There are approximately 7,000 rare diseases worldwide (Rarediseases.info.nih.gov, 2019) ranging from genetic in-borne diseases such as Acute-Lymphoblastic Leukaemia (ALL), to infectious diseases that include Recurrent Respiratory Papillomatosis (RRP). As these diseases only affect a small number of patients, they don’t often receive the same attention when it comes to drug development, as other disease areas hence the creation of orphan drugs.
The development process for an orphan drug follows the same process as a normal drug, biologic or gene therapy; drug discovery, pre-clinical research, clinical development (Phase I, II and III) and market approval (Phase IV) (BioStock, 2019). However, the development of orphan drugs is often more complex thus, their development timeline is longer as they face some additional challenges within their clinical development such as;
- Lack of sponsors – companies are less likely to invest in a drug that targets a smaller disease area as it will yield a smaller profit for them.
- Safety testing – due to the lack of information surrounding rare diseases which require more rigorous patient monitoring. Most of the population affected are pediatric patients, who are in-eligible for later phases of drug development. (Maier, Christensen, and Anderson, 2017)
In recent years pharmaceutical companies’ interest in orphan drug development has risen, which is linked to the enactment of The US Orphan Drug Act (ODA) in 1983 followed by the EU Committee for Orphan Products (COMP) in 2000, the greater understanding of rare diseases and the commercial opportunities presented in typically ignored disease areas.
According to a report by Pomeranz and Urquhart (2019), there are several factors that will help increase the number of orphan drug designations (drugs being developed in an orphan indication, as approved by regulators yet to receive market approval): the recent approval of gene therapy and the higher demand for orphan drugs due to an increased commercial interest in rare diseases. For example, this is seen with Non-Hodgkin Lymphoma (NHL) acquiring the majority of designations in the past 35 years (with 270 designations worldwide).
The US and Europe are two of the biggest markets for orphan drug development yet there are some differences in the criteria for orphan drug designation;
According to the EU, COMP (European Medicines Agency, 2019):
- Prevalent patient pool of or less than 5 in 10,000 people. Alternatively, a disease area where the commercial opportunity of the product is not justified by the costs associated with its clinical development.
- Additional financial incentives include; reduced regulatory fees and reduced charges for protocol assistance.
- Market Approval requires the assessment of Committee for Medicinal Products for Human Use (CHMP).
- Market Exclusivity for indication only, is 10 years (as it can be challenged in other indications outside of the designation).
According to the US, Office of Orphan Products Development (OOPD) (Reese, 2014):
- Prevalent patient pool of less than 200,000 people.
- Additional financial incentives include; tax credits – 50% of clinical trials costs and over $2 million waiver of marketing application fees.
- Market Approval requires the assessment of the Center for Drug Evaluation and Research (CDER) or Center for Biologics Evaluation and Research (CBER).
- Market Exclusivity for indication only, is 7 years (as it can be challenged in other indications outside of the designation).
Overall, it’s clear the development of orphan drugs will continue to rise and promote the progression of new skill sets to overcome the limitations encountered, which in turn will surely bring the success of new orphan drugs that invariably will lead to an improvement in public health.
BioStock. (2019). BioStock’s article series on drug development: The Success of Orphan Drug Designation - BioStock. [online] Available at: https://www.biostock.se/2019/10/biostocks-article-series-on-drug-development-the-success-of-orphan-drug-designation/ [Accessed 29 Oct. 2019].
European Medicines Agency. (2019). Orphan designation: Overview - European Medicines Agency. [online] Available at: https://www.ema.europa.eu/en/human-regulatory/overview/orphan-designation-overview [Accessed 30 Oct. 2019].
Pomeranz, K. and Urquhart, L. (2019). Orphan Drug Report 2019. 6th Edition. EvaluatePharma®.
Maier, W., Christensen, R. and Anderson, P. (2017). Post-approval Studies for Rare Disease Treatments and Orphan Drugs. Advances in Experimental Medicine and Biology, pp.197-205.
Rarediseases.info.nih.gov. (2019). List of FDA Orphan Drugs | Genetic and Rare Diseases Information Center (GARD) – an NCATS Program. [online] Available at: https://rarediseases.info.nih.gov/diseases/fda-orphan-drugs/A [Accessed 29 Oct. 2019].
Reese, J. (2014). FDA Orphan Drug Designation 101. [online] Ema.europa.eu. Available at: https://www.ema.europa.eu/en/documents/presentation/presentation-fda-orphan-drug-designation-101-james-h-reese_en.pdf [Accessed 30 Oct. 2019].