Natco may have First to File approval status for the abbreviated new drug application (ANDA), contingent upon successful litigation outcome of original drug patent, the company said in a press release on Tuesday.
Tamiflu (Roche's trade name for Oseltamivir Phosphate) had US sales of approximately $495 Million for twelve months ending September 2013, according to IMS Health.
Natco has challenged the patent for Tamiflu - a drug to treat bird flu - in the US.
The company's shares were trading at Rs 833.90 on BSE, up 1.19% over the previous close of Rs 824.10.