In an injunction application MSN Laboratories Private Limited, Eris pharmaceuticals, Emcure Pharmaceuticals, Optimus Pharma Private Limited have been injuncted/restrained from advertising, launching, making, using, offering for sale, selling, importing and/or exporting the medicinal product, Linagliptin in any form .

The order of May 2022 disposes applications preferred under Order XXXIX, Rules 1 and 2 of the Code of Civil Procedure by the plaintiffs, praying for interim directions during the pendency of various suits for infringement filed by them. The suits of the plaintiff is for passing of a decree of restraint and permanent injunction against the defendant from infringing the patent rights of plaintiff under Indian Patent No. 243301 (IN’301) covering Linagliptin in any from whatsoever covered by the subject patent granted by the Controller of Patents on October 05, 2010.

While deciding the injunction application the Hon’ble High Court of Himachal Pradesh considered various decisions and laid down the following main principles: –

• The registration of a patent per se does not entitle the plaintiffs to an injunction. The certificate does not establish a conclusive right.
• There is no presumption of validity of a patent, which is evident from the reading of Section 13(4) as well as Sections 64 and 107 of the Patents Act.
• The claimed invention has to be tested and tried in the laboratory of Courts.
• The Courts lean against monopolies. The purpose of the legal regime in the area is to ensure that the inventions should benefit the public at large.
• The plaintiff is not entitled to an injunction if the defendant raises a credible challenge to the patent. Credible challenge means a serious question to be tried. The defendant need not make out a case of actual invalidity. Vulnerability is the issue at the preliminary injunction stage whereas the validity is the issue at trial. The showing of a substantial question as to invalidity thus requires less proof than the clear and convincing showing necessary to establish invalidity itself.
• At this stage, the Court is not expected to examine the challenge in detail and arrive at a definite finding on the question of validity of the patent. That will have to await at the time of trial. However, the Court has to be satisfied that a substantial, tenable and credible challenge has been made.
• The plaintiff is not entitled to an injunction, if the patent is recent, its validity has not been established and there is a serious controversy about the validity of the patent.

The Hon’ble Court applied above principles vis-à-vis the respective contentions of the parties to decipher as to whether the defendants have laid a credible challenge which has rendered the patent of the plaintiffs to be vulnerable at this stage to refuse the grant of interim relief or not.  

The principal ground which has been urged by the defendants is that subject patent is evergreening of IN 227719 (IN719), and in this view of the matter, there is indeed a credible challenge to the subject patent which renders the same vulnerable.  To substantiate their contention, much stress was laid upon:-

• the pleadings of the plaintiffs in the civil suit, which stands filed by the Plaintiff in the High Court of Delhi, wherein the plaintiffs were claiming the infringement of IN719 and IN301 qua Linagliptin, and which as per the defendants, makes it amply evident that IN301 was nothing but evergreening of IN719.
• the queries which were raised by the Patents Office at the time of the consideration of the application of the plaintiff qua the subject patent.

The Court held that the fact that subsequently subject patent was granted to the plaintiffs demonstrates that the Patents Office was satisfied with the response so submitted to its queries by the plaintiffs. That being the case, it cannot be said that by highlighting these very facts or the pleadings of plaint filed before the Delhi High Court, the defendants could be said to have had laid credible challenge to the subject patent so as to make it vulnerable to deny interim relief to the plaintiffs at this stage. In other words, vulnerability of a patent cannot be concluded simply on the assertions/defence of the defendants which is yet to be proved as per law.

The court further held that in the case in hand, the patent in issue, i.e. ‘IN301’ was granted in favour of the plaintiffs in India long patent and the same is an old patent. On the other hand, admittedly, the defendants do not have any patent qua the infringing product and no challenge, either to the application filed by the plaintiffs for grant of patent was laid by the defendant nor any post patent challenge was laid by it. Of course, in light of law laid down by Hon’ble Supreme Court in M/s Bishwanath Prasad Radhey Shyam , grant of patent does not guarantee the validity of a patent, which can be challenged before the High Court on various grounds in revocation or infringement proceedings, but the factum of a patent being there in favour of the plaintiffs and the factum of no pre or post grant challenge to the same by anyone, including the defendant, (except recently by way of a revocation petition which was filed in close proximity to the launch of the infringing product) does creates a prima facie case and balance of convenience in favour of the plaintiffs.

In the light of what has been discussed hereinabove, if an infringer is not restrained from infringing the patent of patent holder, then, but of course, the patent holder will suffer from irreparable loss and it cannot be said that the infringer stands on the same pedestal on which the patent holder is. Of course, the patent of the plaintiffs is vulnerable.

The Court also distinguished the present case form Dhanpat Seth & others Vs. Nil Kamal Plastic Crates Ltd., wherein learned Single Judge of this Court while dealing with an application filed under Order XXXIX, Rules 1 and 2 of the Code of Civil procedure for grant of temporary injunction with regard to the infringement of the Patent granted to the plaintiffs therein in respect of a device of manual hauling of an agricultural produce, after perusing the Patent device in the Court, observed that the basket got patented by the plaintiffs was not a hauling device and the device was made of synthetic polymeric material, which had been invented long back and that the process by which the substance was moulded into various articles like baskets, buckets, mugs, jugs, furniture and so many other articles was also well known and there was nothing new about the so called device; and rejected the prayer for grant of interim relief.

The Court held that the order in Dhanpat Seth & others Vs. Nil Kamal Plastic Crates Ltd is no assistance in the present case, for the reason that here the Patent is of a drug and infringement is also by way of a drug being marketed and sold by the defendants based on the Patent of the plaintiffs. The Court held that by no stretch of imagination this Court by comparing the tablet of the plaintiffs/applicants with the tablet of the defendants/non-applicants with a naked eye can conclude as to whether any inventive step was involved in the Patent of the plaintiff or not. Similarly, by referring to the applications and documents appended therewith, which were submitted by the plaintiffs/applicants for grant of IN’ 719 and IN’ 301, this Court cannot conclude even prima facie that IN’ 301 is evergreening of IN’719.

There is one more aspect of the matter which the Court highlighted.

The Court held that the plaintiffs/applicants do have a Patent in their favour with regard to the compound Linagliptin, the defendants/non-applicants do not have one. Yet knowing fully well that the drug they intended to introduce in the market was duly covered by the subject Patent, they took a calculated risk to do so. The Court further stated that patent IN’ 719, has recently expired, but was in public domain, yet before manufacturing their respective products and before marketing the same, the defendants/non-applicants did not seek revocation of the Subject Patent well in time during the validity of Patent IN’ 719. This also in the considered view of the Court, tilts the balance of convenience in favour of the plaintiffs.