But, eventually, thanks to the work of the lawyers representing the plaintiffs in the Insulin Pricing Litigation, interesting insulin pricing strategy secrets could appear in lawsuit filings.

Some of the plaintiffs involved in the cases want the court to let them represent large classes of plaintiffs in class-action lawsuits, and lawyers could use some of the most interesting facts revealed through "discovery," or the process of getting evidence from the other parties, in filings justifying their requests for class certification, Widlanski said.

For Widlanski, who's a partner at Kozyak Tropin & Throckmorton, one of the goals of the discovery process will be trying to find out just how much questionable manufacturer and distributor activities increased self-funded employer plans' spending on insulin. "I think it's a meaningful number," Widlanski said.

The backdrop: People with diabetes have difficulty maintaining the proper level of blood sugar in their blood. Insulin can help them control blood glucose levels.

About 8.4 million of the 37 million U.S. residents with diabetes use insulin to control their blood sugar, according to the American Diabetes Association.

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The full retail price of many popular insulin products has been about $300 per month.

Many insured patients have ended up paying less than $30 per month out of pocket, but that compares with average prices of less than $10 per month in many countries.

The administration of President Joe Biden tried to limit insulin costs for uninsured people, people with high-deductible health insurance and other people who pay the full price by requiring Medicare plans to set the out-of-pocket costs for the enrollees using insulin at $35 per month or less.

The litigation: The plaintiffs in the insulin cases have accused manufacturers like Eli Lilly, Novo Nordisk and Sanofi-Aventis of working with PBMs like CVS Caremark, Express Scripts and Optum Rx.

The manufacturers and PBMs have rejected allegations that they're teaming up to push up the price of insulin.

Lars Fruergaard Jørgensen, the chief executive officer of Novo Nordisk, said during a Senate hearing that his company gets a lower net price for insulin in the United States than it gets in much of Europe and that the U.S. retail price looks high because many PBMs get paid based on the size of the discounts they negotiate.

For PBMs paid based on discounts negotiated, a high retail price with big discounts is better than a low retail price with no discounts.

The federal courts ended up bundling the suits they received in a "multidistrict litigation" proceeding, In Re: Insulin Pricing Litigation, under Judge Brian Martinotti, a judge at the U.S. District Court for the District of New Jersey.

At this point, much of the court's work involves taking in and organizing the plaintiffs.

The plaintiffs fit in three tracks: a track for state attorneys general; a track for third-party payers; and a track for self-funded employer plans.

Some of the attorneys general appear to be the only plaintiffs making noteworthy efforts to stay out of the multidistrict litigation, Widlanski said.

Eventually, the court could send some cases back to the plaintiffs' home courts for trials, but the judge handling a multidistrict litigation case may handle any trials, as well as pretrial activities, to reduce the need for a new judge to get familiar with a complicated case, Widlanski said.