The Delhi High Court, on 24th April, passed an order that our patent law enthusiast readers will be very interested in! Reviving, (and at least temporarily settling!) questions around what is therapeutic efficacy under Section 3(d) and the distinctions between coverage and disclosure, the 86 page judgement is an interesting one to go through! We’re pleased to bring you this guest post by Shivam Kaushik, who takes us on a quick tour of the order, highlighting points of particular interest. Shivam is an advocate practicing in Delhi. Views expressed here are his alone.
Natco v Novartis 2024: Delhi High Court’s Novartis Moment & Indian Patent Law’s Déjà Vu
By Shivam Kaushik
A Division Bench (DB) of the Delhi High Court recently passed a judgment in Natco Pharma v. Novartis AG 2024:DHC:3198-DB. The judgment could be seen as a sequel of the landmark judgment of the Supreme Court in Novartis v. Union of India, (see here, here) which was pronounced more than a decade back, and deals with an identical set of challenging issues such as coverage disclosure, and Section 3(d). The judgment was passed in an LPA (Letter Patents Appeal – an appeal from a single bench to a larger bench of the same court) preferred by Natco against the order passed by a Single Judge granting interim injunction restraining Natco in a patent infringement suit. The judgment deals with multiple ticklish patent law issues which can broadly be characterized into the following heads:
- Presumption of validity of patents
- Credible challenge to the validity of a patent
- Section 3(d)/ evergreening
- Broad coverage v. coverage
- Genus and species patents
- Coverage v. disclosure
- Therapeutic effect vis a vis bioavailability
This post will touch upon the factual background of the case and discuss the broad legal reasoning and findings given by the DB on the above issues.
Active Legal Ingredient (ALI) of the lis
The case arose out a suit filed by Novartis asserting its patent IN 233161 (IN’161/suit patent). Novartis’s case was that the suit patent discloses Eltrombopag Olamine (ELT-O) and Natco’s product Tromobopag contained ELT-O as it’s Active Pharmaceutical Ingredient (API), therefore infringing IN’161. On the other hand, Natco’s primary contention was that this was a classic case of evergreening, as two separate patents were secured by Novartis in respect of ELT-O. Natco alleged that ELT-O was already covered under an earlier patent number IN213176 (IN’176) which expired on 24th May, 2021. Thus, IN’161 is liable to be revoked under Section 64(1)(a) on account of prior claiming. Novartis’ counter argument was that IN’176 contained a Markush claim which discloses Eltrombopag Free Acid (ELT). However, ELT-O, which is the salt form of Eltrombopag Free Acid is merely covered, and not disclosed in IN’176. It was contended that the same was disclosed only in the species patent IN’161.
Presumption of Legal Validity of a Patent
Before we get to the meat of the matter, let’s deal with housekeeping issues first. It is unfortunate that despite a provision in the Patents Act [section 13(4)], a 1982 Supreme Court judgment [Bishwanath Prasad Radhey Shyam v. Hindustan Metal Industries AIR 1982 SC 1444], and countless judgments of the Delhi High Court [F. Hoffmann LA Roche v. Cipla 2009 SCC OnLine Del 1074, Astrazeneca AB v. Intas Pharmaceuticals 2020 SCC OnLine Del 2765, Boehringer v. Vee Excel Drugs 2023:DHC:2265], ‘presumption of validity of a patent’ is still argued and ruled upon in 2024. If there was a 3(d) equivalent provision prohibiting “evergreening” in legal pleadings, this argument would be its first victim. In the case at hand, the argument met its fate where the DB overruled the single judge and reiterated that there is no presumption of validity of a patent [paras 39 to 41].
Credible Challenge to the Validity of a Patent
Yet another issue that has undeservedly survived more than two decades of rich patent jurisprudence is- what is the standard of challenge to validity of a patent that a defendant has to mount at the interim stage? Relying upon the judgment of Roche v. Cipla, Astrazeneca v. Intas, the DB holds that if a prima facie ground of revocation is made out, the threshold standard of credible challenge is met. Here also, the DB overrules the Single judge who found the threshold to be high and burden on the defendant to be heavy. [paras 42, to 47]
The Meat of the Matter
At the cost of being accused of oversimplification, to my understanding the crux of the factual dispute before the Court was- Is there any difference between Eltrombopag Free Acid and Eltrombopag Olamine? It is this difference that had to be examined from the perspective of Section 3(d) as also claim coverage & disclosure.
The initial answer of Novartis to this question was that the salt form i.e., ELT-O had added advantages of enhanced solubility and bioavailability over the free acid base i.e., ELT. However, later during the hearing Novartis conceded that solubility is a physio-chemical property and not a property of therapeutic efficacy, thus squarely falling within the ambit of Section 3(d) [para 75]. Thus, the only question that stood before the Court was whether increased bioavailability, if any, could be understood as giving greater therapeutic efficacy to ELT-O saving it from 3(d). The DB examined the 2013 judgment of the Supreme Court in Novartis v. UOI (2013) 6 SCC 1 and reviewed scientific literature to hold:
- Enhanced bioavailability is a common property associated with the salt form. [para 69]
- Bioavailability is one of the pharmacokinetic parameters and not a direct measure of therapeutic efficacy. [para 84]
- Enhanced bioavailability is not synonymous with higher therapeutic efficacy, as where a formulation has side effects a lower bioavailability is more desirable. [paras 86 & 87]
Thus, the DB concluded that the ELT-O being pharmaceutical salt of a known substance ELT and not having any significant difference in regard to therapeutic efficacy, was hit by Section 3(d).
Coverage v. Disclosure
However, the most important legal question settled by the Division Bench in the present case was- Can a patentee seek a patent “disclosing” a substance, when admittedly, the said substance was admittedly “covered” by the claims of an earlier patent. Novartis contended that though ELT-O was covered in IN’176, it was disclosed only in IN’161. The argument put forth by Natco was that ETO with its pharmaceutically accepted salts were expressly covered in Claim 6 of IN’176.
Drawing a distinction between ‘broad coverage’ of a claim, and coverage as would entitle patent protection under section 48, the Single Judge ruled that ‘broad coverage’ of a claim may include products for which there is no enabling disclosure in the patent. It was held that claim 6 of IN’176 broadly covers ELT-O as a pharmaceutically acceptable salt of ELT, but ELT-O was not claimed under Claim-6 of IN’176 read with the enabling disclosure. The Single Judge engaged in what can be characterized as ‘re-writing through interpretation‘ of the Supreme Court’s ruling in the Novartis. What I mean to say can be better understood by contrasting the following extract from Novartis SC and the Single judge’s interpretation of the said extract:
Novartis v. Union of India 2013, Supreme Court
139. The dichotomy that is sought to be drawn between coverage or claim on the one hand and disclosure or enablement or teaching in a patent on the other hand, seems to strike at the very root of the rationale of the law of patent. Under the scheme of patent, a monopoly is granted to a private individual in exchange of the invention being made public so that, at the end of the patent term, the invention may belong to the people at large who may be benefited by it. To say that the coverage in a patent might go much beyond the disclosure thus seem to negate the fundamental rule underlying the grant of patents.
Novartis v. Natco 2021 Single Judge, Delhi High Court
14.3.4 Even so, the Supreme Court did not equate “coverage” with “disclosure”. It held that there was no “dichotomy” between “coverage” and “disclosure”, but did not hold that there was no distinction between these two expressions. What was impermissible, according to the Supreme Court, was a wide gap between “coverage” and “disclosure”. The observation that a gap should not be wide, plainly, presumes the possibility of existence of a gap. If coverage and disclosure were to be treated as synonymous, there would be no gap, which would render this finding of the Supreme Court meaningless and superfluous. It is axiomatic that words used by the Supreme Court are, especially in view of their constitutionally binding nature under Article 141 on all authorities in the country, to be regarded as having been carefully chosen.
The DB has overruled the Single judge and held that there can be no gap between coverage and disclosure in a patent [paras 97 – 99]. The judgment holds that the Supreme Court, in unequivocal language, has held that dichotomy between coverage and disclosure negates the fundamental rule underlying the grant of patents.
However, what is worth noting is that the DB has also observed that there can be a gap between Disclosure and Coverage if it can be shown that the though the substance was covered but was “not anticipated” and/or “not obvious” to a person skilled in the art [para 102]. While keeping a foot in the door for non-obviousness makes sense, carving an exception out solely for ’anticipation’ diverts from the fundamental logic on which the judgment is based. It simply means that the show is not over yet.
Conclusion
There can be a view that judgment is not that consequential. It does not lay down any new proposition, as these questions have been answered long back by Supreme Court and Delhi High Court in numerous judgments. Or that it did not consider Section 53(4) [which in turn would have further strengthened DB’s reasoning]. But in my view the judgment is important as it puts to an end the jurisprudential hiccup created for over two years since 2021 by the judgment of the Single judge and FMC Corporation v. Natco Pharma 2021:DHC:1987. The judgment of the DB is a welcome judgment which has put back the proverbial horse before the cart for the time being.
