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Bristol-Myers Squibb obtains Order of prohibition against Mylan regarding efavirenz

On September 27, 2012, Justice Barnes of the Federal Court granted Bristol-Myers Squibb ("BMS") an Order prohibiting the Minister of Health from issuing a notice of compliance ("NOC") to Mylan Pharmaceuticals ULC for a generic efavirenz product (BMS's SUSTIVA) until the expiry of Patent No. 2,101,572 (’572), but not Patent No. 2,279,198 (’198). With respect to the ’572 Patent, Justice Barnes held that the notice of allegation ("NOA") was legally insufficient, and in any event Mylan's inutility allegation was not justified. With respect to the ’198 Patent, Justice Barnes held that Mylan's allegations of anticipation and obviousness were not justified, but that BMS had failed to establish that Mylan's allegation of non-infringement was not justified.

Efavirenz is a non-nucleoside reverse transcriptase inhibitor ("NNRTI") used to treat HIV infection by inhibiting HIV reverse transcriptase ("RT"). The ’572 Patent claims a family of NNRTI compounds including efavirenz, while the ’198 Patent claims a particular crystal form of efavirenz (Form I).

Regarding the sufficiency of the NOA for the ’572 Patent, BMS argued that Mylan failed to put its inutility allegation into play because the evidence of one of its experts, Dr. Romero, substantially differed from the NOA. More specifically, in its NOA, Mylan asserted that the ’572 Patent promised that efavirenz is more effective against "all known resistant mutants of HIV RT than previously known compounds." However, based on the evidence of one of Mylan's experts, Mylan's construction and utility case was premised upon the failure of the inventors to test efavirenz against a specific ’188 mutation. Justice Barnes accepted the arguments of BMS, noting that "BMS's experts were met with evidence from Dr. Romero about the scope of the disputed claims that was significantly different than what Mylan had asserted in its NOA. This approach left BMS to effectively guess about the real grounds for Mylan's allegation of inutility and it represented an inappropriate piecemeal attack on the Patent." As the NOA was legally insufficient, Justice Barnes concluded that BMS had met its burden on the issue of inutility.

Justice Barnes also found in any event that no witnesses accepted Mylan's construction of the promise as set out in its NOA and therefore the allegation of inutility was not justified.

With respect to the ’198 Patent, Justice Barnes concluded that it was neither anticipated nor obvious. Mylan alleged anticipation on the basis that practising a prior patent necessarily produced Form I. Justice Barnes rejected the argument, accepting BMS's expert's evidence that the form produced by the prior patent had a substantially different melting point from that of Form I. With respect to obviousness, Justice Barnes concluded that, although other crystal forms of efavirenz were known in the prior art, the amount of effort required to find Form I of efavirenz was not routine or non-arduous, nor would it be self-evident that Form I of efavirenz would be useful. Accordingly, the allegation of obviousness was not justified.

However, Justice Barnes concluded that Mylan's allegation of non-infringement of the ’198 Patent was justified. BMS argued that the Mylan NOA contains an admission that another form of efavirenz used by Mylan will convert to Form I during tablet manufacturing under mild drying conditions; because Mylan's product will have to be dried during its wet granulation tabletting process, some detectable amount of Form I will be created by polymorphic conversion. Justice Barnes rejected the argument that the NOA constitutes a binding admission, including because the conditions referred to were not shown to be an aspect of Mylan's process. Although Mylan declined to provide samples of its product, detailed information regarding its manufacturing processes, or the final composition of its product to BMS or its own expert, Justice Barnes concluded that BMS could have conducted experiments to establish some level of conversion. Since no such testing was done and BMS's expert's opinion was dependent on the finding of a binding admission in the NOA, BMS had no evidence to support its conversion theory. Justice Barnes also declined to support the infringement allegation by drawing an adverse inference from Mylan's refusal to disclose as that refusal was upheld by a prothonotary, affirmed on appeal, and BMS had the ability to make and test Mylan's form of efavirenz.

As of the publication date, there has been no appeal.

Bristol-Myers Squibb Canada Co et al v Mylan Pharmaceuticals ULC et al, September 27, 2012.

Federal Court decision — 2012 FC 1142.

Kyle A. Ferguson, Toronto

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