The Food and Drug Administration on Wednesday accepted paperwork for approval of a biosimilar version of Amgen Inc.’s Neulasta, a drug that produces white blood cells to fight infection in cancer patients.

Last month, the Thousand Oaks biopharmaceutical company announced its quarterly financial results, showing Neulasta sales up 6 percent to $1.26 billion in the third quarter.

The Neulasta biosimilar is produced by Germany’s Sandoz, the generic pharmaceuticals division of Swiss drug company Novartis International. Biosimilars aim to copy their original counterparts but cannot duplicate them exactly. To be approved by the FDA, biosimilars must show comparability with no adverse side effects.

“Sandoz believes that the totality of evidence in its submission, including three pivotal clinical studies, will demonstrate that the proposed biosimilar is highly similar to the reference product,” the company said in a statement.

Amgen shares closed up $3.32 or 2.1 percent to $160.92 on the Nasdaq.