Orphan Drugs

Orphan Drugs

1. Definition & concept

• An orphan drug is a pharmaceutical that benefits only a small number of patients — i.e. one developed to treat a rare disease ("orphan disease") for which, under normal free-market conditions, the pharmaceutical industry has little commercial incentive to develop or market a medicine (Bennett & Brown 11e Ch.6, p.65; G&G 14e Ch.1, p.18).
• The label "orphan" captures the core economic problem: a free-market economy is liable to leave untreated both (i) rare diseases — e.g. some cancers — in all countries, and (ii) some common diseases of poor countries — e.g. parasitic infections such as malaria and schistosomiasis (Bennett & Brown 11e Ch.3, p.36; G&G 14e Ch.1, p.18).
• Without special intervention, investor-owned companies generally cannot afford to develop products for rare diseases or for diseases common only in economically under-developed parts of the world; funds to invent such drugs therefore often come from taxpayers or wealthy philanthropists rather than private capital (G&G 14e Ch.1, p.18).
• The medicines intended for these small patient populations are termed "orphan medicinal products" in European regulatory usage (Bennett & Brown 11e Ch.6, p.65).
• The classic textbook definition of an orphan drug is qualitative ("benefits a small number of patients"); the precise numerical prevalence threshold differs by jurisdiction. The EU defines it as a prevalence ceiling, while the US ("<200 000 patients", Orphan Drug Act 1983) and Indian (NDCT 2019, ≤ 5 lakh persons) statutory thresholds are count-based, as set out in the next section and the Recent Advances chapter.