Pulmonary arterial hypertension: a rare disease that encourages the development of multiple treatments

Introduction: Rare diseases have often been viewed as offering limited commercial opportunities. Analysis of the current position for the treatment of pulmonary arterial hypertension (PAH) was carried out to highlight the error of such an assumption. Areas covered: The US and European Orphan Drug Registers were searched to identify drugs either approved for use in the treatment of PAH, or with orphan drug designation for potential use in its treatment. In addition, clinical trials databases were searched to identify additional agents undergoing clinical evaluation as potential treatments for PAH. Expert opinion: PAH provides a vibrant commercial market segment that supports multiple treatment options and still offers sufficient incentive for the development of additional treatments. Efforts tend to be focused on improving established treatments by either modifying current formulations or building on established therapeutics. PAH currently attracts very limited de novo research into new therapeutic entities.