GlaxoSmithKline is seeking permission to market its asthma biologic mepolizumab for the treatment of eosinophilic chronic obstructive pulmonary disease (COPD) in the US.

The drugmaker has filed a supplemental new drug application requesting approval for the interleukin-5 (IL-5) antagonist as an add-on to maintenance treatment for patients with the condition.

Interleukin-5 (IL-5) is the main promoter of eosinophil growth, activation and survival.

In November 2015, US regulators approved mepolizumab (under the trade name Nucala) to treat patients with asthma driven by eosinophilic inflammation, making it the first and only approved biologic to target IL-5 and stop it from binding to its receptor, thereby interrupting the inflammation pathway.

The submission to the US Food and Drug Administration is the first to a regulatory authority for mepolizumab for COPD; further filings are anticipated during the course of this year and next, GSK noted.

The filing contains data from two studies: METREX, which showed a statistically significant reduction in the frequency of moderate and severe exacerbations for mepolizumab 100mg compared to placebo in patients with a higher eosinophil count (18 percent, p=0.036 after multiplicity adjustment); and METREO, in which a reduction in the frequency of moderate and severe exacerbations for mepolizumab compared to placebo was seen but did not reach statistical significance.

COPD is a disease of the lungs that includes chronic bronchitis, emphysema or both and limits airflow to the lungs, interfering with normal breathing. It is thought to affect 384 million people across the globe, and currently the fourth leading cause of death.