The Delhi HC (Justice Rajiv Sahai Endlaw) refused to grant interim relief to Merck (plaintiff) seeking to restrain Glenmark (defendant) from launching its products Zita and Zita met. We had blogged about it here and here. The High court however kept the main petition of the US firm pending for evidence filing and other legal proceedings on July 16.The order passed on Friday can be accessed here.Following is summary of arguments presented by either side. (Long post warning!)
|Image from here|
On the issue of separate patents for Sitagliptin and salt form of Sitagliptin:
Senior counsel for the defendant alleged that plaintiffs are guilty of suppression and had failed to disclose that the patent application (probably referring to the 5948/DELNP/2005) for the product for which injunction was sought was not only declined and also abandoned.
Glenmark’s counsel elaborated that its product comprises of three parts “S”, “PD” and “DC” (possibly referring to Sitagliptin, dihydrogenphosphate salt and crystalline form), and that Merck has separate patents for each of these parts in USA. Glenmark’s counsel further detailed that Merck holds the patent in India only for the first part and separate patents for the other two parts i.e. phosphate salt and crystalline form were denied and affirmatively abandoned.
Glenmark’s counsel also argued that Merck in its patent application (5948/DELNP/2005) had described that the combination of S and PD i.e. (Sitagliptin and phosphate salt) as a new discovery not covered by existing Sitagliptin patent. In light of this Merck cannot allege that defendants combination of “Sitagliptin and phosphate salt” infringes Merck’s patent. Glenmark also stated that “plaintiffs patent is for Sitagliptin Hydrochloride only and not for Sitagliptin Phosphate.” Placing reliance on Paras 139 and 156 of the Supreme Court Novartis judgement, it was contended that “coverage in a patent cannot be permitted to go much beyond the disclosure made by the patentee”
It was also argued that if Sitagliptin phosphate and Sitagliptin weren’t distinct products, then Merck wouldn’t have applied for separate patents for each of those in US and India.
It was argued that Sitagliptin was the invention and Sitagliptin phosphate was merely a derivative and therefore wasn’t eligible for patent protection under Section 3(d).The separate patent application for Sitagliptin phosphate filed by Merck was due to some misconception, which is why they affirmatively abandoned the same. It was also stated that, separate patent for Sitagliptin phosphate was applied for since the US has no Section 3(d) equivalent patent law.
On the issue of Infringement
Analogy was drawn to the Roche vs. Cipla (2012) judgement in which the plaintiff sought to injunct the product version for which the patent application was rejected. On the basis of Roche vs. Cipla judgement it was argued that when the role of the variant (in this particular case Sitagliptin phosphate) outweighs the patented claim (Sitagliptin only), there can be no infringement. Shamnad’s posts on Roche vs. Cipla judgement are available here and here.
Merck’s counsel argued that the package insert information reveals that the pharmaceutical composition of plaintiff’s product is similar to composition of Glenmark’s product Zita and hence the infringement is obvious. Merck’s counsels also emphasized that “there is no price difference in the product of the plaintiffs and defendant” to allay the influence of Novartis supreme court decision.
On the presence of other infringers in the market
Glenmark’s counsel also stated that since there are other (about 8-10) infringers in the market selling the same product for which injunction is sought, the ingredients of irreparable injury and balance of convenience are not in favour of the plaintiffs.
It was also argued that grant of patent does not automatically create any presumptive validity (section 10 and 13(4) of Indian patent act) and since there are others in the market using the same formulation for which injunction was sought “there was no new invention.”
The response of the plaintiff to the plea of the defendant that at least 9 to 10 other persons were also marketing Sitagliptin Phosphate was that instructions on that aspect will have to be taken once duly supported documents were handed over.
DECISION :Observations of the Court
Whether Glenmark’s product using a combination of Sitagliptin with its phosphate salt will have a material effect upon the working of Sitagliptin per se?
The learned judge agreed that Merck’s granted patent includes within its ambit “pharmaceutically acceptable salt of Sitagliptin” which may of course include Sitagliptin phosphate (Glenmark’s product).
The judge also reasoned that plaintiff should have shown that, defendant’s product inspite of combining phosphate salt with plaintiff’s patented Sitagliptin remained equivalent to Sitagliptin and that the role of phosphate was inconsequential in treatment of the disease.
The judge also noted that Merck has had made a separate patent application for Phosphate salt form of Sitagliptin, considering it to be a new invention worthy of a separate patent. Plaintiff (Merck) has not satisfactorily pleaded the circumstances for obtaining a separate patent application.
Justice Endlaw also elaborated that the defendant had also pointed out that there were at least 9-10 infringers marketing Sitagliptin phosphate. “Though, ordinarily infringement by others does not constitute a ground for denial of the relief of injunction against an infringer but it can be a consideration in the grant of interim injunction.”
“I therefore do not find the plaintiffs to have made out a case for grant of interim relief”
I may be oversimplifying things here, but claim 15 of Merck’s granted patent on Sitagliptin IN209816 clearly states “The compound as claimed in claim 1 (referring to markush structure of gliptins) selected from the group consisting of
or a pharmaceutically acceptable salt thereof.”
Also the specification of the patent defines salt forms as “When the compound of the present invention is basic, salts may be prepared from pharmaceutical acceptable non-toxic acids, including inorganic and organic acids. Such acids include acetic, benzenesulfonic, benzoic, camphorsuifonic, citric, clhanesulfonic, fumaric, gluconic, glutamic, hydrobromic, hydrochloric, isclhionic, lactic, maleic, malic, mandclic, methanesulfonic, mucic, nitric, pamoic, pantothenic, phosphoric, succinic, sulfuric, tartaric, p-toluenesulfonic acid, and the like. Particularly preferred are citric, hydrobromic, hydrochloric, maleic, phosphoric, sulfuric, fumaric, and tartaric acids.”
So,wouldn’t it be reasonable to conclude that anyone who markets the disclosed salt forms of Sitagliptin infringes the patent claims? So how does it matter that Merck tried and failed to patent the salt form separately in another patent in India. Hope our readers can help me out here!