When seeking the approval of a new drug to treat Cushing’s syndrome, the FDA warned against co-administering the drug with a high dose of another drug without further study. The patentee performed the study directed by the FDA and, after finding that the drugs could be co-administered, obtained a patent on the combination.

In affirming a decision following an Inter Partes Review (IPR) at the USPTO, the Federal Circuit found that the challenger of the patent had ignored the requirement of showing a reasonable expectation of success of the combination. The Federal Circuit found the claims were directed to a specific dose claimed in the combination and that the evidence showed no expectation of success for the combination, which is consistent with the FDA’s warning.