LONDON (Reuters) – A new AstraZeneca inhaler for chronic lung disease has proved worse than a rival GlaxoSmithKline product in a clinical trial, a result AstraZeneca said was inconsistent with earlier findings.

Bevespi Aerosphere – a combination of two kinds of drugs known as LAMA and LABA – was as good as GSK’s Anoro in improving peak breathing levels when patients exhaled but it failed to match Anoro on trough measures, AstraZeneca said on Thursday.

Bevespi Aerosphere is already approved in the United States and Canada for the long-term maintenance treatment of airflow obstruction in chronic obstructive pulmonary disease (COPD). Europe is expected to decide on its approval later this year.

AstraZeneca said the results of the latest Phase IIIb study, known as AERISTO, were surprising.

“The performance of Bevespi Aerosphere in AERISTO is inconsistent with previous data. A full analysis is underway to understand and characterize these findings and will be presented at a forthcoming medical meeting,” said respiratory head Colin Reisner.

(Reporting by Ben Hirschler; editing by David Evans)