British drugmaker GlaxoSmithKline PLC said Monday that it is starting two late-stage patient studies of an experimental biologic drug as an add-on treatment for patients with severe, uncontrolled asthma.
Both studies will compare the safety and effectiveness of mepolizumab, an antibody-based drug produced in living cells, to a placebo treatment.
Two different doses will be tested in patients whose asthma is poorly controlled with use of corticosteroid drugs, which reduce inflammation, and inhalers containing long-acting beta2-agonists, which relax airway passages. Those include the popular inhalers Advair, which is sold by Glaxo; AstraZeneca PLC's Symbicort and Merck & Co.'s Dulera.
Glaxo, a leader in respiratory medicine, said study participants will get injections every four weeks. One study will test how well the medicine reduces asthma flare-ups and the other will test whether it allows patients to reduce use of steroid medications, which can cause significant side effects.
Mepolizumab is an antibody that binds to a substance called interleukin 5 to reduce the frequency of asthma flare-ups by limiting the levels of white blood cells in blood, tissue and sputum.