Copaxone (Glatiramer Acetate) is used in the treatment of relapsing-remitting multiple sclerosis.
In a filing to BSE, Natco said the US Court of Appeals for Federal Circuit has again found Teva's US "patent no. 5.800.808' (the 808 patent)" for Copaxone to be invalid.
The company awaits USFDA approval to launch the product, it said.
Its shares were trading at Rs 2,201.6 on BSE, up 6.03 per cent.
According to reports, Copaxone accounted for USD 3.1 billion out of Teva's total revenue of USD 15.1 billion in the first nine months of the past year.