Amgen's cinacalcet application dismissed based on failure to meet selection patent criteria

4 minute read
01 November 2015

Justice Phelan has dismissed an application by Amgen to prohibit the Minister of Health from issuing a Notice of Compliance to Mylan for Amgen’s secondary hyperparathyroidism medication cinacalcet (SENSIPAR®). In reasons dated Nov. 3, 2015, Justice Phelan agreed with Mylan’s allegations that Amgen’s Canadian Patent 2,202,879 (the “879 Patent) was not a selection patent, and that the claim at issue was not novel or inventive.

The 879 Patent was filed in October 1995 and contained claims to various compounds, including a claim specific to the cinacalcet compound (claim 5). Claim 5 was the only claim at issue. Critical in this proceeding was a different Amgen patent with the same inventors. Canadian Patent 2,115,828 was published in 1993 and disclosed an “enormous” genus of compounds that encompassed cinacalcet. Both the 879 and 828 Patents stated that the claimed compounds were active at calcium receptors in the body.

Mylan alleged that claim 5 was anticipated, obvious and double patented in light of the 828 Patent. Amgen argued that cinacalcet was a selection from the 828 Patent based on the fact that the calcium receptor theory underlying the 828 Patent was not accepted by a skilled person until after the 879 Patent was filed.

Justice Phelan found that the 879 Patent was not a selection patent. He found that the calcium receptor theory was known and accepted in the art by the time that the 828 Patent was filed.  Thus, following Plavix SCC1 and the IG Farbenindustrie2 criteria, cinacalcet did not possess any special advantage.

The Court also found that claim 5 was not novel. Justice Phelan relied on a concession by Amgen’s expert that a skilled person working claim 1 of the 828 patent would have made cinacalcet to establish disclosure, as well as the fact that only “mechanical” testing of about 200 828 Patent compounds was needed to get to cinacalcet.

The Court also found that, as claim 5 was not an inventive selection, the inventive concept was the bare compound itself. Thus, claim 5 was found to be obvious based on the 828 Patent.

The Court’s analysis raises some questions. First, it seems peculiar that so much time was spent analyzing the skilled person’s knowledge as of the filing date of the earlier 828 Patent for the purpose of selection. The appropriate consideration for determining whether a substantial advantage existed should not be based on the skilled person’s understanding at the time of the genus patent; rather, the appropriate consideration is whether the species contains any advantages as compared with the genus patent itself.

Second, the finding that the genus disclosed the species for novelty purposes appears to run contrary to Plavix SCC. The “mechanical” testing of 200 compounds would not meet the necessarily infringe test from Plavix SCC.

1 2008 SCC 61

2 (1930), 47 RPC 289

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