What does it mean to have a rare disease?
In the US, a disease is rare if its patient population is less than 200,000. But 200,000 people is still 200,000 people. That may be a small percentage of the country’s population, but it is more than a few sufferers. Furthermore, although the number of people diagnosed with each rare disease is small, there are more than 7,000 rare diseases in this country. So multiply 7,000 by the number of patients in each disease category, and suddenly the number of rare disease patients outnumbers the amount of US cancer patients.
In reality, only a few rare diseases have very sizeable patient populations. Sickle cell disease, the largest rare disease in the country, has approximately 100,000 patients. Cystic fibrosis has about 35,000. But many rare diseases have only a small number, and some a mere handful with less than 100 patients. This can cause serious clinical challenges.
Effective treatments are limited for most rare diseases. The pharma industry historically has not invested much in discovering new therapies for rare diseases because with only a small patient population, the amount of income they can expect from these patients would not balance their research and development costs. The US government tried to help this situation with the Orphan Drug Act of 1983. This act provided financial incentives to the pharma industry through a seven-year period of market exclusivity for a drug approved to treat an orphan disease, as well as tax credits of up to 50 percent for research and development expenses. In addition, the FDA could provide grants for clinical testing of potential orphan therapies. But despite all this help, there are still many patients waiting for help. There are no effective therapies for approximately 93% of rare diseases have no FDA-approved treatment.
But before a patient can even try to get a treatment, they must first be diagnosed. That is not so easy with rare diseases, especially those of the very rare variety. Primary care physicians, and often specialists as well, are unfamiliar with rare symptoms, so they do not know what tests to order or what to look for. A correct diagnosis could take years, and in some instances, decades. In many cases, clinicians may not believe patients when they describe their experiences, leaving people already physically suffering to feel isolated and depressed, and even question their sanity.
Which will lead be the lead-in to the next blog discussing the emotional and social effects of rare disease. Tune in next time.