In continuation of the last piece over here, let’s now discuss the actual issue of infringement of IN ‘774 patent by Cipla crisply. My apologies for a long delay in writing this piece due to long travelling schedule and back-to-back heavy projects thereafter. Nevertheless, it is better to be late than never. Here it goes.
The claim 1 of IN’774 is read as:
1. A novel [6,7-bis(2-methoxyethoxy)quinazolin-4-yl]-(3-ethynylphenyl)amine hydrochloride compound of the formula A [structure]
The defendant raised several defences resisting the infringement of this claim. The defendant provided an X ray diffraction of Tarceva and concluded that the drug is actually the Polymorphic Form B and that the features of Polymorph B contained in Tarceva corresponds with the US patent 221.
Further the defendant argued that the tablet of Erlotinib Hydrochloride cannot be made by way of simply following IN’774 rather the patent US‘221 is relevant for the same purpose and this shows that there is further process of reaction of the compound of IN’774 with that of other constituents in order to arrive at Polymorphic version. The suit patent compound is thus not automatically leading to Polymorphic version.
Roche then argued that Claim 1 of the suit patent is for the Erlotinib Hydrochloride per se, and not restricted to any particular Polymorphic form or mixture of any forms, nor claims any particular Polymorphic form and that the Active Pharmaceutical Ingredient in the Defendant‘s product Erlocip is also Erlotinib hydrochloride. Roche submitted that the defendant could not have arrived at Polymorph B form without crossing the stage of preparation of combination Polymorph A and B and therefore, the defendant product even if the same is a Polymorphic Form B of the molecule would still infringe IN‘ 774.
Cipla’s main point of argument was that the separate patent applications were filed in India (IN’507) and US (US’221) for Polymorph form B and Erlotinib Hydrochloride and that clear admissions have been made that IN’774 relates to Polymorph A+B and the second patent US‘221 and corresponding application in India IN’507 relates to Polymorph B of Erlotinib Hydrochloride. According to Cipla, if Roche filed a fresh patent on Polymorph B, they themselves believed that Polymorphic version is distinct from that of the main compound and when IN’507is rejected by the Indian Patent Office, they took a U-turn and argued that the somersault and are arguing that the second product is covered by the first patent.
The judge followed the purpotive rule of construction of the patent claim,
“whether the patent claim subsumes the product or the process impugned is a matter to be examined from the standpoint as to whether the patentee could have reasonably included the said product or process in question which is he is impugning on the fair reading of the invention”
According to the Judge there are some of the facts which should have been deposed by Plaintiff in order to show that there is an infringement done by the defendant by manufacturing the Polymorphic version B which is covered in the main compound. Some of those main facts are:
- How many reactants or variants with which the main Erlotinib compound is reacted with in order to arrive at the Polymorphic Form B of?
- Whether the properties and the characteristics of the main compound changes or varies after the said reactants or variants are reacted with or not. The plaintiff in order to show that there is an infringement should have deposed to the effect that the said properties and characteristics are not changed pursuant to the reaction.
However, the plaintiff had not been able to show as to what is the exact nature of the plaintiff and defendant products which are being sold in the market, further, whether the said products corresponds exactly with the claim of the suit patent is also not established, among other facts.
On the other hand, the defendant was able to show that the plaintiff’s suit compound is a combination of A and B and the compound needs to be converted or separated in order to arrive at the Polymorphic version B. Plaintiff argued that the plaintiffs‘ suit compound is not separated but converted, to which Judge remarked that,
“Whether the said compound is covered or separated, the moot question is that there is something which is done besides the compound as contained in the suit patent in order to arrive at Polymorphic B. if the answer is in affirmative, I think, the onus is discharged”.
The issue is accordingly decided in favour of the defendant and the suit and the counter claim were dismissed.
Thus, in the Indian geography, after the patent on the main compound is obtained, firstly it is extremely difficult to get a subsequent selection patent on polymorph (or other forms) on ground of Section 3d and secondly and importantly the marketed drug based on polymorphic form would easily be prone to generic competition without infringement of the main patent.
About the Author: Meenakshi Khurana, Patent Attorney, available at email@example.com