AstraZeneca turned up the pressure in its head-to-head battle with GlaxoSmithKline in the asthma arena yesterday, after winning approval for a new dosing regimen for its combination product Symbicort.

The SMART dosing approved in the European Union is designed to allow asthma patients to increase the dose of Symbicort (budesonide and formoterol) when their asthma is bad, helping them relieve symptoms more effectively and reducing the severity of attacks.

National approvals are expected to be issued throughout the EU over the coming months, said AstraZeneca.

The flexible dosing approach – and data showing that SMART dosing can reduce asthma exacerbation rates and hospitalisations – is a major weapon in AstraZeneca’s arsenal as it tries to dislodge GSK’s Seretide/Advair (salmeterol and fluticasone) from its dominant position in the combination asthma drug market.

Symbicort sales advanced 17% to $585 million during the second quarter of the year; impressive, but not a patch on Advair's sales over the same period, which rose 12% to $4.55 billion).

Meanwhile, other combination therapies for asthma are starting to emerge and could start to steal market share from the leading therapies. Last month India’s Ranbaxy Laboratories launched Avessa, which combines formoterol and fluticasone, in its home market.

Meanwhile, Novartis recently inked a deal with Schering-Plough to develop a once-a-day product combining Schering-Plough's inhaled steroid Asmanex (mometasone furoate) with a novel beta agonist, indacaterol (QAB149), developed by Novartis. And SkyePharma said last month it had entered into an agreement with Mundipharma International for the development, marketing, and distribution of Flutiform (fluticasone and formoterol), which could debut in 2009.

The worldwide respiratory market for therapies to treat asthma and COPD was estimated at approximately $15 billion in 2005 and is expected to grow to $22 billion by 2015, according to IMS. It is estimated that combination therapies for asthma will capture more than 50% of the market by 2010.