Case: Amgen Canada Inc v Mylan Pharmaceuticals ULC et al, 2015 FC 1244
Drug: SENSIPAR (cinacalcet)
Nature of case: Prohibition application regarding validity of selection patent
Successful party: Mylan Pharmaceuticals ULC
Date of decision: November 3, 2015
Amgen Canada Inc. (Amgen) markets and sells cinacalcet hydrocloride in Canada under the name SENSIPAR® for use in the treatment of hypercalcemia. Mylan Pharmaceuticals ULC (Mylan) sought approval of its generic cinacalcet product for the same treatment indication.
The Federal Court dismissed Amgen’s application for an order prohibiting the Minister of Health from issuing a Notice of Compliance (NOC). Justice Phelan held that Mylan’s allegations that the relevant patent was invalid because it is not a valid selection patent, and on the bases of anticipation, obviousness, and obviousness-type double patenting, were justified.
The Canadian Patent No. 2,202,879 (879 Patent) is listed on the patent register in respect of SENSIPAR®. The 879 Patent discloses and claims a class of calcimimetic compounds that includes cinacalcet, and has a specific compound claim for cinacalcet and its pharmaceutically acceptable salts. Claim 5, the compound claim for cinacalcet, was the only claim at issue.
Canadian Patent No. 2,115,828 (828 Patent) is a prior art patent that claims a larger class of compounds, which includes both the entire class of compounds claimed and disclosed in the 879 Patent and cinacalcet.
Several named inventors are common to both patents.
The 879 Patent is Not a Selection Patent
Amgen argued that the 879 Patent, and cinacalcet, are each selections from the 828 Patent. Justice Phelan rejected this argument and held that the 828 Patent teaches all relevant aspects of the compounds disclosed and claimed in the 879 Patent, including in claim 5.
Justice Phelan found that the compounds disclosed and claimed in the 879 Patent, including cinacalcet, had no unexpected advantage over the compounds disclosed and claimed in the 828 Patent. Consistent with this, the 879 Patent makes no promise regarding the biological activity of any claimed compound. Justice Phelan reasoned that a compound selected from a class of compounds does not offer an unexpected advantage where the selected compound has the same activity as is predicted for the entire class.
Claim 5 of the 879 Patent is Anticipated
Mylan argued that the skilled person, starting with the preferred compounds in the 828 Patent and using common general knowledge, would need to test no more than 200 molecules to arrive at cinacalcet and that the testing itself was mechanical. Justice Phelan accepted Mylan’s argument and found that there was no “inventive step” required for the skilled person to arrive at cinacalcet based on the 828 Patent disclosure(s). Justice Phelan held that the 879 Patent was anticipated by the 828 Patent on that basis.
Cinacalcet was not exemplified in the 828 Patent from the class of trillions of compounds disclosed therein, but the 828 Patent disclosure was found to anticipate claim 5 of the 879 Patent nonetheless.
Claim 5 of the 879 Patent is Obvious
Mylan argued that it would have been “obvious to try” to make cinacalcet, since it falls within the class of compounds disclosed in the 828 Patent. Justice Phelan accepted Mylan’s argument and relied on the same reasoning as set out in his analysis of anticipation.
In answer to the often-asked question, “if it is was so obvious, why did you not do it?”, Justice Phelan wrote that the threat of infringing the 828 Patent would have disincentivized Mylan from experimenting with compounds claimed therein.
Obviousness-type double patenting was not addressed separately from obviousness.