Genus–Species Patents, “Person in the Know” and Evergreening: Commentary on Novo Nordisk A/S v. Dr. Reddy’s Laboratories Ltd. (2025 DHC 10820)

Genus–Species Patents, “Person in the Know” and Evergreening: Commentary on Novo Nordisk A/S v. Dr. Reddy’s Laboratories Ltd. (2025 DHC 10820)

1. Introduction

This judgment of the Delhi High Court (Manmeet Pritam Singh Arora, J.) in Novo Nordisk A/S v. Dr. Reddy’s Laboratories Limited & Anr., CS(COMM) 565/2025, decided on 2 December 2025, is a significant development in Indian patent law, particularly for:

  • The treatment of genus vs. species patents in pharmaceuticals.
  • The use of Form 27 “working” statements and foreign PTE/SPC filings as admissions of prior claiming.
  • The strengthening and practical use of the “person in the know” test (as opposed to a generic “person skilled in the art”) where inventors are common to both patents.
  • The Court’s approach to evergreening and double patenting under Sections 64(1)(a), 64(1)(e), and 64(1)(f) of the Patents Act, 1970.
  • The reaffirmation and application of the “clear the way” doctrine in interim injunctions in patent disputes.

The plaintiff, Novo Nordisk, sought an interim injunction against Dr. Reddy’s Laboratories (DRL) and a manufacturing affiliate, alleging infringement of its Indian species patent IN 262697 (IN’697) covering the blockbuster antidiabetic drug Semaglutide. The defendants invoked the Gillette defence and attacked the validity of IN’697 on several grounds, centering on a prior genus patent IN 275964 (IN’964) owned by the same patentee.

The Court ultimately refused to grant an interim injunction restraining manufacturing or exports, while maintaining an injunction (based on the defendants’ undertaking) on sale in India. In doing so, it found a strong prima facie case that the Semaglutide species patent is vulnerable to revocation for prior claiming, anticipation, obviousness and evergreening.

2. Background and Factual Matrix

2.1 The Patents and the Drug

  • Suit patent (species): IN 262697 (“IN’697”), titled “Acylated GLP-1 Analogs Comprising Non‑Proteogenic Amino Acid Residue”.
  • Priority and filing:
    • Priority application: EP 05102171.5, dated 18.03.2005 (later re-dated by the EPO Opposition Division – see below).
    • PCT filing: PCT/EP2006/060855 on 20.03.2006.
    • Indian filing: 02.07.2007; grant: 05.09.2014; expiry: 20.03.2026 (20 years from PCT filing date).
  • Genus patent: IN 275964 (“IN’964”), titled “Novel Conjugates of GLP‑1” – an earlier patent disclosing a broad Markush genus of GLP‑1 analogues, with 66 exemplified compounds, including “Example 61”.
  • The drug: The key compound claimed in IN’697 is Semaglutide, a long‑acting GLP‑1 analogue, commercialised by Novo Nordisk as:
    • Ozempic (injectable),
    • Wegovy (for obesity), and
    • Rybelsus (oral).
    Semaglutide allows once-weekly subcutaneous dosing, compared to earlier GLP‑1 analogues such as Exenatide (twice daily) and Liraglutide (once daily).

2.2 Procedural History and Interim Undertaking

  • In late 2024, Novo Nordisk discovered that DRL and OneSource were importing and exporting Semaglutide APIs in significant quantities.
  • By April 2025, DRL had commenced commercial manufacture of Semaglutide in India under an Indian manufacturing licence.
  • Novo issued a cease-and-desist notice (5 May 2025). In response, DRL filed a revocation petition (C.O. (COMM.-IPD‑PAT) 9/2025) challenging IN’697.
  • In the civil suit, on 29 May 2025, DRL:
    • Admitted manufacturing, but
    • Undertook not to sell Semaglutide in India until it obtained a marketing licence, reserving its right to export to non‑patent countries.
    • The Single Judge recorded the undertaking and did not restrain exports.
  • Novo appealed against the refusal to injunct exports. The Division Bench directed expedited disposal of the interim injunction application (I.A. 14076/2025), which was heard in detail and reserved on 15 September 2025.

2.3 Relief Sought

Novo Nordisk sought an interim injunction under Order XXXIX Rules 1–2 CPC to restrain:

  • Manufacture, sale, offer for sale, import or export of Semaglutide APIs and products by the defendants in alleged infringement of IN’697.

Given DRL’s undertaking not to sell in India, the narrowed interim issue

Whether DRL should be restrained from manufacturing Semaglutide in India for export to countries where Novo has no patent protection, until the expiry of IN’697.

3. Summary of the Judgment

The Court held, prima facie and for interim purposes:

  1. No presumption of validity: Under Section 13(4), the grant of a patent does not guarantee validity. Even a long‑standing unopposed patent can be attacked, and the Court must examine if the defendant has raised a credible challenge under Section 107(1) read with Section 64.
  2. Strong prima facie invalidity of IN’697: The defendants raised a credible challenge that IN’697 is vulnerable to revocation on:
    • 64(1)(a): prior claiming in the earlier genus patent IN’964;
    • 64(1)(e): anticipation by prior publication (once the priority date of IN’697 is correctly fixed);
    • 64(1)(f): obviousness / lack of inventive step, given prior art and the common inventors.
  3. Priority date re-dated via EPO decision: Relying on an Opposition Division (EPO) decision on the corresponding EP patent, the Court accepted, as a matter of fact, that Claim 1 of the EP (and hence IN’697) was not entitled to the 18.03.2005 priority date. Its effective priority date is 20.03.2006, which is after publication of the PCT for IN’964 (WO 2005/027978, 31.03.2005). Thus, IN’964 is valid prior art for novelty and inventive step.
  4. Semaglutide prior‑claimed and enabled in IN’964:
    • The Court carefully compared:
      • Example 61 of IN’964 (often referred to as “Ala‑Semaglutide”), and
      • Example 4 / Claim 23 of IN’697 (Semaglutide).
    • It found that every feature of Semaglutide is claimed or taught in IN’964, except the single change of replacing alanine (Ala) at position 8 with α‑aminoisobutyric acid (Aib), a non‑proteogenic amino acid.
    • Crucially, Claim 16 of IN’964 specifically claims “Aib at position 8” in GLP‑1(7‑37); together with Example 61 and other claims (14, 15, 18, 21), a person in the know is enabled to arrive at Semaglutide.
  5. Admissions via Form 27 and foreign PTE/SPC filings:
    • Novo’s Form 27 statements in India repeatedly declared that IN’964 had been “worked” in India and that the turnover arose from products based on Semaglutide; later, the same forms clubbed IN’964 and IN’697 as “related patents” for the same commercial product.
    • Abroad, Novo obtained Patent Term Extensions (PTEs) and Supplementary Protection Certificates (SPCs) for the IN’964 family, explicitly citing Semaglutide‑containing products.
    • Following the Supreme Court’s reasoning in Novartis AG v. Union of India, such regulatory and patent filings are treated as binding admissions that Semaglutide is covered by the genus patent.
  6. Obviousness and “person in the know”:
    • Given that the inventors of IN’964 and IN’697 are largely identical, the Court applied the “person in the know” test (from AstraZeneca v. Intas and F. Hoffmann-La Roche AG v. Natco (2025)): obviousness must be assessed from the perspective of an inventor fully conversant with the genus patent.
    • Combining IN’964 with Deacon (1998) and Knudsen (2004), the Court found that substituting Ala with Aib at position 8 to improve DPP‑IV resistance and half‑life was obvious to try with a reasonable expectation of success.
  7. Evergreening and double patenting:
    • Novo’s own pleadings stated that Semaglutide was “invented in 2004”, contemporaneous with filing IN’964.
      • prima facie      , known Semaglutide at the time of IN’964 but withheld it from that filing and later sought a separate, later‑expiring species patent (IN’697) on substantially the same inventive concept.
    • This was treated as a classic case of evergreening and double patenting: extending exclusivity for the same invention by splitting protection into a genus and a later species patent.
  8. Balance of convenience and “clear the way”:
    • Despite finding a strong prima facie invalidity case, the Court:
      • Did not release DRL from its undertaking not to sell in India until March 2026.
      • Allowed DRL to continue manufacturing and exporting Semaglutide to countries where Novo has no patent.
    • The Court viewed DRL’s conduct—starting manufacture without first revoking or attacking IN’697—as failing to “clear the way”, a factor weighing against allowing Indian sales before expiry.
  9. Final interim relief:
    • Interim injunction application dismissed: no injunction against manufacture or export.
    • DRL is bound by its undertaking and a Court direction not to sell in India until expiry of IN’697.
    • DRL must maintain and file accounts of all manufacture and exports of the impugned product from April 2025 till patent expiry, to enable damages/account of profits if Novo ultimately succeeds at trial.
    • All findings are expressly prima facie and “without prejudice” to trial.

4. Detailed Analysis of the Legal Reasoning

4.1 No Presumption of Validity and the “Credible Challenge” Standard

Novo argued that IN’697, being nearly 19 years old and unopposed (no pre‑ or post‑grant opposition, no revocation until 2025), enjoyed a prima facie presumption of validity, warranting an injunction upon showing infringement.

The Court rejected any such presumption by relying on:

Citing Mold Tek Packaging Ltd. v. Pronton Plast Pack Pvt. Ltd. (2025), the Court reiterated:

In an infringement suit, once the defendant raises a 107(1) defence, the Court must examine whether the defendant has raised a credible challenge to validity under any ground in Section 64, even at the interim stage.

Thus, the correct approach is not a presumption of validity, but a two‑fold inquiry:

  1. Is there prima facie infringement? (in practice undisputed here), and
  2. Has the defendant shown a credible vulnerability of the patent under Section 64?

4.2 Prior Claiming and Double Patenting under Section 64(1)(a)

4.2.1 Legal framework

Section 64(1)(a) permits revocation where:

“the invention so far as claimed in any claim of the complete specification has been claimed in any claim of a prior dated patent granted in India.”

Section 53(4) supplements this, declaring that once a patent expires, “the subject matter covered by the said patent shall not be entitled to any protection”. Together they bar double patenting of the same subject matter.

The Court drew support from AstraZeneca AB v. Intas Pharmaceuticals (2021), which held that the same pharmaceutical product cannot enjoy overlapping protection under two separate patents with staggered expiry dates.

4.2.2 Claim-to-claim comparison: Example 61 vs. Semaglutide

The crux was whether the Semaglutide species claimed in IN’697 had already been claimed and enabled in IN’964.

Key features of Semaglutide (as pleaded by Novo):

  • GLP‑1(7‑37) backbone.
  • Substitution at position 8: Ala → Aib (α‑aminoisobutyric acid; non‑proteogenic).
  • Substitution at position 34: Lys → Arg.
  • Lys at position 26 acylated with a specific moiety including:
    • two OEG (AEEA) spacers,
    • γ‑Glu, and
    • C18 fatty diacid, with two acidic groups, one terminal.

IN’964 contained:

  • Claim 1: a Markush claim to GLP‑1 analogues with a free choice at position 8 among various amino acids, including Ala and Aib, acylated at Lys‑26 with a moiety B–U′ having at least two acidic groups (one terminal).
  • Claim 16: a dependent claim specifying Aib at position 8.
  • Claim 18: specific GLP‑1(7‑37) analogues, many with Aib at position 8 and Arg at 34.
  • Claim 21 + Example 61: a specific GLP‑1(7‑37) analogue (“Ala‑Semaglutide”) with:
    • Ala at position 8,
    • Arg at 34,
    • Lys‑26 acylated with the same type of C18 diacid/γ‑Glu/AEEA moiety as Semaglutide.

Novo’s own expert comparisons admitted that the only structural difference between Example 61 and Semaglutide is the Ala → Aib substitution at position 8. The Court then reasoned:

  • Claim 1 of IN’964 already covers GLP‑1(7‑37) compounds with either Ala or Aib at position 8, with the same fatty acid side‑chain.
  • Claim 16 specifically points the skilled person to Aib at position 8 as the preferred embodiment.
  • A skilled person (or more so, the common inventors) reading Claim 21/Example 61 together with Claim 16 is directly instructed to replace Ala with Aib at position 8 in that example.

On this basis, the Court held that IN’964 claims and enables the entire feature set that constitutes Semaglutide. It is therefore prior claimed within the meaning of Section 64(1)(a).

4.2.3 Role of Form 27 “working” statements

Form 27 is required under Section 146 and Rule 131 to disclose whether and how a patent is being “worked” in India. The Court examined Novo’s Form 27 filings for IN’964 and IN’697 from 2015–2023 and found:

Year Form 27 for IN’964 Form 27 for IN’697 Comment
2015–2020 States that studies are underway; regulatory approval awaited; not yet worked. Similar statements. Preparation for Semaglutide’s launch.
2021–22 Single combined Form 27 for IN’964 and IN’697 stating the patent(s) are “worked” in India via import of Semaglutide products and reporting turnover (~INR 36 crore). Explicit admission that both patents are commercially worked via Semaglutide.
2022–23 Combined Form 27; imports of Semaglutide worth ~INR 147 crore. Reinforces admission.

The Court held, following Boehringer Ingelheim v. Vee Excel (2023), that such Form 27 disclosures are binding admissions. They show Novo itself treated Semaglutide as the commercial embodiment of both IN’964 and IN’697, undermining its case that the genus patent did not claim or enable Semaglutide.

4.2.4 Admissions via foreign PTEs and SPCs

The Court then considered Novo’s applications for PTEs and SPCs in jurisdictions such as Australia, Japan, South Korea and several EU states, where:

  • The same genus patent family as IN’964 was extended,
  • Explicitly citing Semaglutide‑containing products as the basis for extension.

Following the Supreme Court’s approach in Novartis AG v. Union of India (2013) and the Delhi High Court’s decision in Bayer Healthcare LLC v. NATCO Pharma Ltd. (2023), the Court held that:

  • Such filings are strong evidence that the patentee itself considered Semaglutide to be covered and disclosed by the genus patent.
  • The difference in foreign statutory frameworks for PTE/SPC does not dilute the factual admission that the product derives from the genus patent.

These admissions, combined with the claim language and Form 27, solidified the finding of prior claiming and double patenting.

4.3 Priority Date and Use of the EPO Opposition Division Decision

Novo initially contended that IN’697 enjoyed an effective priority of 18.03.2005 via the EP 05102171.5 application, making IN’964’s publication (31.03.2005) post‑priority and hence not prior art for novelty/inventive step.

However, the EPO Opposition Division (EOD), in a decision dated 25.01.2013 concerning the EP counterpart, held that:

  • Claim 1 of the EP patent was not entitled to the 18.03.2005 priority date because the priority document did not unambiguously disclose the later‑amended claim’s subject matter.
  • The effective priority for Claim 1 was thus the PCT filing date of 20.03.2006.
  • Therefore, the PCT publication of IN’964 (WO 2005/027978) was prior art under Article 54(2) EPC (equivalent to Sections 64(1)(e), (f) in India).

The Delhi High Court:

  • Accepted this priority re‑dating as a finding of fact binding on Novo, especially since Novo itself relied on the same EP priority in its pleadings.
  • Held that this made IN’964 relevant prior art for Section 64(1)(e) and 64(1)(f) analysis.
  • Nonetheless declined to treat the EOD’s legal conclusion (that EP Semaglutide was novel and inventive) as binding, emphasising that Indian standards of novelty and inventive step (Sections 2, 64, and Indian case law) must govern.

4.4 Anticipation by Prior Publication – Section 64(1)(e)

Under Section 64(1)(e), a patent is revocable if the invention is anticipated by prior publication. The Court drew on:

  • The Manual of Patent Office Practice (Section 09.03.02) and
  • The structured test for novelty articulated in LAVA v. Ericsson (2024).

Having already concluded under Section 64(1)(a) that the same invention was claimed and enabled in IN’964, the Court held that:

  • IN’964 (published before the effective priority of IN’697) constitutes prior art.
  • Example 61 + Claim 16 (Aib at position 8) of IN’964 explicitly and implicitly disclose all material features of Semaglutide.
  • A skilled person could reproduce Semaglutide without undue experimentation.

Accordingly, the Court found a strong prima facie case that IN’697 is anticipated by prior publication of IN’964 within Section 64(1)(e).

4.5 Obviousness and the “Person in the Know” – Section 64(1)(f)

4.5.1 The test for obviousness

The Court applied the five‑step test from F. Hoffmann‑La Roche Ltd. & Anr. v. Cipla Ltd. (2015):

  1. Identify the ordinary (or in this case, “in the know”) person skilled in the art.
  2. Ascertain the inventive concept of the claims.
  3. Determine the common general knowledge at the priority date.
  4. Identify the differences between prior art and the claimed invention.
  5. Decide whether those differences would be obvious without hindsight.

4.5.2 Who is the “person in the know”?

In AstraZeneca v. Intas and F. Hoffmann‑La Roche AG v. Natco (2025), the Delhi High Court held that where the same inventors file both a genus and a later species patent:

  • The standard “person skilled in the art” is supplanted by a “person in the know” – effectively an inventor familiar with the specifics of the genus patent.
  • Something obvious to such a person cannot be transformed into a “new invention” merely by claiming it in a later species patent.

Here, five lead inventors were common to IN’964 and IN’697. The Court thus evaluated obviousness from the standpoint of:

A medicinal chemist of ordinary skill, but also fully conversant with IN’964 and the state of GLP‑1 analogue research (Deacon 1998; Knudsen 2004).

4.5.3 Inventive concept of IN’697

The inventive concept of IN’697 is:

  • GLP‑1(7‑37) analogues with at least one non‑proteogenic amino acid at positions 7 or 8 (particularly Aib at 8),
  • acylated at Lys‑26 with a C18 diacid/γ‑Glu/OEG (AEEA) linker,
  • with the aim of prolonging half-life and enabling less frequent dosing (up to once weekly) for Type 2 Diabetes.

4.5.4 Common general knowledge in prior art

The Court found that by the priority date:

  • Knudsen (2004):
    • Recognised GLP‑1(7‑37) as a promising therapeutic for Type 2 Diabetes.
    • Identified extremely short half‑life due to rapid DPP‑IV cleavage and renal clearance.
    • Highlighted that modifications at position 8 (Ala) affected DPP‑IV stability and potency (see Figure 3).
  • Deacon (1998):
    • Studied N‑terminal and position 8 modifications to achieve DPP‑IV resistance.
    • Specifically identified Aib8‑GLP‑1(7‑37) as DPP‑IV resistant, with improved metabolic stability and retained receptor activity.
  • IN’964:
    • Disclosed GLP‑1(7‑37) analogues modified with fatty acid side chains to extend half‑life via albumin binding.
    • Explained the same therapeutic objective: longer‑acting GLP‑1 analogues for Type 2 Diabetes, obesity, etc.
    • Through Claims 14, 15 and 16, taught:
      • “DPP‑IV protected” and “DPP‑IV stabilised” GLP‑1 analogues, and
      • Preference for Aib at position 8.
    • Example 61 already achieved substantial half‑life and potency (as per Novo’s own efficacy data to the IPO).

4.5.5 Differences and obviousness

The only structural difference between Example 61 (Ala‑Semaglutide) and Semaglutide is:

  • Position 8: Ala → Aib.

The Court reasoned that:

  • A person in the know would:
    • Recognise from Deacon and Knudsen that Aib at position 8 is a well‑known, effective way to increase DPP‑IV stability and half‑life.
    • See that IN’964 already enshrined this in Claim 16 and in a majority of its examples.
  • Example 61 had already been identified by Novo (in data filed with the IPO in 2014) as a particularly promising compound, with strong half‑life and potency.
  • It was therefore natural and obvious to take Example 61 as a lead compound and apply the Ala → Aib substitution at position 8 that:
    • was specifically claimed (Claim 16 IN’964), and
    • had been well‑documented in the literature as conferring DPP‑IV resistance.

The Court explicitly rejected Novo’s charge of “hindsight reconstruction”, holding that the path from IN’964 + Deacon + Knudsen to Semaglutide was straightforward and motivated for a person in the know, not an ex post facto cherry‑picking exercise.

Consequently, the Court found a strong prima facie case that Semaglutide (IN’697) was obvious and lacking in inventive step under Section 64(1)(f).

4.6 Evergreening and Double Patenting

Several strands converged on the evergreening conclusion:

  • Novo’s own pleadings: Semaglutide was “invented in 2004”, the same period as the filing of IN’964 (17.09.2004).
  • IN’964 and IN’697 share the same inventive concept: GLP‑1 analogues with improved half‑life and reduced injection frequency for Type 2 Diabetes.
  • Semaglutide is enabled and prior claimed in IN’964 (as discussed above).
  • Novo’s Form 27 filings and foreign PTE/SPC applications admit that Semaglutide is the only commercial product arising from both patents.

From this, the Court inferred that:

Novo, knowing Semaglutide in 2004, did not disclose it as such in IN’964, but later claimed it as a separate species patent (IN’697) to artificially extend the monopoly for essentially the same invention.

This is precisely the mischief that:

  • Novartis v. Union of India (2013) sought to prevent in the context of Section 3(d), and
  • AstraZeneca v. Intas and F. Hoffmann‑La Roche AG v. Natco condemned in the genus‑species context.

The Court thus characterised Novo’s approach as evergreening via double patenting, reinforcing the vulnerability of IN’697 under Sections 64(1)(a) and 64(1)(f).

4.7 Balance of Convenience, Non‑Working and “Clearing the Way”

4.7.1 Non‑working and imports

Novo initially pleaded that it manufactured Semaglutide products in India. DRL showed this was incorrect; Novo held only import licences, not manufacturing licences. Novo then accepted that all Indian sales were via imports.

In Boehringer Ingelheim v. Vee Excel, the Delhi High Court had held that non‑working of a patent in India can weigh against an injunction, particularly where public interest in cheaper generics is strong.

Here:

  • Novo did not manufacture in India.
  • The defendants had invested ~INR 1,000 crore in manufacturing facilities and were already exporting.
  • However, DRL did not contest the ban on Indian sales and undertook not to sell in India pending expiry.

4.7.2 Failure to “clear the way”

The Court placed considerable weight on DRL’s procedural conduct:

  • After expiry of IN’964 in September 2024, DRL sought a licence from Novo to manufacture Semaglutide in India, implying acknowledgement of IN’697.
  • DRL commenced commercial manufacturing in April 2025 without first:
    • filing a revocation petition, or
    • seeking a declaratory suit for non‑infringement.
  • Revocation was filed only after receiving Novo’s cease‑and‑desist notice.

Referring to Merck v. Glenmark and FMC Corp. v. Natco (2025), and the English “clear the way” principle (Terrell on the Law of Patents; Smithkline Beecham line of cases), the Court held:

A defendant who knows that litigation is “bound to ensue” if it launches a product should first clear the way by revoking or challenging the patent. Failing to do so is a relevant factor in deciding interim relief.

4.7.3 Final balancing

Although the Court accepted that:

  • Exports from India are, legally, acts of “making” and thus potential infringement under Section 48,
  • And that Novo’s losses are compensable by damages if DRL ultimately loses,

it chose an intermediate course:

  • DRL may continue manufacturing and exporting Semaglutide to countries where Novo has no patent.
  • DRL is injuncted from selling in India until expiry of IN’697, via its own undertaking reinforced by Court order.
  • DRL must maintain accounts of all manufacture and exports to facilitate a future damages/account of profits exercise.

This solution addresses:

  • Concerns about evergreening and unjust extension of monopoly,
  • DRL’s investment and legitimate export business to non‑patent countries,
  • While still protecting Novo’s Indian market until the statutory expiry of IN’697 (March 2026), in view of DRL’s failure to clear the way.

5. Precedents and Their Influence

5.1 Bishwanath Prasad Radhey Shyam v. Hindustan Metal Industries

Established that grant of a patent does not imply a presumption of validity, a principle now codified in Section 13(4). The Court used this to reject Novo’s argument of a de facto presumption based on the age and unchallenged status of IN’697.

5.2 F. Hoffmann‑La Roche Ltd. & Anr. v. Cipla Ltd. (2015)

Provided the five‑step test for obviousness under Section 64(1)(f), which was directly applied.

5.3 AstraZeneca AB & Anr. v. Intas Pharmaceuticals Ltd. (2021)

  • Held that a single formulation cannot be protected by two patents with different validity periods, given the limited‑term nature of patent monopolies.
  • Created the “person in the know” test for cases with common inventors across genus and species patents.

These principles guided the Court’s analysis of both double patenting and obviousness.

5.4 F. Hoffmann‑La Roche AG & Anr. v. Natco Pharma Ltd. (2025)

Reiterated and elaborated the “person in the know” methodology and warned against evergreening via minor modifications when genus and species have common inventors. The Court expressly borrowed this reasoning.

5.5 Novartis AG v. Union of India (2013)

  • Introduced a strict approach to evergreening and clarified that mere new forms of known substances without enhanced therapeutic efficacy are not patentable (Section 3(d)).
  • Demonstrated that foreign PTE/extension applications and regulatory filings are probative admissions that a product is covered by a given patent.

The Court used Novartis to justify reliance on Novo’s foreign PTE/SPC applications for the genus patent as admissions that Semaglutide derived from IN’964.

5.6 Boehringer Ingelheim v. Vee Excel (2023)

Crucial for:

  • Recognising Form 27 statements as binding admissions on how a patent is “worked”.
  • Stressing that non‑working of a patent in India is relevant to interim relief and public interest.

The present decision extends that approach by using Form 27 to infer prior claiming in a genus patent.

5.7 Merck v. Glenmark and FMC Corp. v. Natco (2025)

These cases anchored the Court’s use of the “clear the way” doctrine as a factor in balancing convenience, especially where a defendant launches a potentially infringing product without pre‑emptively challenging the patent.

6. Complex Concepts Simplified

6.1 Genus vs. Species Patents

  • Genus patent: Broad claim covering a family of related chemical structures (often via a Markush formula). Example: IN’964 (many GLP‑1 analogues).
  • Species patent: A narrower claim to a specific compound (or small subset) within that family. Example: IN’697 (Semaglutide).

A valid species patent typically requires that:

  • The specific compound was not already disclosed or enabled by the genus patent, and
  • It represents a non‑obvious technical advance over the genus.

6.2 Prior Claiming vs. Coverage vs. Disclosure

  • Coverage: The theoretical scope of a patent claim (e.g., all compounds that could be generated by a Markush formula).
  • Disclosure: What is actually taught and enabled by the specification and claims, such that a skilled person can reproduce it.
  • Prior claiming (Section 64(1)(a)): When a later patent claims an invention already claimed and enabled in an earlier patent.

Indian courts have repeatedly held (e.g., Novartis AG v. Natco, FMC Corp.) that mere coverage is not enough: invalidity requires enabling disclosure (and here, such disclosure was found in IN’964).

6.3 “Person Skilled in the Art” vs. “Person in the Know”

  • Person skilled in the art: A hypothetical, unimaginative techno‑legal construct with average proficiency in the relevant field – used to assess obviousness, sufficiency, etc.
  • Person in the know: A refined construct, used when the same inventors are behind genus and species patents; it assumes familiarity with the specific teachings and nuances of the genus patent. What is obvious to such a person cannot be repackaged as a fresh inventive step.

6.4 Evergreening

“Evergreening” is the practice of obtaining successive patents on minor variations of the same drug to extend exclusivity beyond the statutory term. It is disfavoured in Indian law and checked via:

  • Section 3(d) (new forms of known substances),
  • Strict tests for inventive step and prior claiming, and
  • Doctrines developed by courts in genus‑species cases (e.g., AstraZeneca, F. Hoffmann‑La Roche AG v. Natco).

6.5 The Gillette Defence

The Gillette defence (from Gillette Safety Razor Co. v. Anglo‑American Trading Co., 1913) says:

If what the defendant does is already fully disclosed by prior art, then either: (a) The patent is invalid (no invention over prior art), or (b) The patent must be construed narrowly enough not to be infringed.

DRL’s defence was essentially that Semaglutide falls within the expired genus patent IN’964. The Court’s analysis supports this at least prima facie.

7. Likely Impact of the Judgment

7.1 Doctrinal Impact

  • Stronger scrutiny of genus–species strategies: Innovator companies will face heightened risk that later species patents will be treated as invalid if:
    • They share the same inventive concept as the earlier genus, and
    • There is evidence (including their own filings) that the specific species was known or enabled at the genus stage.
  • Elevated role of Form 27: “Working” statements can:
    • Be used to prove which products embody which patents, and
    • Support a case for prior claiming in genus patents.
  • Foreign PTE/SPC and regulatory filings as admissions: Patentees must expect Indian courts to scrutinise such filings for:
    • Admissions that a product is “covered by” or “emanates from” a particular patent,
    • Which can boomerang in Indian validity challenges.
  • Reinforcement of “person in the know”: This case consolidates Delhi High Court jurisprudence that, with common inventors, obviousness is judged from a stricter vantage point.

7.2 Practical Impact for Litigation Strategy

  • Defendants:
    • Will be emboldened to attack late‑life species patents by mining:
      • Genus patent claim structures,
      • Form 27 filings, and
      • Foreign PTE/SPC filings and regulatory submissions.
    • Must, however, clear the way before launch to avoid adverse inferences on balance of convenience.
  • Patentees:
    • Need to ensure consistency across global filings; statements made abroad about coverage may be used in India.
    • Should be cautious when filing combined Form 27s for “related patents” and ensure they reflect a defensible patent mapping.

7.3 Public Interest and Access

While the Court’s relief does not immediately permit DRL to sell generics in India (due to the undertaking), it:

  • Allows the Indian manufacturing base to support cheaper Semaglutide supplies in countries without patent protection.
  • Signals judicial willingness to prevent evergreening of life‑saving drugs, consistent with the public interest orientation of Indian patent law.

8. Conclusion: Key Takeaways

  • No automatic presumption of validity: Even a long‑standing, unopposed patent like IN’697 is subject to a full “credible challenge” analysis at the interim stage.
  • Genus–species coherence is critical: Where a genus patent enables a specific compound (Semaglutide), and the same inventors later claim it as a species, the species patent is at high risk of being seen as prior claimed, anticipated and obvious.
  • Form 27 and foreign PTE/SPC filings matter: They are not procedural formalities but can function as decisive admissions regarding the scope and working of patents.
  • “Person in the know” test is entrenched: This decision further entrenches the doctrine that in common‑inventor genus–species disputes, the court looks through the lens of an informed inventor, not a generic skilled person.
  • Evergreening is closely policed: Attempting to extend monopoly life by splitting a known invention between a genus patent and a later species patent is unlikely to find favour, particularly for essential medicines.
  • Clear‑the‑way remains potent in interim relief: Defendants who commence manufacture without first challenging patents do so at their own peril, even if they ultimately raise a strong validity challenge.

In sum, Novo Nordisk A/S v. Dr. Reddy’s Laboratories Ltd. deepens Indian jurisprudence on genus–species patents, prior claiming, obviousness, and evergreening, while offering a nuanced approach to interim relief that balances innovation incentives, procedural fairness, and public interest.

Case Details

Year: 2025
Court: Delhi High Court

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