Orphan drug

An orphan drug is a pharmaceutical agent that has been developed specifically to treat a rare medical condition, the condition itself being referred to as an orphan disease.

In the US and EU it is easier to gain marketing approval for an orphan drug, and there may be other financial incentives, such as extended exclusivity periods, all intended to encourage the development of drugs which might otherwise lack a sufficient profit motive. The assignment of orphan status to a disease and to any drugs developed to treat it, is a matter of public policy in many countries, and has resulted in medical breakthroughs that may not have otherwise been achieved due to the economics of drug research and development.^[1]

Orphan drug legislation

Orphan drugs generally follow the same regulatory development path as any other pharmaceutical product, in which testing focuses on pharmacokinetics and pharmacodynamics, dosing, stability, safety and efficacy. However, some statistical burdens are lessened in an effort to maintain development momentum. For example, orphan drug regulations generally acknowledge the fact that it may not be possible to test 1,000 patients in a phase III clinical trial, as fewer than that number may be afflicted with the disease in question.

Since the market for any drug with such a limited application scope would, by definition, be small and thus largely unprofitable for pharmaceutical companies, government intervention is often required to motivate a manufacturer to address the need for an orphan drug. Critics of free market enterprise often cite this as a failure of free market economic systems.

The intervention by government on behalf of orphan drug development can take a variety of forms:

• Tax incentives.
• Enhanced patent protection and marketing rights.
• Clinical research financial subsidization.
• Creating a government-run enterprise to engage in research and development (see Crown corporation).

Currently there are more than 400 orphan designated drugs in clinical trial process. Majority of these drugs are being developed in the US followed by Europe. The US dominate the development of orphan drugs with more than 300 orphan designated drugs being under clinical trial process.

• Orphan Designated Drugs in Clinical Phase: 600
• Marketed Orphan Designated Drugs: 281
• Highest Number of Drugs in Phase-2 Trial: 231
• US Dominates Clinical Trial Process: 350 in Pipeline (Research till Registration)
• Indication for Clinical Trials for Orphan Drug: More than 30% for Cancer Treatment
• Share of Biological in Orphan Drug: More than 60%
• Key Market: US (Sales > US$ 40 billion)^[2]

United States

Orphan Drug Act

The Orphan Drug Act (ODA) of January 1983, passed in the United States, with lobbying from the National Organization for Rare Disorders and many other organizations,^[3] is meant to encourage pharmaceutical companies to develop drugs for diseases that have a small market. Under the law, companies that develop such a drug (a drug for a disorder affecting fewer than 200,000 people in the United States) may sell it without competition for seven years,^[4] and may get clinical trial tax incentives.^[4]

Orphan drug designation means that the sponsor qualifies for certain benefits, such as reduced taxes, from the federal government. It does not mean the drug is safe and effective and legal to manufacture and market in the United States.

Rare Diseases Act

In 2002 the Rare Diseases Act was signed into law. This legislation amended the Public Health Service Act to establish the Office of Rare Diseases. It also increased funding for the development of treatments for patients with rare diseases.^[5]

European Union

The European Union (EU) has enacted similar legislation, Regulation(EC) No 141/2000, in which pharmaceuticals developed to treat rare diseases are referred to as "orphan medicinal products". The EU's definition of an orphan condition is broader than that of the USA, in that it also covers some tropical diseases that are primarily found in developing nations.^[6] Orphan drug status granted by the European Commission gives marketing exclusivity in the EU for 10 years after approval.^[7] The EU's legislation is administered by the Committee on Orphan Medicinal Products of the European Medicines Agency (EMA).

Regulatory harmonization

In an effort to reduce the burden on manufacturers applying for orphan drug status, the FDA and EMA agreed in late 2007 to utilize a common application process for both agencies. However, the two agencies will continue to maintain separate approval processes.^[8]

Other countries

In addition to the United States and the European Union, legislation has been implemented by Japan, Singapore, and Australia that offers subsidies and other incentives to encourage the development of drugs that treat orphan diseases.^[9]

Effectiveness

Under the ODA and EU legislation, many orphan drugs have been developed, including drugs to treat glioma, multiple myeloma, cystic fibrosis, phenylketonuria, snake venom poisoning, and idiopathic thrombocytopenic purpura.

The ODA is nearly universally acknowledged to be a success.^[1] Before Congress enacted the ODA in 1983 only 38 drugs were approved in the USA specifically to treat orphan diseases.^[10] In the USA, from January 1983 to June 2004, a total of 1,129 different orphan drug designations have been granted by the Office of Orphan Products Development (OOPD) and 249 orphan drugs have received marketing authorization. In contrast, the decade prior to 1983 saw fewer than ten such products come to market. From the passage of the ODA in 1983 until May 2010, the FDA approved 353 orphan drugs and granted orphan designations to 2,116 compounds. As of 2010, 200 of the roughly 7,000 officially designated orphan diseases have become treatable.^[1] Some critics have questioned whether orphan drug legislation was the real cause of this increase (claiming that many of the new drugs were for disorders that were already being researched anyway, and would have had drugs developed regardless of the legislation), and whether the ODA has really stimulated the production of truly non-profitable drugs; the act also received some criticism for allowing some pharmaceutical companies to make a large profit off of drugs that have a small market but still sell for a high price.^[4]

Although the European Medicines Agency grants market access its 27 member states, in practice, medicines only reach the market when each member state decides that its national health system will reimburse for the drug. For example, 35 orphan drugs reached the market in Belgium, 44 in the Netherlands, and 28 in Sweden in 2008. 35 such drugs reached the market in France and 23 in Italy in 2007.^[11]

Orphan diseases

A rare disease, also referred to as an "orphan disease", is any disease that affects a small percentage of the population. Most rare diseases are genetic, and thus are present throughout the person's entire life, even if symptoms do not immediately appear. Many rare diseases appear early in life, and about 30 percent of children with rare diseases will die before reaching their fifth birthday.^[12] With a single diagnosed patient only, ribose-5-phosphate isomerase deficiency is presently considered the rarest genetic disease. No single cutoff number has been agreed upon for which a disease is considered rare. A disease may be considered rare in one part of the world, or in a particular group of people, but still be common in another.

Research has found that as many as one-in-ten Americans suffers from rare disease.^[13] Over 55 million people are estimated to suffer from a rare disease in Europe and in the US. Global estimates are between 5000 to 7000 rare diseases. New rare diseases are discovered every week and many have no treatments available. Currently, 350 orphan drugs have been approved for sale in the US.^[14]

Cystic fibrosis

In the 1980s, cystic fibrosis patients rarely lived beyond their early teens. However, drugs like Pulmozyme and Tobramycin, both developed with aid from the ODA, revolutionized treatment for cystic fibrosis patients by significantly improving their quality of life and extending their life expectancies. Now, cystic fibrosis patients often survive into their thirties and some into their fifties.^[5]

Homozygous familial hypercholesterolemia

The 1985 Nobel Prize for medicine went to two researchers for their work related to homozygous familial hypercholesterolemia, an orphan disease that causes large and rapid increases in cholesterol levels. Their research led to the development of statin drugs that are commonly used to treat high cholesterol.^[9]

Wilson's disease

Penicillamine was developed to treat Wilson's disease, a rare hereditary disease that can lead to a fatal accumulation of copper in the body. This drug was later found to be effective in treating arthritis.^[9] Bis-choline tetrathiomolybdate is currently under investigation as a therapy against Wilson's disease.

Activism

Numerous advocacy groups such as the National Organization for Rare Disorders, Global Genes Project, Children's Rare Disease Network, Abetalipoproteinemia Collaboration Foundation, Zellweger Baby Support Network, and the Friedreich's Ataxia Research Alliance have been founded in order to advocate on behalf of patients suffering from rare diseases with a particular emphasis on diseases that afflict children.^[1]

Industry involvement

Key orphan drug developers are Synageva BioPharma Corp., Swedish Orphan Biovitrum, Shire plc, GlaxoSmithKline, Pfizer, Novartis, Genzyme, Lundbeck, Prosensa, Agilis Biotherapeutics, QOL Medical and BioMarin. These pharmaceutical companies work together with national bodies such as the U.S.'s National Organization for Rare Disorders (NORD), Avella Specialty Pharmacy^[15] and the European Organization for Rare Diseases (EURORDIS) to advance this field.

Research centers

The Center for Orphan Drug Research at the University of Minnesota College of Pharmacy provides help to small companies with insufficient in-house expertise and resources in the areas of drug synthesis, formulation, pharmacometrics, and bio-analysis.^[16] The Keck Graduate Institute Center for Rare Disease Therapies (CRDT) in Claremont, California, supports projects to revive potential orphan drugs whose development has stalled by identifying barriers to commercialization such as problems with formulation and bio-processing.^[16]

See also

• Drug development
• European Organization for Rare Diseases
• Supplementary protection certificate

References

External links

• Drug Information Association (DIA)
• EVENT: DIA/FDA Orphan Drug Designation Workshop November 2010
• European Commission - The Orphan drugs strategy
• List of European Orphan Drugs
• USA Food and Drug Administration: The Orphan Drug Act (as amended)
• US FDA List of Orphan Designations and Approvals

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