The study evaluated the dose response, efficacy and safety of five doses of GW642444 (‘444) administered once-daily for four weeks. All doses achieved statistically significant increases in lung function (trough FEV1) compared to placebo.
The changes were dose-dependent with the two highest doses (25 and 50mcg) exceeding a predefined threshold of 130mL increase in FEV1 at trough. The companies said that ‘444 exhibited a rapid, dose-dependent onset of action with sustained bronchodilator effect over 24 hours. Improvements in lung function 24 hours after the first dose were maintained throughout the 28-day treatment period.
Favorable efficacy trends were also seen in a number of other endpoints including improvements in peak expiratory flow both in the morning and evening and reduced use of rescue medication. Throughout the four-week study period, ‘444 was well tolerated at all doses and the frequency of adverse events was comparable to placebo, the two companies said.
Rick Winningham, CEO of Theravance, said: “These positive results bring us closer to achieving the goal of the Horizon collaboration which is to develop novel, once-a-day inhaled medicines to bring relief to patients with asthma and chronic obstructive pulmonary disease (COPD).”