Patentability Of Chemical Compounds
Patentability of Chemical Compounds: Overview
Chemical compounds can be patented if they meet the general criteria of patentability:
Novelty (Section 2(1)(j), Indian Patents Act, 1970) – The compound must be new; it should not be disclosed anywhere in the world before the filing date.
Inventive Step / Non-Obviousness (Section 2(1)(ja)) – The compound must not be obvious to a person skilled in the art.
Industrial Applicability (Section 2(1)(ac)) – It must be capable of being made or used in any industry.
Not Falling Under Non-Patentable Inventions (Section 3(d)) – Mere discovery of a new form of a known substance is not patentable unless it results in enhanced efficacy.
Chemical patents often face scrutiny under Section 3(d) (to prevent “evergreening”) and novelty/inventive step challenges. Courts and patent offices have refined these principles in many cases.
Key Cases in Chemical Compound Patentability
1. Novartis AG v. Union of India (2013) – The Glivec Case
Facts: Novartis sought a patent for imatinib mesylate, a beta-crystalline form of a known substance used in cancer treatment.
Issue: Whether a new form of a known chemical compound with improved properties qualifies as a patentable invention under Section 3(d).
Held: The Supreme Court rejected the patent because:
The new crystalline form did not demonstrate a significant increase in efficacy.
Section 3(d) prevents patents on minor modifications unless efficacy is enhanced.
Significance: This case is foundational in preventing “evergreening” of pharmaceuticals and chemicals in India.
2. Bayer Corporation v. Union of India (Sorafenib Case)
Facts: Bayer applied for a patent on a modified version of Sorafenib, an anti-cancer compound.
Issue: Whether the modified version is patentable over prior art.
Held: The patent was rejected as it was considered an obvious modification of an existing chemical compound.
Significance: Reinforces the principle that mere structural modifications without inventive step are not patentable.
3. Roche v. Cipla (Roche’s Erlotinib Case)
Facts: Roche held a patent for erlotinib, a cancer treatment compound, and Cipla produced a generic version.
Issue: Patent infringement and validity of the chemical patent.
Held: Indian courts examined novelty and inventive step and emphasized Section 3(d):
Only compounds showing enhanced therapeutic efficacy can be patented if derivative.
Significance: Emphasizes that secondary patents must prove enhanced efficacy, not just new forms.
4. Eisai Co. Ltd. v. Dr. Reddy’s Laboratories
Facts: Eisai had patents for memantine hydrochloride derivatives.
Issue: Validity challenged due to prior art.
Held: Court upheld the patent for derivatives showing unexpected properties or benefits, differentiating it from known compounds.
Significance: Demonstrates that unexpected properties of a chemical derivative can support inventive step.
5. Bayer Corporation v. Union of India (Ciprofloxacin Case)
Facts: Bayer attempted to patent ciprofloxacin hydrochloride derivatives.
Issue: Whether simple salts or polymorphic forms of an existing antibiotic were patentable.
Held: Patent was rejected because:
These forms were already known in prior art.
Did not show enhanced efficacy over known forms.
Significance: Confirms that pharmaceutical salts or polymorphs require demonstrable improved properties to qualify.
6. Merck v. Glenmark (Letrozole Case)
Facts: Merck held patents for Letrozole, a breast cancer drug. Glenmark attempted to launch generics.
Issue: Whether derivatives or enantiomers were patentable.
Held: Courts rejected secondary patents that did not demonstrate superior efficacy.
Significance: Strengthens the position against “evergreening” in chemical patents, particularly in pharma.
7. Novartis v. Natco (Beta-Crystalline Form Case)
Facts: Another challenge to Novartis’ Glivec patent by Natco (generic manufacturer).
Held: Reinforced that secondary patents must demonstrate improved therapeutic efficacy.
Key Legal Principles from These Cases
Novelty: A chemical compound must not have been disclosed anywhere in the world. Prior art is scrutinized very strictly.
Inventive Step: Minor modifications or salts of existing compounds are not sufficient. The modification must be non-obvious and preferably show enhanced properties.
Enhanced Efficacy (Section 3(d)): Secondary patents must improve therapeutic or functional properties.
Evergreening Prevention: Courts actively prevent patenting of known compounds with minor modifications just to extend monopoly.
Secondary Patents: New forms, derivatives, enantiomers, or polymorphs of a known compound can be patentable only if they show unexpected benefits.
Industrial Applicability: All chemical compounds must have practical utility (therapeutic or industrial).
Summary Table of Key Cases
| Case | Compound | Issue | Outcome | Principle |
|---|---|---|---|---|
| Novartis v. India | Imatinib Mesylate | Section 3(d) | Patent rejected | Secondary forms must enhance efficacy |
| Bayer v. India | Sorafenib derivative | Inventive step | Patent rejected | Obvious structural modifications not patentable |
| Roche v. Cipla | Erlotinib | Novelty, efficacy | Patent challenged | Secondary patents need efficacy |
| Eisai v. Dr. Reddy | Memantine derivatives | Prior art & benefits | Patent upheld | Unexpected properties can support inventive step |
| Bayer v. India | Ciprofloxacin salts | Novelty & efficacy | Patent rejected | Known salts/polymorphs not patentable without improvement |
| Merck v. Glenmark | Letrozole | Secondary patent | Patent rejected | Enhanced therapeutic efficacy required |
| Novartis v. Natco | Beta-crystalline form | Secondary patent | Patent rejected | Confirms Section 3(d) application |
RELATED Blog
comments