Court Of Appeal Confirms Genentech Herceptin Formulation Patents Invalid

The Court of Appeal has confirmed that two Genentech patents concerning lyophilised formulations of trastuzumab (the active ingredient in Herceptin) are invalid for obviousness. It also confirmed that a finding of obviousness does not require, in every case, that the skilled person "would" have arrived at the claimed invention without inventive effort.

Giving the leading judgment, Lord Justice Floyd took the opportunity to provide a succinct summary of the law regarding inventive step and the place of the 'obvious to try' doctrine within it.

The law regarding inventive step

Floyd LJ made clear that there is only one statutory question, namely, whether the invention was obvious at the priority date.

Asking whether the invention was "obvious to try" is not a substitute test for obviousness, merely one of many considerations which it may be appropriate for the court to take into account in addressing the statutory question. In any case, it must be coupled with a reasonable or fair prospect (or expectation) of success.

There is no single standard of what amounts to a fair expectation of success. How much of an expectation is needed depends upon the facts of the case. Jacob LJ's statement in Saint Gobain v Fusion-Provida [2005] EWCA Civ 177 that it must be "more-or-less self-evidence that what is being tested ought to work" is, said Floyd LJ, "far from being a test of universal application".

A finding of obviousness also does not require in every case that the skilled person, acting only on the basis of the prior art and his common general knowledge, "would" have arrived at the claimed invention. A "would" test, said Floyd LJ, can be misleading as it is liable to bring in irrelevant considerations, such as whether it would be worthwhile commercialising an otherwise technically obvious product. Such a test would also place another straightjacket on the law of obviousness.

In practice, the skilled person may be faced with a range of obvious possibilities, making it statistically unlikely that he will settle on any of them, but they will all be obvious:

In an empirical field it will...seldom be possible to predict in advance that any individual experiment will work. In many cases, the fact that a routine screening exercise could be carried out will be inadequate to establish obviousness. Nevertheless, on the facts of an individual case ... the team may have a reasonable degree of confidence that a series of experiments will produce some which will...