The US Federal Trade Commission filed an amicus brief arguing that licensing of pending patents can pose an antitrust risk, pointing to how Amgen’s exclusive rights to two etanercept-related patent applications extended Enbrel protection later than expected for biosimilar competition. The FTC said the mechanism effectively delayed entry. The filing targets a time-sensitive antitrust question in the Fourth Circuit, referencing the Hart-Scott-Rodino review framework and the unusual timeline where exclusive rights were granted years before the underlying patents issued. The dispute centers on whether the licensing structure can restrict competition beyond what biosimilar developers would have anticipated. The case highlights how IP strategy is increasingly scrutinized as biologics markets mature and biosimilar launches accelerate—especially where exclusivity timing is influenced by patent prosecution and licensing terms.