BATON ROUGE - A lawsuit pitting Louisiana against major manufacturers of insulin is headed to federal court.

The case -- filed in March at the state level by Attorney General Jeff Landry -- will now be heard in US District Court in Baton Rouge.

It focuses on what the plaintiff describes as a concerted and coordinated effort to hike the price of insulin, which is essential for diabetics working to manage their condition.

More than half a million Louisiana residents are believed to have diabetes.

The state is one of a growing number to file suit against pharmaceutical firms and drug distributors, alleging that they are working in concert to overcharge for insulin.

In the lawsuit, the State claims that "the prices paid by the citizens of Louisiana for certain insulin products are artificially inflated by a sprawling 'Insulin Pricing Scheme' between certain Pharmacy Benefit Managers and certain insulin manufacturers."

It seeks to cap and reduce the cost of insulin.

The list of defendants includes Sanofi LLC, Caremark Health and CVS Health Corp., along with others.