When 0.77% is greater than 1%: salutatory lessons from the Court of Appeal
All new drugs rely, to a greater or lesser extent, on pre-existing research and development. Much of this pre-existing research will have resulted in patented methods and products. A major challenge for all researchers is therefore to develop new drugs which do not infringe other company’s patents.
Assuming one can work out which patents are likely to be infringed by the new research, determining whether a new drug infringes a patent should be a straightforward process: read the patent; determine the patented characteristics or methods; and see whether the new product infringes those. However, the English courts have recently confirmed that this is not sufficient: a product can infringe a patented method even when, on a literal reading, the new product would not. How can this be? And what lessons does this teach researchers?
The judgment in question was handed down on 24 June 2015 by the English Court of Appeal. It determined that a method, invented by Smith & Nephew, for producing a silver-impregnated dressing infringed a patent held by ConvaTec. As is well-known, silver is a beneficial additive to dressings due to its antimicrobial properties. However, due to its sensitivity to light, it is a difficult to use. ConvaTec’s patent aimed to solve this problem by various techniques, one of which used a solution where an agent was “present in a concentration of between 1% and 25%”.
Smith & Nephew has also been developing silver-impregnated dressings. This patent was clearly a problem to the company. They sought, but failed, to revoke the patent and, also, worked on a new method which they hoped would not infringe. This method utilised a concentration of the agent at 0.77%. Since this was not “between 1% and 25%”, they considered that it did not infringe and sought a declaration from the court to that effect. At the trial, before Mr Justice Birss, they won but ConvaTec appealed. Many grounds were advanced but, by the time the case was decided on appeal, the central issue was simply this: was 0.77% “between 1% and 25%”?