AstraZeneca Seeks Seroquel XR Approval Extension

AstraZeneca said on Wednesday it was seeking approval from U.S. regulators to sell an extended-release version of its Seroquel drug to treat both manic and depressive episodes associated with bipolar disorder.

The Anglo-Swedish company said it based its submission to the U.S. Food and Drug Administration on clinical studies showing the once-daily pill effective in treating depression.

Seroquel XR is currently approved in eight countries -- including the United States -- to treat schizophrenia in adults and represents a key product for the company struggling with a sparse pipeline of its own.

In December, AstraZeneca said the extended release version of its blockbuster schizophrenia drug Seroquel had proved effective in treating depression, opening up a potential new market for the product.

Clinical data showed patients with major depressive disorder and generalised anxiety disorder who received Seroquel XR once daily experienced significant reductions in symptom severity compared with those on placebo in each of three trials. The effect was seen with all of the doses of the drug tested.

Analysts have said the new indication could be a valuable addition to the franchise.

The original version of Seroquel, launched in 1997, achieved sales of $2.94 billion worldwide in the first nine months of 2007 as a treatment for schizophrenia and bipolar disorder. But its future is uncertain, since generic drugmakers are challenging patents protecting its exclusivity.

The new patented follow-on version of the medicine, Seroquel XR, is designed to extend the brand's life. It was launched in the key U.S. market last year.