Read the case study and answer the following questions given at the end : A patent (IN 161) was granted to AA, the plaintiff in October, 2015. The invention patented was titled "3-[(2Z)-[1-(3,4-Dimethylphenyl)-1, 5 Dihyd

CS Professional · Intellectual Property Rights - Laws and Practices · PYQS · December 2022
Read the case study and answer the following questions given at the end : A patent (IN 161) was granted to AA, the plaintiff in October, 2015. The invention patented was titled "3-[(2Z)-[1-(3,4-Dimethylphenyl)-1, 5 Dihydro-3-Methyl-5-Oxo-4H-Pyrazol-4- Ylidene] Hydrazino]-2'-Hydroxy- [1,1'-Biphenyl]-3-Carboxylic Acid Bis-(Monoethanolamine)". Reckoned from 21 May, 2003, being the International Filing Date of the patent, the patent would remain alive till 21 May, 2023, by virtue of section 53(1) of the Patents Act, 1970 (Patents Act, for brief), read with the Explanation thereto. The invention was granted the non-proprietary name "Eltrombopag Olamine" (abbreviated, for the sake of convenience, as "EO"). The Complete Specifications of the patent, as filed with the Indian Patent Office (IPO) for grant of the patent declares that Eltrombopag "is a compound which is disclosed and claimed, along with pharmaceutically acceptable salts, hydrates, solvates and esters thereof. EO is used for the treatment of thrombocytopenia, denoting insufficiency of platelets in the body and is marketed, by AA, the plaintiff, under the tradename "REVOLADE". BB, the defendant in this case launched its branded EO in the market. This, alleges the plaintiff, infringes the patent (which is still alive) as the defendant had not obtained any licence from the plaintiff. Ergo, the plaintiff through a suit filed by it seeks an injunction against the defendant from infringing the patent. The plaintiff emphatically averred that, it was disentitled to seek to contend that IN 176 did not claim EO. The defendant BB contests the suit by questioning the validity of the patent IN 161, invoking, for the purpose, section 107(1), read with clauses (a), (d), (e), (f), (j), (k) and (m) of section 64 of the Patents Act. The challenge is predicated on treating IN 213176 (in short, 'IN 176'), also held by the plaintiff, as prior art. The title of IN 176 is "a compound and a pharmaceutical composition for use in enhancing platelet production". The International Filing date of IN 176 was 24th May, 2001; ergo, the patent expired on 24 May, 2021. EO was, according to the defendant, the subject matter covered by IN 176; hence, it was not entitled to any protection after 24 May, 2021, by virtue of section 53(4) of the Patents Act. However, the plaintiff emphatically averred that IN 176 did not claim EO. The defendant submitted its contentions questioning the entitlement of AA, the plaintiff to an injunction, a summary of which runs as follows: The Active Pharmaceutical Ingredient (API), which provides therapeutic activity against thrombocytopenia, is Eltrombopag, and not EO. EO functions only as a pro-drug, which enables delivery of Eltrombopag to the target site. EO does not have any inherent therapeutic activity. Reliance was placed, in this regard, on the leaflet prescribing information for REVOLADE, which indicated that EO was present, in the tablets, in a quantity which was sufficient to enable providing of equivalent specified, amounts/dosages of Eltrombopag to the patient. The defendant further submitted that the patent was invalid on the ground of anticipation by prior claiming, under section 64(1)(a) of the Patents Act. BB's counsel exhorted the Court to read section 64(1)(a) in conjunction with section 13(1) (b). IN 176 being a patent granted in India, with priority dates (25 February, 2000 and 30 August, 2000) earlier than the priority date of the patent IN 161 (22 May, 2002), the coverage of the subject matter of the claims in the patent by the claims in IN 176, disentitles the claims of AA to any protection after 24 May, 2021. Counsel of BB further submitted that the plaintiff AA cannot, seek to "evergreen" IN 176 beyond the life of the latter patent. As, according to him, IN 161 is invalid on the various grounds urged by him, Manufacture and marketing of EO, by his client, cannot be alleged to amount to infringement. AA had, while applying for grant of patent CA 2486697 ('CA 697' in short) in respect of the compound claimed in the suit patent IN 161, before the Canadian Intellectual Property Office (IPO), admitted, in its response to objections raised by the Examiner in the Canadian IPO, that a salt form of some of the final compounds was inevitably formed during the reaction towards the final step. The following recital, as contained in the said response of AA to the objections of the Examiner in the Canadian IPO, was emphasised by BB's counsel : "{i] it is noted that the reaction conditions for the final step in certain Examples (e.g. 64 and 85) involve a solution that contains a strong acid, such as trifluoroaceticacid. Even though none of the final compounds in International Application No. PCT/US01/16863 specifically disclose a salt form, a salt form of some of the final compounds appears to have inevitably formed." The sum and substance of BB's counsel was that AA having made the aforesaid admissions, before foreign jurisdictions, in respect of patents corresponding to IN 176, it was disentitled to seek to contend that IN 176 did not claim EO. Referring to section 3 (d) of the Patents Act, BB's counsel submitted that the subject matter of IN 161 was not patentable, in view of the said express provision. Eltrombopag being a "known substance" by virtue of IN 176, he contended that in order for any new form of Eltrombopag to be eligible for a patent, the complete specifications had to disclose the existence of additional efficacy. The only assertions of the plaintiff, regarding the advantages of EO over Eltrombopag per se, were that EO had better solubility and bioavailability and, therefore, better pharmacodynamic factors. Therapeutic effect, even to EO, was owing to Eltrombopag. He added that the Supreme Court in the Novartis case, had clearly held that enhanced bioavailability was insufficient to indicate enhanced therapeutic efficacy, for the purposes of the Explanation to section 3(d). IN 161 was, therefore invalid on this ground as well. It has also been sought to be contended by BB that its price was lower than that of the plaintiff's product and that public interest justified the refusal of the plaintiff's prayer for interlocutory injunction. BB's counsel repeatedly emphasised the fact that, at the interlocutory stage, the defendant was only required to make out a case of a credible challenge regarding the vulnerability of the suit patent to revocation. This standard, he submitted, had amply been met by the grounds raised by him. Responding to the submissions of BB, the counsel for the plaintiff submitted that EO was a novel and inventive compound. EO, he submitted, was a salt which did not form part of any approved drug prior to the suit patent IN 161. It was a technical advancement over Eltrombopag per se, which was claimed and disclosed in prior art. EO, was, therefore, a new and inventive product. Comparing IN 176 with the suit patent IN 161, counsel for AA submitted that the subject matter of IN 176 was Eltrombopag per se. EO, the subject matter of the suit patent IN 161, was the outcome of protracted research and development undertaken on Eltrombopag. EO was a breakthrough drug used for treatment of chronic idiopathic thrombocytopenia, and had been marketed, in India, since 2011 under the brand name "REVOLADE". EO itself had been granted patent protection in over 60 jurisdictions. The therapeutic efficacy of EO stood recognised in over 90 countries, in which patent protection had been granted to it. EO was, therefore, a novel, inventive and technical advancement over IN 176. The subject matter of the invention claimed in the suit patent IN 161 was, therefore, distinct and different from the entity IN claimed in Claim of IN 176. AA's counsel contended that there could be no question of any claim, or disclosure, of EO in IN 176, as EO was not a pharmaceutically acceptable salt of Eltrombopag prior to the priority date of IN 161. Acceptance of the submissions canvassed by BB, submitted the counsel for AA, would render incremental inventions, resulting in technical advancements over the known prior art, non-patentable, as all derivatives would be covered by the prior art. Section 3(d) would, thereby, be rendered otiose. Thereafter, the counsel for AA addressed section 3(d) of the Patents Act. This provision, he submitted, was ex facie inapplicable, as no drug came out of IN 176 and no drug, containing Eltrombopag, was ever approved prior to IN 161. The subject matter of IN 161, i.e. Eltrombopag Olamine, he submitted, was not a "known substance" within the meaning of section 3(d), but was a "new compound" altogether. Even if, it were to be assumed that EO was a new form of a known substance, within the meaning of section 3(d), he submitted that it would, nonetheless, be patentable, as it had enhanced therapeutic efficacy over the claims in IN 176. IN 176, he submitted, claimed the free acid Eltrombopag, which had no known efficacy. He relied on the decision in Bristol-Myers Squibb Holding Ireland Unlimited Co. v. B.D.R. Pharmaceuticals International Pvt. Ltd. to contend that the very fact that the marketable drug had first emerged from the suit patent IN 161 was itself an indicator of its enhanced efficacy over the claims in IN 176. As EO had higher yield of Eltrombopag, as well as enhanced solubility and bioavailability as compared to the free acid form, counsel for AA submitted that the therapeutic efficacy of EO was greater than Eltrombopag in the free acid form. He also submitted that the maximum plasma concentration of EO was thrice the plasma concentration of Eltrombopag in free acid form. This indicated that the bioavailability of EO was thrice the bioavailability of Eltrombopag in free acid form. This enhanced solubility and bioavailability, he submitted, had led to drug development and consequently, enhanced therapeutic efficacy of the compound claimed in the suit patent IN 161. It needs to be mentioned that BB acknowledged before the Court that the fact that it is manufacturing and dealing in Eltrombopag Olamine. Furthermore, BB contended that the plaintiff may have itself applied for grant of patent in respect of the allegedly infringing product but it did not. The defendant, in the present case, neither launched any pre-grant nor any post-grant, opposition to IN 161. It has not initiated any proceeding before IPAB or any other authority, for revocation, cancellation or removal of the suit patent from the register of patents. Counsel for AA further observed that, in the present case, EO was an unknown substance prior to IN 161. As such, the suit patent IN 161 could not be regarded as vulnerable to invalidity on the ground of section 3(d) of the Patents Act. He pointed out that the grounds of challenge, raised by BB to the validity of the suit patent IN 161 were, thus, without substance. Infringement of the suit patent having been admitted by the defendant, AA would be entitled to injunction and that the defendant should not be entitled to manufacture and market EO, during the subsistence of the suit patent IN 161. Both the parties relied on the judgements of the Indian Courts and Foreign Courts. After going through the narrative above, answer the following questions with supporting legal principles and case law if any. What do you understand by 'credible challenge' and 'vulnerability' in the context of the case narrative ?

Answer & Explanation:

Credible Challenge: A patentee enjoys the rights to his patent, but the mere grant of a patent does not mean that the patent is valid. A patent is valid as long as it is not challenged. Revocation proceedings against a granted patent under section 64 of the Indian Patents Act, 1970, can be initiated any time after the grant of a patent. However, it is necessary that a credible challenge to the validity of a patent has to be raised. The moot point is when one can say that a credible challenge has been raised against a granted patent? The answer lies in convincing a court that a triable question arises with respect to the validity of a patent. If the court is convinced that a triable question to validity has been raised, interim injunction can be granted. However, other factors also need to be kept in mind before granting interim injunction. The question of deciding whether the patent is valid can only be decided during a trial. In other words, it is the question of vulnerability of a patent to invalidation which needs to be decided when preliminary injunction is sought while actual validity of a patent is the issue to be decided at trial. A defendant should, therefore, raise a substantial question regarding the invalidity and such a question does not require as hard evidence as is required at the trial stage. Thus, a credible challenge can be said to have been raised only when a substantial question regarding invalidity has been raised and that the claims at issue are vulnerable. For supporting its averments, the Court referred to judgements of other jurisdictions like Abbot Laboratories v. Andrx Pharmaceuticals Inc. and Helifix North America Corporation v., Blok-Lok, Ltd. Vulnerability: There appears to be a fundamental misconception relating to the concepts of "credible challenge" and of "vulnerability", if one were to read the narrative and in particular the contentions of both AA and BB. The submissions advanced by BB seem to have been predicated on the premise that the slightest shadow of doubt, which could be cast on the suit patent, was sufficient to constitute a credible challenge, exposing its vulnerability to revocation. This proposition appears to be misconceived. During the examination of a patent application, a thorough study is normally undertaken by the Patent Office, regarding the validity of the patent sought. When an infringer seeks to defend infringement on the ground that the patent that he infringes is invalid, the onus, to prove such invalidity heavily lies on him. This standard has to be met, when applying the principle of "credibility". Repeated attempts were made to the Court that any and every ground that BB sought to raise, and for which a cast iron response from AA was not immediately forthcoming, was sufficient to establish vulnerability of the suit patent to revocation. Revocation is a drastic act, and a patent, once granted, cannot be treated as easily vulnerable to revocation. Even if, prima facie, a ground for revocation is made out, revocation is not automatic, but remains a matter of discretion, for the patent authority. The grant of such discretion is itself a pointer to the legislative intent that, before revoking a patent, the authority is required to satisfy itself, that, all considerations having been borne in mind, revocation is absolutely necessary. Vulnerability to revocation has also to be judged on the same standard. It is only when, judged on that standard, a credible challenge to the validity of the patent as vulnerable to revocation is made out and that an infringer can escape the consequences of infringement. The standard is, therefore, high, rather than low. In the comprehensive judgment of FMC Corporation & Anr. vs Natco Pharma Limited with respect to grant of interim injunctions involving a patent relating to "Chlorantraniliprole" (also known as CTPR), the Delhi High Court rejected a valiant effort by the defendant based on several grounds under the patent law. The Court refused to grant permission to the defendant to manufacture and sell the insecticide during the pendency of the suit. While coming to its conclusion, the Court pointed out that the defendant failed to make a credible challenge with respect to vulnerability of patent validity. The Court stated that the Supreme Court's judgment in Novartis does not state that disclosure is equal to claim coverage, but simply points out that there cannot be a large gap between the two. The Court also observed that disclosure of a compound in a markush claim does not necessarily make the species patent susceptible to anticipation, prior claiming, obviousness or Section 3d challenge. It then went on to cite some principles pertaining to analyzing patentability of selection patents by equating selection patents to species patents in this case.

Topics: Patents Act, 1970

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