UPDATE 2-Teva version of Amgen drug delayed by US FDA

* Teva’s biotech drug Neutroval similar to Neupogen

* Teva already selling version in Europe

* Teva up 0.6 pct; Amgen up 0.5 pct (Adds analyst comment, share prices, byline; previous dateline LOS ANGELES)

NEW YORK, Sept 30 (Reuters) - U.S. health regulators on Thursday delayed approval of Teva Pharmaceutical Industries Ltd's TEVA.OTEVA.TA biotechnology medicine to boost white blood cells that is similar to Amgen Inc's AMGN.O big-selling Neupogen.

The U.S. Food and Drug Administration issued a complete response letter seeking “several items” related to Teva’s drug, known as Neutroval, as a treatment for cancer patients undergoing chemotherapy, the Israel-based company said in a statement.

The FDA did not ask for additional clinical trials of the drug, Teva said. Such clinical studies can often mean lengthy delays, so analysts viewed the lack of such a request as positive for Teva. A company spokeswoman declined to comment beyond the statement.

If the Teva drug were launched commercially in the United States, it would be the first competitor in the country for Amgen’s Neupogen, which had U.S. sales of $225 million in the second quarter. Teva has already been selling the drug, also known as XM02, under the name TevaGrastim in several European countries.

Teva and Amgen are involved in patent litigation over two Neupogen patents expiring in 2013. Should Teva launch sales of its drug before settlement of the litigation, it would face the risk of having to pay damages to Amgen, according to analysts.

“Given the slow uptake in Europe of biosimilars and patent litigation filed by Amgen against Teva on the product, we believe expectations were quite contained both in terms of financial impact and launch timing,” Needham & Co analyst Elliot Wilbur, who covers Teva, said in a research note.

The newly passed U.S. healthcare reform law creates an approval process for similar versions of pricey biotechnology medicines. But Teva, which has criticized the new process as flawed, sought approval for Neutroval before the law passed under the standard marketing application for brand-name biotechnology medicines, known as a Biologics License Application.

Although Neupogen remains a significant product for Amgen, the downside from new competition will be mitigated by the fact that the company now gets far more revenue from a newer, longer-lasting version, known as Neulasta, which had $643 million in second-quarter U.S. sales.

Teva is also developing a similar version of Neulasta.

On Nasdaq, Teva was up 0.6 percent at $52.89, and Amgen rose 0.5 percent to $55.21 at mid-afternoon. (Reporting by Lewis Krauskopf and Deena Beasley; Editing by Gerald E. McCormick and Richard Chang)