By Joe Elia
An inhaled dual phosphodiesterase inhibitor, RPL554, shows promise against asthma and chronic obstructive pulmonary disease in a series of preliminary studies in the Lancet Respiratory Medicine. Inhibiting phosphodiesterases 3 and 4 would, in theory, both increase bronchodilation and control inflammation.
The studies, each including less than 35 subjects, were conducted by the drug developer. They ranged from safety studies in healthy people to studies of bronchodilation and inflammatory control in patients with asthma or COPD.
Generally, RPL554 produced rapid bronchodilation in both conditions and also had an anti-inflammatory effect, as measured by neutrophil counts in sputum after challenge. The drug had a good safety profile, but the courses of therapy were brief — none lasting more than a week.
A commentator urges careful studies of RPL554’s cardiovascular effects. She concludes that the drug “could be one of the most substantial advances for some time” in managing these conditions.