Introduction

In KEMIN INDUSTRIES, INC. v. Controller of Patents [1]¹, the Madras High Court overturned the rejection of a patent application concerning a method of improving animal feed by supplementing bacterial ferulic acid esterase (FAE) with four specific enzymes. The Patent Office had denied the application under Sections 2(1)(j), 3(d), and 3(i) of the Patents Act, citing lack of inventive step and patent ineligibility. However, the Court held that the claimed enzyme combination was neither obvious nor disclosed in the prior art, demonstrated a synergistic effect, and did not constitute a method of treatment under Section 3(i), thereby clearing the way for grant of the patent.

Facts of the Case

The Indian patent application titled “Use of Ferulic Acid Esterase to Improve Performance in Monogastric Animals” was filed by Kemin Industries, Inc. before the Indian Patent Office. A First Examination Report (FER) was issued citing objections under Section 2(1)(j) (lack of novelty and inventive step), Section 3(d) (prohibiting mere use of known processes unless they yield a new product or use a new reactant), and Section 3(i) (excluding methods for the treatment of animals to cure disease or increase their economic value). In response to the FER, the applicant submitted detailed technical and experimental data and attended a hearing. Despite these submissions, the Controller refused the application, stating that the invention lacked an inventive step in light of prior art (D1 and D2), and remained non-patentable under Sections 3(d) and 3(i). Kemin then appealed this decision under Section 117-A of the Patents Act, 1970 before the Madras High Court.

Appellant’s Arguments

The Appellant submitted that the sole claim of the rejected application relates to a method of supplementing ferulic acid esterase (FAE) produced from bacteria with four main chain degrading enzymes, namely, cellulase, xylanase, glucanase and amylase which leads to significant improvement in the metabolizable energy. The Appellant supplemented the arguments with Experimental data demonstrating the unexpected effects, including significantly lower feed conversion ratio (FCR) to establish the synergistic effect of the claimed composition and argued that the claimed combination of FAE with all four main chain degrading enzymes was not obvious and not disclosed by any of the cited prior art documents D1 or D2. Appellant further contended that combination disclosed by cited documents is limited to FAE and xylanase only and the structure of xylanase is quite different from that of the other three main chain degrading enzymes.

The Appellant relied upon the judgments in case of Biswanath Prasad Radhey Shyam v. Hindustan Metal Industries Ltd. [2]², F.Hoffman La Roche v. Cipla [3]³ and Bristol-Myers Squibb Holdings Ireland Unlimited Company v. BDR Pharmaceuticals International Private Limited [4]⁴ for establishing the non-obviousness of the claimed invention. Appellant further contended that there exists a vast array of enzymes and the Appellant has exercised ingenuity in picking four enzymes and combining them with FAE. Therefore, the claimed invention is inventive as required under Section 2(1)(j)(a) of the Act.

For rejection under Section 3(d), Appellant contended that claimed process is novel and more than one reactant is deployed.

Further, for rejection under Section 3(i), the Appellant strongly contended that the claimed invention is directed solely at a method of supplementing FAE with main chain degrading enzyme and nowhere relates to a method of treatment of animals. While supplemented feed might ultimately increase the animal’s economic value (e.g., fattening poultry), the invention is directed at the feed itself and not at the method of treatment of animal itself. The Appellant further distinguished their case from Kymab Limited v. Controller of Patents [5]⁵, which was cited by the Respondent, by specifically pointing out that Kymab involved claims directed to a method of treating animals while the claimed invention relates to method of supplementing FAE.

Contentions of the Respondent

The Respondent submitted that the Appellant’s patent application relates to the use of FAE along with main chain degrading enzymes to improve the availability of metabolizable energy in animal feed. Prior art documents D1 and D2 teaches the combination of FAE and xylanase which further discloses the highest enzymatic activity of xylanase in comparison to other three enzymes mentioned therein. Respondent further questioned regarding the bacterial origin of FAE of impugned application in the absence of any relative data in contrast to the fungal origin of FAE of the prior art.

The Respondent also relied upon the judgment of this Court in Kymab Limited v. the Assistant Controller of Patents & Designs [5] and contended that use of the method of the impugned application would result in the fattening of the poultry to which the animal feed is administered and therefore fall under the provision of Section 3(i) of the Patents Act for being a process for the treatment of animals so as to increase their economic value. The Respondent also raised issues about the lack of data for FAE concentrations above 40 units/kg in the provided tables whereas the invention claims 20 to 200 units per kg of FAE, and the rejection of corresponding patent application by the European and US Patent Offices.

Court’s Analysis

Section 3(i) – Treatment of Animals

The Court clarified that Section 3(i) applies to processes for the treatment of animals only if they are intended:

1. To render them free of disease;
2. To increase their economic value; or
3. To increase the economic value of their products.

The Court held that the invention merely supplements animal feed to improve digestibility, and not a method of treating animals. The Court distinguished Kymab [5] by noting that Kymab involved direct treatment, while Kemin’s invention modifies feed composition.

“Section 3(i) cannot be extended to a method of supplementing an animal feed merely because the use of such animal feed may ultimately result in improving the economic value of the animal or its products.” Thus, the invention was held not to fall under Section 3(i).

Section 3(d) – Mere Use of a Known Process

The Court compared the claimed invention to the prior arts D1 and D2. While D1 teaches combination of FAE and xylanase, and D2 teaches combination of FAE and one polysaccharide modifying enzyme selected from a group consisting of xylanase and arabinase, glucanase, a pectinolytic enzyme and a rhamnogalacturonase. The Court found that neither D1 nor D2 disclosed the specific combination of FAE with all four enzymes as claimed in the impugned application. The Court concluded that the impugned application relates to a new process involving more than one new reactant and therefore does not fall under Section 3(d) of the Act.

Section 2(1)(j) – Inventiveness

The Court observed that:

• D1 only teaches FAE with xylanase.
• D2 suggests the use of one polysaccharide enzyme from a group, not a combination.
• The combination of four specific enzymes (cellulase, xylanase, glucanase, and amylase) with FAE is neither disclosed nor suggested by D1 or D2.
• Experimental data (Tables 1, 7; Figures 7, 8) demonstrated unexpected results such as improved metabolizable energy and significantly lower FCR.

In light of these findings, the Court held that the invention involves an inventive step and is not obvious to a person skilled in the art.

Our Analysis

This judgment sets a crucial precedent for the biotech and animal nutrition sectors, especially for inventions that involve feed formulations rather than therapeutic treatments.

By clarifying the narrow scope of Section 3(i), the Court ensures that innovations aimed at improving feed efficiency or metabolic extraction are not excluded from patentability simply because they indirectly impact animal productivity.

The distinction from Kymab [5] is critical. The Court rightly emphasized that Kemin’s invention is a feed composition, not a medical treatment, and thus does not violate public policy concerns around monopolizing therapeutic methods.

This decision also reinforces that experimental synergy and enzyme selection can contribute to inventiveness—particularly when the field contains numerous known options and no obvious path to the claimed combination.

Conclusion

This judgment reinforces the fact that Section 3(i) aims to prevent patents on methods of treatment of humans and animals for the three specific purposes (i) To render them free of disease; (ii) To increase their economic value; or (iii) To increase the economic value of their products., However, it is not designed to roadblock the inventions like the impugned application. Therefore, the High Court allowed the appeal by setting aside the Controller’s refusal order and directing that impugned application shall proceed to grant.

References

1. [1] CMA(PT). No.46 of 2024 ↩︎
2. [2] AIR 1982 SC 1444 ↩︎
3. [3] 2016 (65) PTC 1 (Del), ↩︎
4. [4] Manu/DE/0299/2020 ↩︎
5. [5] 2024:MHC:3498 ↩︎