Orphan Drugs

An orphan drug is a medicine intended to treat a rare disease or condition affecting a very small patient population. Whether it qualifies depends on the prevalence threshold and any additional criteria prescribed by the relevant jurisdiction.

Indian regulatory criterion

Under the New Drugs and Clinical Trials Rules, 2019, an orphan drug is a drug intended to treat a condition affecting not more than five lakh persons in India.

• The threshold concerns the number of people affected by the condition in India, rather than the number currently receiving treatment.
• Qualification is linked to the intended indication; the same medicine may be used for both a rare condition and a common condition.

Why criteria differ across countries

There is no universal numerical definition of rarity. Orphan-drug criteria are jurisdiction-specific, reflecting differences in population size, disease prevalence and regulatory policy.

• Some jurisdictions supplement a prevalence threshold with factors such as disease seriousness, absence of satisfactory treatment, significant clinical benefit or inability to recover development costs.
• A rare disease describes the condition, whereas orphan classification concerns a medicine intended to treat that condition.

Designation and drug approval

Orphan status identifies a drug for regulatory support aimed at encouraging development for small patient populations. It is not equivalent to marketing approval and does not by itself establish the medicine's safety, efficacy or quality.