The Delhi High Court’s judgment on product-by-process claims represents an important moment in the interpretation of product-by-process claims in India, making way for an important discussion on the scope and interpretation of product by process (PBP) claims under patent law. This landmark decision stands in contrast to a previous interpretation by a Single Judge of the Delhi High Court, emphasizing that PBP claims should focus on the product itself rather than being strictly limited to the associated process. 

Factual matrix 

On February 7, 2024, the Delhi High Court delivered its judgment in Vifor (International) Limited & Anr. v. MSN Laboratories Pvt. Ltd., Vifor (International) Limited & Anr. v. Reddy’s Laboratories Ltd. & Anr in Vifor (International) Limited & Anr. v. Corona Remedies Pvt. Ltd. MSN Laboratories Pvt. Ltd. These cases arise from litigation initiated by the Vifor Pharma Group regarding their novel product, ferric carboxymaltose (FCM), protected under Indian Patent No. 221536 (IN’536). The current batch of appeals addressed the refusal to grant an interim injunction in three lawsuits filed by Vifor in 2021 and 2022, aimed at protecting FCM. 

The Division Bench of the Delhi High Court faced the significant challenge of interpreting product-by-process claims, marking the first such adjudication in the Indian legal framework. The court’s ruling is expected to have far-reaching implications for patent rights, setting a precedent for future cases. 

Cardinal principles 

In its judgment, the Division Bench articulated several cardinal principles that will guide Indian courts in interpreting product-by-process claims: 

1. Recognition of Product-by-Process Claims: The court emphasized that these claims are globally recognized in instances where a novel product cannot be fully described by its structure. Therefore, unique attributes of the product must reference the process used in its manufacture. By doing so, the court granted judicial legitimacy to product-by-process claims, recognizing them as a blend of both product and process claims. 

2. Novelty in Product-by-Process Claims: The court held that the aspects of novelty and non-obviousness must be evaluated with reference to the product. If the product is not novel, the claim defaults to a process claim, meaning that a novel process alone cannot justify a patent. This principle underscores the necessity of evaluating the product itself to determine patentability. 

3. Fluidity in Interpretation: The Division Bench clarified that the distinction between product and process should not be overly rigid. In cases where specific characteristics cannot be identified without reference to the process, a flexible interpretation is warranted. This approach allows for a more nuanced understanding of how product-by-process claims operate in practice. 

4. Infringement Analysis: The court ruled that infringement of product-by-process claims cannot be restricted solely to the process itself. If a novel product is claimed, it warrants broader protection under Section 48(a) of the Patents Act, 1970. This principle reflects an understanding that the scope of protection extends beyond the specific processes involved in creating the product. 

5. Consistent Novelty Tests: The court stated that the standards for assessing novelty during the patent grant process and during infringement analysis should align, given that the claim language remains unchanged. This consistency is essential for ensuring fair and equitable treatment of patent rights. 

6. Understanding Claim Language: The Division Bench addressed the significance of the terminology used in claims, distinguishing between “obtained by” and “obtainable by.” An “obtained by” claim typically indicates a limited scope closely tied to the process, while “obtainable by” aligns more closely with the novelty requirements of Section 48(a). This distinction is critical for understanding the breadth of protection afforded to patentees. 

7. Departure from U.S. Jurisprudence: Notably, the Division Bench departed from the approach adopted by the United States Court of Appeals for the Federal Circuit. It criticized inconsistencies in analysing infringement versus novelty in U.S. case law, citing relevant decisions that have faced scrutiny for their double standards. The court referred to the “Angora Cat” principle from European jurisprudence to support its position. 

8. INN Allocation and Patentability: The allocation of the international non-proprietary name (INN) has no bearing on the determination of whether a claimed product is novel. The court emphasized that INN allocation is merely corroborative and does not influence the core assessment of patentability. 

International perspectives 

Japan 

The Japanese Supreme Court’s decision in 2012 has significantly shaped the understanding of product-by-process claims in Japan. It emphasized that claim scope should be determined by the language of the claim itself. Japanese patent practice recognizes that certain terms in claims may be ambiguous or have multiple meanings, necessitating a careful examination of the specification and file history to clarify intent. In Japan, product-by-process claims are allowed only when it is impractical to explicitly specify the product’s structure or properties; otherwise, such claims may be invalidated for lack of clarity. 

Germany 

In Germany, product-by-process claims are characterized by the necessity to describe the product at least partially through the manufacturing process. German law maintains that the claims must not be confined solely to the process described. This broad interpretation allows for the protection of the product while recognizing the importance of the process in establishing certain characteristic properties. 

Australia 

While there has been no recorded judicial consideration of product-by-process claims in Australia, the Australian patent authority (IP Australia) has provided guidance on the matter. It differentiates between claims that are “produced by” or “obtained by” a specified process and those that are “obtainable by.” Claims phrased as “produced by” or “obtained by” tend to limit the product to that which can only be created by the disclosed process. However, in cases where the term “obtainable by” is used, the authority has held that it does not restrict the claim to products produced solely by the specified process, thereby allowing for broader interpretations. 

Conclusion 

The Delhi High Court’s ruling significantly expands the enforcement of patentee rights in India, particularly in the pharmaceutical and mechanical sectors. Although the court denied Vifor an injunction due to the expiration of IN’536, it affirmed the company’s right to seek a percentage of sales from infringers. This decision enhances the protection and flexibility for patentees, particularly in non-standard-essential patent litigation. The principles established by the court lay the groundwork for future cases, potentially reshaping how product-by-process claims are understood and enforced in Indian patent law.