improvement in walking speed.
The Court noted that this was similar to the allegedly anticipatory art in Hospira Healthcare v Kennedy Trust, 2020 FCA 30 (“Hospira”). In Hospira, the Federal Court of Appeal reiterated that the disclosure requirement is satisfied if performing what is described in the prior art reference would necessarily result in infringement.
The Court held that, despite the lack of results from MS-F202, performing the MS-F202 study protocol would necessarily result in infringement of the 277 Patent, and hence the disclosure requirement was satisfied for some of the claims of the 277 Patent.
For enablement, the Court noted that, as highlighted by the Federal Court of Appeal in Hospira, what must be enabled are the essential elements of the claims, not any particular experiments disclosed (and not claimed) in the 277 Patent. Therefore, the focus of the Court’s analysis remained on the essential elements of the claims, rather than the skilled person’s ability to perform the specific post hoc responder analysis detailed in the disclosure.
The Court determined that, following the MS-F202 protocol, the skilled person would have been able to perform the claimed invention without the exercise of inventive ingenuity or undue experimentation. Therefore, the Court held that the MS-F201 results and the MS-F202 protocol contained in Acorda S-1 both disclosed and enabled the skilled person to perform the subject matter of claims 17, 18, 31 and 32 of the 277 Patent.
Because the narrower claim limitation of dosing “every 12 hours” was not disclosed in Acorda S-1, claims 23, 28, 37 and 42 were not anticipated.
The Court found that all of the asserted claims of the 277 Patent were invalid for obviousness.
The Court noted that, in keeping with Hospira, so long as prior art can be proven to have been publicly available before the relevant claim date, it will not be excluded from the obviousness analysis solely because the skilled person would not have found it conducting a reasonably diligent search.
In the Court’s view, the skilled person would have routinely bridged the gap between the state of the art and the inventive concept (i.e., the essential elements) of the asserted claims. The skilled person would have understood that 10 mg bid dosing of fampridine SR was therapeutically effective to improve walking and increase walking speed for at least some patients with multiple sclerosis, and would have routinely verified this understanding by studying fixed doses of 10 mg bid fampridine SR.
The Court held that Acorda S-1 anticipated claims 17, 18, 31 and 32 and that all asserted claims of the 277 Patent were invalid for obviousness.