However, the obvious advantages of the EPO opposition procedure over national revocation procedures favor an EPO opposition despite this long delay. For example, the unique possibility of using a single opposition procedure to revoke the patent in all designated Member States in which it has effect significantly underscores the preference for using the EPO opposition procedure as opposed to commencing individual national proceedings. Furthermore, the costs for opposition before the EPO are relatively low, as any party bears its own costs. Other advantages are the facts that there are separate Opposition Divisions and there are compulsory Oral Proceedings , if requested by one party. Last but not least, there is the advantage that decisions made by the Opposition Divisions are appealable.

As a result of the Opposition, the patent may be maintained as granted, it may be maintained in restricted form with amendments; or it may be revoked in its entirety.

For further illustration, figure 1 shows a statistical outline of the number of European patents granted and percentage of Oppositions before the EPO.

Figure1: Granted and opposed European Patents [Eps]

As evident from Figure 1, during the past decade, an average of approximately 6% of all granted European patents were or still are opposed.
As a result of the opposition proceedings in the years 2001 and 2002 approximately 70% of the opposed European patents were maintained before the first instance, even though in some cases in amended form . According to the author’s own experience during the last 15 years, the real percentage of maintenance in restricted form before the Opposition Divisions is almost 80%. Needless to mention that the other party in Opposition proceedings, i.e. the community of Proprietors, cordially appreciates these statistical results.
Experience of professional representatives shows that the prior art provided by the Opponents is strong enough to challenge validity of a patent. Therefore, the question arises, how such high percentages of maintenances are justified.
For US patents, for example, one statistical analysis shows that at least 46% of patents (50% could not be ruled out) are invalidated in litigation , whereas current EPO practice appears to be to maintain any EP for which no novelty destroying printed piece of prior art can be provided. Whenever discussion of inventive step becomes an issue during opposition proceedings, it becomes more and more unlikely that a first instance decision of complete revocation of the opposed European patent is arrived at.
In about half of the Opposition cases, an Appeal before the Technical Boards of Appeal is filed, resulting in significantly lower maintenance rates. Nevertheless, among the above mentioned three possible results, entire revocation of a European patent is a very rare event in European Opposition proceedings, and hence, the Opposition proceedings very often finally turn out to be a blunt tool as they lead to results being dissatisfying for the Opponent who, for example, might additionally be involved in parallel patent infringement proceedings, and might have hoped for suspension of the litigation proceedings.
Where do such – from the perspective of the challenger – apparently ineffective Opposition results come from? One explanatory approach might be the composition of the EPO’s Opposition Divisions according to Art. 19 (2) EPC:
“An Opposition Division shall consist of three technical examiners, at least two of whom shall not have taken part in the proceedings for grant of the patent to which the opposition relates. An examiner who has taken part in the proceedings for the grant of the European patent shall not be the Chairman. Prior to the taking of a final decision on the opposition, the Opposition Division may entrust the examination of the opposition to one of its members. Oral proceedings shall be before the Opposition Division itself. If the Opposition Division considers that the nature of the decision so requires, it shall be enlarged by the addition of a legally qualified examiner who shall not have taken part in the proceedings for grant of the patent. In the event of parity of votes, the vote of the Chairman of the Division shall be decisive.”

In other words, Art. 19 (2) EPC means that the Examiner who was in charge of the Examination of the application in question is usually the Reporter  in the corresponding Opposition Division, although not the Chairman. Nevertheless, this Examiner (who now has to question his own decision to grant) at least kind of “guides” the written proceedings – a situation which is worth at least some consideration of amending Art. 19 EPC in the future .
Another important negative impact in Opponent’s view might be the assignment of insufficient time for the Opposition Divisions by EPO’s administration, and in consequence, not enough Opposition Divisions .
A further major hook of European Opposition proceedings is their timeline. The Opposition period is far too long with nine months plus two to three years for the first instance, and an additional two to three years for the final Appeal decision . In other words, Proprietors as well as Opponents face an up to seven year period of legal uncertainty with respect to a challenged European patent’s validity.
In complex biotechnology cases such as the Oncomouse patent EP 0 169 672, this can be even more extreme: On 13 May, 1992 the EPO granted a patent to the University of Harvard in respect of its European patent application of 24 June, 1985. Oppositions against the patent were filed by a number of parties. The opposition procedure terminated in November 2001 and led to maintenance of the patent in amended form. Appeals against the decision of the Opposition Division were lodged in March 2003, oral proceedings were held from 5-9 July, 2004 , 12 years after grant. The patent has expired on 24 June, 2005.
Such long Opposition proceedings constitute an unbearable situation for the parties concerned, again, particularly if parallel infringement proceedings are pending , but also with respect to the market and marketing situation of both competitors. This is why it more often occurs that Opposition results only show up when the product’s shelf life has already expired or its turnover decreases significantly.
These circumstances lead to the fact that European Opposition turns more and more into an ultimately expensive but blunt tool which requires looking for alternatives.
One such alternative are the very uncommon, if not almost unknown, “Observations by third parties” according to Art. 115 EPC:
“Following the publication of the European patent application under Art. 93 EPC, any person may present observations concerning the patentability of the invention. Such observations must be filed in writing and must include a statement of the grounds on which they are based. That person shall not be a party to the proceedings before the EPO. The statement of grounds must be presented in one of the official languages, i.e. German, English or French. Although receipt of the Observations is acknowledged to the third party, the EPO does not inform him of the further action taken by the Office in response to his observations.”

With these Observations by third parties, a new and highly effective tool comes into play, namely the EPO’s online file inspection system which can be used to carry out a monitoring of the process of the Observations filed. This service of online public file inspection provided by the EPO implements Article 128 of the European Patent Convention, according to which the public is entitled to inspect the complete contents of the files relating to all European patent applications after they have been published. In connection with Art. 115 observations, it is advisable to check the corresponding file on a bi-weekly to monthly basis. The “observing” party, which may remain anonymous, will find the Examiner’s first post-Observations Communication, which may read as follows:

“The subject-matter as claimed in currently pending claim 1 is not novel in view of document Dx provided by a third party. For detailed reasons, see enclosed Observations by third parties.”

Usually, the applicant is immediately provided with these observations by the EPO and he may comment on them. If, in whole or in part, the patentability of the invention is called into question by the observations, they must be taken into account in any proceedings pending before a department of the EPO until such proceedings have been terminated. This means that the observations must be introduced into the proceedings. If the observations relate to alleged prior art available other than from a document, e.g., from use, this should be taken into account only if the alleged facts are either not disputed by the applicant or established beyond reasonable doubt. Observations by third parties received after the conclusion of proceedings will not be taken into account and will simply be added to the file .
In this context it is important to know that in drafting Observations in accordance with Art. 115 EPC, not only prior art can be submitted but also extensive argumentation. Additionally, it should be emphasized that all questions of patentability within the frame of the EPC can and naturally should be addressed in the petition. This includes powerful and often successful attacks based upon alleged and proven invalidity of priority claims, inadmissible amendments of the claims within the scope of original disclosure under the “anti-new-matter” provision of Art. 123 (2) EPC, non-enabling teaching  in view of Art. 83 EPC, as well as lack of clarity in violation of Art. 84 EPC.
In the Observation in accordance with Art. 115 EPC, an Observation supported by lack of clarity of a certain claim is admissible, as the application is still in the Examination phase. In contrast, such an Observation supported by lack of clarity of a certain claim is inadmissible in an Opposition, as a violation of Art. 84 EPC is not listed in the grounds of Opposition as mentioned in the introductory part.
Additionally, a challenger has the advantage that filing Observations prolongs Examination time, pushing him to a position where he otherwise is moved post grant by the Patentee in Opposition proceedings, however, the delay is within the time frame of a maximum of 12 months, which is much quicker then in Opposition proceedings. After the Examiner’s decision to grant or not to grant at least both parties will have a higher level of legal certainty putting them in a position to commercially deal with the result.
In the event that the Observations are not successful there still remains the option to file Opposition. However, Opposition will of course only be promising if the opponent is in the position to provide newly cited material.
Generally, from a psychological point of view, supported by the author’s personal experience, an Examiner appears to be far more inclined to seriously consider well reasoned pre-issue Observations under Art. 115 EPC than considering post-issue alleged invalidity reasons in long lasting expensive Opposition proceedings, when even the best Examiner has already forgotten why she or he had considered a certain argument in a specific manner.
As experience and statistical numbers clearly show that a European patent once granted is hard to get rid of, in summary it can be said that Art. 115 Observations  during pending Examination combined with the quality assurance control of online file inspection, and optionally filing a second and third Observation as a reaction to Applicant’s amendments, have proven to be a very powerful and sharp tool in challenging threatening patent (applications). This is why I am of the opinion that the modern secret in challenging a patent lies in not letting a competitor’s threatening application proceed towards grant.
Consequently, the above-demonstrated advantages of Art 115 Observations by third parties versus long lasting Opposition proceedings will turn them into an important element in a European patent attorneys’ consulting practice.

About the author
Dr Jürgen Kaiser is a partner in the patent and law firm Winter Brandl Füerniss Huebner Roess Kaiser Polte Partnerschaft, Freising-Munich, Germany, (www.WBetal.com) since 1993, specialising in biotech prosecution, opposition and litigation proceedings. He further holds teaching contracts for intellectual property at Weihenstephan University of Applied Sciences, Faculty of Biotechnology and Bioinformatics, and at Deggendorf University of Applied Sciences, Faculty of Business Management.