Recommendations on value assessment and funding processes in rare diseases.

Rare diseases are an important public health issue with high unmet need. 

A rare disease is generally defined as one that is found in less than 1 in 2,000 people - fewer than 200,000 people in the United States. That being said, over 300 million people live with one or more of at least 6000 rare diseases worldwide, and less than 5% have an approved treatment.

Most rare diseases are childhood diseases, with a staggering 85% of rare diseases being inherited (genetically passed down from parent to child) - 1 in 40 children are born with an inherited disease, and half of those will not reach adulthood.

Biopharmaceutical products targeted at these rare conditions are often called 'orphan drugs'.

While there are many factors that affect orphan-drug uptake, one of the most important is the challenging task of determining (and implementing) pricing and reimbursement decisions. There has been little consensus on the most appropriate assessment criteria, perspective or appraisal process. 

This 2018 article from researchers at the Institute for Clinical and Economic Review explore steps taken by Health Technology Assessment (HTA) bodies worldwide to define the level of rarity that would necessitate special measures and the modifications to their assessment and valuation processes needed, and the contextual components for rare-disease evaluation that lie outside of the assessment framework.

While there is no simple solution, many HTA and public payers worldwide have developed and operationalized their own specific approaches for accommodating orphan drugs.