The US Food and Drug Administration (FDA) has accepted for review Mylan Pharmaceuticals’ abbreviated new drug application (ANDA) for a generic version of Teva’s lead multiple sclerosis drug Copaxone.

Mylan has submitted the application for glatiramer acetate injection (20mg/mL), the generic version of Copaxone, which accounted for around 20% of Teva’s $11.1bn in sales in 2008.

Mylan has previously entered into a license and supply agreement with Natco Pharma, which granted Mylan exclusive distribution rights for glatiramer acetate pre-filled syringes in the US and all major markets in Europe, Australia, New Zealand, Japan and Canada.

Teva has issued a statement saying that it remains committed to vigorously defending its property rights against infringement.

Teva has also previously said that Copaxone would be very difficult to manufacture and that it has serious doubts about the ability of any generic applicant to demonstrate its product is identical to Copaxone.