Patent Post

Trial and error

Nick Burrows gives an account of some errors that led to wrong judgements in some important patent challenges.

Not so obvious!

Pfizer's cholesterol pill ,Lipitor has been the best-selling drug in the world for the last five years. It was originally invented by Warner-Lambert and was acquired by Pfizer in 2000. Lipitor's annual sales last year ($12.9 billion) were more than twice as much as those of its closest competitors. Ranbaxy is challenging the Lipitor patent in many countries around the world.

In May 1986, Warner-Lambert filed a patent application describing how to make Lipitor by a procedure that results in a racemate mixture. One example described the free acid form of the compound and another described the sodium salt. The description also listed seven possible metal ions that might form pharmaceutically acceptable salts. In July 1989, after publication of these examples, they filed another patent application directed to the calcium salt of one of the two enantiomers of the racemate mixture. European patents were granted, and in UK, the patents were extended beyond their 20-year term by the grant of a Supplementary Protection Certificate lasting until 2011. Ranbaxy filed in the UK for the revocation of the latter patent and requested a declaration of non-infringement of the earlier patent.

The EPO Board of Appeal found the selection of the calcium salt and the particular enantiomer to be inventive. But the UK Patents Court found otherwise, expressing a preference for the historical English Windsurfer analysis approach over the EPO's problem-solution approach. The two judgements compare and contrast the working of the two rival tests for obviousness, at a time when the UK test for obviousness is under review.

The EPO Board of Appeal reversed their original rejection (based on obviousness) on the basis that the selection of calcium from the seven pharmaceutical metal salts, together with selection of one of the two enantiomers from the racemic mixture, formed an inventive selection. This combination was said to improve the handling properties of the solid salt (particularly, its hygroscopicity and solubility).

The English Patents Court Decision

Senior English Patents Court Judge, Justice Pumfrey, decided as follows:

• There was no inventiveness in resolving the racemate into its enantiomers and in selecting a particular enantiomer as the procedure was a preferred procedure in the industry
• There was no inventiveness in selecting a particular salt from the seven possibilities, and least of all the calcium salt. Conducting a salt screen is a standard procedure to identify the best salt for administration after a pharmaceutically active component has been isolated and it is most usual to use potassium, sodium and calcium salts.

Where did they go wrong?

Pumfrey went on to give reasons why, in his view, the EPO Board of Appeal had erred:

• The EPO heard only the patentee's argument, an inherently risky strategy
• The EPO chose the wrong example from the earlier patent document as the closest prior art, beginning its analysis with the sodium salt example, rather than the free acid along with the description of possible metal ions
• The judge found there to be no technical problem to be solved

Pfizer has declared the decision a victory, as the other part of the judgement (not discussed here) held that, although the formula claimed by Warner-Lambert in the earlier patent was a formula that denotes the racemate, the claim was not so limited, but extends also to the individual enantiomers, one of which Ranbaxy intended to offer for sale. Thus, the judge held that Ranbaxy's proposed sale of the enantiomer fell within Warner-Lambert's claim.

Pumfrey expressed concerns over the methodology used by the EPO Board of Appeal in analysing obviousness, but in the end, concluded that he could not discern any differences in principle. Any differences that emerge are "mere differences in appreciation" and the same result is often reached. The judge also warned against using a strict "over-meticulous" approach to claim construction, which, if used in this case, would have led to the patent being construed as including only the racemate, as this was what was explicitly disclosed. Instead, he opted for a more general approach and looked at construction through the eyes of what a person, skilled in the art, would have understood the language of the claim to mean, which led him to his decision that the patent claims included not only the racemate, but also each enantiomer. Is summary judgment suitable to deal with a claim for trademark infringement following events, which led to the ownership of a trademark in different countries?

Doncaster Group vs Bolton

Doncaster Pharmaceuticals Group & Ors vs Bolton Pharmaceutical involved a claim for trademark infringement in respect of parallel imports. The appellant importers of pharmaceutical products (Doncaster) appealed against a summary judgment granted in favour of the respondent pharmaceutical manufacturer (Bolton) for an injunction restraining infringement of Bolton's trademark. The original owner of the Spanish trademark for Kalten had assigned its rights to a separate Spanish company, which took over the manufacturing of the pharmaceutical product in Spain.

Doncaster then imported the product from Spain, re-packaging and relabelling it for sale in the UK, under the name Kalten. The original owner then assigned its UK trademark for Kalten to Bolton, which also began to manufacture and sell the product in the UK. Bolton immediately began trademark infringement proceedings on the basis that Doncaster was using the Kalten trademark without its consent. Bolton claimed that it was justified to prohibit imports by Doncaster on the grounds of "the protection of industrial and commercial property" under Article 30 of the EC Treaty.

During the trial, Doncaster argued that the original Spanish owner, the Spanish assignee and Bolton were economically linked, so the essential function of the trademark had been exhausted. However, the Deputy Judge decided that any defence based on the exhaustion of rights doctrine had no real prospect of success and granted summary judgment in favour of Bolton.

Court of Appeal

The Court of Appeal held that the Deputy Judge had erred in treating the case as suitable for summary judgment. There was insufficient evidence about the events leading to ownership of the trademark in different countries, the possible economic links between the original owner and assignees of the trademark, and the application of the doctrine of exhaustion of rights.

Prior to the assignments, the original owner possessed the Kalten trademark in Spain and UK. Further, the parallel importation into the UK of products circulated on the market in Spain had been lawful. A trial with complete disclosure of documents and witness statements would be required to establish the facts relevant to the issue At trial, there was insufficient evidence before the Court to enable a final decision on the exhaustion of rights issue.

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