Inutility finding overturned by Federal Court of Appeal in first application of Supreme Court's Esomeprazole decision

The Federal Court of Appeal's (FCA) first application of the Supreme Court of Canada's (SCC) decision in AstraZeneca Canada v Apotex[1] [esomeprazole] overturns a Federal Court decision in which allegations of inutility based on a failure to demonstrate or soundly predict a promise were found to be justified. The FCA in Bristol-Myers Squibb v Apotex finds that a demonstration of in vitro kinase inhibition "certainly meets the minimal utility requirements that are now applicable following the decision of the Supreme Court in esomeprazole."[2]

Background

Dasatinib is the active ingredient in Bristol-Myers Squibb's (BMS) SPRYCEL®, indicated for the treatment of chronic myeloid leukemia in adults. As of the filing date of the patent at issue (the 932 Patent) the inventors had established via in vitro testing that dasatinib inhibits enzymes known as protein tyrosine kinases or "PTKs". However, the ability of dasatinib to treat PTK-associated disorders was not demonstrated or soundly predicted as of the filing date.

The 932 Patent contains claims to the compound dasatinib itself (claim 27) as well as to various uses, such as the use of dasatinib as a treatment of a PTK-associated disorder (claim 31). Further, the disclosure of the 932 Patent contains a section entitled "Utility" that states, among other things, that "[t]he compounds of the present invention inhibit [PTKs]…and are thus useful in the treatment, including prevention and therapy, of [PTK]-associated disorders".

The underlying application was held before the release of esomeprazole. At first instance, Apotex argued that the 932 Patent promises, among other things, use in treatment of PTK-associated disorders.[3] By contrast, BMS argued that there is no explicit promise contained in the 932 Patent and thus the fact that dasatinib was demonstrated to be a PTK inhibitor was satisfactory to meet the utility requirement.[4] Manson J. accepted Apotex's position and held that the patent's specification makes an overarching promise of utility of use in the treatment of PTK-associated disorders.[5] Apotex's allegation of inutility was thus found to be justified as this use was not demonstrated or soundly predicted by the filing date.[6]

The FCA's Application of Esomeprazole

The FCA unanimously overturned the lower court decision on the basis of esomeprazole. The FCA began its analysis by setting out the two-part utility test identified in esomeprazole, which requires:

1. Identifying the subject-matter of the invention; and
2. Asking whether any scintilla of utility connected to that subject-matter was demonstrated or soundly predicted as of the filing date.[7]

The FCA found the subject-matter to be the bare compound dasatinib and that there was a demonstration of at least a scintilla of utility based on the ability of dasatinib to inhibit PTKs.[8]

Apotex attempted to argue that PTK inhibition could not have satisfied the utility requirement because in vitro inhibition purportedly did not constitute a practical use. In particular, in submissions directly addressing the impact of esomeprazole, Apotex argued that "inhibition of this sort [i.e. kinase inhibition] cannot constitute a use at law", as it "is precisely the sort of "laboratory curiosity" and mere "starting material" for further research that AstraZeneca SCC held was incapable of satisfying the utility requirement imposed by the Patent Act."[9]

The FCA's decision directly addressed Apotex's submissions and rejected them, stating:

I disagree [with Apotex's submissions]. Establishing that a compound has the ability to inhibit a biological target implicated in disease is doubtlessly a useful discovery. Here, it was known as of the relevant date that enhanced activity of PTK was involved in many diseases, as stated in the specification and confirmed in the evidence of several of the experts. Thus, discovery of a substance that acted to inhibit certain PTKs represented an important advance and certainly meets the minimal utility requirements that are now applicable following the decision of the Supreme Court in Esomeprazole.[10]

Conclusion

While esomeprazole is clear on its face, the FCA has now confirmed that any scintilla of utility related to the subject-matter of the invention is sufficient to meet the Patent Act's utility requirement. The reference to the need for a "practical utility" in esomeprazole in no way elevates the utility requirement. Uses such as in vitro inhibition can meet the scintilla test as they relate to "actual results" and "known objectives".[11]