Biosimilars aim to copy biologic products, which are made inside living cells, but they can never be exact duplicates, so biosimilar manufacturers need to conduct clinical trials to show their products work as intended.
Enbrel, or etanercept as the drug is known generically, is a big prize since it was the world's fifth-biggest selling medicine in 2014 with sales of nearly $9 billion.
Amgen, which sells the drug in North America, booked Enbrel sales of $4.7 billion last year. Pfizer sells Enbrel elsewhere.
Merck and Samsung Bioepis last month won approval for biosimilar etanercept in South Korea and a copy is also on the way in Europe, where Samsung is working with Biogen, but Sandoz said it believed it was the first company to receive a U.S. FDA file acceptance.
Sandoz is seeking approval for all indications included in the label for Enbrel, a so-called anti-TNF drug, which is used to treat a range of autoimmune diseases including rheumatoid arthritis and psoriasis, it said in a statement.
Novartis last month launched the first biosimilar drug in the United States after a U.S. appeals court declined to stop the sale of the company's copycat version of Amgen's blockbuster cancer drug Neupogen.
Insurers and government healthcare systems hope biosimilars will cost the public 40 percent to 50 percent less than the original drugs and experience in Europe suggests that steep discounts are being offered in some markets.
"Sandoz believes that the totality of evidence in its submission, including two pivotal clinical studies, will demonstrate that the proposed biosimilar is essentially the same as the reference product," Novartis said on Friday.
The potential for biosimilars to take a large slice of the market is grabbing the attention of both healthcare providers, who see big budget savings, and investors, worried about the impact on the profts of companies making original products. (Reporting by Michael Shields and Ben Hirschler; Editing by Muralikumar Anantharaman ad Greg Mahlich)
Pharm.D @ SRIPMS-CBE-TN