The US Food and Drug Administration (FDA) has given its stamp of approval to once-daily Seroquel XR (quetiapine fumarate) as an add-on treatment to antidepressants in adults with major depressive disorder (MDD).

The drug manufactured by AstraZeneca is the only medication in its class that has been approved to treat major depressive disorders as adjunctive therapy and acute depressive episodes associated with bipolar disorder as monotherapy.

MDD affects approximately 14.2 million American adults a year, but treatment, usually in the form of selective serotonin reuptake inhibitors, is often unsuccessful with as many as 63% of patients not achieving remission, according to a National Institute of Mental Health study.

The approval for Seroquel XR therefore provides physicians with a new adjunctive treatment option for MDD patients who have an inadequate response to their current antidepressant.

AstraZeneca has also received a Complete Response Letter from the FDA asking for additional information for Seroquel XR as acute monotherapy and maintenance monotherapy for the treatment of MDD in adult patients.