Biotechnology patents in India have always been subject to stringent scrutiny and examination. While overcoming patent matter eligibility conditions, i.e., Section 3, is an arduous task, meeting the enablement and sufficiency of disclosure is also challenging, considering the nature of the biotechnological inventions. The present article focuses on said sufficiency and enablement requirements, in view of recent jurisprudence. Section 10(4) of the Indian Patents Act requires that every invention must be described in a manner sufficiently clear and complete for it to be carried out by a person skilled in the art. This is crucial for inventions relating to biological materials. If a patent application fails to sufficiently describe how to make or use the claimed subject matter, or if such information is not available to the public, the application may be completed by depositing the biological material to an International Depository Authority (IDA) under the Budapest Treaty. The patent specification must include all necessary details (i.e., name, address of the depository institute and the date and number of the deposit) about the deposited material to meet the enablement requirement. Further, Section 10(5) requires that claims shall be clear and succinct and shall be fairly based on the matter disclosed in the specification.

A recent case, The Regents of the University of California v. The Controller of Patents, dated February 21, 2025, (2025 SCC OnLine Del 987), provides valuable insights into these requirements. The Delhi High Court's decision on February 21, 2025, upheld the refusal of Indian Patent Application No. 201717005699, titled 'Vaccine for Livestock Production Systems'. This application pertained to a recombinant Salmonella microorganism-based live vaccine aimed at preventing enteric bacterial infections in livestock.?

Case Background: The applicant, the Regents of the University of California, filed the patent application on February 17, 2017. The application underwent examination, and the Assistant Controller of Patents and Designs issued a refusal order on July 14, 2022. The refusal was based on three primary grounds:?

1. Non-compliance with Section 10(4) and 10(5): The Controller found that the claims lacked clarity and precision, failing to meet the requirements of enablement and full disclosure.?
2. Non-patentability under Section 3(c): The subject matter was deemed to pertain to a mere discovery of a scientific principle or abstract theory, not constituting patentable subject matter.?
3. Broad Claims: The claims were considered overly broad, encompassing any Salmonella microorganism with specific genetic mutations, without adequate support or disclosure.?

Before dwelling in to the order of the High Court, let us understand the invention and the claimed subject matter. The refused claim 1 reads as follows:

“A recombinant Salmonella microorganism, wherein said microorganism comprises a loss of function mutation in the dam gene and at least one further sifA, spvB and mgtC in a gene selected from the group consisting of: sifA, spvB and mgtC wherein the microorganism is a Salmonella enterica subsp. Enterica serovar selected from the group consisting of S. Typhimurium, S. Enteritidis, S. Dublin, S. Newport, S. Choleraesuis, and S. Bovismorbificans”

In the claim, the recombinant Salmonella is claimed as having loss of function mutation in the dam gene and in at least one of sifA, spvB or mgtC genes. Therefore, the invention relates to double mutants of Salmonella for use as vaccines. It is also important to note that the corresponding applications filed in several other jurisdictions such as US, EP, China, Japan, Canada, Russia, and Mexico are granted.

Court's Analysis: The Delhi High Court examined the appeal under Section 117A of the Patents Act, 1970 and upheld the rejection decision, emphasizing the following points:?

• Enablement, disclosure, and broad claims: The Court highlighted that Section 10(4) requires a complete specification to "particularly describe the invention and the manner in which it is to be performed." In this case, the Court agreed with the Controller's assessment that the claims were not sufficiently supported by the description, leading to a lack of enablement.

According to the Court, the application claimed a broader inventive concept of a vaccine composition for inducing an immune response in a subject to a Salmonella microorganism, where it claims both genetically modified Salmonella microorganisms used in the vaccine composition and the vaccine itself. The genetically modified Salmonella strains are obtained through specific loss-of-function mutations in the dam gene and at least one additional gene selected from sifA, spvB, and mgtC through insertion, deletion and/or substitution mutations. While the Salmonella serovars mentioned in claim 1, i.e., S. Typhimurium, S. Enteritidis, S. Dublin, S. Newport, S. Choleraesuis, and S. Bovismorbificans, the genes referred above, and loss- of-function mutations can occur naturally, the inventive contribution of the subject patent application lay in the deliberate introduction of mutations at specific sites of multiple genes that disrupted gene function to attenuate virulence, making these modified strains suitable for use in vaccine compositions.

The Court opined that working example and detailed description, were limited to deletion mutations and did not disclose the inventive contribution fully that also covered insertion and substitution, and thus concluded that the application lacked specific disclosures in respect of insertion and substitution mutations resulting in an insufficiency of disclosure. Further, the partial disclosure as made in the subject patent application would also not be sufficient to enable a person skilled in the field of microbiology to perform the invention, without additional guidance. Given that the disclosure itself was incomplete, it could not be said to be compliant with the requirement to disclose the best method for performing the said invention in terms of Section 10(4)(b) of the Act. Further, the Court emphasised that there was no deposition of the biological material i.e., the recombinant Salmonella claimed in the subject patent application. The Court opined that being a modified bacteria which was not accessible to the public, it was liable to be deposited in the recognised depository according to the Budapest Treaty referred to in Section 10(4)(d)(ii) of the Patents Act, 1970.

With regards to the claims, Section 10(5) states that claims must be "clear, succinct, and fairly based on the matter disclosed in the specification." The Court concurred that the broad claims did not meet this standard, as they covered a wide range of Salmonella strains without adequate disclosure and opined that “the claims of the subject patent application fail to provide a clear and precise definition of the full scope of recombinant Salmonella organisms covered in the subject patent application, even after a conjoint reading of the claims and the complete specification”. The Court highlighted that there was absence of detailed support or working embodiments demonstrating the mutations as claimed.

According to the Court, while claim 1 covered only seven combinations of the loss of function mutations for six organisms limiting the total combinations to 42 combinations, according to claim 2 if insertion, substitution and/ or deletion, are performed on one or more nucleotides it would cover large number of mutants, which had not been clearly defined. Thus, the Court concluded that the claims of the subject patent application covered and encompassed various types of ‘loss of function’ mutations in selected genes of Salmonella microorganisms and asserted that innumerable permutation and combinations were possible, and therefore, the complete specification lacked adequate support for the full extent of the claims. While the Court acknowledged that the detailed description further specified the relevance of genetic mutations, however, the detailed description clarified that the target genes did not necessarily need to be deliberately mutated if the expression of the native gene product is functionally disrupted in some way. This broadened the scope of the subject patent application to include any method of gene disruption, not limited to deliberate genetic modifications.

• Non-Patentable Subject Matter: The Court upheld the finding that the claims were directed to naturally occurring endogenous mutations, falling under the non-patentable subject matter category of Section 3(c). The Court opined that several loss-of-function mutants of Salmonella microorganisms referred to in claim 1 are present naturally. Hence, the broad claim on such endogenous mutations also covered naturally occurring variants of Salmonella bacteria with loss of function mutation is not permissible under Section 3(c). The Court also observed that the detailed description ought to have ensured that the subject patent application does not cover naturally mutated Salmonella microorganism, which is excluded under Section 3(c) of the Act.

Issues with the order: There seems to be several issues in the reasoning provided in the order. First, in arriving at the rejection, the Court overly focused on the breadth of claims, which is common in biotech inventions, without adequately considering whether the claims could be worked by a skilled person without undue experimentation. The Court did not fully consider the underlying invention of identification and claiming the genes for loss-of-function mutations, and that the specification covered all possible mutations (insertions, deletions, substitutions), including loss-of-function mutations, which are critical to the invention. Secondly, with regards to Section 3(c), the Court treated the recombinant microorganism as a natural discovery, despite human intervention in its creation through loss-of-function mutations and hence appears to be an incorrect interpretation.

Conclusion and recommendations while drafting biotech patents: The ruling could create a precedent that undermines patentability of recombinant genes by equating them to natural discoveries, merely for lack of specific examples in the specification. Despite its short comings, the case underscores the importance of meeting the enablement and disclosure requirements set forth in Section 10 of the Patents Act. This judgment seems also in line with the Amgen v. Sanofi Judgment of the US Supreme Court (598 U.S. 594 (2023)) wherein on enablement it was explained that “if a patent claims an entire class of processes, machines, manufactures, or compositions of matter, the patent’s specification must enable a person skilled in the art to make and use the entire class. In other words, the specification must enable the full scope of the invention as defined by its claims. The more one claims, the more one must enable.” 

Therefore, considering the above, it is incumbent for patent applicants in the biotech domain to provide clear and concise claims that are fully supported by detailed description and experimental data. Deposition of biological materials is also essential in biotech patent application. Overly broad claims without adequate disclosure are susceptible to rejection. This case also serves as a critical reminder to ensure that patent applications are meticulously drafted and compliance with enablement and disclosure standards is essential to secure patent protection.