The European Commission announced Thursday it had imposed an antitrust fine exceeding 460 million euros ($500 million) on Israeli generic drugmaker Teva for unlawfully extending patent protection for its multiple sclerosis drug and for undermining a competitor's work on a similar treatment.

Teva said it planned to appeal the judgment.

The European Commission said the pharmaceutical firm "misused the patent system to artificially extend patent protection" for its blockbuster MS drug Copaxone, whose active ingredient is glatiramer acetate.

To do that, Teva conducted a "disparagement campaign" against Synthon, the only other company with an authorized drug in Europe containing glatiramer acetate, the commission said in a statement.

Teva "spread information contradicted by health authorities’ findings, seeking to sow doubt on the safety, efficacy and therapeutic equivalence of the rival product," the EU Commission said.

It said Teva officials targeted doctors and groups involved in drug pricing and reimbursement, "with the target of slowing down or blocking its competitor's entry" into several countries.

"We send a clear message to dominant pharmaceutical companies that we will not tolerate the use of disparagement campaigns to foreclose competing medicines," said EU antitrust chief Margrethe Vestager.

The commission said Teva's actions may have prevented significant savings by countries across Europe, with other versions of the drug possibly 80% cheaper than Copaxone. Teva will have to pay a fine of 462.6 million euros and refrain from similar practices in the future, it said.

The EU's long-running case against Teva started with dawn raids in 2019 that led to the opening of an investigation in 2021.

Teva said it disagreed with the basis of the EU's ruling.

"The company is deeply disappointed by this decision and has been cooperating extensively with the European Commission since 2019," it said in a statement.

"Teva disagrees with the Commission’s legal theories which are legally untested and, Teva believes, not supported by the facts. The company will vigorously defend its position on appeal and is well prepared financially to mount a defense."

Last year, Teva was ordered to pay $225 million to settle price fixing charges in the U.S. related to sales of a cholesterol-lowering drug.

The Department of Justice said the agreement also required Teva to divest its business making and selling the drug pravastatin, a generic version of the brand-name medicine Pravachol.