UPDATE 2-US panel partly backs wider use of AstraZeneca drug

(Adds panel member, company comments)

By Lisa Richwine

SILVER SPRING, Md., April 8 (Reuters) - AstraZeneca PLC (AZN.L) won partial support from U.S. advisers on Wednesday for its bid to expand the approved uses of a blockbuster schizophrenia drug.

A committee of Food and Drug Administration advisers said Seroquel XR was safe enough for treating some patients with depression but opposed use of the drug for fighting anxiety given the serious side effects.

The panel voted 6-3 that Seroquel XR had acceptable risks if it was added to other medicines to find a workable combination to alleviate depression. Several panel members stressed that doctors should try other treatments for depression first before deciding to add Seroquel XR.

"I think this represents a second-line therapy," said panel member Frank Greenway, an endocrinologist at Pennington Biomedical Research Center in Louisiana.

The panel split 4-4, with one abstention, when asked if it was safe enough to use Seroquel XR as the only treatment for depression in some cases. Panelists said there were safer medicines that should be tried if only one medicine was going to be used.

The FDA will consider the panel's input as it decides whether to approve the expanded use for Seroquel XR. The agency usually follows panel recommendations.

Seroquel is AstraZeneca's second-best-selling drug with $4.5 billion in 2008 sales. Seroquel XR is an extended release version of the medicine with a longer patent life than the original formula.

Doctors are free to prescribe approved medicines for any use they see fit, but winning FDA approval for wider use would allow AstraZeneca to promote Seroquel XR more widely.

The FDA asked the panel to weigh wider use of the drugs versus known side effects including weight gain and tardive dyskinesia, a movement disorder that causes jerking, lip smacking and grimacing.

A recent study also raised concern about sudden deaths of patients taking atypical antipsychotic drugs including Seroquel, known generically as quetiapine.

Depression and anxiety affect millions of people and are much more common than schizophrenia.

Panel chairman Wayne Goodman said he was "concerned about the wide scale use of the medicine in various settings" with its known side effects and potential unknown risks.

Dr. Robert Harrington, a panel member and cardiologist at Duke University School of Medicine, said he did not think "the long-term risks have been adequately characterized."

The committee voted that the drug's risks were not acceptable for treating anxiety even though they felt it was effective for the condition.

A recent study in the New England Journal of Medicine found the chances of sudden cardiac death were twice as high for patients treated with one of the atypical antipsychotics, including Seroquel, compared with others who did not take them.

An FDA reviewer said that study had limitations, and AstraZeneca said its own analysis did not find a higher risk of sudden death with Seroquel.

The company told the panel that Seroquel XR could be a valuable option for patients with moderate to severe cases of anxiety or depression who are not helped by current options.

"We are not looking for use of quetiapine for all patients" with depression or anxiety," Mark Scott, executive director of clinical development for AstraZeneca Pharmaceuticals, told the panel.

AstraZeneca is facing lawsuits from thousands of patients who say they developed diabetes from taking Seroquel. Weight gain is a risk factor for diabetes.

AstraZeneca shares gained 0.7 percent to close at $34.50 on the New York Stock Exchange. (Reporting by Lisa Richwine; Editing by Tim Dobbyn and Carol Bishopric)