- Whether the subject matter of the species patent held by Astrazeneca was disclosed in the genus patent held by the same person?
- Whether the 2020 order passed by the Delhi High Court denying Astrazeneca interim relief in a suit for injunction was wrong.
PATENT CASE LAW SUMMARY
- Patent no. IN 235625 (Patent ‘625) covers the compound named Dapagliflogin (DAPA) used in treatment of Type II Diabetes Mellitus. DAPA acts as an inhibitor of Sodium dependant glucose transporter SGLT2 in the kidneys. The selective inhibition of SGLT2 normalises plasma glucose by enhancing excretion of glucose in the urine, thereby, improving insulin sensitivity and, thus, delaying the development of diabetic complications such as neuropathy, nephropathy, and retinopathy, wound healing and other related diseases.
- Patent No. IN 205147 (Patent ‘147) also held by Astrazeneca covers in its ambit “C-Aryl Glucoside SGLT2 inhibitors and method” which was a Markush structure capable of producing millions of permutations and combinations.
- Astrazeneca held Patent ‘147 as the genus patent, granted on 15.03.2007, with a priority date of 12.10.1999. The specie patent, Patent ‘625 was granted on 09.07.2009, bearing a priority date 20.05.2002. Patent ‘147 expired on 02.02.2020 while Patent ‘625 is valid until 15.05.2023.
- The Defendant companies sought to manufacture and sell drugs containing DAPA and hence, Astrazeneca filed a suit seeking a permanent injunction from manufacturing and selling of any drugs containing the compound DAPA.
- The defendants resisted the suit on the claim that the patent lacked inventive step and further, the terminal disclosure filed by Astrazeneca in the USPTO was proof of admission that DAPA was indeed covered by the genus patent held by them, in the US.
- The High Court of Delhi rejected the interim relief prayed for by Astrazeneca, as Intas had prima facie established a credible case of revocation of patent. (Astrazeneca v. Intas, 2020 SCC Online Del 1446)
- Aggrieved, Astrazeneca filed the present appeal.
SUBMISSION BY APPELLANT
- The Appellant contested that IN’147 is a Markush structure containing millions of compounds and hence, while DAPA was covered in its wide ambit, it was not specifically disclosed therein. DAPA had been granted patent protection in 70 countries and in India, it had not faced any pre or post grant opposition.
- While patent IN’625 for DAPA had been granted in the year 2009, the new drug created with DAPA had been granted approval only in 2020. This drug was to be officially distributed by Astrazeneca through Sun Pharma Laboratories Limited and Abbott Healthcare Private Limited.
- DAPA was first synthesized only in 2001, after the priority date of IN ‘147 (August, 1999) and hence, there was no question of DAPA being covered by IN’147.
- The concept of genus and specie patents is well recognised under Indian Patent Law. Just because a compound occurs in the periphery of a claim does not mean the compound is disclosed in specificity, in the said patent.
- DAPA is not obvious in the teachings if IN’147 and any derivation of DAPA from the Markush claim would require cherry picking from numerous parameters contained therein, and such picking would be possible only in hindsight.
SUBMISSION BY RESPONDENT
- The Appellant have claimed infringement of both their patents numbered IN ‘147 and IN ‘625 by the production and sale of DAPA containing drugs. This would imply that IN ‘147 covers DAPA and hence, with the expiry of that patent in October 2020, DAPA has entered public domain.
- The implication that IN ‘147 covers DAPA would also mean that IN ‘625 is an invalid patent, as it does not display any inventiveness. It seeks to protect a compound that is obvious in the Markush structure of IN ‘147.
- There was an objection by the United States Patent and Trademark Office (USPTO) to the approval of a patent which if granted would have been the equivalent of IN ‘625. The Office had raised the issue of obviousness/double patenting as the new compound DAPA was hit by a prior claim in the Markush patent. The Appellant had in the US filed a terminal disclosure and accepted that the term of the DAPA patent would end along with the expiry of the Markush structure patent. This acceptance by the Appellant would act as estoppel by conduct.
- The Supreme Court in Novartis AG[(2013) 6 SCC 1] rejected the argument that there was a dichotomy between coverage and disclosure and ruled that all molecules covered by the genus patent in that case were/are known therefrom; once the appellants/plaintiffs admitted that DAPA is covered by IN 147 and asserted that the respondent(s)/defendant(s) have infringed IN 147, it is evident that DAPA is also known from IN 147;
- Thus, there was a credible challenge to the validity of patent IN ‘625. There was no inventive step as claimed by Astrazeneca and hence, they should not be granted any interim relief. The impugned order was lawful and must be upheld.
- On a comparison of relevant extracts from both patents ‘147 and ‘625 there emerges no substantial technical advancement or economic significance that would make the synthesis of DAPA an “inventive step” under Section 2(1)(ja).
- The proceedings against Astrazeneca in the USPTO though not a complete bar place an estoppel by conduct and hence, Astrazeneca cannot plead that IN ‘147 did not disclose DAPA.
- The Court therefore , upheld the impugned order, and ruled that Astrazeneca was not entitled to any interim injunction.
Citation: 2021 SCC OnLine Del 3746