Janssen Inc v Teva Canada Ltd, 2015 FC 247

The Federal Court (“FC”) has reminded us that a selection patent will typically require something more than routine testing to justify the reclaiming of a particular compound within a previously known class of compounds. Although a selection patent is not in principle assessed differently than any other patent, the non-obviousness requirement for a selection patent will be informed by whether the reclaimed compound possesses a special property or an unexpected character from those comprising the genus. [18] A person skilled in the art is not doing anything inventive when he or she simply performs routine bench work to choose between options that have been disclosed in a prior patent to build a molecule that he or she expects will work. [70]

Background: The ‘936 Patent for Bortezomib as a Proteasome Inhibitor for Cancer Treatment

Janssen Inc. (“Janssen”) brought an application under the Patented Medicines (Notice of Compliance) Regulations, to prohibit Teva Canada Ltd. (“Teva”) from being issued a Notice of Compliance for the compound bortezomib until after the expiration of Canadian Patent No. 2,203,936 (the “’936 Patent”). [1]

Bortezomib, a boronic acid compound, is a proteasome inhibitor, which is useful in treating proliferative cell diseases like cancer. [1] Bortezomib was being sold by Janssen in Canada under the brand name Velcade for the treatment of two forms of cancer. [2] Teva brought a Notice of Allegation against the ‘936 Patent alleging that it was invalid on the ground of anticipation, obviousness, invalid selection and lack of demonstrated or predicted utility. The allegations of anticipation and lack of sound prediction were later withdrawn by Teva. This FC decision dealt only with the issue of obviousness. [2]

Three claims were at issue:

• Claim 69, which claims bortezomib or the pharmaceutically acceptable salts or esters of bortezomib;
• Claim 78, which covers a therapeutically effective amount of bortezomib, its salts or esters, to treat cancer in a patient; and
• Claim 135, which claims bortezomib in solution suitable for administration to a patient. [6]

The FC began the obviousness analysis with reference to the four-part test to be applied, as set out by the Supreme Court of Canada in in Apotex v Sanofi-Synthelabo Canada Inc, (2008 SCC 61). [13]

The inventive concept was not limited to the compound bortezomib itself. It also included its property as a proteasome inhibitor. However, the FC held that the inventive concept did not “incorporate any enhanced aspects of potency or selectivity nor does the [‘936] Patent assert any such relative advantages.” [20]

The ‘904 Selection Patent Disclosed Bortezomib as a Proteasome Inhibitor

Teva alleged that the ‘936 Patent was a selection from the ‘904 Patent, a genus patent that disclosed bortezomib. [26] The FC recognized that a compound falling within a previously claimed genus of compounds could be reclaimed as a valid selection so long as it had not been made previously and it possessed a special property of an unexpected character from those comprising the genus. [18, see also Sanofi 9-10]

The FC agreed with Teva that the ‘936 Patent was a selection patent from the ‘904 Patent, in which it was claimed for exactly the same use, as a proteasome inhibitor. [26-27] The FC favoured the evidence of Teva’s experts that a person of skill would know that various substitutions recognized by the prior art would lead to a potent inhibitor of the proteasome. [40] The FC did not find that bortezomib possessed “a special property of an unexpected character” or “a substantial advantage over the genus from which it was selected.” [44]

One of the key structural features of bortezomib that was material to the obvious analysis was that it had an N-terminal pyrazinecarbonyl moiety. [9] Janssen argued that bortezomib was not a selection from the ‘904 genus of compounds because the ‘904 Patent did not disclose pyrazinecarbonyl as a potential N-terminal blocking group. The FC disagreed and held that it was known in the prior art. [54, 57] The FC further determined that even if it was not known in the prior art, then its selection would have been obvious to the person skilled in the art. [56]

Janssen attempted to argue that the course of conduct followed to select the pyrazinecarbonyl blocking group was “arduous or fraught with difficulty.” [69] However, the FC did not believe that the evidence supported that assertion. There were no inventive steps involved. The FC held that Janssen “simply selected a blocking group from among a group of available choices with an expectation that it would provide the requisite protection to the active part of the bortezomib molecule.” [70]

The FC held that “the ‘904 Patent provided the person of skill with a clear roadmap to bortezomib,” [40] and therefore held that Teva’s allegation of obviousness was justified and dismissed Janssen’s prohibition application.

Commentary

While selection patents encourage inventors to discover new advantages for compounds within a known class, a valid selection patent must disclose something that is new, useful and not obvious, which typically necessitates that the selection possess a special property of an unexpected character from those of the genus. The FC analyzed the evidence proffered by both parties’ experts and identified strengths and weaknesses in both. However, on balance, the FC accepted and favoured Teva’s experts evidence over Janssen’s in coming to its conclusion that the ‘936 Patent was obvious.