Kudos Pharma v. Natco Pharma: A case on patent claims, coverage, validity and infringement.

The Delhi High Court on March 1, 2024, pronounced an order in a suit for infringement filed by Kudos Pharmaceuticals Limited against Natco Pharma Limited. The suit involved, Kudos Pharma’s anti-cancer drug Olaparib and Natco’s generic version of the drug sold under the brand name BRACANAT.

The sixty nine page judgement in the present case has been summarized below and highlights the following aspects of law:

  • Meaning of credible challenge.
  • Patent vulnerability to invalidity.
  • Patent coverage versus patent disclosure.
  • Genus Patents versus Species Patents
  • Anticipation by Prior claiming and Prior Publication.

Brief facts:

Kudos Pharmaceuticals Ltd. and Maybridge Limited (hereinafter referred to as “Plaintiff” or “Kudos”) jointly filed a patent application titled “Phthalazinone derivative” with the Indian Patent Office on March 12, 2004. The said application was granted on February 10, 2009 bearing patent no. 228720. The Phthalazinone derivative claimed in the application was assigned the IUPAC name “Olaparib”. During the subsistence of the patent, Natco (hereinafter referred to as “Defendant”) manufactured and sold its own generic version of Olaparib under the brand name BRACANAT. Kudos therefore, instituted a suit for infringement against Natco seeking a decree of permanent injunction, restraining Natco from manufacturing or selling or otherwise dealing with any product with Olaparib, either under the brand name BRACANAT or any other name.


The Court was called on to decide on the following issues:

  • Was Natco able to set up a credible challenge to the validity of the patent?
  • Does coverage imply disclosure? Is there a difference between coverage and claiming?
  • Did Natco infringe Kudos Pharma’s patent?
  • Was Kudos Pharma entitled to an interim injunction?


The court heard the parties at great length and addressed the aforementioned issues in the order of the points of defence submitted by the Defendant.

  • Credible challenge

At first, the court took up the question of credible challenge and observed that a defendant is only required to raise a credible challenge to the vulnerability of the suit patent in order to succeed in its defence against infringement. However, in order to understand what “credible challenge” means, the Court revisited its decisions in FMC Corporation v. Best Crop Science LLP [i](FMC-2); Novartis AG v. Natco Pharma Ltd[ii](Novartis-1) and Novartis AG v. Natco Pharma Ltd.[iii] (Novartis-2) and reiterated that, a credible challenge is not one which is incredible, fanciful, or moonshine. It is that, which on the face of it simply merits favourable consideration and is prima facie acceptable. It is not enough for the defendant to raise a challenge which is worthy of consideration. The challenge must be more than that; it must partake of the character of prima facie acceptability. “credibility”, even by itself, connotes a fairly high standard.

On the assertion by the Defendant that there was simultaneous Assertion of Genus and Species patents in this case and that the same circumstances existed in the case of Astrazeneca v. Intas [iv](Astrazeneca-1), the Court observed that Astrazeneca had simultaneously claimed infringement of both the genus and species patents. Unlike the situation in the Astrazeneca case, in the present case, Kudos asserted infringement of only the species patent and the decision in Astrazeneca-1 does not apply to the present circumstances.

  • Coverage v. Disclosure

In order to determine whether coverage and disclosure are the same and whether coverage implies disclosure, the Court relied on the decisions made in Novartis AG v. UOI[v], FMC Corporation v. Natco Pharma Ltd[vi], and Novartis AG v. Natco Pharma Ltd (Novartis-2) to reiterate that coverage is distinct from disclosure. Reading from the judgment in Novartis AG v. UOI, the court further clarified that there exists a dichotomy between the terms “coverage” and “disclosure”. The scope of coverage is distinct from the scope of disclosure in a patent and coverage that is granted in respect of a patent is not always coextensive with what is disclosed in the patent.  Etymologically, “dichotomy” is not the same as “distinction”. The Court noted that in the judgment of Novartis v. UOI, the Supreme Court had not held that coverage and disclosure were the same. Nor did it hold that there is no distinction between coverage and disclosure. Choosing its words with precision, the Supreme Court held that there is no “dichotomy” between “coverage” and disclosure”.

  • Infringement vis-à-vis validity

The defendant challenged the validity of Kudos’ patent on the grounds of obviousness and lack of inventive step, anticipation by prior claiming, anticipation by prior publication, non-patentability under section 3(d) and non-compliance with the requirements under section 8 of the Patents Act. The court addressed each of the grounds raised by the defendant and observed that, the defendant was exercising hindsight reconstruction to claim that Olaparib was obvious in light of the Markush Claim of the genus patent IN 245218. The court also observed that, if Olaparib were so obvious from the suggested prior arts, there is no explanation why it took 19 years, after the genus patent had been granted, for Natco to synthesize Olaparib.

On the ground of anticipation by prior claiming, the Court stated that a claim is even more specific than a disclosure. On a plain claim to claim comparison, it was clear that Olaparib, as Claimed in the present patent, had never been claimed in any earlier patent and therefore there was no prima facie case of anticipation by prior claiming. In examining vulnerability on the ground of anticipation by prior publication, the court held that a case for prior publication could not be stablished in the present suit as, prior to the date of filing of the complete specification of the suit patent, the asserted invention was not published in India or elsewhere in any document.

  • Injunction

The court found that no credible case of vulnerability could be made out by Natco. None of the grounds raised by Natco under section 64 of the Patents Act posed a credible challenge to the validity of the suit patent. Kudos’ prayer for interlocutory injunction had to be therefore necessarily granted.


While the observations of the Hon’ble Delhi High Court are not entirely new, the decision underscores and reaffirms many of the common principles which form the basis of patent law in India and other jurisdictions around the world.

[i] FMC Corporation v. Best Crop Science LLP; (2021) 87 PTC 217;

[ii] Novartis AG v. Natco Pharma Ltd; (2023) SCC OnLine Del 106;

[iii] Novartis AG v. Natco Pharma Ltd; (2021) SCC OnLine Del 5340; 

[iv] Astrazeneca v. Intas; (2021) 87 PTC 374 (DB)

[v] Novartis AG v. UOI; (2013) 6 SCC 1

[vi] FMC Corporation v. Natco Pharma Ltd; 2023 SCC OnLine Del 106


Citation: KUDOS PHARMACEUTICALS LIMITED & ORS. vs NATCO PHARMA LIMITED, High Court of Delhi, 01st March, 2024 I.A. 907/2023 in CS(COMM) 29/2023

Authored by Mr. Gaurav Mishra, Patent Team, BananaIP Counsels.


The case note/s in this blog post have been written by IP Attorneys at BananaIP Counsels based on their review and understanding of the Judgments. It may be noted that other IP attorneys and experts in the field may have different opinions about the cases or arrive at different conclusions therefrom. It is advisable to read the Judgments before making any decisions based on the case notes.

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