Canada: Supreme Court Amends Earlier Decision: Viagra Patent Not Void

In Teva Canada Ltd v Pfizer Canada Inc, the Supreme Court of Canada (the "SCC") held Pfizer's Canadian Patent No. 2,163,446 (the '446 Patent) to be "void" for not disclosing that sildenafil, the active ingredient in Viagra^TM, was the compound that had been demonstrated to work in patients. (Please click here for further details.) The SCC has now revised and clarified the wording of its decision. However, the immediate effect of the revised decision on the marketplace has not changed because generic sildenafil still has marketing authorization and is available for sale in Canada.

The Background

The holding by the SCC that the '446 Patent was "void" was unusual in that the appeal had originated as an application brought by Pfizer under the Patented Medicines (Notice of Compliance) Regulations (the "PM(NOC) Regulations"). Teva (then Novopharm) had asserted to the regulator, Health Canada, that the '446 Patent was invalid and therefore should not prevent Teva from getting authorization (aka a Notice of Compliance "NOC") to market sildenafil for the use covered by the '446 Patent. Pfizer then initiated the application to request an order prohibiting the Minister of Health from issuing the marketing authorization to Teva until the expiry of the '446 Patent.

An application brought under the PM(NOC) Regulations is not the same as a full patent infringement or validity (impeachment) action. Applications are summary in nature and not determinative of the validity of a patent. Instead, a court determines whether or not the applicant (typically a brand name pharmaceutical company) has established, on a balance of probabilities, that allegations of invalidity put forward by the party seeking marketing authorization (typically a generic drug company) are not justified. If the court finds that these allegations are not justified, Health Canada is prohibited from giving the generic company its NOC until the patent expires. On the other hand, if the court finds allegations of invalidity put forward by the generic company are justified, it receives its NOC and can sell a generic version of the drug.

Irrespective of the litigation under the PM(NOC) Regulations, a patent impeachment action can still be brought separately. For example, another generic company, Apotex, has brought such an action seeking to invalidate the '446 Patent.

Why the SCC Order Changed

Subsequent to the SCC decision, (as reported here) Pfizer brought a motion requesting an order amending the judgment of the SCC or alternatively, an order directing that a motion for a re-hearing on the issue of remedy be made.

The SCC released a decision on the motion on June 4, 2013, granting it in part. The order granted amends the original reasons of the SCC to insert a passage indicating that the appeal originated as an application brought by Pfizer under the PM(NOC) Regulations. Portions of the reasons suggesting that the patent is "invalid" or "void" have now been replaced with language indicating that Teva established its allegation that the patent is not valid and that Pfizer's application for an order of prohibition is dismissed. Similar amendments were also made to the formal order.

These amendments indicate that the SCC did not invalidate Pfizer's '446 Patent in this case. In the separate Apotex impeachment action, the Federal Court of Appeal has yet to consider a lower court decision declaring the '446 Patent to be invalid and void. In the decision, the lower court had suggested that the SCC's determination that the '446 Patent did not meet the disclosure requirements was binding on it and would invalidate the patent regardless of whether the SCC went on to grant Pfizer's motion. A ruling that a patent is invalid in an impeachment action affects the patent itself and not just the parties involved in the case. Therefore, if all avenues of appeal uphold the lower court decision in the Apotex case, the '446 Patent (which will expire on May 13, 2014) will no longer stand in the way of parties seeking authorization to market generic sildenafil. If an appeal overturns the lower court decision, then Pfizer and Apotex may continue on with the lawsuit toward a final determination of validity.

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