Orphan Drugs: Lifelines for Rare Diseases

By Dr. Sk Sabir Rahaman, MBBS, MD (Pharmacology), DFM(Family Medicine), FCFM, CCEBDM, CCLSD  

🌍 What Are Rare Diseases?

Rare diseases affect only a small portion of the population but are often chronic, debilitating, and life-threatening.

Definitions Around the World:

• WHO: ≤ 1 in 1000 people

• USA (FDA): < 200,000 individuals

• EU (EMA): ≤ 5 in 10,000 people

• Japan: < 50,000 patients

• India (NDCT Rules, 2019): ≤ 5 lakh persons

👉 Around 6000–8000 rare diseases exist, but 80% of cases come from just 350 diseases.

Examples:

• Genetic: Cystic fibrosis, Huntington’s disease, Wilson’s disease

• Infectious: Leishmaniasis, Cryptococcal meningitis

• Neuromuscular: ALS, Duchenne muscular dystrophy

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💊 What Are Orphan Drugs?

An orphan drug is developed to treat rare diseases.

• India (NDCT 2019): For conditions affecting ≤ 5 lakh people

• USA (FDA): For diseases affecting < 200,000 people OR where sales won’t recover development costs

• EU: Life-threatening or chronic disease affecting <1 in 2,000 persons

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💡 Examples of Orphan Drugs

Drug	Orphan Use
Sodium Nitrite	Pulmonary arterial hypertension
Fomepizole	Methanol/Ethylene glycol poisoning
Somatropin	Growth hormone deficiency
Liposomal Amphotericin B	Cryptococcal meningitis
Digibind (Digoxin Fab)	Digoxin overdose
Imatinib	Chronic Myeloid Leukemia (CML)
Lenalidomide	Multiple Myeloma

👉 Imatinib revolutionized CML treatment by targeting BCR-ABL fusion protein, showing how powerful orphan drugs can be.

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🌀 Partial Orphan Drugs

Some drugs treat both common and rare conditions.

Drug	Common Use	Orphan Use
Azathioprine	Rheumatoid Arthritis	Renal Transplant
Adalimumab	RA	Pediatric Crohn’s Disease
Rosuvastatin	Dyslipidemia	Familial hypercholesterolemia

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📜 Regulation of Orphan Drugs

🇮🇳 India

• Governed by NDCT Rules, 2019

• Incentives:

  • Fast-track approval

  • Fee waivers

  • Relaxed trial requirements

  • State reimbursement up to 60% of treatment costs

🇺🇸 USA (Orphan Drug Act, 1983)

• Incentives:

  • 7 years market exclusivity

  • 50% tax credit for clinical trials

  • Waiver of application fees

  • Grants up to $500,000/year

  • Rare Pediatric Disease Priority Review Vouchers

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🧪 Orphan Vaccines & Devices

• Vaccines: Japanese Encephalitis, Epstein-Barr, Parvovirus B19

• Devices: Imaging & diagnostic tools for thyroid cancer, ovarian cancer, pheochromocytoma

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⚠️ Challenges in India

• No national rare disease registry

• High cost: ₹18 lakh–₹1.7 crore/year per patient

• Only ~5% of rare diseases have approved treatments

• Limited trials → greater reliance on post-marketing surveillance

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🔮 Future Prospects

• Pharmacogenomics – identifying genetic drivers

• Gene therapy – correcting defective genes

• Stem cell therapy – treating hematological & neurological disorders

• Therapeutic cloning – hope for degenerative diseases

• Global collaboration – shared databases & harmonized regulations

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✅ Conclusion

Orphan drugs are not just medicines — they are lifelines for patients with rare diseases.

Yet, in countries like India, cost, availability, and lack of structured policies limit access. The way forward lies in global innovation + local policy reform, ensuring that no patient is left behind.

#OrphanDrugs #RareDiseases #PharmaInnovation #GlobalHealth

#DrugPolicy #GeneTherapy #FamilyPhysician #DrSKSabirRahaman #Pharmacologist 

📘 Prepared by Dr. Sk Sabir Rahaman

📍 Specialist Family Physician | Consultant Pharmacologist | Lifestyle & Diabetes Expert

📧 dr.sabir.rahaman@gmail.com 

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