## Introduction
The legal battle between Amgen Inc. and the Assistant Controller of Patents, with Intas Pharmaceuticals Limited as the opposing party, is rooted in the complexities of patent law relating to biologics. The case revolves around the patentability of a lyophilized therapeutic peptibody formulation, its constituent excipients, and methods of manufacture. The adjudication by the High Court of Madras delves deep into scientific, technical, and legal nuances of patent claims under the Patents Act, 1970, particularly in context of Sections 2(1)(ja), 3(d), 3(e), and 10(4), and addresses the broader question of inventive step and sufficiency of disclosure.
## Factual Background
The core invention in question involves a lyophilized formulation of a therapeutic peptibody intended for the treatment of thrombocytopenic conditions. The peptibody mimics the function of thrombopoietin (TPO), stimulating platelet production, and is engineered by fusing a peptide on the Fc region of an antibody. The formulation specifically cites the use of excipients: 10 mM histidine buffer at pH 5.0, 4% w/v mannitol as bulking agent, 2% w/v sucrose as stabilizer, and 0.004% w/v polysorbate-20 as surfactant. Amgen had previously obtained patent rights and regulatory approvals in other jurisdictions for related APIs (namely romiplostim), marketed as Nplate.
## Procedural Background
Amgen filed Indian Patent Application No. 5857/CHENP/2008, seeking a grant for the lyophilized therapeutic peptibody formulation. After a series of examinations and objections by the Patent Office, objections were raised under Sections 3(d), 3(e), 2(1)(ja), and 10(4), asserting the invention as not patentable. Responding to the First Examination Report and engaging in hearings, Amgen made amendments and filed supplementary data. In parallel, Intas Pharmaceuticals filed a pre-grant opposition on grounds of obviousness, lack of inventive step, insufficiency of disclosure, and lack of synergy. The Assistant Controller of Patents eventually rejected the application on 31.03.2023, prompting Amgen to appeal under Section 117A of the Patents Act before the High Court of Madras.
## Core Dispute
The principal dispute centered on the patentability of the claimed lyophilized peptibody formulation. This involved questions about whether the invention constituted a mere aggregation of known components or exhibited patentable synergy, whether the process was a mere use of a known method, and whether the disclosures sufficed to enable a person skilled in the art to reproduce the invention across the breadth of the claims. The court had to determine if the claimed invention passed the tests of novelty, inventive step, and sufficiency, and whether exclusions under Sections 3(d) and 3(e) were validly invoked.
## Discussion on Judgments
In support of their respective positions, parties cited numerous judicial precedents and decisions from Indian and foreign jurisdictions.
Amgen's counsel referred to:
Nippon Steel Corporation v. Controller General of Patents, Designs and Trade Marks & Anr., CA (Comm. IPD-PAT) 323 of 2022, order dated 29.08.2024, for the proposition that the “known process” in Section 3(d) must be specifically identified.
Dhama Innovations Private Limited v. Assistant Controller of Patents and Designs, CMA(PT) No.12 of 2024, dated 19.07.2024, arguing against dissecting a combination into constituent elements for obviousness.
Net MoneyIN, Inc v. Verisign Inc., US Court of Appeals for the Federal Circuit 2007-1565, especially pages 15 and 19, clarifying combination inventions standards.
In Re: Stepan Company, Court of Appeals for the Federal Circuit, MANU/USFD/0346/2017, regarding sufficiency of disclosure.
Steel Strips Wheels Limited v. Wheels India Limited & Anr., 2025:MHC:922, discussing inventive step in process patents.
Caleb Suresh Motupalli v. Controller of Patents, 2025:MHC:293, about sufficiency of disclosure.
Yunnan Tobacco International Co. Ltd. v. Philip Morris Products S.A., Enlarged Board of Appeal, G 0001/24, decision dated 18.06.2025, on inventive step mosaic.
Teva Pharmaceutical Industries Ltd v. United States of America, rep. By Secretary, Department of Health and Human Services, T 2395/22-3.3.02, EPO Technical Board of Appeal, decision dated 31.01.2024, for teachings on excipient selection for stability.
Ajantha Pharma Limited v. Allergan Inc., ORA/21/2011/PT/KOL, regarding combination patents.
General Electric Company's Applications 81 RPC 413, on description and enablement.
Intas Pharmaceuticals and the Patent Office cited:
British Celanese Ltd. v. Courtaulds Ltd. 52 RPC 171, rejecting patentability absent synergy in known ingredient combinations.
Bishwanath Prasad Radhey Shyam v. Hindustan Metal Industries, (1979) 2 SCC 511, for distinguishing workshop improvements from inventive step.
Rhodia Operations v. The Assistant Controller of Patents and Designs, 2024:MHC:449, specifically paras 45 and 49, on obviousness analysis.
Fresenius Kabi Oncology Limited v. Glaxo Group Limited and Another, 2013 SCC OnLine IPAB 121, paras 58 and 60, about optimization versus invention.
Indian Institute of Technology v. The Controller of Patents and Designs and Others, 2024:MHC:2264, paras 29 and 35, inventive step standards.
Novozymes v. Asst. Controller of Patents & Designs 2023 MHC 4261.
Sankalp Rehabilitation Trust v. F. Hoffman-LA Roche AG 2012 SCC OnLine IPAB 167.
Mahesh Gupta v. Asst. Controller of Patents and Designs 2024 SCC OnLine Del 4000.
Exxonmobil Oil Corporation v. Treofan Germany GmbH & Co. KG, T 0532/00 – 3.3.9, EPO, mosaic approach.
In re Aller et al., 220 F.2d 454, on obviousness in formulation claims.
Foreign decisions such as the EPO order in Teva Pharmaceutical Industries (T 2395/22-3.3.02) and the Enlarged Board's Yunnan Tobacco International (G 0001/24), provided persuasive guidance on inventive step and the challenge in mosaicing disclosures from unrelated prior arts.
## Reasoning and Analysis of the Judge
Justice Senthilkumar Ramamoorthy adopted a comprehensive analytical approach, dissecting the scientific basis of biologics and the technical requirements for patent protections under Indian law. Recognizing the novelty of peptibodies and the challenge of lyophilization for biologics, the judgment identified core issues as being whether the claimed invention represented an inventive step or was an obvious aggregation of known elements, and whether the disclosure sufficed for enablement.
On Section 3(d), the judge observed that existing prior arts disclosed the individual peptibody structure and lyophilization as a process but failed to teach the specific combination of excipient concentrations for the claimed peptibody. The court held that the mere presence of lyophilization in prior art did not render the process claimed as a mere use of a known process, especially given the tailored excipient concentrations for the unique therapeutic peptibody.
On Section 3(e), the judge determined that Amgen’s experimental data, specifically Tables 39 to 41 of the specification, evidenced synergy, particularly between tween-20 and other excipients, resulting in beneficial stability and anti-aggregation effects. The decision clarified that contrary to respondents' contentions, synergy and technical advancement did not necessitate comparison of pre- and post-lyophilization formulations, but rather a demonstration that the composition was more than the sum of its parts.
Turning to inventive step under Section 2(1)(ja), the judge reasoned that PSITA (person skilled in the art) would not be naturally led to combine excipients and their specific concentrations from D5 (which concerned IL-12 proteins) with the peptibody of D4, given the pharmacological differences between the proteins. The judgment extensively relied on scientific literature regarding the selection and prevalence of excipients in biologics, concluding that formulation choices are not obvious and depend on empirical, case-specific optimization.
For sufficiency of disclosure, the judgment reconciled the breadth of claims with the extent of exemplification. While the specification enabled the sequence SEQ ID 1017 and its family, the court found enablement lacking for all 52 mimetic peptides in Table 6 and consequently narrowed the monopoly claim accordingly. The court interpreted Section 10(4) to require full enablement only of the exemplified sequence(s), not all possible embodiments claimed.
## Final Decision
The High Court set aside the rejection order, allowed Amgen’s appeal, and directed that the patent application should proceed to grant, subject to the amendment of independent claims restricting their scope to peptide sequences exemplified and enabled in the specification. The court thus granted patent protection limited to the specific therapeutic peptibody composition and method related to SEQ ID NO.459, accepting the existence of inventive step and synergy, and finding the disclosure sufficient for the exemplified sequences.
## Law Settled in This Case
This judgment clarifies several principles in Indian patent law. First, it distinguishes between the mere use of a known process and the inventive adaptation of such a process for a specific biologic, holding the latter to be patentable when accompanied by tailored technical solutions. Second, it refines the test for synergy under Section 3(e), emphasizing empirical demonstration over rigid data comparisons. Third, the judgment sets a pragmatic standard for sufficiency of disclosure: exemplary enablement suffices for closely related sequences within a family, but wide genus claims require broader enablement. Finally, it confirms the Indian stance against hindsight mosaicing of prior arts for obviousness unless clear teaching or motivation exists linking disclosures.
Case Title: Amgen Inc. Vs Assistant Controller of Patents
Date of Order: August 22, 2025
Case Number: CMA (PT) No.28 of 2023
Neutral Citation: 2025:MHC:2096
Name of Court: High Court of Judicature at Madras
Name of Judge: Justice Senthilkumar Ramamoorthy
Disclaimer: The information shared here is intended to serve the public interest by offering insights and perspectives. However, readers are advised to exercise their own discretion when interpreting and applying this information. The content herein is subjective and may contain errors in perception, interpretation, and presentation.
Written By: Advocate Ajay Amitabh Suman, IP Adjutor [Patent and Trademark Attorney], High Court of Delhi
### Suggested Titles for Law Journal Publication
1. "Patentability of Biologic Formulations: A Case Study of Amgen Inc. v. Controller of Patents"
2. "Inventive Step and Synergy in Indian Patent Law: Judicial Analysis in Amgen Inc. Appeal"
3. "Lyophilized Peptibodies and the Indian Patent Regime: Critical Reflections from High Court of Madras"
4. "Section 3(d), 3(e), and the Challenge of Enablement: Lessons from Amgen Inc. v. Patent Office"
5. "Formulation Patents for Biologics: Landmark Decision by Madras High Court"
6. "Biologics, Excipients, and Inventive Step: Detailed Examination of Amgen Inc. Litigation"
7. "Judicial Standards for Enablement and Inventive Step in Pharmaceutical Patents"
8. "Deciphering Patent Law for Biologic Drugs: Insights from Amgen Inc. v. Assistant Controller"
9. "Patent Prosecution of Peptibody Compositions: Legal Commentary on Amgen v. Patent Office"
10. "Patent Law, Pharmaceutical Innovation, and Judicial Reasoning: The Amgen Case"
