More than 7,000 rare diseases have been identified globally, affecting over 50 million people. In Europe they are defined as diseases that affect 5 in 10,000 lives and are life-threatening or chronically debilitating, whilst in America they are defined as any disease that affects fewer than 200,000 lives.
Developing drugs for these rare conditions is challenging. There is often a lack of prior research, and limited patient populations make randomised control trials costly and difficult to perform. As a result, orphan drugs are sometimes approved through adaptive or conditional pathways on the basis of only a small number of patients. Ongoing evidence generation is then required to support these approvals.
Real world evidence is one way by which clinical benefit can be demonstrated. It can sit alongside and complement clinical trial data, providing information on the use of orphan drugs in the ‘real world’. In addition, real world evidence can provide a range of other data, including patients’ utilisation of healthcare resources, information on treatment pathways and, of increasing importance, an understanding of patient experience.
pH Associates have worked on a large number of studies in the rare disease area, utilising data from patient registries, service evaluations and patient notes, to create individual evidence bases that meet specific requirements. For example, Hospital Episode Statistics data was used to describe resource use for patients with hidradenitis suppurativa in England. The findings indicated high hospital attendances for patients of working age. Similarly, the impact of rifaximin-α on the resource use of patients with hepatic encephalopathy was investigated using a retrospective, observational methodology. The treatment was found to significantly reduce hospitalisations and other resource use.
When expert consensus guidelines for the management of pulmonary carcinoid tumours were published in 2015, pH Associates were involved in describing follow-up practices across the UK. The study highlighted large variations in practice, and opportunities for use of the new guidelines to optimise treatment for patients. In a similar study, with the Paediatric Familial Hypercholesterolaemia (FH) Register, pH Associates worked to determine how well current NICE guidance was being adhered to for children with FH in the UK, and demonstrated that treatment decisions were being appropriately reached.