Jan 5 (Reuters) - Staff reviewers at the U.S. Food and Drug Administration recommended approval for Novartis AG's copy of Amgen Inc's blockbuster cancer drug Neupogen.

Novartis's drug is the first to be reviewed in the United States under the so-called biosimilar pathway.

The reviewers found no "clinically meaningful differences" between the two drugs, the FDA said. (http://1.usa.gov/1DoT7eb)

The injectable biotech medicine, known generically as filgrastim, is designed to fend off infections in breast cancer patients undergoing chemotherapy, which reduces white blood cells, giving rise to a condition called neutropenia.

The Swiss drugmaker already sells copies of Neupogen, made by its generics arm Sandoz, under the brand name Zarzio in more than 40 countries.

Biosimilars are yet to make inroads into the United States as the country has lagged behind in establishing a regulatory framework for these drugs.

Data from a late-stage trial, unveiled last month, showed Novartis's drug had similar efficacy and safety as Neupogen.

The reviewers recommended that Novartis's copy should be approved for all the five indications for which Neupogen is approved, the FDA said on Monday.

Independent experts are scheduled to meet on Wednesday to discuss the drug and recommend whether it should be approved.

Biosimilars, which typically cost 20-30 percent less than the original drug, are expected to account for about one quarter of the $100 billion sales stemming from off-patent biological drugs by the end of the decade, according to Thomson Reuters BioWorld.

Amgen's shares were down 1.8 percent at $157.08 in light premarket trading on Monday. Novartis shares were up about 2 percent at 94.30 Swiss francs.

(Reporting by Natalie Grover and Samantha Kareen Nair in Bengaluru; Editing by Kirti Pandey)