The FDA authorized Novartis' Sandoz unit to sell its version of the Amgen drug in the United States. Sandoz intends to market it under the brand name Zarxio.
The decision is expected to pave the way for other "biosimilar" drugs to hit the U.S. market in coming years, a move that many say will lower drug costs by increasing competition.
"Biosimilars will provide access to important therapies for patients who need them," said FDA Commissioner Margaret A. Hamburg, M.D., in a statement. "Patients and the health care community can be confident that biosimilar products approved by the FDA meet the agency's rigorous safety, efficacy and quality standards."
Amgen, the biotech giant based in Thousand Oaks, has other drugs that could face new competition from biosimilars. Competitors are seeking FDA approval to sell versions of at least three other Amgen drugs in the United States.
For Amgen, the introduction of biosimilars could be costly. Competitors are expected to steal sales volume and drive down pricing.
Neupogen increases white blood-cell counts to help patients fight infection, primarily after chemotherapy. Amgen said the drug accounted for $839 million of sales in the United States last year and $1.2 billion worldwide.
Biologic drugs like Neupogen had faced competition from knockoff drugs outside the United States for several years, but not in the United States. Sandoz sells biosimilars in more than 60 foreign countries. It has sold the Neupogen knockoff under the name Zarzio overseas since 2009.
Although pill medications had faced generic competition for years in the United States, the FDA had never before approved a copycat version of a biologic drug.
Things started to change in 2010 when the Affordable Care Act included a clear, concise approval process for knockoff versions of biologics. The move was intended to increase competition and reduce costs of the effective, but often expensive, drugs.
Biologic drugs are made from living cells or tissue and are impossible to replicate exactly. That's why knockoff versions are called "biosimilars" and not generics.
In its application to the FDA, Sandoz said studies had found its version to be "highly similar" to Neupogen with patients receiving similar medical benefits.
Amgen has fought to delay the sale of Sandoz's Zarzio. In October, Amgen sued Sandoz in federal court for allegedly infringing on its patent. Last month, Amgen asked a judge to temporarily block Sandoz from selling its Neupogen version, even if it wins FDA approval.
Sandoz has said it followed the law and looks forward to its day in court. A hearing on Amgen's request is scheduled for March 13 in San Francisco.
Sandoz also is pursuing FDA approval of two other Amgen drugs, Neulasta, which also boosts white blood-cell counts, and Enbrel, which treats rheumatoid arthritis. Another company, Hospira Inc., has applied to the FDA for approval of a biosimilar version of Amgen's anemia drug Epogen.
The four Amgen drugs targeted by biosimilar competition generated nearly $11 billion in U.S. sales last year.
Outside the United States, biosimilars have typically sold at a 20% to 30% discount to the original drug, while generic pills often sell at up to 90% discounts. Analysts expect roughly the same discounts in the United States.