Cobb County said Wednesday it had joined a multistate legal effort to recoup what it alleges were illegally high prices for insulin drugs used to treat diabetes.

The lawsuit, filed on Tuesday in the United States District Court for the District of New Jersey, said an “unfair and deceptive conspiracy” by drugmakers and distributors fixed prices for Georgians.

Novo Nordisk, Eli Lill, Sanofi-Aventis and three companies that process about 80% of prescriptions in the United States — Caremark, Express Scripts and OptumRx — are the defendants in the suits.

The county north of Atlanta is one of the several jurisdictions seeking damages.

On Tuesday, Massachusetts also joined the effort, its attorney general said in a news release.

Cobb County, the states and the federal government say the alleged scheme illegally drove up prices.

Pharmacy benefit managers run prescription drug coverage for insurers, large employers and other clients. They set up formularies, or lists of covered drugs, and negotiate rebates off the drug prices.

When it also sued these companies in September 2024, the U.S. Federal Trade Commission said the rebating practices of the three companies have led to artificially inflated list prices.

List prices are what a drugmaker initially sets for a product and what people who lack insurance or who have plans with high deductibles are sometimes stuck paying for prescriptions.

In Georgia alone, diabetes costs an estimated $7.8 billion per year in direct medical expenses, and 1 million Georgians, or 12.1% of the adult population, have diabetes, the Cobb County court filing said.

In Cobb County, approximately 7.9% of adults ages 20 and older have been diagnosed with diabetes as of 2021, the filling said.

Cobb County is represented by Natalia Salas of The Ferraro Law Firm P.A. in Miami and Caroline G. McGlamry of Pope McGlamry P.C. in Atlanta, it said in the court filing.