Delhi High Court Reinforces Strict Limits on Patent Amendments: Insights from AbbVie, Allergan & Ovid Cases

House no. 316, Ground Floor "A" Sector, Yelahanka New Town Bengaluru- 560 064

1203, The Spire-2, Shital Park BRTS, 150 Feet Ring Road,Rajkot - 360007 Phone : +91 281 242 731

203, 2nd Floor, Shriji Palace,Savsar Plot, Main Road, Morbi-363641 INDIA Phone:91 2822225263

312-313, 3rd Floor,
Abhishek Complex, Akshar Chowk, Old Padra Road,
Vadodara 390 020 INDIA
Phone: (0265) 2322015

Delhi High Court Reinforces Strict Limits on Patent Amendments: Insights from AbbVie, Allergan & Ovid Cases

Introduction:

The Delhi High Court has recently revisited the critical principles surrounding amendments under Section 59(1) of the Patents Act, 1970 through a trio of important rulings — AbbVie Biotherapeutics Inc. v. Controller, Allergan Inc. v. Controller, and Ovid Therapeutics Inc. v. Controller. These decisions firmly establish that Indian law permits only narrow, non-broadening amendments and emphasizes the limited scope allowed when transforming method claims into product claims.

Section 59(1) of the Patents Act: The Core Principle Section 59(1) restricts amendments to only:

• Disclaimer, correction, or explanation.
• For the purpose of incorporation of actual facts.
• Without adding new subject matter or broadening the original claims' scope.

Indian courts demand strict compliance, preventing applicants from reshaping their inventions post-filing to gain broader protection than originally disclosed.

Case Analyses:

• AbbVie Biotherapeutics Inc. (April 2025)
•  
• Facts: AbbVie originally claimed methods for treating cMet- over expressing cancers using antibody-drug conjugates (ADCs).
• Amendment Attempt: Shifted claims from methods to standalone ADC products.
• Court’s Findings:
  • Proposed amendments impermissibly broadened the scope.
  • Amendment was not a disclaimer or correction but a substantial transformation.
  • Industrial applicability under Section 2(1)(j) was also not satisfied.
• Ruling: Amendment rejected. Original method claims were non-patentable under Section 3(i) and could not be saved by recasting them into product claims.

• Allergan Inc. (January 2023)
•  
• Facts: Originally filed method claims for ocular treatment via sustained release implants.
• Amendment Attempt: Shifted to implant product claims.
• Court’s Observation:
  • Amendment was allowed because the implants were disclosed in the original specification, and the field of invention remained consistent (ocular treatment).
  • The amendments were considered as a clarification, not an expansion.
• Important Nuance:
  • Indian courts permit amendment where new claims are narrower and supported by the originally filed specification.
  • Filing method claims at the PCT stage does not preclude amendments in India to align with Indian patentability standards.

• Ovid Therapeutics Inc. (February 2024)
•  
• Facts: Original claims directed to a method for treating secondary insomnia via Gaboxadol compositions.s
• Amendment Attempt: Shifted to pure pharmaceutical composition claims without reference to any disease.
• Court’s Analysis:
  • Deletion of disease-specific limitations broadened the invention's scope.
  • Removing context of use transformed the invention beyond the originally filed disclosure.
• Ruling: Amendment was not permitted as it violated Section 59(1).

Technical Takeaways:

• Amendments Must Stay Within Original Disclosure: Any amendment must "fall wholly within the scope" of the filed claims and specification.
• No New Matter or Enlarged Protection: Courts strictly disallow amendments that introduce new technical features or expand the claims' ambit.
• National Phase Flexibility is Limited: Even though PCT filings might reflect patentability standards of other jurisdictions (e.g., US), Indian amendments must still conform to Section 59(1) without overstepping.
• Distinction Between Clarification vs Expansion:
• • Allowed: Narrowing down by adding specific compositions, ingredients, or ranges (e.g., specifying a 10–30 mg range of a drug already disclosed).
• • Not Allowed: Adding an entire new product claim when originally only therapeutic methods were claimed.

Conclusion: The trio of decisions — AbbVie, Allergan, and Ovid — sends a strong signal to patent applicants: Strategic, compliant drafting at the PCT stage is essential when India is a designated state. Amendments must be modest, clarificatory, and within the original disclosure, or face rejection under Section 59(1).