F. Hoffmann-La Roche AG & Another Vs. Natco Pharma Limited

Patent Infringement and Person in the Know

The Appeal: In this matter, the High Court of Delhi was called upon to decide an appeal by F. Hoffmann-La Roche AG against Natco Pharma Limited regarding the manufacture and sale of the drug "Risdiplam." The appellants, holders of Indian Patent IN 3343971 concerning compounds for treating spinal muscular atrophy, sought an injunction to prevent Natco from producing and selling Risdiplam.

Facts: The facts of the case are straightforward. F. Hoffmann-La Roche AG is the patentee for Risdiplam, marketed under the brand name EVRYSDI used for spinal muscular atrophy. Natco Pharma began manufacturing and marketing Risdiplam, which the appellants argued amounted to patent infringement under Section 48 of the Indian Patents Act. The legal question was whether Natco's actions amounted to patent infringement and, if so, whether Natco could successfully invoke statutory defenses to avoid liability.

The Procedural Background: The dispute arose after a single judge of the High Court declined the injunction against Natco, leading the appellants to file the present appeal. Natco Pharma, as defendant, admitted to making and selling Risdiplam but asserted a legal defense under Section 107 of the Patents Act. This defense relies on Section 64(e) and 64(f), which allow a patent to be revoked if the invention is not new (lacking novelty) or is obvious (lacking an inventive step).

The Court’s detailed reasoning began by clarifying the law surrounding appellate review, citing Wander Ltd. v. Antox India P Ltd. (Supreme Court: 1990 Supp SCC 727), emphasizing that appeals against discretionary relief like injunctions are not appeals on facts but on principles. The Court would not substitute its own judgment for that of the original judge unless the lower court exercised its discretion arbitrarily or ignored settled legal principles.

The Legal Provision: Legal provisions under scrutiny included Section 48 (patentee’s rights), Section 64(e) (lack of novelty), and Section 64(f) (obviousness) of the Patents Act. Notably, infringement as such is not strictly defined in the Act, but Section 48 grants patent owners the exclusive right to control the making, using, selling, or importing of the patented product.

The Single Judge, whose decision was under appeal, found in favor of Natco based on these defenses. The core legal issue centered around two concepts: whether Risdiplam was "disclosed" within the scope of prior art (other earlier patents), and whether the claimed invention was obvious to a skilled person in the field.

The Single Judge and the Division Bench focused on whether Risdiplam, though covered under a so-called "Markush" chemical claim in earlier patents (WO916, US955), had been "disclosed" in such a way as to destroy novelty under Section 64(e). The difference between "coverage" (a compound is one of many possible encompassed by a broad patent claim) and "disclosure" (the compound is specifically taught or enabled) was discussed at length, referencing notable precedents including Novartis AG v Union of India (2013 6 SCC 1) and Astrazeneca AB v Intas Pharmaceutical Ltd (2020 84 PTC 326 Del).

While earlier cases such as Astrazeneca held that a plaintiff alleging infringement of both a genus (broad) and a species (narrow) patent amounts to admitting disclosure in the genus patent, the Division Bench in this case questioned whether infringement (predicated on coverage) was the same as invalidity (predicated on disclosure). The Bench favored the view that disclosure must be enabling – it should teach a skilled person how to make the specific compound; mere theoretical coverage is not sufficient. However, as the Single Judge's ruling was consistent with the then-prevailing interpretation of Astrazeneca, it was not faulted.

The obviousness: On the question of obviousness under Section 64(f), the Court examined whether, based on teachings in earlier patents and general knowledge, a skilled person could have arrived at Risdiplam without inventive effort. It was observed that Risdiplam differed from "Compound 809" of the prior art only by a single atom – a nitrogen (N) in place of a CH group. The Division Bench elaborated that several compounds in the prior art involved variations at this very position, and chemical principles (such as those set out in the Grimms Hyride Displacement Law) suggested substituting nitrogen for carbon-hydrogen as a routine modification. The Court also referred to the fact that in pharmaceutical chemistry, it is common to make such changes to optimize properties like potency and stability.

Person in the Know: Importantly, the decision observed that where the inventors of both the earlier patent and the current patent are the same, the "person skilled in the art" test shifts. The actual inventor, being "in the know," is presumed to choose relevant modifications more easily and to know how to arrive at the claimed invention. This mitigates against permitting so-called "evergreening," where a small, obvious change is used to obtain a new patent and extend exclusivity, especially in the realm of essential or life-saving drugs.

The Court cautioned that patent protection is intended only for true inventions, and that prolonging monopolies by minor modifications that would have occurred to the original inventors themselves conflicts with public interest. If inventors are allowed to obtain new patents for minor, obvious changes, society may suffer by not having access to important drugs at affordable rates.

In the concluding part, the Division Bench stated that its appellate review was limited to checking whether the judge below applied the correct legal principles. Since the judge did so, and no arbitrary or capricious conduct was shown, the appeal was dismissed. The Bench did not find it necessary to examine every nuance of the parties’ arguments in detail, since the core legal findings were unimpeachable. A credible challenge to the validity of the patent had been established, so the injunction was rightly denied.

Decision: The appeal was dismissed, affirming that a credible defense of obviousness had been shown. The Court did not interfere with the lower court’s exercise of discretion, leaving the validity of the patent and the parties’ broader disputations to potential further proceedings or trial stages if warranted.

Case Title: F. Hoffmann-La Roche AG & Another Vs. Natco Pharma Limited

Order Date: 9th October 2025

Case Number: FAO(OS)(COMM) 43/2025

Neutral Citation: 2025:DHC:8943-DB

Name of Court: High Court of Delhi at New Delhi

Hon’ble Judges: Mr. Justice C. Hari Shankar and Mr. Justice Ajay Digpaul

Disclaimer: The information shared here is intended to serve the public interest by offering insights and perspectives. However, readers are advised to exercise their own discretion when interpreting and applying this information. The content herein is subjective and may contain errors in perception, interpretation, and presentation.

Written By: Advocate Ajay Amitabh Suman, IP Adjutor [Patent and Trademark Attorney], High Court of Delhi