Patent validity
Suspensory effect of appeal


On June 17 2016 the Maritime and Commercial High Court invalidated AstraZeneca's Danish quetiapine sustained release patent in a litigation against Teva Denmark A/S and Accord Healthcare Ltd.

The patent concerned a sustained release formulation of the anti-psychotic drug quetiapine, comprising the active ingredient quetiapine and a gelling agent together with one or more pharmaceutically acceptable excipients.

Before this judgment, the validity of AstraZeneca's patent had been successfully challenged in several European countries, including the United Kingdom, Spain, Germany and the Netherlands.


On April 17 2012 AstraZeneca was granted a preliminary injunction against Teva's sale of the drug Quetiapin Teva SR and on December 20 2013 AstraZeneca entered a procedural agreement with Accord granting a preliminary injunction against Accord's sale of the drug Quetiapin Accord SR. Subsequently, AstraZeneca filed confirmatory actions against both Teva and Accord. These cases were tried together in the present case before the Maritime and Commercial High Court.(1)

Patent validity

Teva and Accord claimed that AstraZeneca's patent was invalid due to the lack of inventive step. They argued that it was standard practice for Danish courts to employ the European Patent Office's problem-and-solution approach (PSA method) when assessing the inventive step of European patents with effect in Denmark.

According to Teva and Accord, the closest prior art was a review by Gefvert describing experiments where patients with schizophrenia were given quetiapine in an immediate-release formulation three times daily. They argued that the solution with the sustained release was obvious to the person skilled in the art, since Gefvert would encourage the skilled person to provide a formulation with a sustained release of quetiapine using a gelling agent, which was a well-known routine procedure in sustained release formulations.

AstraZeneca argued that:

  • the assessment of the inventive step should not be based on the PSA method, as this approach is not always suited to identifying the relevant prior art; and
  • the court should instead employ the traditional Danish test for the inventive step.

AstraZeneca also argued that the invention was not obvious to the skilled person on the priority date, as the lack of available information about the physicochemical and pharmacokinetic characteristics of quetiapine would have prevented the skilled person from making a formulation with sustained release.

Suspensory effect of appeal

In order to have the preliminary injunction lifted in the event of invalidation, Teva and Accord claimed that any appeal of the judgment should not have suspensory effect.

The general rule is that an appeal has suspensory effect. However, the courts may deviate from this rule if special circumstances apply. Teva and Accord argued that such special circumstances applied in the present case as it would be unreasonable to maintain the effect of the preliminary injunction during an appeal, since AstraZeneca could then lodge an appeal with the single purpose of keeping Teva and Accord off the market for as long as the appeal was pending. They argued that the European patent had been invalidated without recourse in the most important European jurisdictions, and that it was therefore unlikely that the judgment would be reversed during appeal in Denmark.

AstraZeneca argued that an appeal's suspensory effect is a basic principle of law and that it clearly follows from the legislative history of the act that it should be an exception not to grant suspensory effect. AstraZeneca further argued that – because of the special nature of drugs – AstraZeneca would lose a significant share of the market within a short period, which would cause a large and irretrievable loss, whereas Teva's and Accord's potential losses would be limited.


The court applied the PSA method and noted that it appeared to be undisputed that the person skilled in the art regarding the disputed patent was a team consisting of a drug formulation expert and a clinician with experience of mental disorders.

The court found that Gefvert was the closest prior art and noted that Gefvert had strongly indicated that:

  • quetiapine could potentially be used as an atypical anti-psychotic remedy; and
  • the document further indicated that a more convenient dosing regimen would be beneficial given the importance of patient compliance with schizophrenic medication.

The court further agreed that the objective technical problem was to provide a formulation of a pharmaceutical product which could be administered less frequently and resulted in a more stable and uniform plasma concentration.

On the basis of the expert opinions and specialist literature, the court considered that:

  • on the priority date of the disputed patent, it was part of the skilled person's general knowledge to prepare a sustained release formulation using a gelling agent; and
  • HPMC (the gelling agent used) was a well-known and generally used gelling agent in this connection.

The court also considered that the sustained release formulation of quetiapine was one of several obvious options as a solution to the technical problem. Thus, the invention was obvious to a person skilled in the art. The fact that other obvious solutions to the problem existed (eg, depository injections), did not change the fact that the solution of the disputed patent was obvious.

Consequently, the court invalidated AstraZeneca's patent and acquitted Teva and Accord from AstraZeneca's claims.(2)

Teva's and Accord's separate claim that a potential appeal should not have suspensory effect was denied without reasoning from the court.


A number of similar invalidity cases concerning AstraZeneca's patent are final or pending around Europe. For now, the patent has been invalidated by appeal courts in the United Kingdom, Germany, Spain and the Netherlands. In Belgium and Sweden, the appeal of the first instance invalidity judgment is pending, and in Italy the patent was invalidated in the first instance.

Thus, in terms of patent invalidity, the Maritime and Commercial High Court followed suit.

The case has been appealed by AstraZeneca.

For further information on this topic please contact Jeppe Brinck-Jensen or Kamilla Kelm Demant at Accura Advokatpartnerselskab by telephone (+45 3945 2800) or email ([email protected] or [email protected]). The Accura Advokatpartnerselskab website can be accessed at


(1) A similar preliminary injunction was granted against Hexal. For further information please see "No particular importance attached to European invalidity judgments regarding European patent".

(2) For details of the judgment (in Danish only) see: