AstraZeneca has received a miserable Christmas present from regulators in the USA who want more information before approving a new indication for the schizophrenia drug Seroquel.

The Anglo-Swedish drugmaker has received a complete response letter from the U.S. Food and Drug Administration asking for additional information for the supplemental New Drug Application for Seroquel XR (quetiapine) extended-release tablets for the treatment of major depressive disorder in adults.

AstraZeneca gave few details about the content of the letter and limited itself to saying that it is “evaluating the contents of the CRL and the proposed labelling revisions”. The company added that it will continue discussions with the FDA and “provide a response to the agency in due course”.

Seroquel XR, a once-daily formulation of quetiapine, was approved in the USA in 2007 for the acute and maintenance treatment of schizophrenia in adults and in October this year for depressive episodes associated with bipolar disorder. The news from the FDA hit AstraZeneca shares and the stock was down 2% to £26.55 at 10am UK time.