The Eight Circuit, in FTC v. Lundbeck, Inc., No. 10-3458/3459 (Aug. 19, 2011), upheld the district court’s finding that the FTC failed to show a relevant market, and thus was unable to challenge the acquisition of the drug NeoProfen. It already owned a drug called Indocin IV, which, along with NeoProfen, was used to treat a condition in low-birth-weight infants, known as patent ductus arteriosus. Although these two drugs had different active ingredients, they were both approved by the FDA to treat this condition.
Physicians would choose which drug to use apparently based on their preferences, and somewhat different side effects.
This paragraph in the court’s decision caught my eye:[...]