On 8th August, the Single Bench of the Delhi High Court vacated the interim orders granted in favour of AstraZeneca (‘plaintiff’) preventing Micro Labs, Natco Pharma and Dr. Reddy’s Laboratories (‘defendants’) from selling, marketing or dealing with TICAGRELOR (an effective platelet aggregation inhibitor) or any other product violating the plaintiff’s registered patents- IN 907, IN 984 and IN 674. The case relates to two important issues, namely, selection patents and the difference between coverage and disclosure in a patent. The interim applications dealt with in the instant case were IA 3986/2018 in CS (Comm.) 749/2018, IA 4771/2018 in CS (Comm.) 792/2018, IA 9332/2018 filed in CS (Comm.) 1023/2018 filed by the plaintiffs, and IA 5096/2018 in CS (Comm.) 749/2018 filed by the defendants seeking vacation of the interim orders.
TICAGRELOR is a platelet aggregation inhibitor produced by AstraZeneca which is prescribed to patients who have suffered a recent heart attack or unstable angina (chest pain) for reducing the chances of another heart attack or stroke. According to the plaintiff, TICAGRELOR was first approved in the US in 2011 and is being marketed by the plaintiff under the trademark, BRILINTA. In India, the plaintiff received drug regulatory approval in May 2012 and was commercially launched in India in October 2012 as BRILINTA and AXCER.
In 2018, the plaintiff received information from various sources that the defendants were planning to launch generic versions of TICAGRELOR in India and accordingly filed patent infringement suits. In 2018, the Delhi HC passed orders in the plaintiff’s interim applications restraining the defendants from selling, marketing or dealing with TICAGRELOR tablet or any other drug violating the plaintiff’s registered patents- IN 907 (‘species patent’), IN 984 (‘polymorph patent’) and IN 674 (‘formulation patent’). The plaintiff alleged that the defendant’s drug TICAGRELOR fell within the scope of IN 907 (published in 2005) and IN 984. Further, the plaintiff argued that the finished formulation of TICAGRELOR was covered within the scope of IN 674. Micro Labs’ petitions for revocation of IN 907 and IN 984, are pending before the IPAB.
All the defendants in the instant case filed similar arguments. The salient arguments are as follows:
- The plaintiff’s patent IN 229 is the genus patent which expressly covers and discloses TICAGRELOR and has expired on 14.7.2018.
- Form 27 filed in India for IN 229 expressly refers to BRILINTA and AXCER being covered by IN 229.
- The plaintiff has deliberately failed to mention that the foreign patent equivalents of the plaintiff’s Indian patents have been invalidated in contested proceedings in China, Europe and South Korea. In doing so, the plaintiff has failed to comply with section 8 of the Indian Patents Act which requires intimation to the Indian Patent Offices of the status of all corresponding foreign applications.
- The instant case is a “textbook instance of patent ever-greening by the plaintiffs”- As the genus patent IN 229 has already expired, any party is free to manufacture or sell generic versions of TICAGRELOR in India. By obtaining patents (IN 907 and IN 984) on the same Markush, namely, TICAGRELOR, the plaintiff has sought to illegally extend the monopoly granted under IN 229.
- The plaintiff’s patents- IN 907, IN 984 and IN 674- lack novelty and are obvious.
- The plaintiff is creating a false dichotomy between “coverage” and “disclosure” wherein they argue that IN 229 generically covers but does not specifically disclose TICAGRELOR; this amounts to artificially extending the monopoly under the expired patent 229 through subsequent patents on TICAGRELOR.
- The plaintiff’s patents are liable to be revoked under section 3(d) because they do not exhibit any enhanced therapeutic efficacy over the known substances disclosed in IN 229.
The plaintiff rebutted the defendants’ arguments on the following grounds:
- The genus patent (IN 229) was published on 2nd February 1999 after the priority date of the species patent (IN 907). Therefore, the genus patent does not constitute prior art for evaluating novelty of the species patent.
- There is no specific or enabling disclosure of TICAGRELOR in the genus patent. The genus patent only discloses (1.5×1020) compounds one of which was later discovered to be TICAGRELOR. The defendants’ argument that TICAGRELOR can be derived from the general Markush formula in the genus patent is untenable and a case of hind sight basis (i.e. cherry picking based on ex post facto knowledge).
- Mere structural similarity is not sufficient to trigger section 3(d). The plaintiff relied on the affidavit of expert, Dr. Robert Riley, to argue that TICAGRELOR has demonstrably greater therapeutic efficacy than IN 229, owing to TICAGRELOR’s vastly superior metabolic stability and a far greater availability of the drug in the body.
- On non-disclosure of various revocation patents outside India, the plaintiff argued that the equivalent of IN 907 was revoked in China but an appeal was filed by the plaintiff; the appeal implies an automatic stay of the operation of the revocation order and does not amount to non-disclosure.
- Form 27 only states that the genus patent has worked through TICAGRELOR and does not imply that TICEGRELOR has been disclosed in IN 229. It is possible that multiple patents cover a single product.
- The plaintiff relied on Novartis v. UOI to argue that coverage (for the purpose of infringement) will not be granted by the court unless a specific disclosure has been made in the patent. However, this does not mean that disclosure is equivalent to coverage.
Noting that the defendant’s claims challenged patentability of the plaintiff’s invention, the court stated that the issue of patentability of pharmaceutical inventions is highly technical and a mixed question of fact and law. Therefore, the court would rely on expert evidence to determine this issue (citing Merck v. Glenmark Pharmaceuticals (2015) and Martin F.D’Souza v. Mohd. Ishfaq (2009)). The court then proceeded to examine the claims made by the parties.
Statement of Working in Form 27 as Proof that TICAGRELOR is Disclosed in the Genus Patent
The court found that the plaintiff had declared TECAGRELOR as the patented invention in Form 27 filed for the local working of patented inventions of IN 229, IN 907, IN 984 and IN 674. In Form 27 for all the above patents, the plaintiff had stated the same quantum of sale of BRILIANTA and AXCER.
The court also referred to a litigation in the US by the plaintiff against Mylan Inc. to enforce US Patent 6251910 (equivalent of IN 229). In this litigation, the plaintiff had stated that dealing in TICAGRELOR was in breach of the US Patent 910.
The court rejected prima facie the plaintiff’s argument that although the genus patent had worked through TICAGRELOR, TICAGRELOR was not disclosed in 229. The court relied on Novartis v. UOI wherein the SC rejected the dichotomy between coverage and disclosure in a patent; the SC in Novartis held that such a dichotomy negated the fundamental rule underlying the grant of patents.
Suppression of Material Facts by the Plaintiff Related to the Genus Patent
The court found that the plaint did not disclose important information regarding IN 229, especially Form 27 for IN 229 and the US court proceedings instituted against Mylan. Further, it was only in response to the defendant’s arguments that the plaintiff had stated that IN 229 was worked (although not disclosed) through TICAGRELOR.
The court held that this was a case of clear omission of mentioning important facts in the plaint.
Section 3(d) – Lack of Proof of Enhancement of Known Therapeutic Efficacy for the Suit Patents
The court found that the plaint was completely silent about any enhancement of known therapeutic efficacy for the suit patents. The court then examined the affidavit of Dr. Robert Riley- the court found that while the affidavit stated that the species patent had some advantages over the genus patent, the fact that both IN 907 and IN 229 could be used as platelet inhibitors pointed to a prima facie finding that the suits were not altogether new or unconnected to IN 229.
The court relied on Novartis v. UOI wherein the SC held that only those properties of a drug which directly related to therapeutic efficacy were relevant in a case involving section 3(d).
The court found that the plaintiff’s argument that the suit patents had advantages such as lower does and increased metabolic stability did not prove enhanced therapeutic efficacy of the suit patents over IN 229.
No Suppression of Material Facts under Section 8 – Information and Undertaking Regarding Foreign Applications
On the issue whether the plaintiff had failed to disclose relevant patent revocation proceedings in foreign jurisdictions, the court was of the opinion that the plaintiff had not suppressed material facts. The court accepted the plaintiff’s submission that as the revocation orders had been appealed by the plaintiff, this implied an automatic stay on the revocation order.
According to the court, the determining factor when deciding whether the court should continue the interim injunction granted in a patent infringement case was whether the defendant had raised a credible challenge to the validity of a patent held by the plaintiff (citing F. Hoffman-LA Roche v. Cipla (2015)).
The court found that in the instant case the defendants had raised a credible challenge to the validity of the patent on various grounds including section 3(d). Accordingly, the court set aside the interim injunctions against the defendants.
Hat tip to Mr. Sandeep Rathod for bringing this important development to our notice!
[Update: An appeal against the Single Bench order has been filed in the Division Bench]