Case: Leo Pharma Inc v Teva Canada Limited et al, 2015 FC 1237
Drug: DOVOBET® (calcipotriol monohydrate / betamethasone dispropionate)
Nature of case: Prohibition application regarding validity of a formulation patent
Successful party: Leo Pharma Inc.
Date of decision: November 18, 2015
Leo Pharma Inc. (Leo) markets and sells 50 mcg/g calcipotriol and 0.5 mg/g betamethasone (as dipropionate) ointment in Canada under the name DOVOBET® for use in the treatment of psoriasis. Teva Canada Limited (Teva) sought approval of its generic ointment product for the same treatment indication.
The Federal Court granted Leo’s application for an order prohibiting the Minister of Health from issuing a Notice of Compliance. Justice Locke held that Teva’s allegations that the relevant patent is invalid for obviousness, lack of utility and insufficiency were not justified.
Canadian Patent No. 2,370,565 (565 Patent) is listed on the patent register in respect of DOVOBET®. The 565 Patent describes and claims a combined formulation of: i) at least one vitamin D or vitamin D analogue (Component A); ii) at least one corticosteroid (Component B); and iii) a solvent (Solvent C). The addition of the Solvent C resolves the instability issue that results when Components A and B are mixed together on their own.
Teva argued that the 565 Patent is obvious because, inter alia, the simultaneous topical use of Components A and B for the treatment of psoriasis was part of the common general knowledge at the relevant date. Justice Locke rejected this argument on the following bases: use of the combination was known, but not common, among skilled persons; and, it was neither known, nor obvious, that a pharmaceutical combination of Components A and B would be stable enough to be a practical pharmaceutical product with the addition of a Solvent C.
Justice Locke also found that the patented combination was not “obvious to try” since there were many possible combinations of Components A, B and C, not all of which would work.
No lack of utility
Teva argued that the 565 Patent lacked utility on two grounds: 1) it contains no drug-release or skin-penetration data and therefore, the skilled person could not soundly predict that all formulations would be effective; and 2) it claims millions of formulations, not all of which could be soundly predicted to be stable and effective. Justice Locke rejected both arguments.
Justice Locke rejected Teva’s first argument on the basis that it was not raised in notice of allegation (NOA). Justice Locke rejected Teva’s second argument on the basis that at least claim 17, the narrowest of the claims, was soundly predicted. It is enough that one claim of the 565 Patent is valid and infringed for Leo to succeed in its application.
Teva argued that because the 565 Patent is silent as to which of Components A or B has to be dissolved in Solvent C (if any) and that therefore, the skilled person could not put the invention into practice. Justice Locke rejected this argument on the basis that it was not raised in Teva’s NOA.
In any event, Justice Locke commented that Teva’s allegation was not justified. The Court reasoned that the process for making ointments was well-known at the time and that the skilled person would be able to make the claimed formulation using the teachings in the 565 Patent and her/his own knowledge.