Merck & Co has decided to pull a submission for its new asthma treatment Zenhale in Europe, after the regulator required more data.

The European Medicines Agency says it has been formally notified by Merck's Schering-Plough Europe unit of its decision to withdraw an application for a centralised marketing authorisation for Zenhale (mometasone/formoterol). The drug, which combines an inhaled corticosteroid - Nasonex/Asmanex (mometasone) - with the long-acting beta2-agonist Foradil (formoterol) - was intended to be used for long-term, twice-daily maintenance treatment of asthma, including reduction of exacerbations, in adults and children aged 12 years or older.

The combo was approved in June by the US Food and Drug Administration under the brandname Dulera, and that green light was principally based on two Phase III trials involving over 1,500 patients with persistent asthma uncontrolled by medium or high-dose corticosteroids. However at the time, the agency did not approve Dulera for the relief of acute bronchospasm and it seems the road to approval in Europe has not been straightforward.

Merck says that its withdrawal of the submission of Zenhale is based on its inability to address requests made by the EMA's Agency's Committee for Medicinal Products for Human Use (CHMP) "to provide additional data within the timeframe allowed in the centralised procedure". Pulling the file does not prejudice the possibility of Merck making a new application at a later stage and it expects to do so, although no timeframe has been given.

More information about Zenhale and the state of the scientific assessment at the time of withdrawal will be made available will be published on the EMA's website after the next CHMP meeting on November 15-18.