AstraZeneca is asking US regulators to give the go-ahead for its combination asthma drug Symbicort to be marketed as a treatment for chronic obstructive pulmonary disease.

The Anglo-Swedish drugmaker has submitted a supplemental New Drug Application to the US Food and Drug Administration to seek approval of the COPD indication for Symbicort (budesonide/formoterol). The inhaled drug is currently approved for the long-term maintenance treatment of asthma in patients 12 years and older.

The submission is based on results from two efficacy and safety trials involving 3,668 patients and Symbicort was found to be effective and well-tolerated for up to 12 months in patients with moderate to very severe COPD. AstraZeneca added that its treatment was also well tolerated compared to budesonide and formoterol on their own and placebo. The most common adverse events were bronchitis, oral candidiasis and the common cold.

Howard Hutchison, chief medical officer at AstraZeneca, said that the firm is confident in the data from the trials, known as SHINE and SUN “and we look forward to discussions with the FDA about this potential expanded indication.”

More than 12 million people in the USA suffer from COPD, and it is the fourth leading cause of death in the nation. Approval would mean that Symbicort would go up against GlaxoSmithKline’s combination drug Advair/Seretide (salmeterol and fluticasone).