The recent judgment dated October 9, 2024, by the Hon’ble High Court of Delhi in F. Hoffmann-La Roche AG & Anr. v. Zydus Lifesciences Limited, CS(COMM) 159/2024 [Neutral Citation: 2024:DHC:7868}, has brought the process of claim mapping to the forefront in patent infringement litigation. The case revolved around allegations by F. Hoffmann-La Roche AG and its subsidiary Genentech Inc. that Zydus’s biosimilar drug “Sigrima” infringed their Indian patents concerning Pertuzumab. The court’s decision to deny interim relief due to the absence of claim mapping underscores its importance in patent disputes. This article analytically explores the judgment, the concept of claim mapping, and its implications for patent enforcement.

Case background

F. Hoffmann-La Roche AG and Genentech Inc. filed a suit alleging that Zydus’s biosimilar drug, marketed as “Sigrima,” infringed two Indian patents (IN ‘646 and IN ‘632) related to Pertuzumab. The plaintiffs sought a permanent injunction to prevent Zydus from manufacturing and selling the drug, arguing that it violated their intellectual property rights. Zydus contested these claims, pointing to the plaintiffs’ prior knowledge of their product launch and the lack of evidentiary substantiation in earlier proceedings. The court emphasized the necessity of establishing a prima facie case, with claim mapping as a critical component, to determine whether the plaintiffs’ patents were being infringed.

Claim mapping: definition and purpose

The court outlined claim mapping as the systematic comparison of a patent’s claims with the features of an allegedly infringing product or process. This involves analyzing whether the elements described in the patent claim are present in the accused product.

The purpose of claim mapping is twofold. The first part is establishing prima facie infringement to demonstrate that the product contains each element of the patent claim, ensuring a clear case of infringement. The second part is avoiding overgeneralization to prevent reliance solely on the general similarities between the patented invention and the accused product, which may not suffice under the rigorous scrutiny of patent law.

The plaintiffs’ oversight

The court noted that the plaintiffs failed to present any claim mapping to substantiate their allegations. Despite their assertions regarding the biosimilarity of “Sigrima” to Pertuzumab, the absence of detailed claim mapping left a critical evidentiary gap. This omission precluded the court from making any conclusive findings of infringement.

The judgment reinforced several principles of patent law:

• No presumption of automatic infringement: The mere existence of a patent does not entitle the patentee to interim relief without adequate proof of infringement.  

• Thorough scrutiny is required: Courts must carefully analyze claims and alleged infringements through tools like claim mapping before granting relief.  

• The burden of proof on the patentee: The onus is on the patent holder to substantiate infringement claims with precision and clarity.

• Significance of claim mapping in patent litigation: The judgment highlights claim mapping as an indispensable tool in patent infringement cases, particularly during the interim injunction stage. Its role is pivotal in ensuring robust prima facie cases; a well-prepared claim mapping demonstrates the likelihood of infringement and strengthens the plaintiff’s case.

• Preventing misuse of patent rights: By requiring specific evidence, claim mapping deters frivolous claims and upholds the balance between patentee rights and market competition.

• Guiding judicial decision-making: Clear claim mapping aids courts in making informed decisions based on technical and legal grounds.

Role of claim mapping for stakeholders

The case serves as a cautionary tale for patentees to prioritize claim mapping in infringement suits. A failure to provide comprehensive claim mapping can result in the denial of crucial interim relief, potentially affecting the commercial viability of their patents. Defendants can leverage the absence of claim mapping to contest allegations of infringement effectively. This reinforces the need for robust defenses grounded in factual and legal analysis.

The Delhi High Court’s decision in F. Hoffmann-La Roche AG v. Zydus Lifesciences Limited underscores the criticality of claim mapping in patent infringement litigation. By denying interim relief due to the plaintiffs’ failure to provide claim mapping, the court reinforced the principle that patent rights must be enforced through meticulous and substantiated claims.