Delhi High Court Denies Roche Injunction, Cites Obviousness and Public Interest in SMA Drug Patent Dispute

New Delhi – In a significant ruling with far-reaching implications for pharmaceutical patent litigation and access to medicine in India, a Division Bench of the Delhi High Court has upheld a single judge's decision to refuse an interim injunction sought by Swiss pharmaceutical giant F. Hoffmann-La Roche AG. The decision permits Indian drugmaker Natco Pharma Ltd to continue manufacturing and selling its generic version of Risdiplam, a critical drug for treating the rare genetic disorder Spinal Muscular Atrophy (SMA).

The judgment, authored by a bench of Justice C. Hari Shankar and Justice Ajay Digpaul, dismissed Roche's appeal, finding a credible challenge to the validity of Roche's "species patent" for Risdiplam (IN'397). The court's decision hinged primarily on the ground of obviousness, or lack of inventive step, under Section 64(1)(f) of the Patents Act, 1970, while also underscoring concerns about patent "evergreening" and the overriding public interest in making life-saving medication affordable.

This ruling paves the way for a drastically cheaper version of the drug, marketed by Roche as Evrysdi, to be available in India. Natco announced it would launch its product immediately at a maximum retail price of ₹15,900 per bottle, a stark contrast to Roche's price of approximately ₹6 lakh per bottle.

The Core of the Dispute: Infringement vs. Invalidity

The legal battle commenced when Roche sued Natco for infringing its species patent for the Risdiplam compound, which is valid until 2035. Natco did not contest that its product fell within the claims of Roche's patent. Instead, it mounted a robust defense under Section 107(1) of the Patents Act, arguing that Roche's patent was invalid and therefore unenforceable. Natco’s "credible challenge" was based on two key grounds: lack of novelty (Section 64(1)(e)) and, more pivotally, obviousness in light of prior art (Section 64(1)(f)).

The prior art in question was Roche’s own earlier, broader "genus" patents (WO 2013/119916 and US Patent 9586955), which disclosed a class of compounds, including a specific example, "Compound 809," for treating SMA. Natco contended that Risdiplam was an obvious modification of Compound 809, differing only by a classical bioisosteric substitution—replacing a –CH group with a nitrogen atom.

Obviousness and the 'Person in the Know' Test

The Division Bench found "no reason to interfere" with the Single Judge's prima facie finding that the Risdiplam patent was vulnerable to invalidity on the ground of obviousness. The bench endorsed a nuanced "person in the know" test, giving significant weight to the fact that the inventors of both the genus and the subsequent species patents were the same.

In its analysis, the court observed:

“The inventor of the genus patent would obviously be conversant with its specifics and would also be in a position to more easily appreciate the manner in which the Markush formulations in the genus patent, or the compounds exemplified in the genus patent, would have to be modified... Something which is obvious to a person skilled in the art would, therefore, be more obvious to the inventor of the genus patent, who would be in the know of things.”

This reasoning suggests that when the same inventive entity is involved, the threshold to demonstrate an inventive step over their own prior art may be higher, as they are presumed to possess a deeper understanding of the invention's "angularities and peculiarities."

A Warning Against Evergreening

The court's decision also carried a strong policy message against the practice of "evergreening," where companies make minor, obvious modifications to existing patented drugs to extend their monopoly period. The bench issued a stern warning, stating:

“By no means can an inventor be permitted, by making changes to an invented pharmaceutical preparation, which is essential or life-saving in nature, to keep the invention out of the public domain beyond the period of life of the patent, by making modifications which, perceptibly, would be obvious to the inventor.”

This statement reaffirms the judiciary's role in balancing patent rights with public health imperatives, ensuring that the patent system incentivizes genuine innovation rather than incremental changes designed to prolong market exclusivity.

Appellate Restraint and the Wander v. Antox Standard

In dismissing the appeal, the Division Bench strictly adhered to the precedent set in Wander Ltd v Antox India Pvt Ltd , which establishes a high bar for appellate interference in discretionary orders, such as the grant or refusal of an interim injunction. The bench concluded that Roche had failed to demonstrate that the Single Judge's decision was arbitrary, perverse, or legally untenable. The court reiterated that as long as a credible challenge to a patent's validity exists under any provision of Section 64, it constitutes a valid defense against an infringement claim at the interim stage.

The court noted, "As a credible challenge to the validity of the suit patent under any of the clauses of Section 64 would suffice to constitute a valid defence to infringement under Section 107, the impugned judgment of the learned Single Judge is entitled to be upheld."

The Nuance of Coverage vs. Disclosure

Interestingly, the Division Bench did engage with a complex argument raised by Roche concerning the distinction between "coverage" and "disclosure." Roche argued that while Risdiplam might be covered by the broad Markush claims of its earlier genus patents, it was not explicitly disclosed in a way that a person skilled in the art could arrive at it without undue experimentation.

The bench expressed prima facie agreement with Roche on this principle, stating:

“To our mind, infringement is predicated on coverage, whereas invalidity is predicated on disclosure. This distinction, to our mind, the decision in Astrazeneca overlooks… if it is to be held, as we feel, that infringement requires only coverage whereas invalidity requires disclosure, and coverage by itself does not necessarily imply disclosure, then the filing of the suit in the US by the appellants would not by itself render the claim in the species patent vulnerable to invalidity...”

Despite these observations, which may be significant in future patent cases, the court found it unnecessary to overturn the Single Judge’s order. The strength of the obviousness argument, independent of the novelty challenge, was sufficient to deny the injunction.

Impact on Patients and the Pharmaceutical Industry

The immediate impact of the ruling is profound for patients with SMA in India. The annual cost of treatment with Roche's Evrysdi can range from ₹60 lakh to over ₹1 crore. Natco’s generic version promises to reduce this cost by over 95%, bringing it within the ₹50 lakh one-time aid provided by the government for rare diseases.

For the pharmaceutical industry, the judgment reinforces a trend in Indian jurisprudence that prioritizes public interest and scrutinizes patents for evergreening, especially for life-saving medicines. While Roche expressed disappointment and reiterated its commitment to protecting its intellectual property, public health advocates hailed the decision as a victory for access to medicine. The ruling serves as a crucial reminder for innovator companies that securing a species patent over an existing genus patent requires demonstrating a clear, non-obvious inventive step.

Roche has the option to appeal the decision to the Supreme Court of India. Meanwhile, the main suit for patent infringement will proceed to trial, where the validity of Roche's patent will be decided conclusively.