Interpretation Of Section 3(D) And Evergreening Prohibition
1. Introduction
Evergreening is the practice of obtaining secondary patents for minor modifications of existing drugs, often extending patent protection and delaying generic competition.
Section 3(d) of the Indian Patents Act, 1970 (as amended in 2005) was introduced to prevent evergreening and to ensure access to affordable medicines.
Key provisions of Section 3(d):
Section 3(d):
“The mere discovery of a new form of a known substance which does not result in the enhancement of the known efficacy of that substance shall not be patentable.”
Objective:
Prevent trivial modifications from obtaining new patents
Ensure only genuine inventions get patent protection
Protect public health and affordable access
2. Interpretation of Section 3(d)
Key Points:
Primary vs Secondary Patents
Primary: Novel compound → patentable
Secondary: New forms (salts, isomers, polymorphs, formulations) → patentable only if enhanced efficacy
Efficacy Requirement
Mere improved stability, solubility, or convenience is not enough
Must show therapeutic efficacy
TRIPS Compliance
Section 3(d) is TRIPS-compliant
Provides flexibility for public health without violating international obligations
Judicial scrutiny
Courts require scientific evidence to demonstrate enhancement of efficacy
3. Landmark Case Laws on Section 3(d) and Evergreening
Case 1: Novartis AG v. Union of India (2013) – Gleevec
Facts:
Novartis applied for patent for imatinib mesylate, a modified form of imatinib (cancer drug)
Indian Patent Office rejected application under Section 3(d)
Issue:
Whether imatinib mesylate constituted enhanced efficacy
Judgment:
Supreme Court rejected patent
Held that increase in bioavailability alone does not amount to enhanced efficacy
Minor modifications for patent extension = evergreening
Significance:
Landmark ruling on evergreening prohibition
Set precedent for pharmaceutical patent evaluation in India
Case 2: Bayer Corporation v. Natco Pharma Ltd. (2012) – Nexavar
Facts:
Bayer’s patented cancer drug Nexavar
Natco applied for compulsory license citing unaffordable pricing
Judgment / Implication:
While not directly 3(d), this case shows secondary patents alone cannot block access
Section 3(d) prevents trivial modifications from extending monopolies
Significance:
Reinforced public health protection against evergreening
Case 3: GlaxoSmithKline (GSK) Anti-Retroviral Patents (2012)
Facts:
GSK held patents for ARV drugs
Indian generic companies challenged secondary patents
Judgment:
Patent for minor chemical modifications rejected under Section 3(d)
Only compounds with enhanced therapeutic effect are patentable
Significance:
Reinforced Section 3(d) as a barrier to evergreening in essential drugs
Case 4: Roche v. Cipla (2008) – Tamiflu
Facts:
Roche patented Tamiflu formulations
Cipla challenged secondary patents for minor chemical changes
Judgment:
Court highlighted that incremental improvements must demonstrate enhanced efficacy
Reiterated scientific evidence requirement under Section 3(d)
Significance:
Clarified legal threshold for efficacy
Case 5: Bayer Corp. v. Union of India (2009) – Secondary Patents
Facts:
Bayer tried to patent minor salt form of drug
Indian Patent Office rejected under Section 3(d)
Judgment:
Salt form did not demonstrate enhanced efficacy
Rejected as evergreening attempt
Significance:
Showed patent offices actively applying Section 3(d) to block trivial patents
Case 6: Novartis AG (Interim Orders 2006)
Facts:
Early stage application for Gleevec
Patent office initially rejected under Section 3(d)
Judgment:
Supreme Court interim ruling emphasized rigorous proof of efficacy required
Prevented early monopolization
Significance:
Set procedural and evidentiary standards for Section 3(d) enforcement
Case 7: Natco Pharma v. Bayer (Nexavar) Compulsory License
Reinforced Section 3(d) principle indirectly
Shows that even patented drugs cannot prevent generic production if access is denied
4. Principles Established from Case Law
Evergreening is prohibited
Minor modifications alone cannot extend patent term
Therapeutic efficacy is key
Section 3(d) requires measurable improvement in efficacy
TRIPS-compliant but public-interest-oriented
Balances innovation and access to medicines
Evidence-based assessment
Courts and patent office require scientific studies
Generic competition protected
Prevents blocking of affordable medicines through secondary patents
5. Key Takeaways
| Case | Drug | Key Issue | Outcome / Principle |
|---|---|---|---|
| Novartis v. India (2013) | Gleevec | Secondary patent / efficacy | Patent rejected; no evergreening |
| Bayer v. Natco (2012) | Nexavar | Access / compulsory license | Generic allowed; royalty payable |
| GSK ARV Patents (2012) | ARVs | Secondary patents | Rejected; efficacy not enhanced |
| Roche v. Cipla (2008) | Tamiflu | Minor chemical modification | Patent rejected; efficacy standard |
| Bayer v. India (2009) | Cancer drug salts | Secondary patent | Rejected under Section 3(d) |
6. Conclusion
Section 3(d) is a powerful legal tool to prevent evergreening
Ensures patents reward true innovation
Balances pharmaceutical innovation and public health
Indian courts consistently enforce:
Scientific evidence of enhanced efficacy required
Minor modifications alone cannot block generics
Public access and affordability prioritized
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