Drug innovators and Section 3d

Many World Trade Organisation member states have an impression that in the pharmaceutical space, India is a no holds barred country where generic companies can copy invention and live-happily-ever after. However, the reality may be quite different. With the Indian pharmaceutical market growing at double digit rates, competition between the innovator companies and the generic companies is fierce.

The rights of the applicant are enshrined in the Indian Patents Act, 1970 that gives the exclusive right to the innovator to prevent others, without applicant’s consent, from the act of making, using, offering for sale, selling or importing the patented product in India. In case of a process under Section 104, it is the exclusive right to prevent others, without applicant’s consent, from using that process and from using, offering for sale, selling or importing for those purposes the product obtained directly by that process in India. The patentee can file a suit for infringement against the infringer. The Court can grant relief to the patentee in the form of an interim or permanent injunction or in the form of damages to be paid. The Court can also order seizure of infringing goods. For granting injunction, the Courts consider the patentability of the invention, scope of the infringing aspects within the granted claims and validity of the granted patents.

Generally one major factor of concern to innovators is Section 3d, which does not allow the grant of speciepatents of genus drug molecule. What follows below is the trend in grant of injunctions in the pharmaceutical space in recent years for the protection of various drug molecules.

Sitagliptin is a Merck Sharp and Dohme’s (MSD) blockbuster anti diabetic drug. MSD found infringement of its patent covering the molecule Sitagliptin, an anti-hyperglycemic drug of the DipeptidylPeptidase-4 (DRP-4) inhibitor class for which they filed infringement suits against several parties. The generic version of the drug is the phosphate salt and the specie patent for the said phosphate salt has been granted in the United States and other jurisdictions and the same under Section 3d had been abandoned in India. The Court granted interim ex-parte injunction against eight defendants, while refused injunction against Glenmark. In case of infringement suit against Glenmark, the Court held that Merck Sharp and Dohme had failed to prove that Sitagliptin phosphate was identical in its properties to Sitagliptin, hence the product (Sitagliptin phosphate) of Glenmark would be outside the purview and scope of the applicant’s genus patent. The Court might have opined that since the species patent for Sitagliptin phosphate had been rejected by the Indian patent office, it may not be within the scope of the genus patent which covers Sitagliptin molecule as a chemical entity. The fact that the plaintiff had obtained patents on Sitagliptin phosphate in the United States and Europe by showing that it was a new product worked against them as it supports the fact that these are two different products which intern supports the defendant’s argument that the species patent which was filed by the applicant as a separate patent application has been rejected by the Indian patent office, therefore, not within the scope of the genus patent which pertains only to the basic drug molecule. The matter had been referred for mediation, however, since attempts to settle disputes have failed and the matter is into the trial phase.

Erlitinib is a drug molecule "Human Epidermal Growth Factor Type-I/Epidermal Growth Factor Receptor (HER/EGFR)" inhibitor for the treatment of cancer. Roche had filed several infringement suits against a number of generic drug companies. Only in Cipla's case Court rendered its decision. Roche’s genus patent for Erlotinib drug molecule was held valid by the Court. Roche had filed a species patent for polymorphic form in United States and other jurisdictions, and the same had been granted. Based on the priority of species patent for polymorphic form in United States, Roche had filed patent for the same specie in India. The species patent for polymorphic form was rejected by the Indian patent office under Section 3d. In this case Roche was denied permanent injunction based on the Court view that Cipla did not infringe on the genus patent claiming drug molecule as a product, though patent was held valid by the Court. The High Court recognized the validity of the genus drug patent, but opined that Roche’s drug and Cipla’s generic products have different molecular structure, therefore, not infringing. In fact the genus product claim for a drug molecule pertains to a chemical entity which includes all the physical and chemical species of the genus molecule. A separate patent application for the species patent may exclude the species from the scope of the claim of genus molecule.

Novartis based on United States priority had filed a patent for the species mesylate salt of the genus Imatinib drug molecule in India. Under Section 3d, it was rejected as it could not prove increase in clinical efficacy in the species variant of the genus molecule. The genus product for the Imatinib drug molecule owing to priority date in United States pre 1995 could not be filed in India. The Novartis had challenged the Indian patent office decision of rejecting the patent application indecision in High Court and Supreme Court and the Intellectual Property Appellate Board (IPAB) decision of rejecting the patent application was withheld by both the Courts.

United States and EP States of European Union patent law permit the patents for specie variants of the drug molecule. Generally the filing date of the species variants which are eventually used in the eventual dosage form is later than the filing date of the genus patent and accordingly the expiry date of the species patent is later compared to the expiry date of the genus patent thereby providing a longer term for the drug molecule in its specie variant form. For example, the expiry date of the polymorphic form 2 of blockbuster drug Clopidorgel is 2019 compared to genus product patent which was 2010. Vividly there is a nine years delay in the launch of the generic version of the drug which is used in the dosage form of the drug. This approach can be termed as evergreening of the proprietary rights of the drug molecule in patent form.

During pre 1995 era under Section 5, product patent for drug molecule was not patentable in India. However, in order to comply with Trade-Related Aspects of Intellectual Property Rights (TRIPS) agreement, India amended the patent law and Section 5 was deleted from the Indian patent law. To check evergreening Section 3d was introduced which bars the grant of patent for specie variants of the drug molecule such as salts, polymorphic forms, enantiomeric forms and the likes unless an improved efficacy is demonstrated by the specie variant. As evident from the case studies stated here in above, the patent for the specie variant of the drug molecule which is used in the dosage form of the drug is not granted. The generic player may argue that logically inventor him/herself feels that the specie variants are different products and not within the scope of the genus patent and for that reason files a separate patent applications for the respective specie variants. May be owing to this the honourable opined that the product claimed in the genus patent which is valid and the product claimed in the specie patent which has been rejected are different, therefore, decided in favour of Cipla in case of Erlotinib and similarly neither interim nor permanent injunction was granted to Merck against Glenmark in case of Sitagliptin.

In view of above it can be inferred that the specie patents of the genus drug molecule dilute the scope of the claim of drug molecule of the genus patent, therefore, the innovator company in the light of Section 3d should refrain from filing patent for any specie variant of the drug molecule and instead patent application draft should include scope of all the specie variants in the genus patent itself.

The patent application is filed based on the priority document filed in the jurisdiction of the origin of the invention. The national phase entry in India has to be same as originally filed in the original jurisdiction. The original genus patent application does not include the scope of specie variants for which a separate patent application for each specie variant is filed with varying filing dates later than the filing date of the genus patent application.

There has been a lot of pressure on India from United States and other EP States of European Union to allow patents for specie variants as otherwise the new drug molecules are not protected in India. The issue can be addressed, if India considers enacting intellectual property policy allowing filing the genus patents based on multiple priory applications of genus and species variants based on the earliest priority date of the date of filing of the genus patent. This suffices the requirements of third as there is no extra patent term for the new chemical entity and also ensures scope of all the specie variants in the genus patent. As an alternate, a divisional application or addition of patent to the genus patent based on the earliest priority date can be considered for the specie variants of the genus which provides a protection to the innovator for all the specie variants for which separate patents for respective species have been granted. This will ensure same protection term for all the genus and specie patents avoiding evergreening for which Section 3d has been enacted in Indian patent law.