What are orphan drugs?
Certain diseases are very rare and if we need to research, develop and market drugs for such rare diseases the cost or expenses that occurs will be unrecoverable by the manufacturer or pharmaceutical company from selling these drugs. Such drugs are called as orphan drugs.
A drug is said to be an orphan drug if that particular drug is considered vital in life threatening diseases either to diagnose, prevent or to treat but are not commercially viable to produce because the disease is affected in fewer people. Another concept for a drug to qualify as an orphan drug is that if any alternative treatment exist then it must be less efficacious compared to that of this newly found orphan drug.
Rare diseases
As the name suggests these are diseases with rarity. They are found only in limited number of people say 5 in 10000 people. There is no fixed range and changes with country, may be higher or lower. Most rare diseases are of genetic origin and thus present throughout the persons entire life, even symptoms do not appear immediately. Some examples are
- Inherent cancer
- Autoimmune disorders
- Congenital malformations
- Infectious diseases for which widespread treatment not available.
- Along with this, haemangiomas, Hirsch Sprung disease, Gaucher disease, lysosomal storage disorder and some other diseases also comes under this category.
Governments in developed countries offer tax benefits and other incentives to pharmaceutical companies for developing and marketing of orphan drugs.
Some of the orphan drugs are:
- Sodium nitrite.
- Fomepizole
- Liposomal amphotericin B
- Miltefosine
- Rifabutin
- Succimer
- Somatropin
- Digoxin immune Fab (Digoxin antibody)
- Liothyronine (T3)
Orphan drug act (1983)
In order to encourage the development of drugs for rare diseases (development of orphan drugs) United states passed The Orphan Drug Act (ODA) in 1983.
- Federal grants for research
- A tax credit to defray the cost of clinical trials
- 7 year of market exclusivity for new orphan drug products.
If a drug is already on the market and the company gains an approval for an additional orphan indication, seven year exclusivity benefit that comes under this act applies only to the new orphan indication and not the entire drug. US, the first country to initiate the orphan drug programme followed by Japan, Australia, EU and other countries.
How to diagnose rare diseases?
- Genetic testing: Looks for changes or variants in a persons genes or DNA that can cause the disease.
- Looking for changes in a single gene – Single gene tests.
- Looking for changes in many genes- Gene panel tests.
- Look for changes in all of a persons genes (exome testing) or in all of a persons DNA (Genomic testing)
- Positive result – a gene change found and that can be the cause of a disease.
- Negative result – no gene change found that can be the cause of a disease.
- However the results are termed uncertain when gene changes are present but not enough information to know whether they can be the cause of a disease.
Written by Gayathri Gopinadh