Case: Novartis Pharmaceuticals Canada Inc. v. Teva Canada Limited, 2013 FC 283

Drug: ACLASTA® (zoledronate)

Nature of case: Prohibition Application pursuant to s. 6 of the PM(NOC) Regulations

Successful party: Novartis Pharmaceuticals Canada Inc.

Date of decision: March 19, 2013

Overview

Novartis Pharmaceuticals Canada Inc. (“Novartis”) brought an application pursuant to s. 6 of the Patented Medicines (Notice of Compliance) Regulations for an order prohibiting the Minister of Health from issuing a notice of compliance to Teva Canada Limited (“Teva”) in respect of Teva’s proposed zoledronate tablets until the expiry of Canadian Patent Nos. 1,338,895 (the “859 Patent”) and 1,338,937 (the “937 Patent”). Zoledronate (sold by Novartis under the brand name ACLASTA®) is used, inter alia, to treat osteoporosis.

The ‘859 Patent is directed to a class of heteroarylalkane diphosphonic acids, of which zoledronate is a member. The ‘859 Patent does not contain a specific claim to zoledronate. Teva alleged that the ‘859 Patent was invalid for obviousness, lack of utility and insufficiency. The ‘937 Patent is directed to zoledronate and pharmaceutical compositions containing zoledronate. Teva alleged the ‘937 Patent is invalid for obviousness, lack of utility, insufficiency, and overbreadth.

The Court held that Teva’s allegation of lack of utility in respect of the ‘859 Patent was justified, as “there is nothing in the description of the ‘859 Patent that any witness said would establish a basis for sound prediction that all members of the class would have utility.” However, Justice Hughes found that Teva’s allegations in respect of the ‘937 Patent were not justified and issued a Prohibition Order.

Claims in Issue

Both the ‘859 Patent and the ‘937 Patent were filed prior to October 1, 1987 and are thus considered “Old Act” patents. At filing, the patents had overlapping claims and would have been subject to conflict proceedings, however, the patent owners resolved amongst themselves that the ‘859 Patent would contain the genus claims and the ‘937 Patent would contain claims specific to zoledronate.

Novartis asserted Claim 14 of the ‘859 Patent, which the Court construed as claiming “a class of some 1.2 million compounds all sharing a selection of molecules at the R1 and R2 positions placed on a biphosphonic backbone; zoledronate is but one of such compounds. "The ‘937 Patent contains only two claims, both of which were asserted by Novartis. Justice Hughes construed claim 1 as claiming the compound zoledronate and claim 2 as claiming a pharmaceutical composition containing zoledronate and pharmaceutical excipients.

Obviousness

As both patents are “Old Act” patents, obviousness is to be assessed as of the date of invention. The date of invention for the ‘859 Patent was held to be no earlier than the priority application, wherein the ‘class’ of compounds was articulated. The date of invention for the ‘937 Patent was held to be July 1987, the date on which the inventors made and tested zoledronate in rats.

(i) Inventive Concept

The Court held that the inventive concept of the ‘859 Patent was “a family of (about 1.2 million members) novel compounds containing a 5-membered, ring, which is connected to the geminal BP [bisphosphonate] carbon by a one-carbon linker (-CH2-). These BP’s have biological activity as calcium complex formers and inhibit bone resorption.”

Although the claims of the ‘937 Patent are directed only to zoledronate, the description of the ‘937 Patent discusses a larger class of compounds. Consequently, the Court considered whether the inventive concept of the ‘937 Patent could be construed as being broader than just zoledronate. Justice Hughes distinguished the Supreme Court’s recent VIAGRA decision, noting that as the ‘937 Patent only contained claims that related to a single compound the inventive concept could be limited to zoledronate “as a useful inhibitor of bone resorption in rats and that, as such, is suitable for use as a medicament in the treatment of diseases in humans associated with impairment of calcium metabolism.”

(ii) Differences between the State of the Art and the Inventive Concept

Teva argued that, at the relevant dates, it was known that bisphosphonate compounds inhibited bone resorption. Teva’s experts opined that, based upon the state of the art, the person of skill in the art would have known that members of the class of compounds would have bone resorption inhibition activity. They further opined that the person of skill in the art would know how to make zoledronate and know that it would have bone resorption inhibition activity.

Justice Hughes dismissed Teva’s experts’ opinions as being based on hindsight. The Court held that there was “too much uncertainty” as to whether particular chemical structures would be useful. Consequently, it was not “self evident” that what is claimed in either patent ought to work.

Utility

(i) ‘859 Patent

The evidence showed that the inventors named in the ‘859 Patent tested two compounds before the priority application was filed, neither of which was zoledronate, and only one of which falls within the scope of claim 14 of the ‘859 Patent. The inventors went on to make and test zoledronate prior to the filing of the Canadian application.

The Court held that the question in respect of utility was whether the testing of a few compounds could establish the utility for the claimed class. Justice Hughes found that “there is nothing in the description of the ‘859 patent that any witness said would establish a basis for sound prediction that all members of that class would have utility. In brief, the state of the art was at the empirical stage where compounds would have to be assessed individually. There was no consensus in the state of the art at the time that there was a basis for drawing conclusions as to a class.” On this basis, the Court found Teva’s allegation of invalidity to be justified.

(ii) ‘937 Patent

Justice Hughes held that the inventors made and tested zoledronate before the filing date and found it to be “useful for the stated purpose namely, a pronounced regulatory action on the calcium metabolism of warm-blooded animals”.

Sufficiency

The Court noted that Canadian law was not clear as to what the relevant date is for considering sufficiency. After reviewing English and Canadian jurisprudence, Justice Hughes determined that the “most appropriate date for consideration of sufficiency of a Canadian patent is the date of publication”. In the case of an “Old Act” patent, this would be the date the patent was granted. In the case of a “”New Act” patent, this would be the date of publication.

For the same reasons as discussed with respect to utility, Justice Hughes found that Teva’s allegations of insufficiency in respect of the ‘859 Patent were justified.

With respect to the ‘937 Patent, Justice Hughes distinguished the VIAGRA decision, as the claims in this case are directed to a single compound. As a result, the Court held Teva’s allegation of insufficiency was not justified. The Court noted that, at the time of filing, the ‘937 Patent contained additional claims to several compounds. Justice Hughes noted that if sufficiency had been assessed as at the filing date, the Court would have found that the application was no different than that considered by the Supreme Court in VIAGRA, and would have found the allegation of insufficiency justified.

Link to decision:

Novartis Pharmaceuticals Canada Inc. v. Teva Canada Limited, 2013 FC 283