In a relief to Natco Pharma, the US court of appeals has invalidated Teva’s Copaxone patent. This may help generic pharma companies to launch one of the top-selling multiple sclerosis drugs, Copaxone.

“The US Court of Appeals for Federal Circuit has again found Teva’s US 808 patent for Copaxone to be invalid as indefinite. The company awaits approval from the US Food and Drug Administration (USFDA) to launch the product,” said Natco in a filing to the exchanges.

Last year, the US Supreme Court had denied Teva’s application for an injunction seeking to prevent the launch of a generic version of Copaxone.

The pharma companies involved in the generic forms of Copaxone are Novartis’ Sandoz, Momenta Pharmaceuticals, Mylan and Natco Pharma.

As per available estimates, the annual sales of Copaxone is about $4.3 billion worldwide and account for more than half of Teva’s profit. In 2003, Natco began research to develop a generic version of Copaxone in order to make a cost-effective version of the drug available to patients in India.

Later, Natco developed a process for producing copolymer-1 and filed patent applications covering its process.

A senior official of Natco said that the firm has submitted all the information to FDA with regard to the generic version of Copaxone, used in the treatment of relapsing-remitting multiple sclerosis.

“We have done everything from our side. Once approval comes, we are ready to launch the product. We manufacture the drug and Mylan will market it,” the official said.

Mylan chief executive officer Heather Bresch, in a separate statement, said: “We have stated all along that the ‘808 patent on Copaxone is invalid… We continue to remain very confident and look forward to bringing our product to market upon approval from the US Food and Drug Administration.”

Bresch further said the ruling underscores concerns of Teva’s ongoing financial prospects as the Copaxone franchise has historically been its largest and most significant revenue driver.