Why should you exercise caution in what you say to the EPO during a prosecution?

One of the actions you can take to improve your chances of success at the UPC is being careful of what you say to the EPO during the prosecution of your application.

At the moment, it is not clear if, and to what extent, the UPC will consider the prosecution history when construing claims.

Real life example – Munich Local Division

In the SES-Imagotag vs Hanshow preliminary injunction case at first instance[1], the Munich Local Division decided that the claims as originally filed could be used as an aid to interpretation in relation to amendments made during the grant procedure.

In the subsequent appeal (by which time SES-Imagotag had changed its name to VisionGroup)[2], the Court of Appeal did not comment on that aspect of the first instance case, so arguably left the door open to looking at the prosecution history for pointers as to claim construction.

Real life example – Dusseldorf Local Division

In contrast, in two decisions of the Dusseldorf Local Division, the Court of First Instance decided that the prosecution history should not be used to interpret the claims.

In Ortovox vs Mammut[3], the Dusseldorf Local Division decided that the prosecution history “does not constitute admissible material for interpretation”, saying that:

“If the applicant has commented on the meaning of a feature or term during the examination procedure, this can at best be of indicative significance for how the person skilled in the art understands the feature in question”.

In 10X Genomics vs Curio Bioscience[4], the Dusseldorf Local Division agreed with its previous comments, again saying that statements made by the applicant during the granting procedure “are not admissible material for interpretation”, and that

“If the applicant has commented on the meaning of a feature or term during the examination procedure, this may at best be indicative of how a person skilled in the art would understand the relevant feature”.

Conclusion

I would expect the question of whether the prosecution history can be used to interpret the claims in a UPC action to be resolved by the UPC Court of Appeal fairly quickly. However, until it is, you should remember that any comments you make during the prosecution of a European patent application become part of the public record for the application. Therefore, anything you say could potentially come back to haunt you in later UPC proceedings.

In conclusion, just be careful and exercise caution about statements you make during prosecution.