Dapagliflozin – India

Brief background of the case is like this. Plaintiff, Astrazeneca filed suit against number of generic companies for launching generic dapagliflozin (DAPA) product in India. Two patents-in-suit are IN 205147 (Genus patent - expired on Oct 02, 2020) & IN 235625 (specific patent – expires on May 15, 2023). Defendants filed counterclaim alleging invalidity of IN’625 patent based on IN’147 patent. Astrazeneca then asked for interim injunction.  Both Plaintiff & Defendants (Alkem & Intas) filed their respective briefs.

Court said that the issue at this stage of preliminary injunction is whether defendants have raised a credible challenge to IN 625? Actual validity issued would be tried at trial stage. The challenge to the species patent i.e. IN 625 is, broadly, laid on the grounds such as lack of novelty in view of prior claiming, lack of novelty due to prior publication, lack of inventive step, failure of the plaintiffs to make full and fair disclosure as required under Section 8 of the Act. Court said that the fact that both in the pleadings and in the documents, there is a definitive assertion that DAPA is covered in the genus patents granted in India. Plaintiff said that DAPA is covered but it is not disclosed in genus patent. Plaintiff further argued that coverage does not necessarily include disclosure which is founded on the Markush claim/group. But court said that the fact that the plaintiffs have taken out an infringement action both for IN 147 and IN 625 is a sufficient clue, at least at this juncture, that DAPA is claimed in both suit patents. Therefore, the defendants submission that IN 625 should be revoked on account of prior claiming under the provisions of Section 64(1)(a) of the Act has substance, at least at this stage.

With respect to anticipated by what was published or publicly known, court said that while counsel for the defendants, based on the affidavit of Mr. Martin, did try to convey that a person skilled in the art could iterate the claims and arrive at 8 molecules based on prior publication and not hindsight, this is an aspect which would be required to be tested in a trial. Therefore, on this score, the defendants' defence, at this stage, in my opinion, does not inject vulnerability.

With respect to inventive step, court said that there is no clue in IN 625 of an unknown technical effect on its priority date. Plaintiff tried to persuade the court with post filing evidences. But court said that post priority date evidence can only be taken into account to confirm the existence of technical effect which is found embedded in the specification of IN 625 and is capable of being understood by a skilled person having common general knowledge and not to rely upon the same to establish its effect for the first time. The plaintiffs have not been able to demonstrate, at least at this stage, the existence of such technical effect in the specifications.

With respect to Section 8 requirement, court said that in the instant actions, specific details were sought by the Indian Patent Office concerning search and examination report. What was submitted by the plaintiffs to the Indian Patent Office via the letter dated 10.01.2005 were the corresponding US patents and not the examination reports. It is also not denied by the plaintiffs that their response of 19.08.2002, whereby, the validity period of US 117 was voluntarily aligned with the US genus patent i.e. US 126 was not placed before the Indian Patent Office. The submission advanced on behalf of the plaintiffs that the terminal disclaimer is an obviation and not an admission of obviousness is not an answer to the provisions of Section 8(2) of the Act which is mandatory.

With respect to other injunctive factors such as balance of convenience, irreparable harm & public interest, court found these in favor of defendants. Court thus denied injunction but asked defendants to place on record the details, quantum, and value of drug manufactured and sold. The defendants via their affidavits will also undertake to pay damages as and when called upon to do so by the Court.