Robins Kaplan LLP

Case Name: Mitsubishi Tanabe Pharma Co. v. Sandoz, Inc., No. 17-5319, 2021 WL 1845499 (D.N.J. Apr. 7, 2021) (Wolfson, C.J.) 

Drug Product and Patent(s)-in-Suit: Invokana® and Invokamet® (canagliflozin), U.S. Patents Nos. 7,943,788 (“the ’788 patent”), 8,222,219 (“the ’219 patent”), and 8,785,403 (“the ’403 patent”)

Nature of the Case and Issue(s) Presented: Invokana and Invokamet treated type 2 diabetes by inhibiting SGLT2 in the kidneys and suppressed glucose reabsorption, which, in turn, increased glucose levels in urine and reduced glucose levels in the blood. The patents-in-suit were all related and claim the drug-molecule canagliflozin or methods of using the same. Defendant stipulated that it infringed the patents-in-suit, but argued that: (i) they were invalid as obvious; and (ii) the ’788 patent was invalid for obviousness-type double patenting.

Why Plaintiffs Prevailed: Defendant argued that a POSA would have selected dapagliflozin as a lead compound because it was a “promising biological mechanism” that had shown potential in “animals and even in people of lowering blood sugar.” More particularly, SGLT inhibitors, such as dapagliflozin, were “just right” for development, as there were scientific advances to be made, patients in need, and “lots of money to be made.” Further, according to Defendant, a POSA would have selected dapagliflozin as a lead compound because it was not subject to the metabolic instability that plagued other C-glucoside compounds.

According to Plaintiff, though, in choosing a lead compound for potential antidiabetic treatment, a POSA would have considered: (i) compounds previously approved by the FDA; (ii) compounds with a demonstrated efficacy in humans; and (iii) compounds with preliminary activity data at the biological target. Based on this explanation, the court found that Defendant failed to establish why a POSA would focus specifically on SGLT inhibitors and, in particular, dapagliflozin. The court also found that even if dapagliflozin were chosen as a lead compound, a POSA would not have had a motivation or expectation of success in arriving on the claimed compound.

Next, Defendant argued that the expiration date of a patent dictated the obviousness-type double patenting (“OTDP”) inquiry. Here, Defendant argued that the ’788 patent—that was subject to a 1,079 day priority term adjustment (“PTA”) based on delays caused by the patent office during prosecution—was invalid for OTDP based on the earlier expiration date of the related ’219 patent. The court noted that the Federal Circuit had yet to consider whether a later-filed, later-issued patent that expired before the earlier-filed, earlier-issued patent due to a PTA can act as an OTDP reference. The court concluded, however, that absent the PTA—that was properly granted by the patent office—both the ’788 patent and the ’219 patent would have the same expiration date, and thus there was no potential for gamesmanship (i.e. inventors using a second, later expiring patent for the same invention). For this reason, the ’788 patent was not invalid for OTDP.