Has the difference in EPO and UK approach to intermediate generalisations vanished in a ‘puff’ of smoke?

For US patent attorneys seeking patent protection via the European Patent Office (EPO), European amendment practice and so called ‘added matter’ objections can be a real headache. One particular added matter issue arises from so called ‘intermediate generalisation’. This may occur when a feature is isolated from an embodiment and added to a claim without other features of that embodiment.

It is often the case that, in practice, the UK Intellectual Property Office (UKIPO) and the English courts approach the question of added matter and intermediate generalisations more flexibly than the EPO. The recent decision of the High Court in Philip Morris v British American Tobacco (BAT) [2021] EWHC 537 (Pat) does not seem to follow this trend.

EPO v UK ‘added matter’ practice

The EPO Guidelines state that it is only permissible to isolate a feature from an embodiment and add it to a claim if:

            (i)         the feature is not related or inextricably linked to the other features of that embodiment, and;

            (ii)        the overall disclosure justifies the generalising isolation of the feature and its introduction into the claim.

Although the UK Manual of Patent Practice (see 76.15.5 in link) defines a similar approach to that set out in the EPO guidelines, in practice the application of standards at the UKIPO is less rigid. This might be because the manual explains a number of real-life practical examples of claim amendments which do not find verbatim basis in an application, but which are not to be objected to as added matter. There are also some significant decisions of the English courts which appear to follow a more liberal approach from that which we see applied by the EPO.  

The recent Philip Morris v BAT decision

In the High Court judgment Philip Morris v BAT [2021] EWHC 537 (Pat), [4] the patent in suit included a claim which had been amended based on an embodiment.

A cigarette (150) for use with a powered aerosol generating device (10) comprising … at least one electrical resistance heating unit (72) … and a controller mechanism (50) including a sensor (60) that is capable of selectively powering the electrical resistance heating element (72) at least during periods of draw…

In attacking validity, Philip Morris argued that this claim added matter because it didn’t recite a puff actuated sensor which, in the application as filed, was functionally related to the electrical resistance heating unit. In the judgment, the judge stated: “It is not enough that the skilled reader would think that they might be, or were likely to be independent, or that the skilled reader would not know, or would not think about it.

The patentee, BAT, argued that the original application taught that certain features were optional. The judge accepted that the heater and puff actuated sensors were optional in the embodiment seen in Figure 1 and 2. The claim found basis in the embodiment of Figure 3, the description of which referred back to Figure 1 and said that this was “generally comparable”. However, the judge was not convinced that this was a sufficiently clear disclosure of omitting the puff actuated sensor when using the embodiment of Figure 3 as basis to amend the claim, so the amendment was found to add matter by intermediate generalisation.

The UK judge did not explicitly say that he was applying the EPO test, but we believe the EPO test would have led to the same result. We are, however, less sure of agreement between this decision and the guidance set out in the UKIPO’s Manual of Patent Practice.

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