In Actavis UK Ltd v Novartis AG  EWCA Civ 82, the Court of Appeal of England and Wales upheld the decision of Mr Justice Warren that Novartis' European Patent for a sustained release version of a drug was invalid for obviousness over an immediate release formulation.
Fluvastatin is a cholesterol reducing drug patented in the 1980s. The drug was first marketed in 1994 in an immediate release formulation.
The Novartis patent (having a priority date of 1996) related to a sustained release formulation of a sodium salt of fluvastatin. In the patent description, Novartis cited the benefits of a sustained release formulation over an immediate release formulation as improved therapeutic effects, reduced side effects and increased patient compliance as a result of simplified dosage regime.
The patent stated that "the drug release from sustained release formulations is related to the drug solubility". Consequently, there were special challenges when developing a sustained release formulation of a water soluble drug.
It further noted that fluvastatin sodium is highly water soluble so a fast release rate of the drug can be expected. The patent went on to state that, surprisingly, it was found that fluvastatin sodium also exhibits characteristics favourable to developing a sustained release formulation.
Actavis sought to revoke the patent on grounds of obviousness and insufficiency.
Novartis's case was that given the high solubility of fluvastatin sodium, a skilled person would not have had a sufficient expectation of success to attempt to develop the formulation.
At first instance Warren J rejected this argument and the invention was held to be obvious. Warren J stated that the physicochemical characteristics of fluvastatin sodium, including its solubility, were not so undesirable that a skilled team would not have considered it as a candidate for a sustained release formulation.
The judge also held that the purported benefits of improved therapeutic effects and reduced side effects were not supported by the evidence provided.
COURT OF APPEAL DECISION
On appeal, Novartis submitted that the judge had defined success erroneously in terms of the patent to mean improved therapeutic effects and reduced side effects. Instead, it was simply whether a sustained release formulation of fluvastatin sodium would be expected to work.
In order to determine obviousness, Lord Justice Jacob applied two tests: the Pozzoli/Windsurfing test and the problem-andsolution approach (PSA).
Applying the Pozzoli/Windsurfing test, Jacob LJ concluded that "the only difference between the prior art and the claim is the idea of making a sustained release formulation".
Applying the PSA test, Jacob LJ concluded that the "objective technical problem" was to develop a sustained-release formulation of fluvastatin.
Novartis claimed that, given the high solubility of fluvastatin sodium, a skilled person would not have had a sufficient expectation of success to attempt a sustained release formulation of the drug. Jacob LJ pointed out that this was not the case; the solubility was not so high as to discourage a skilled person from attempting such a formulation. Thus, the technical problem that the patent claimed to solve was nonexistent. Using both Pozzoli/Windsurfing and PSA, only one conclusion could be reached: the skilled person would expect that a sustained release formulation of fluvastatin would work. Furthermore, the benefit of improved patient compliance was enough motivation to attempt to develop such a formulation.
Consequently, the invention was held to be obvious.
This decision highlights the importance of the nature of the “problem” in assessing obviousness. In this case, the immediate release version of the drug was known, there were found to be obvious advantages in formulating a sustained release version and the evidence proved that there would be an expectation of success and that there was no reason, technical or otherwise, not to attempt such a formulation.