On Feb. 16, 2021, Federal Circuit affirmed New Jersey district court which found alogliptin compound patent valid in a Hatch-Waxman litigation.
Plaintiff, Takeda owns US 7,807,689 patent which is related to alogliptin, a uracil-containing DPP-IV inhibitor useful for treating type II diabetes. Defendants, Torrent and Indoco filed ANDA with P-IV certification to US’689 patent. Defendants presented their case on obviousness-type double patenting and obviousness theories. District court after trial concluded that Defendants failed to prove by clear and convincing evidence that the challenged claims are invalid. You can read the summary reported “here“.
Defendants appealed district court’s several fact findings. Torrent based their obviousness-type double patenting theories using F162 compound as the lead compound. Torrent argued that POSA would have found it obvious to replace F162’s pyrimidinone scaffold with uracil, citing other references. But court said that these references failed to teach that uracil has some kind of DPP-IV inhibitory activity. Torrent’s another theory with respect to replacement of fluoro-olefin unit in F162’s pyrimidinone scaffold with an amide unit also fails. Court said that –
“Torrent has not identified anything in the prior art that would have motivated a skilled artisan to dispose of F162’s fluoro-olefin unit, let alone replace it with an amide, given myriad more conservative and predictable modifications that were available for transforming F162 into a “novel” compound”.
On the other hand, Indoco used DCAX as a lead compound and argued that DCAX’s xanthine scaffold can be replaced with uracil because xanthine and uracil are “interchangeable” naturally occurring nitrogenous bases. Court said that even assuming, arguendo, that the prior art would have motivated POSA to modify DCAX by replacing its xanthine scaffold with uracil, Indoco “failed to show that POSA would have [had] a reasonable expectation of success” with “this particular scaffold replacement.” The interchangeability references on which Indoco relies do not pertain to DPP-IV inhibitors or diabetes. And in the relevant art of pharmaceutical development, very small changes in molecular structure can have dramatic effects on the properties of the molecule.” Therefore, Indoco failed to prove this modification with reasonable expectation of success.
Thus, district court did not clearly err in their finding.