In Sanofi-Aventis U.S., LLC v. Dr. Reddy’s Laboratories, Inc., [2018-1804, 2018-1808, 2018-1809] (August 14, 2019), the Federal Circuit affirmed the determination that claims 1 and 2 of U.S. Patent No. 5,847,170 were not invalid for obviousness.

The Federal Circuit noted that in cases involving new chemical compounds, it remains necessary to identify some reason that would have led a chemist to modify a known compound in a particular manner to establish prima facie obviousness of a new claimed compound. The reason need not be the same as the patentee’s or expressly stated in the art, but charting a path to the claimed compound by hindsight is not enough to prove obviousness. The Federal Circuit observed that any compound may look obvious once someone has made it and found it to be useful, but working backwards from that compound, with the benefit of hindsight, once one is aware of it does not render it obvious.

In its obviousness analysis, the district court considered the testimony of seven witnesses and seventeen prior art references and ultimately concluded that Defendants failed to prove that claims 1 and 2 of the ’170 patent would have been obvious. In addition, the district court found that some secondary considerations evidence supported nonobviousness and that there was a nexus between claims 1 and 2 and the marketed product Jevtana®. The Federal Circuit agreed with Sanofi and concluded that Fresenius’s “convoluted” obviousness theory lacks merit.

The Federal Circuit concluded that the district court did not clearly err in its assessment of these references or in finding that they would not have motivated a skilled artisan to modify the lead compound to achieve the claimed compound.