Delhi High Court Allows Natco To Sell Spinal Muscular Atrophy Drug, Rejects Roche's Patent Infringement Appeal

The Delhi High Court on Thursday upheld a single judge's refusal of an interim injunction sought by Swiss pharmaceutical giant F Hoffmann-La Roche AG against Natco Pharma Ltd, in a patent dispute over Risdiplam, a drug used to treat Spinal Muscular Atrophy (SMA).A Division Bench of Justice C Hari Shankar and Justice Ajay Digpaul dismissed Roche's appeal against a Single Judge's decision, which had allowed Natco to continue manufacturing and selling the drug in India. Roche had argued that Natco's product infringed its suit patent IN'397, valid until 2035, which claimed compounds for treating spinal muscular atrophy.The bench found “no reason to interfere with the findings of the learned Single Judge that Risdiplam is vulnerable to invalidity in terms of Section 64(1)(f) of the Patents Act, as being obvious vis-à-vis prior art in the form of the claimed Compound 809 in WO'916/US'955,” and held that “no case for interference with the said decision, within the parameters of Wander, can be said to have been made out.” The case arose out of Roche's claim that Natco's manufacture and sale of Risdiplam infringed its Indian patent containing compounds for treating SMA.Natco did not deny infringement but invoked a statutory defence under Section 107(1) of the Patents Act, 1970, claiming that the patent was invalid under Section 64(1)(e) (lack of novelty) and Section 64(1)(f) (obviousness).Roche's main claim was that while Risdiplam might fall within the scope of broader Markush claims in its earlier genus patents (WO 2013/119916 and US Patent 9586955), it was not disclosed in those patents. The company stressed that mere coverage does not amount to disclosure, and that a person skilled in the art could not have arrived at Risdiplam without undue experimentation. It maintained that disclosure must be "enabling in nature."The division bench agreed prima facie with Roche on this point, observing,“To our mind, infringement is predicated on coverage, whereas invalidity is predicated on disclosure.This distinction, to our mind, the decision in Astrazeneca overlooks…However, 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 on the ground of disclosure in genus patent WO'916/US'955.”Despite these observations, the court declined to overturn the Single Judge's finding on novelty, stating that Roche had not made out a clear case for interference.It upheld the Single Judge's finding that the suit patent lacked "inventive step" under Section 64(1)(f). Natco had argued that Risdiplam was an obvious modification of Compound 809, disclosed in the genus patents, differing only by replacing a –CH group with a nitrogen atom, a classical bioisosteric substitution.The court endorsed the “person in the know” test and gave weight to the fact that the inventors of both patents were the same:“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 in order to arrive at formulation or product which achieves the objectives that the species patent aspires to achieve. 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, and of all the angularities and peculiarities of the genus patent.”Applying the precedent in Wander Ltd v Antox India Pvt Ltd, the Bench concluded that Roche had failed to demonstrate that the Single Judge's decision was arbitrary or perverse. It held:“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 court also underscored the broader policy rationale behind the obviousness bar, warning against evergreening.“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.”As a result, the appeal was dismissed, and the injunction denied.Title: F. HOFFMANN-LA ROCHE AG & ANR. V NATCO PHARMA LIMITEDCitation: 2025 LiveLaw (Del) 1288Case No: FAO(OS) (COMM) 43/2025 Appearance: Senior Advocates Sandeep Sethi with Advocates Pravin Anand, Archana Shanker, Shrawan Chopra, Prachi Agarwal, Devinder Rawat, Achyut Tewari, Elisha Sinha, Krisha Baweja, Aayush Maheshwari, N. Mahabir, Shreya Sethi and ...

Delhi High Court Allows Natco To Sell Spinal Muscular Atrophy Drug, Rejects Roche's Patent Infringement Appeal

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