Results mean patients could switch to once-daily inhaler use
Growth elsewhere will soak up impact of US competitor, says Sir Andrew Witty.
Lung research needs support as fifth of UK diagnosed with respiratory condition.
Earlier use of montelukast could save NHS millions, says NICE.
MSD drug will not face competition from BMS rival in this use.
But drug will not be funded for longer than two years.
Companies confirm takeover talks.