Limitations and partial invalidity of a patent

In a recent order (no. 3339 of December 1st 2021), the Italian Supreme Court of Cassation stated that a limitation of a patent, due to the lacking of inventive character of the main claim, implies  its partial invalidity.

As in the case under exam, the limitation of the patent occurs when the main claim – which defines the protection scope of the patent itself – results not grantable because it was anticipated from a novelty and inventive step point of view.

If the main claim results invalid, the whole patent risks to be declared invalid.

However, if one of the dependent claims contains some secondary characteristics that – added to those of the main claim that at this point constitutes known-art – give an inventive value to the proposed solution, the patent can be limited and therefore maintained in force but with the protective scope reduced to the mere secondary characteristics above mentioned.

The limitation sets many interpretative doubts, one of them being the fate of the originally obtained patent.

Many consider that, once limited, the patent must be declared partially invalid with regards to the part of the patent contained in the main claim lacking validity. The Supreme Court states precisely this principle.

In the order we read as follow:

“The partial invalidity of a patent implies as a matter of fact, as we saw, a simple limitation of the patent itself (art. 76, comma 2, CPI). It is true that the limitation, when it is requested in a judgment through submission of a reformulation of the claims to the Judge, must be within the confines marked by the content of the patent application as initially filed and cannot extend the protection given by the obtained patent (Art. 79, comma 3, CPI) but this applies to delimit the scope of operativity of the limitation, certainly not to exclude that a partial invalidity of an industrial property right could be configured when the object of protection results muted in a limitative way”.

Therefore, the Supreme Court recognizes that the limitation of a patent, through merging, like in this case, of the main independent claim with the dependent claim, keeps the patent in force due to the conservation principle of the patent right, but at the same time it entails the declaration of the partial invalidity of a patent limited in relation to the part of the patent involved in the limitation and that therefore does not have its autonomy anymore.

The Supreme Court then referred the case back to the Court of Appeal of Venezia, which will have to reformulate the order considering the following principle of law:

“The partial invalidity of a patent now provided for by art. 76 comma 2 CPI, which provides for the need to keep the validity of the other concurrent claims presented with the law requirement for the patent, is likely to be declared in the presence of invalidity of the independent claim (in this case: for lack of inventive capacity) where the patent consists of another dependent claim with validity, in respect to which the object of the invalidity claim can be considered as known art”.

Such principle is not trivial. The invalidity of a patent operates “ex tunc”, that is to say from the filing date of the patent application, which means that the partial invalidity declaration could involve possible agreements or counterfeiting damage compensation requests based on the protection originally granted to the main claim then declared invalid.