Filling the gaps for rare and orphan diseases
In the European Union, a rare disease is defined as one that affects no more than one person in 2000.
With such a small number of patients, often heterogeneous and geographically scattered, it can be difficult to develop drugs to treat rare diseases. Orphan diseases, the subset of rare diseases without any current approved treatments, pose an even greater challenge, as there often is incomplete information regarding the disease pathology, and identifying patients can be difficult.
Study designs
Natural history studies often begin early in the development timeline, and can extend for years to capture data over time. Each clinical trial comes with its own unique needs and timelines, which can be used to guide how best to approach the use of a natural history study. For sponsors planning to implement such a study, there are a number of designs that can be used, each with distinct advantages and disadvantages.
Data from a natural history study are often used in an external control arm, to be compared with data gathered from the treatment arm of a clinical study. This is beneficial because the patient population with a given rare disease tends to be small, and most participants wish to receive active treatment. Additionally, this can increase the operational efficiency of trials, lowering trial costs and getting life-saving therapies to market faster.
Hurdles to overcome
Because of their unique nature, natural history studies of rare and orphan diseases face a variety of challenges that typical studies do not. For example, with many rare and orphan diseases, there is little existing clinical research to build upon. As a result, studies of these conditions often break new ground by collecting patient data.