Introduction

On March 25, 2025, the Delhi High Court denied the request of F. Hoffmann-La Roche AG for an interim injunction against Natco Pharma in a high-stakes pharmaceutical patent dispute in F. Hoffmann-La Roche Ag & Anr. vs Natco Pharma Limited [1]¹. At issue was Roche’s species patent on “Risdiplam,” a life-saving drug for Spinal Muscular Atrophy (SMA). The court, while recognizing the seriousness of the disease and the value of innovation, ultimately found that the plaintiffs had not established a prima facie case for interim relief. It emphasized concerns about evergreening and strongly favored the public interest in affordable access to critical medicines.

Background

The dispute centres around Indian Patent No. 334397 (“Suit Patent”), a species patent for the compound Risdiplam, an oral treatment for SMA. Roche markets the drug globally under the brand name EVRYSDI®. The suit alleged that Natco’s planned manufacture and launch of Risdiplam constituted infringement of this patent.

The plaintiffs also hold a genus patent (WO 2013/119916 A2, or WO’916) in multiple jurisdictions but notably did not file for the Indian counterpart of this genus patent. They asserted that Risdiplam was not disclosed in WO’916 and that the species patent stood independently valid.

Risdiplam is a small-molecule drug used to treat SMA, a rare neuromuscular disease. It was granted an International Non-Proprietary Name (INN) in 2018 and received patent protection in over 60 countries. The Indian patent in question is valid until 2035.

Plaintiff’s Contentions

Roche alleged that the defendant admitted infringement by expressing its intention to launch Risdiplam. They emphasized that:

• Their case was based on the validity and subsistence of the suit patent, granted in 2020.
• Corresponding patents had been granted in over 60 countries without any revocation.
• Risdiplam was a new chemical entity with a WHO-assigned INN, and that the International Search Authority (ISA) had found the suit patent novel and non-obvious after reviewing WO’916.
• Risdiplam could not be anticipated or rendered obvious from WO’916, which did not specifically disclose it.
• Their investment in R&D was significant, unlike the defendant’s, and they were voluntarily offering the drug at discounted prices to the Indian government.

Defendant’s Arguments

Natco countered that the plaintiffs were attempting evergreening by obtaining a species patent instead of filing the Indian genus counterpart of WO’916. They asserted that:

• Interim injunctions should not be granted readily in pharma suits, especially when a credible validity challenge exists.
• WO’916 was prior art relevant to the suit patent.
• Plaintiffs had admitted, while seeking PTEs abroad, that Risdiplam was covered by WO’916.
• All substituents in Claim 1 were disclosed in the genus patent and that the derivation of Risdiplam required no inventive step.
• Plaintiffs imported Risdiplam and did not manufacture it in India, whereas the defendant planned to produce it locally at a much lower cost

Submissions of Interveners

Two interveners—SMA patients—were allowed to submit on public interest. They:

• Highlighted the exorbitant cost of Risdiplam and limited access through the plaintiffs’ assistance programs.
• Argued that the defendant could improve accessibility.
• Emphasized the constitutional right to health and the inadequacy of government support for rare diseases.

Issues before the Court

1. Whether the defendant had raised a credible challenge to the validity of the Suit Patent
2. Whether the balance of convenience favoured the grant of an interim injunction.
3. Whether public interest considerations justified denial of interim relief.

Court’s Findings

Issue 1 – Validity of the Suit Patent

The court framed the primary challenge to the suit patent’s validity under Sections 64(1)(e) (anticipation by prior publication), 64(1)(f) (obviousness), and 64(1)(d) (non-patentability) of the Indian Patents Act.

Anticipation by Prior Publication u/S 64(1)(e) – The court observed that India follows an absolute novelty standard. The key question was whether Risdiplam was explicitly or implicitly disclosed in the international genus patent WO’916. The plaintiffs admitted that WO’916 claimed a genus of compounds to which Risdiplam belonged but did not specifically disclose it. Citing Novartis AG v. Union of India [2]², the court emphasized that mere coverage in a genus patent does not constitute disclosure. It also referred to the Manual of Patent Office Practice and Procedure, clarifying that Markush claims require clear and specific disclosure, and generic formulae cannot anticipate without identification of the specific compound.

Obviousness u/S 64(1)(f) – The court considered the structural similarities between Risdiplam and Compound 809 exemplified in WO’916. While Risdiplam differed at one position by having a nitrogen atom instead of a CH group, the Court held that WO’916 disclosed various heterocyclic compounds with Nitrogen at different positions. It accepted the defendant’s argument that such substitution would be routine for a person skilled in the art or a “person in the know,” especially since Nitrogen and CH groups are bioisosteres. The Court concluded that the modifications made to derive Risdiplam from WO’916 could be considered obvious.

Foreign Prosecution History and Admissions – The court attached substantial weight to the plaintiffs’ statements made in their Patent Term Extension (PTE) applications in the US (US’955) and Australia (AU’870), where they acknowledged that Risdiplam was covered or generically disclosed by the genus patent. The Court cited precedents such as AstraZeneca AB v. P. Kumar [3]³ and Boehringer Ingelheim v. Vee Excel [4]⁴ to establish that admissions made by a patentee in foreign jurisdictions, even post-grant, can be considered relevant. The court also noted the inventors of the genus and species patents were the same, and referred to AstraZeneca AB v. Intas [5]⁵, where it was held that the test should be applied from the perspective of a “person in the know.” The plaintiffs’ contradictory stance—claiming in India that Risdiplam was not disclosed in the genus patent, while simultaneously representing in foreign jurisdictions that it was—constituted a credible challenge to the patent’s validity.

Non Patentability u/S 64(1)(d)  – The court did not deliver a prima facie finding on this ground, noting that it was not extensively argued. However, the issue was left open for trial.

Misrepresentation to the Patent Office u/S 64(1)(j) – The court observed that the plaintiffs’ response to the First Examination Report (FER) in India appeared inconsistent with representations made in foreign filings. However, it determined that this issue required further evidence and was thus triable.

Non-Compliance with Section 8 u/S 64(1)(m) – Alleged non-disclosure of foreign prosecution history was noted, but the Court did not make a finding at this stage and directed the matter to be tried during the final proceedings.

In conclusion, the Court held that the defendants had raised a credible challenge to the validity of the Suit Patent, satisfying the standard required to deny interim relief.

Issue 2 – Balance of Convenience

The Court observed that Roche was only importing Risdiplam into India, whereas Natco intended to manufacture the drug domestically. Roche’s drug was priced at approximately INR 1.5 crore (175,000 USD) annually, while Natco’s proposed price was 80–90% lower. Although Roche offered a Patient Assistance Program, its coverage was limited, and the drug remained unaffordable for most patients.

Given that damages could adequately compensate Roche in case of success at trial, and considering the impact of withholding affordable treatment from Indian patients, the Court held that the balance of convenience weighed against the grant of an injunction.

Issue 3 – Public Interest

The Court gave considerable weight to submissions made by two SMA patients who intervened in the suit. It acknowledged that SMA is a life-threatening, progressive condition with no known cure, and that access to Risdiplam was critical.

It noted:

• The steep price of Roche’s formulation.
• The limited reach of existing assistance schemes.
• The inadequate financial support under the National Rare Disease Policy.

The Court emphasized that equitable relief must factor in the constitutional right to health. It cited precedents where public access to life-saving drugs was prioritized over the enforcement of patent rights, particularly at the interim stage.

As Held

The Delhi High Court denied the interim injunction application, holding that:

• The defendant raised a credible challenge to the validity of the Suit Patent.
• The plaintiffs failed to establish a strong prima facie case.
• The balance of convenience favoured the defendant 
• Public interest strongly weighed against injunctive relief, however, the plaintiffs could be compensated by damages.

The main suit is now pending before the Joint Registrar. Roche has filed an appeal before the Division Bench, which remains to be decided.

Our Analysis and Conclusion

The Delhi High Court’s order continues a clear trend in Indian pharmaceutical‑patent jurisprudence: interim relief will be withheld where (i) the patent is credibly vulnerable on prior‑art grounds and (ii) the patentee’s commercial conduct does not advance public access. Several take‑aways stand out:

• Foreign‑filing candour is no longer optional: Roche’s own PTE statements abroad supplied the decisive link that WO’916 “covered” Risdiplam.  Practitioners should assume that Indian courts will mine foreign records and treat prosecution history estoppel as a live doctrine, even at the interim stage.
• Species patents face a steep evidentiary burden: Where a genus claim already exists, the patentee must marshal robust data—enhanced efficacy, safety, or unexpected technical advantage—to overcome a prima‑facie obviousness objection. Mere Markush carve‑outs or routine hetero‑atom swaps will not suffice.
• Section 8 compliance is a ticking clock: Although the Court reserved final findings, its explicit mention of possible non‑disclosure under Section 8 signals that incomplete foreign‑prosecution updates can haunt an injunction application even years after grant.
• Public‑interest evidence is becoming granular: The intervention by individual SMA patients, coupled with hard price differentials (₹1.5 crore (175,000 USD) vs ₹20–30 lakh per year (23,000 – 35,000 USD)), supplied the factual substrate for denying equitable relief. Innovators must increasingly quantify the reach of Patient Assistance Programmes if they hope to neutralise affordability arguments.
• Damages as a safety valve: The Court’s willingness to view monetary compensation as adequate for Roche indicates that, in India, the true battleground may be the final trial, not the interim stage.

Strategic Implications

• For Innovator: Front‑load comparative data when filing species applications, maintain global consistency in patent‑office statements, and expand India‑specific access programmes to strengthen equitable arguments.
• For Generics: Detailed mapping of Markush disclosures and vigilant monitoring of foreign‑filed PTEs can provide potent invalidity ammunition without waiting for revocation proceedings.

Overall, the ruling reinforces a “due‑diligence first, injunction later—if at all” philosophy, signalling that Indian courts will continue to privilege substantive public‑interest considerations over formal patent rights where life‑saving medications are concerned.

References

1. [1] CS(COMM) 567/2024 & I.A. 33088/2024, I.A. 44310/2024, I.A. 44384/2024 ↩︎
2. [2] (2013) 6 SCC 1 ↩︎
3. [3] 2019 SCC OnLine Del 9555 ↩︎
4. [4] 2023 SCC OnLine Del 1889  ↩︎
5. [5] 2021 SCC OnLine Del 3746 ↩︎