Rare lung disease and orphan drug development.

Rare diseases are a major health-care burden worldwide. Very little is known about the cause, behaviour, and treatment of these disorders, and thus non-specialist health-care providers and patients are left without sufficient knowledge to manage these diseases. Up to 3 million Europeans are estimated to have a rare lung disease. Several organisations-many of which are patient led-attempt to raise the profile of rare lung diseases to improve understanding and management of these disorders. Incentives have now been introduced in the USA and Europe that encourage the pharmaceutical industry to invest in targets that might otherwise not appeal because of small target populations. Despite many intrinsic challenges and obstacles, considerable progress is constantly being made in the research and development of drugs for rare disorders.