Pharmacy benefit manager Express Scripts sued the U.S. Federal Trade Commission on Tuesday over the regulator's recent drug pricing report, calling the report's conclusion that the prescription middlemen raise drug costs defamatory.

Regulators say the nation's largest pharmacy benefit managers are partly to blame for the soaring cost of insulin in the U.S.

Express Scripts, one of the country’s largest pharmacy benefit managers, sued the Federal Trade Commission (FTC) Tuesday and demanded the agency retract a report saying the industry middlemen