02:19 PM EDT, 06/24/2025 (MT Newswires) -- Cigna Group ( CI ) filed a lawsuit against Bristol Myers Squibb ( BMY ) , accusing the pharmaceutical giant of violating US antitrust laws by preventing generic versions of its blood cancer drug Pomalyst from entering the market.

The complaint, filed Tuesday in federal court in Manhattan, claims that Bristol Myers' Celgene unit "unlawfully extended, and continue to extend, a monopoly in the market" for the drug. Cigna ( CI ) also alleged that Celgene used "sham" patent lawsuits and paid off generic drugmakers to avoid competition.

Cigna ( CI ) also alleged that Celgene misled the US Patent and Trademark Office by failing to disclose that a patent for pomalidomide, the chemical name for Pomalyst, had already been granted to another inventor years earlier, according to the court filing.

"Plaintiff seeks monetary relief in the form of treble damages, and because the effect of the wrongdoing is ongoing, injunctive relief," the filing said.

Bristol Myers didn't immediately reply to a request for comments from MT Newswires.

Cigna ( CI ) shares fell 0.2% in recent trading Tuesday, and Bristol Myers eased 0.1%.

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