A U.S. Court of Appeals for the Fifth Circuit judge seemed skeptical Wednesday of a new Medicare drug price negotiation program meant to lower prescription costs, which pharmaceutical manufacturers and related groups across the country are challenging as unconstitutional.

"This is challenging to a novel, unprecedented drug-price setting program in an industry that the government is the 800-pound gorilla [in], the purchaser with the most monopsony power in the United States," Judge Jennifer Walker Elrod said during oral arguments in New Orleans.

However, the Fifth Circuit has not been asked to zero in on constitutional questions in the underlying appeal. Instead, the court is being asked to decide whether the National Infusion Center Association, PhRMA and the Global Colon Cancer Association could even bring their challenge in the first place.