(Reuters) -Three pharmacy benefit management (PBM) companies are being sued in Ohio over allegations of drug price fixing, the Wall Street Journal reported on Monday.

The lawsuit filed in an Ohio state court alleged that PBM units of Cigna Corp and Humana Inc, along with Prime Therapeutics LLC, shared pricing and other information gathered by a related Swiss company to gain leverage during negotiations with drugmakers for rebates, the report said.

Express Scripts, a PBM owned by health insurer Cigna, set up a firm called Ascent Health Services in Switzerland in 2019, with Prime Therapeutics, another PBM, later taking a minority stake, the report said, citing the lawsuit.

PBMs act as middlemen in the drug supply chain, negotiating drug prices with pharmaceutical companies for employers and health insurers.

The lawsuit alleges that Express Scripts, Prime and Humana's PBM, which is a customer of Ascent, used it to coordinate their negotiations and fix amounts of rebates.

The companies restricted coverage of some insulin products and other medicines due to the collusion, the lawsuit said, according to the report.

A spokesperson for Prime said the company does not comment on pending litigation.

Cigna and Humana did not respond to Reuters' requests for comment.

(Reporting by Mariam Sunny and Raghav Mahobe in Bengaluru; Editing by Devika Syamnath and Maju Samuel)