⚖ Oral Arguments, with Context

We hear the Federal Circuit in Heron Therapeutics versus Fresenius. This dispute grew out of a proposed generic version of Heron's drug formulation. Fresenius sought federal approval, and Heron sued over patents covering the formulation. After a trial, the district court found infringement and rejected Fresenius's challenge that the asserted claims were obvious. Fresenius now appeals. The formulation carries the drug aprepitant in an emulsion: tiny oil droplets dispersed in water. Egg-yolk lecithin acts as an emulsifier, helping stabilize that mixture. The claims at issue require fourteen percent lecithin by weight. An earlier Chinese patent application disclosed concentrations from half a percent to ten percent. The question is whether reaching fourteen percent would have been ordinary formulation work rather than a patentable advance. Obviousness asks what a person of ordinary skill would have been motivated to do, with a reasonable expectation of success, based on what was already known, not merely whether an earlier recipe was identical. Fresenius will argue that the judge effectively treated ten percent as a ceiling and wrongly discounted another article describing higher concentrations. Heron will defend the judge's assessment of the experimental evidence and the differences between the formulations. Listen for the distinction between an error of law and disagreement with the trial judge's factual findings.

Heron Therapeutics, Inc. v. Fresenius Kabi USA, LLC (No. 25-1355) — U.S. Court of Appeals for the Federal Circuit, argued November 3, 2026.