Ajinomoto Co., Inc. v. Abtis Co Ltd

Case Overview: Ajinomoto Co., Inc. v. Abtis Co Ltd (IPR2025-00283)

This case involves an inter partes review (IPR) proceeding initiated by Ajinomoto Co., Inc. against Abtis Co Ltd before the Patent Trial and Appeal Board (PTAB) to challenge the validity of U.S. Patent No. 11,896,675.

Parties and Their Business:
Petitioner, Ajinomoto Co., Inc., is a Japanese multinational food and biotechnology corporation with a broad portfolio including seasonings, food additives, frozen foods, amino acids, and pharmaceuticals. They are also a technology provider for biopharmaceuticals and own Ajinomoto Bio-Pharma Services, which offers contract development and manufacturing services. Ajinomoto has its own proprietary site-specific bioconjugation technology called AJICAP®, which is used in the development of antibody-drug conjugates (ADCs).

Patent Owner, Abtis Co Ltd, is a South Korean biotechnology company founded in 2016 and acquired by Dong-A ST in 2023. Abtis specializes in site-selective antibody conjugation, leveraging its proprietary AbClick® platform technology to develop diverse bioconjugate treatments, including ADCs, by enabling site-selective conjugation of therapeutic payloads to antibodies without requiring antibody modification.

Patent at Issue and Technical Sketch:
The patent at issue is U.S. Patent No. 11,896,675, titled "Site-Specific Antibody Conjugation and Antibody-Drug Conjugate as Specific Embodiment Thereof". This patent generally relates to methods for creating modified antibodies for use in antibody-drug conjugates (ADCs). More specifically, the invention involves modifying a lysine residue, particularly at position 248 of an antibody's heavy chain, to include a terminal bio-orthogonal click chemistry functional group. This technology aims to enable the labeling of a specific number of chemical functional groups or cargo moieties at specific sites of an antibody, thereby providing antibody products with high uniformity and undiminished functions such as avidity and half-life.

Accused Product/Service and Procedural Posture:
The IPR proceeding, IPR2025-00283, was filed by Ajinomoto Co., Inc. against Abtis Co Ltd on December 24, 2024, challenging claims 1-13 of the '675 patent. The status of this IPR is "Instituted." While the IPR petition itself primarily focuses on the validity of the patent, it is Ajinomoto's assertion that the '675 patent is not entitled to its claimed priority date, which allows them to use earlier published prior art, including a 2019 poster presentation by Yamada et al. describing Ajinomoto's own AJICAP™ technology. This suggests a competitive landscape in the field of antibody-drug conjugate technologies between the two biotechnology companies. As an IPR, the case is being heard by the Patent Trial and Appeal Board (PTAB), a quasi-judicial body within the U.S. Patent and Trademark Office (USPTO). The PTAB is often seen as a significant venue for challenging patent validity, potentially offering a quicker and less expensive alternative to district court litigation. There is no explicit mention of an accused product or service in the provided IPR context, which is common for IPRs focused solely on patent validity rather than direct infringement allegations in parallel district court litigation.

Notability of the Case:
This case is notable due to its direct involvement of two biotechnology companies, Ajinomoto and Abtis, both developing and specializing in antibody-drug conjugate (ADC) technologies. The IPR centers on the validity of Abtis's patent, with Ajinomoto challenging it, partly by citing its own earlier technology (AJICAP™) as prior art. This indicates a dispute over foundational intellectual property in the competitive and rapidly evolving field of biopharmaceutical drug development, particularly in targeted therapies like ADCs. The outcome of this IPR could have implications for the competitive landscape of site-specific antibody conjugation technologies and the strategic patent portfolios of companies in this sector.

The case in question, IPR2025-00283, is an inter partes review (IPR) proceeding before the Patent Trial and Appeal Board (PTAB), not a district court patent infringement litigation. Therefore, the typical milestones for a patent infringement lawsuit (e.g., complaint, answer, Markman, discovery, trial, JMOL) are not directly applicable. Instead, the focus will be on the IPR process and any related district court litigation.

Here are the key legal developments for IPR2025-00283:

• IPR Petition Filing (2024-12-24): Ajinomoto Co., Inc. filed a petition for inter partes review against Abtis Co Ltd, challenging claims 1-13 of U.S. Patent No. 11,896,675. The challenged patent, titled "Site-Specific Antibody Conjugation and Antibody-Drug Conjugate as Specific Embodiment Thereof," relates to methods for creating modified antibodies for use in antibody-drug conjugates (ADCs), specifically involving the modification of a lysine residue at position 248 of an antibody's heavy chain.

• Grounds for Unpatentability: Ajinomoto asserted two main grounds for unpatentability:

  • Ground 1 (Anticipation over '959 Publication): Ajinomoto argued that claims 1-13 are anticipated by the '959 Publication (CA 3132959A1). The petitioner contended that Patent 11,896,675 is not entitled to its claimed priority date due to an inadequate written description for a negative limitation in claim 1 in its priority applications. This alleged break in the priority chain renders the '959 Publication, a Canadian application from the same patent family published before the '675 patent's effective filing date, as invalidating prior art under 35 U.S.C. §102. The '959 Publication's specification is considered essentially identical to that of the '675 patent and is argued to disclose every element of claims 1-13.
  • Ground 2 (Anticipation over PepTalk Poster): Ajinomoto asserted that claims 1, 4, and 8-10 are anticipated by the PepTalk Poster (a 2019 poster presentation by Yamada et al.). The petitioner argued that the PepTalk Poster, describing AJICAP™ technology for preparing ADCs, was publicly disseminated before the patent's priority date.

• Institution Decision (Pending - Instituted): The PTAB has instituted the IPR proceeding. While the exact date of institution is not provided in the snippets, the case status confirms institution has occurred. The institution decision would have determined that Ajinomoto demonstrated a reasonable likelihood that it would prevail with respect to at least one challenged claim.

• Outcome/Current Posture: The IPR proceeding IPR2025-00283 is currently "Pending - Instituted." This means the trial phase of the IPR is underway, where both parties will submit arguments and evidence regarding the patentability of the challenged claims. A Final Written Decision has not yet been issued.

Parallel District Court Litigation:
There is no information in the search results directly linking U.S. Patent No. 11,896,675 to an active patent infringement litigation in a U.S. District Court between Ajinomoto Co., Inc. and Abtis Co Ltd. Ajinomoto Co., Inc. has been involved in other patent litigation, including a settled U.S. patent litigation with CJ Group concerning Tryptophan manufacturing processes (settled 2022-03-09), and a successful patent infringement suit in the Tokyo District Court against CJ Japan Corp. regarding MSG products (judgment 2020-09-24). However, these cases do not involve Patent 11,896,675 or Abtis Co Ltd. Without information about a related district court case, the effect of this IPR on any hypothetical parallel litigation cannot be determined.

Ajinomoto Co., Inc., the petitioner in IPR2025-00283, is represented by the following counsel:

• Stephen B. Maebius

  • Role: Lead Counsel
  • Firm: Foley & Lardner LLP, Washington, D.C.
  • Relevant experience: Partner and intellectual property lawyer with over 30 years of experience, he leads teams handling IP due diligence, infringement and validity opinions, international portfolio management, licensing, and litigation with parallel inter partes reviews. He successfully served as lead counsel in the defense of six inter partes reviews against Orange Book-listed pharmaceutical patents. He is a former patent examiner in the Biotechnology Group of the U.S. Patent & Trademark Office.

• Jason N. Mock

  • Role: Back-up Counsel
  • Firm: Foley & Lardner LLP, Washington, D.C.
  • Relevant experience: An intellectual property attorney focused on all facets of the patent life cycle, including developing and obtaining patent rights, portfolio management, due diligence for transactions, and enforcing or defending rights. His practice spans pharmaceuticals, diagnostics, biotechnology, and other scientific fields, and he is a member of the firm's PTAB Trials Practice.

The counsel of record representing Abtis Co Ltd, the Patent Owner in IPR2025-00283, is not publicly available in the provided search results without a subscription to the docket analysis platforms. While the case details confirm Abtis Co Ltd as the Patent Owner in the inter partes review concerning patent 11896675, the specific attorneys, their roles, firms, and experience for Abtis are not disclosed in the accessible information.

The available records indicate that Ajinomoto Co., Inc. (the Petitioner) has appointed Stephen Maebius as lead counsel and Jason N. Mock as back-up counsel. However, similar information for Abtis Co Ltd is not present in the public snippets.