Supreme Court stayed the Delhi High Court order of injunction against Glenmark over the Generic drug “Sitagliptin”

2nd April, 2015 - 10:04 am Categories: India IP Litigation IP Practice in India News & Updates patent infringement Patent Litigation Patents pharma Pharma/Biotech Patent Litigations 0 Comments

Reportedly, Hon’ble Supreme Court of India on Special Leave Petition filed by Glenmark stayed the Delhi High Court order which passed injunction against Glenmark for the generic drug Sitagliptin till 28th April 2015. The Delhi high court on dated 20th March 2015 set aside an order of single judge bench of Delhi High Court which rejected the injunction application by MSD against Glenmark. This article aims to analyze the Delhi High Court judgment by the Division bench in detail.

Facts of the case:

Merck Sharp & Dohme (hereafter “MSD”) aggrieved by the dismissal of its application for an ad interim injunction restraining the respondent/defendant Glenmark Pharmaceuticals (hereafter “Glenmark”) from using its patented product Sitagliptin (Indian Patent No. 209816) filed an appeal. MSD filed an application before single bench Delhi High Court for permanent injunction, restraining infringement of the patent, damages, rendition of accounts and delivery up. The suit patent relates to a drug which lowers blood sugar levels in Type 2 Diabetes Mellitus (“T2DM”) patients. Glenmark opposed the application for ad interim injunction and relied on documents produced during the hearing. The learned Single Judge rejected the injunction application. Aggrieved by the dismissal of interim injunction Merck sought to obtain an interim injunction against Glenmark seeking to restrain Glenmark from selling its Generic products Zita (generic version of Januvia) and Zitamet (generic version of Janumet, combination of sitagliptin+metmorphin).

Argument advanced by the Appellant (MSD): 

The learned Senior Counsel, Mr. T.R. Andhyarujina for MSD argues, that its drug Sitagliptin is the first in its class of compounds that inhibits the enzyme Di Peptidyl Peptidase-IV (“DPP-IV”). The learned counsel argued that the suit patent is infringed because Sitagliptin and any of its acceptable salts are covered by its claims, thus resulting in the making, using or offering for sale, importing into India etc. of Sitagliptin or any of its salts or any form amounting to infringement of the suit patent. It was further argued that Glenmark, by manufacturing, selling, offering for sale and advertising the pharmaceutical combinations Sitagliptin Phosphate Monohydrate under the brand Zita and Sitagliptin Phosphate Monohydrate and Metformin Hydrochloride under the brand name Zitamet infringes the suit patent and all its claims. It was underlined that Sitagliptin Phosphate Monohydrate cannot be prepared without manufacturing the active ingredient Sitagliptin molecule. Therefore, the use of Sitagliptin claimed by IN 209816 to prepare Sitagliptin Phosphate Monohydrate by Glenmark infringes the suit patent. MSD argued that its non-disclosure of applications (which were not pursued by it) was an inessential detail which should not have clouded the debate on whether Glenmark infringed its suit patent. It was submitted that the subject of the European Patent, and the application No. 5948/DELNP/2005 (filed on 18.06.2004 – in respect of the Phosphoric Acid Salt of a DPP-IV inhibitor that claimed Dihydrogenphosphate salt of Sitagliptin and was abandoned under Section 21(1) on 23.08.2010) could not have been the basis for refusing ad interim injunction. In India, on account of Section 3(d) and the interpretation of the expression “efficacy” by courts, MSD abandoned the phosphate salt application.

The learned counsel for MSD argued that Glenmark’s US Process Patent No. US8334385 is for “Process for the preparation of R. Sitagliptin and its pharmaceutical salts”. It was further contended that this patent clearly admits that Sitagliptin is developed for the treatment of T2DM and is the active free base. It also gives the full description of the process for preparing Sitagliptin freebase in the patent specification which is Scheme 6 in Merck’s patent. The claim of Glenmark’s patent is for a crystalline salt of Sitagliptin. The learned counsel relied upon the disclosures made to the suit patent IN 209816 to state that the basic invention for which patent protection was sought was Sitagliptin “with pharmaceutically acceptable salts thereof”. It is submitted that this is clearly stated in claims 1, 15, 17 and 19. Thus learned counsel stressed that Glenmark”s ZITA (Sitagliptin Phosphate Monohydrate) and ZITA-MET (Sitagliptin Phosphate Monohydrate and Metformin) infringe the suit patent because Sitagliptin is made and used by Glenmark in ZITA and ZITA-MET when it makes salt Sitagliptin Phosphate Monohydrate. It was underlined that the phosphoric acid salt of Sitagliptin was disclosed in the suit patent itself as one of the pharmaceutically acceptable salts.

Arguments advanced by the Respondent:

 The counsel for the respondent argued that the suit patent is obvious and does not involve an inventive step over and above previous disclosures in the prior art. It was further argued that the suit patent is anticipated by prior arts European Patent 1406622 and WO/01/34594.

Further it was argued by the Counsel for the respondent that the suit patent drug Sitagliptin as well as Sitagliptin Hydrochloride are unstable compounds possessing incapability of commercial production and industrial use.

The respondent argued that the claim goes much beyond the limited disclosures in the specification, and thus the claim is overbroad or an impermissible Markush claim that creates a false monopoly. It was also contended that the patent monopoly is too broad to be workable as it includes possibly 4.9 billion compounds and such elastic claims cannot be sustained.

It was argued that the complete specification of the suit patent does not sufficiently and fairly describe the invention and the method by which it is to be performed, since the patent does not describe the preparation of the Sitagliptin free base or Sitagliptin phosphate monohydrate, but only its hydrochloride salt.

Further it was argued that MSD did not comply with its obligation under Section 8 of the Act to disclose patent applications made for the “same or substantially the same invention” – it did not disclose 5948/DELNP/2005 (for Sitagliptin Phosphate Monohydrate), 1130/DELNP/2006 (Sitagliptin Phosphate Anhydrate), 2710/DELNP/2008 (Sitagliptin plus Metformin) or subsequent international applications for these compounds either. It was also argued that such suppression and concealment – contrary to statutory obligations – results in the invalidity of the patent, and at any rate, militates against the grant of an interim injunction that is premised on good faith and complete disclosure.

It was argued by the respondent that the suit patent by the plaintiff’s own admission is different from its product. The only exemplified salt being Sitagliptin Hydrochloride, no other salt can be claimed or covered in the impugned salt patent and the plaintiff, by its own admission equivocally, through several documents admitted that the suit patent is distinct and different from the Sitagliptin Phosphate Monohydrate (SPM) as well as its combinations with Metformin Hydrochloride. Urging that the latter two products are the subjects of separate patents, Glenmark highlighted that this is clear admission that they are not covered by the suit patent. In this respect, the details of the plaintiff’s application, i.e. 5148/DELNP/2005, especially, Claim no.1 and International Patent US 2004027983, again claim no.1 are relied upon. The said salt, i.e. SPM was also claimed to possess tremendous advantages over free base and previously disclosed hydrochloride salt. MSD‟s said patent application no. 5948/DELNP/2005 for SPM was specifically abandoned.

Conclusion:

Considering the arguments advanced by both the parties, the court evaluated the three grounds Prima facie case, irreparable injury and balance of convenience for passing interim injunction as below:

1) The court on the first ingredient held that prima facie case had been established by MSD for the fact that Glenmark uses Sitagliptin free base as the active component in its chemical formulation.

2) The court on the issue of whether the claimant would suffer irreparable injury in the absence of interim injunction or not, held in affirmative. The court rejected the argument of Glenmark that injunction should not be granted as the monetary compensation may be granted. On the contrary court opined that prices may not recover after the patentee ultimately prevails, even if it is able to survive the financial setback (or “hit”) during the interim, which may take some time.

3) On the issue of balance of convenience the court held in favor of MSD. On the issue of price difference between the commercial products by MSD and Glenmark is not so startling as to compel the court to infer that allowing Glenmark to sell the drug, at lower prices would result in increased access. However, the court observed that Permitting Glenmark to operate would not necessarily result in lowering of market prices. Hence according to court the balance of convenience lies in favor of MSD.

The court conclusively held that all the three ingredients for passing the order of injunction were established by MSD and hence injuncted Glenmark from manufacturing and selling of Zita and Zitamet.

About the Author: Meenakshi Khurana, Partner at Khurana & Khurana, Advocates and IP Attorneys and can be reached at: meenakshi@khuranaandkhurana.com