UPDATE 2-Eli Lilly's Cymbalta gets FDA nod for pain

* FDA approves Cymbalta for chronic musculoskeletal pain

* Fifth use for Cymbalta to be approved by FDA (Adds background about the drug)

NEW YORK, Nov 4 (Reuters) - Eli Lilly LLY.N said on Thursday U.S. regulators approved the use of Cymbalta, its blockbuster anti-depressant drug, for chronic musculoskeletal pain, including lower back pain and osteoarthritis.

The approval could lead to a sales boost for the drug, which at annual sales of some $3.5 billion, is already the No. 2 product for Lilly. But any increase would be temporary as Cymbalta loses its U.S. patent protection in mid-2013.

Moreover, Cymbalta is already heavily used “off-label” for various conditions such as musculoskeletal conditions, headaches and nerve pain, according to FDA data over the summer.

While doctors are generally free to use approved medications for non-approved uses, the FDA’s stamp of approval would allow Lilly to legally promote the new pain use.

The Indianapolis-based drugmaker, which is battling pipeline setbacks and facing patent expirations in coming years, said this was the fifth use for Cymbalta approved by the U.S. Food and Drug Administration.

The drug is also cleared to treat depression, anxiety, diabetes-related pain and fibromyalgia.

Lilly said the exact way that Cymbalta works to reduce chronic musculoskeletal pain is not known, but it said it is believed the drug helps by enhancing the body’s natural pain suppressing system.

Osteoarthritis affects some 27 million U.S. adults, Lilly said. About 70 percent to 85 percent of the adults experience low back pain at some time, with some reports estimating that 2 percent to 10 percent of these people go on to experience chronic low back pain, the company said.

In August, a U.S. FDA panel of outside advisers backed the drug’s wider use to help ease chronic pain in certain patients, but was split over whether it effectively treated lower-back pain and osteoarthritis.

The panelists voted 8-5 to approve its use for back pain. But by a 4-9 vote they found there was not enough data to support its use to treat osteoarthritis.

FDA officials said at the time they were concerned about the impact of widening approval for a drug that has known serious side effects such as liver damage. Other risks with Cymbalta, also known as duloxetine and first approved in 2004, include suicidal thoughts and behaviors, nausea and drowsiness. [ID:nN19251810]

In September, Lilly CEO John Lechleiter told Reuters he believed the company would overcome regulatory worries about using Cymbalta to treat pain. [ID:nLDE6861CP] (Reporting by Paritosh Bansal; Editing by Muralikumar Anantharaman)