The case concerned a long-running dispute between pharmaceutical giants Synthon BV and SmithKline Beecham (now known as GlaxoSmithKline) over the validity of a patent for an ingredient in the popular antidepressant drug Seroxat.
Both firms discovered the substance at about the same time, and in June 1997 Synthon filed an international application under the Patent Application Treaty for a patent covering the compound. This was not published until December 1998.
In the meantime, SmithKline Beecham sought a UK patent for the substance, filing an initial paper with the Patent Office in October 1998 and filing the application itself in April 1999. The UK patent was published in May 2000.
Synthon sought to revoke SmithKline Beecham’s patent, arguing that it did not cover an invention that was new, and was therefore unpatentable.
Synthon won its case in December 2002, despite a set back for the firm when two chemists who had been instructed to make the compound following the details outlined in Synthon’s application, could not make the experiment work until they worked round the prescribed method using their own expertise.
SmithKline Beecham appealed, and in June 2003 the Court of Appeal reversed the lower court ruling, finding in favour of SmithKline Beecham. Synthon appealed to the House of Lords, which last week, in a unanimous ruling, found in favour of Synthon and revoked the SmithKline Beecham patent.
Lord Hoffman, giving the opinion of the five-panel court, set out the process by which Synthon had to prove its case.
Firstly, in a “disclosure” stage, Synthon had to show that its application had disclosed the invention that had later been patented by SmithKline Beecham.
In effect, said Lord Hoffman, this means that the “matter relied upon as prior art must disclose subject matter which, if performed, would necessarily result in an infringement of the patent.”
This applies whether or not the person infringing the patent is actually aware that he is infringing the patent. According to Lord Hoffman:
“It follows that, whether or not it would be apparent to anyone at the time, whenever subject-matter described in the prior disclosure is capable of being performed and is such that, if performed, it must result in the patent being infringed, the disclosure condition is satisfied. The flag has been planted, even though the author or maker of the prior art was not aware that he was doing so.”
Secondly, Synthon had to show that “an ordinary skilled man would be able to perform the disclosed invention if he attempted to do so by using the disclosed matter and common general knowledge”. The judge called this stage “enablement”.
Both concepts are distinct from each other – as is the role of the ordinary skilled man when considering each concept, said Lord Hoffman.
“In the case of disclosure, when the matter relied upon as prior art consists (as in this case) of a written description, the skilled person is taken to be trying to understand what the author of the description meant. His common general knowledge forms the background to an exercise in construction,” he explained.
“But once the meanings of the prior disclosure and the patent have been determined, the disclosure is either of an invention which, if performed, would infringe the patent, or it is not. The person skilled in the art has no further part to play,” added the judge.
Looking at enablement, Lord Hoffman found that the question is “no longer what the skilled person would think the disclosure meant but whether he would be able to work the invention which the court has held it to disclose”.
In this case, he said, Synthon’s application did disclose an invention that, if performed, would infringe on the SmithKline Beecham patent. The existence of the compound was clearly disclosed on the application.
The judge then had to decide whether the disclosure would have enabled a person skilled in the art to create the compound. He concluded:
“Synthon, as I have said, got off to a bad start by specifying, in their main example, a solvent which proved unsuitable for crystallisation. Nevertheless, the judge found that the skilled man would have tried some other solvent from the range mentioned in the application or forming part of his common general knowledge and would have been able to make PMS crystals [the compound under dispute] within a reasonable time. This is a finding of fact by a very experienced judge with which an appellate court should be reluctant to interfere”.