We have completed a pilot study investigating the efficacy and safety of AKL1 as 'add-on' therapy for adult patients diagnosed as having obstructive lung disease whose symptoms remained uncontrolled on standard medication. Whilst there was no significant differences in lung function, there were trends to clinical improvements in the patient-centered outcomes e.g. cough, health status and exacerbation frequency. Hence a larger adequately powered study is needed to investigate these outcomes further.