. That decision was anything but a complete victory for the Commission's position. Indeed, Justice Breyer wrote a relatively nuanced opinion holding, most importantly, that such settlements were not a per se antitrust violation (the FTC's original position). Rather, the Court held that such agreements must be evaluated under the "rule of reason." However, reasonableness ( i.e., how tightly tethered to reality) of any such determination depends in larger part on the reasoner, and this characteristic (or flaw) is illustrated in the first full-fledged appellate affirmance of the FTC in a reverse payment settlement case, The case arose over a settlement between branded drug maker Endo against Impax over its extended-release oxymorphone opioid drug product, Opana ER. The agreement, entered into before the Supreme Court's