• chronic obstructive pulmonary disease
• treatment

There is a major need to develop new treatments for chronic obstructive pulmonary disease (COPD), as no currently available drug therapy reduces the relentless progression of the disease. In particular, there is a need to develop drugs that control the underlying inflammatory and destructive processes. There have been few therapeutic advances in the drug treatment of COPD, in contrast to the enormous advances made in asthma management which reflect a much better understanding of the underlying disease.^1–3 Although COPD is commonly treated with drugs developed for asthma, this is often inappropriate as the inflammatory processes in the two conditions differ markedly.^4,5 Recognition of the global importance and rising prevalence of COPD and the absence of effective treatments has now led to a concerted effort to develop new drugs for this disease.^6,7

Rational treatment depends on understanding the underlying disease process and there have been recent advances in understanding the cellular and molecular mechanisms that may be involved. COPD involves a chronic inflammation in the small airways and lung parenchyma with the involvement of neutrophils, macrophages, and cytotoxic (CD8+) T lymphocytes. This inflammation results in fibrosis with narrowing of the small airways (chronic obstructive bronchitis) and lung parenchymal destruction due to the action of various proteases such as neutrophil elastase and matrix metalloproteinases (emphysema). This inflammation is quite different from that seen in asthma, indicating that different treatments are likely to be needed.⁴