FDA asks for more info on Symbicort in young

US regulators have asked for more information before they will approve Anglo-Swedish drug major AstraZeneca's asthma therapy Symbicort  (budesonide/formoterol fumarate) in young children.

In its complete response letter, the US Food and Drug Administration  stated that AstraZeneca did not provide adequate data to demonstrate the  appropriate dose or doses of the individual components of Symbicort and  to establish how they contribute to the combination product in the  target population - patients aged between six and 11 years.

The London-based firm is evaluating the letter and says it will provide  a response to the agency "in due course." Last year, Symbicort was its  fourth biggest selling product, generating $2.0 billion.