Delhi High Court Reins in Patent Claim Amendments: AbbVie’s Attempt to Convert Method Claims Rejected
Introduction
In a recent judgment in Abbvie Biotherapeutics INC & ANR. v. Assistant Controller of Patents and Designs [1]1, the Delhi High Court upheld the patent refusal order issued by the Controller of Patents for Indian patent application No. 201817047767, highlighting the strict limitations on amendment in patent claims and the importance of Section 59(1) of the Indian Patents Act, 1970. The Court affirmed the Controller’s observation that converting method of treatment claims to product claims were neither in the nature of “correction, explanation or disclaimer” nor to incorporate actual fact, but was a clever move to avoid the provisions of Section 59 (1) of the Patents Act which expressly bars amendments that result in enlarging the scope of the claims from the originally filed claims.
Facts
AbbVie Biotherapeutics Inc. and AbbVie Inc. (Appellants) filed a patent application titled ‘Anti-cMet antibody drug conjugates and methods for their use’ in the Indian Patent Office. Original claims were entirely drawn to methods of treating various cMet‐overexpressing cancers reciting dosing regimens, frequency of administration, specific patient populations, and details such as combination therapy with other anti‐cancer agents. To address an objection under Section 3(i) of the Patents Act raised in the First Examination Report (FER), the Applicants amended the claims from method-of-treatment to product claims, specifically, to an anti-cMet antibody drug conjugate.
The Controller of Patents refused the subject patent application under Sections 2(1)(j), 3(i) and 59(1) of the Patents Act. He concluded that amendments made in response to the FER were not in the nature of a correction, explanation, or disclaimer, but rather a clever move to avoid the provisions of Section 59(1) of the Patents Act. He further held that the amended product claims are not limited to a specific method of treatment or disease, and thus had a broader scope than the originally filed method claims, which were limited to specific cancers like non-small cell lung cancer (NSCLC) and specific treatment protocols.
Contentions of Appellants
The Appellants argued that the amended claims directed to anti-cMet antibody drug conjugates (ADCs) are supported by the patent specification and original claims of the specification as per the requirement of the Section 59(1) of the Patents Act. They relied on Delhi High Court decision in case of Allergan Inc. v. Controller of Patents [2]2, asserting that the case involved similar facts, where similar amendments were allowed.
Contentions of Respondent
In contrast, the Respondent submitted that the Appellants entered the national phase in India with all claims related to method of treatment only and despite some revisions in claims, no product claims were present at that stage. The Appellants chose to add the product claims only in order to avoid the rejection under Section 3(i), and that the amended claims were beyond the scope of allowable amendment under Section 59(1). Respondent relied on Delhi High Court judgement in case of Nippon A & L Inc. v. Controller of Patents [3]3 to support the reasoned refusal order.
Issues before the Court
- Whether the proposed claim amendments in the present case is permissible with reference to the previous judgement in case of Allergan (supra).
- How the claim amendments in the present case are different than that of Allergan.
- What are the permissibility criteria for the amendment in claims as per Section 59(1) of the Patent Act.
Observations and Decision of the Court
The Court noted that the original claims covered a method of treating specific cancers using anti-cMet ADCs, while the amended claims covered the anti-cMet ADC product/composition itself without these disease or treatment limitations. This removal of limitations broadened the scope of claims beyond the original specification and claims because the specification does not have reference to a stand‐alone product/composition claim without the treatment details. This shifting of the methods of treatment claims defined by specific therapeutic regimens to a wide‐ranging product/composition, not only broadens the scope of the invention but introduces entirely new categories of claims and expands legal protection beyond the original disclosure. Further, it effectively rewrites the core of the patent application, seeking a monopoly over the anti c-Met ADC product itself, beyond its original claimed use. The court held that this introduction of new subject matter and broadening of scope violated Section 59(1).
The Court reiterated the requirements of Section 59(1), stating that amendments are allowed only as disclaimers, corrections, or explanations. Furthermore, the amendment must be for the purpose of incorporating actual facts, and the amended specification cannot claim or describe matter not in substance disclosed originally, nor can an amended claim fall outside the scope of an originally filed claim. Citing Nippon A&L (supra), the court stressed that all conditions under Section 59(1) must be fully met. Applying this strict interpretation, the court found that the Appellant’s proposed amendments failed to meet any of these criteria of Section 59(1).
It noted that allowing such an amendment would permit Applicants to “sidestep” the Section 3(i) exclusion for method of treatment by later claiming a product never originally claimed in that manner. Citing the Supreme Court’s cautionary remarks in Novartis AG v. Union of India [4]4, the court stressed that Indian Patent law does not favor artificially broadening of claims through “artful drafting”.
The Court also distinguished the present case from Allergan on which the Appellants relied upon. In Allergan, the amendment was within the scope of the specification without specifically addressing the limited nature of the amendments i.e., correction, explanation or disclaimer. Further, the amended claims in Allergan also pertained to the same disease as disclosed in the unamended claims and the specification. In contrast, the amended claims in the present case removed the limitation to any specific disease, thereby substantially broadening the scope in comparison to the original claims.
Thus, the appeal was dismissed due to absence of any merit and the court upheld the impugned order passed by the Controller to refuse the application under Section 15 of the Patents Act.
Our Analysis and Conclusion
This judgement clarifies the strict interpretation of Section 59(1) of the Indian Patents Act, which prohibits amendments which introduce subject matter that extends beyond the content of the originally filed specification or enlarge the scope of the Claims. While, Allergan allowed amendments from method of treatment to product claims since they pertained to the same disease as disclosed in the unamended claims and the specification, in the present case, claims for treating specific cancers with anti-cMet ADCs were amended to product claims without any disease-specific limitations, thereby extending the scope of the claims beyond the original claims.
Hence, this judgement sets a legal precedent with regards to amendments for the applicants taking undue advantage by relying on the judgement such as Allergan by providing clear-cut demarcation between the two.
Therefore, when amending claims from method–of–treatment to compound or product claims, disease-specific limitations must be retained in the amended claims. Such an approach may help ensure the amendments stay within the original scope and could positively influence both the Controller’s assessment and the Court’s review.