Commonalities Of Rare Diseases

By Jennifer Dennis-Wall, Ph.D.

Collectively, rare diseases affect a huge number of people: about 25 million in the US and 400 million globally. To qualify as a rare disease per the US standard, fewer than 200,000 Americans must be affected by the condition, or per the EU standard, fewer than 1 in 2000 Europeans must be affected. That is still a significant number of people.

Unfortunately, many rare diseases were previously treated as orphan diseases – or diseases whose drug development was halted because of the lack of a promising ROI – and have fallen behind in the pharmaceutical sector. That is changing now that pharmaceutical companies are realizing the many niches that have been left untouched; about 7,000 rare diseases have been classified up to this point.

Aside from a fear of a low ROI, pharmaceutical companies have been hesitant to take on rare disease drug development because the indications can be challenging to study.

Although each rare disease is unique, some elements of the clinical operations of rare disease trials are consistent across indications. Following are some common challenges experienced during the course of researching rare diseases.