Patents and the Expectation of Success Doctrine

Description

Several Federal Circuit decisions have addressed the requirement for reasonable expectation of success in the obviousness context. Recent cases discuss the requirement and the degree of predictability required and demonstrate increased emphasis on a showing of obviousness increasingly relies on a showing of reasonable expectation of success.

In Salix Pharmaceuticals v. Norwich Pharmaceuticals (Fed. Cir. 2024), the Federal Circuit explained that, while it was "hesitant to conclude as a general matter that the disclosure of a Phase II clinical trial plan, standing alone, provides an expectation of success sufficient to render obvious a dosage that was not included within the planned clinical trial," the drug dosage protocol was not submitted alone. It included that "the optimal dosage ... may, in fact, be higher than that used in our study."

The Federal Circuit's decision in OSI Pharmaceuticals v. Apotex (Fed. Cir. 2019) highlighted the importance of a reasonable expectation of success in the obviousness analysis. In OSI, the court ruled nonobvious a method of treating non-small cell lung cancer (NSCLC) that used a known compound, but there was no data on the compound's efficacy with NSCLC.

In Endo Pharmaceuticals Inc. v. Actavis L.L.C. (Fed. Cir. 2019), the Federal Circuit held that a prior art reference that discloses a goal but not an explanation of how to reach that goal does not provide a reasonable expectation of success. Moreover, in Allergan Sales L.L.C. v. Sandoz Inc. (Fed. Cir. 2019), the Federal Circuit explained that a showing of expectation of success must be met for functional aspects of a claimed invention as well.

Nor is the reasonable expectation of success limited to chem/bbiotechnologies in University of Strathclyde v. Clear-Vue Lighting (Fed. Cir. 2021), the Federal Circuit emphasized that a reasonable expectation of success requires more than the mere possibility of the claimed result. The court relied on studies that had shown the likely impossibility of the claimed result. These studies, which predated the cited references, showed that blue light would not inactivate antibiotic-resistant bacteria without a photosensitizing chemical, as claimed.

Listen as our authoritative panel of patent attorneys discusses recent Federal Circuit cases and potential implications of these cases. The panel will also examine the relationship between the requirement for a reasonable expectation of success and enablement. The panel will offer best practices for patent drafting and patent prosecution in light of recent case law.