Perspectives for improving the evaluation and access of therapies for rare lung diseases in Europe.

The approach to treating a rare disease is different to that taken for more common diseases. Small patient cohorts alter clinical trial design and limit enrollment, and the picture for rare lung diseases is further complicated by the fact that most are composed of a variety of clinical phenotypes. Since the outcome measures of lung impairment have considerable test-to-test variability, potential new therapies face a substantial challenge. In this paper we will review the current sources of clinical data for rare lung diseases and the regulatory challenges encountered by their treatment, with particular reference to alpha(1)-antitrypsin deficiency, lymphangioleiomyomatosis, cystic fibrosis, and pulmonary alveolar proteinosis. Strategies will also be identified for the better utilization of available data from patients with rare lung diseases, recognizing that the development cost of new therapies and the number of patients who will ultimately use them may not be aligned. Also important is improved communication between patients and their organizations, basic researchers, clinicians and their registries, drug developers, regulators such as the European Medicines Agency, and national health services. At present, licensing and reimbursement requirements are not aligned, either nationally or internationally, and variations also exist in drug availability between countries because of different national licensing and reimbursement rules. The changes needed to optimize European rare lung disease therapies include a commitment to develop empowered patient communities as advocates for therapy, the development of novel trial designs with new endpoints, and for regulatory bodies to be willing to accept nontraditional models of efficacy for orphan drugs