Petition for revocation - Obviousness - Defendant company holding patent for a sustained release formulation of an anti-psychotic drug
Teva UK Ltd and other companies v Astrazeneca AB: ChD (Pat) (Mr Justice Arnold): 22 March 2012
The defendant company was the holder of a European Patent (UK) No 0 907 364. The patent was for a sustained release formulation of an anti-psychotic drug, quetiapine, and marketed by the defendant under the trade mark ‘Seroquel’.
The patent claim had been for a sustained release formulation comprising a gelling agent and quetiapine, or a pharmaceutically acceptable salt thereof, together with one or more pharmaceutically acceptable excipients. The patent had identified a number of problems to which the invention had been addressed, in particular it had identified that it was difficult to formulate sustained release formulators of soluble medicaments and gelling agents, such as hydroxypropyl methylcellulose (HPMC), for a number of reasons.
The problems were said to have been encountered in making sustained release formulations of soluble medicaments with gelling agents such as HPMC. The claimants in three claims sought revocation of the defendant’s patent on the grounds that it was invalid on the ground of obviousness over an item of prior art referred to as ‘Gefvert’. Gefvert was an abstract of an article which had disclosed a number of points to the skilled team, concluding that once or twice daily dosing might have maintained sufficient receptor occupation for therapeutic efficacy with low extrapyramidal side effects. It was common ground that, if considering a new formulation of a drug, the skilled team would, as a matter of routine, have carried out a literature search to try and ascertain the relevant properties of the drug.
The claimants submitted that the skilled team would have concluded from Gefvert that: dosing of an immediate-release formulation of quetiapine once a day was unlikely to be efficacious; the skilled team would have considered that, rather than an immediate-release formulation, a sustained release formation was likely to be efficacious and would have offered advantages in terms of compliance and convenience; and the skilled team would have expected to be able successfully to formulate a sustained release formulation of quetiapine using HPMC, which would have been a routine choice of matrix, and would in fact have achieved success without difficulty.
The court ruled: The perception of the skilled team, in the instant case the formulator, would have been that dosing once a day was to be preferred to twice daily, both because it might lead to better patient compliance, although there was no hard evidence that it did so, and because it was more convenient to patients and carers. Further, the skilled team would have been well aware that one of the advantages of sustained release formulations was that they enabled less-frequent administration and, in particular, once a day rather than twice a day.
The skilled team would have concluded from Gefvert that a single dose of an immediate-release formulation daily would not have been efficacious. The skilled team would have regarded once-daily administration as desirable. To have achieved once-daily administration, a sustained-release formulation and a higher dose of an immediate-release formulation would have been both obvious possibilities. The skilled team would neither have expected from its common general knowledge, nor concluded from the formulator’s literature search, that quetiapine had been likely to saturate the first pass metabolism.
It would therefore not have been deterred from developing a sustained-release formulation. Nor would its expectation of success have been adversely affected. Therefore, the skilled team would have expected to be able successfully to have formulated a sustained-release formulation of quetiapine using HPMC, which would have been a routine choice of matrix (see , , ,  of the judgment. Accordingly, the patent was invalid (see  of the judgment).
Daniel Alexander QC and Tom Mitcheson (instructed by Pinsent Masons) for the claimants in the first claim; Daniel Alexander QC and Adrian Speck (instructed by Taylor Wessing) for the claimants in the second and third claims; Piers Acland QC and Mark Chacksfield (instructed by Bristows) for the defendant.