Opposition procedure before the European Patent Office

[4] An opposition can be based on the grounds that the subject-matter of the patent is not patentable (Article 100(a) EPC, for instance because the claimed invention is not new or not inventive), on the ground that the invention is insufficiently disclosed to allow a person skilled in the art to carry it out (Article 100(b) EPC), or on the ground that the content of the patent extends beyond the content of the application as filed –"or, if the patent was granted on a divisional application or on a new application filed under Article 61 EPC, beyond the content of the earlier application as filed"– (Article 100(c) EPC).

[12] In order for an opposition to be admissible it must meet the provisions of[13] In addition, an opposition is also rejected as inadmissible if it fails to meet the requirements of Rule 76(2)(a), (b) and (d) EPC[16] after the opponent was invited to remedy to these failures within a given time limit.

[19] An opposition may be filed by a straw man to conceal the identity of the party actually interested in having the patent revoked.

"[20] In 1999, the Enlarged Board of Appeal held that the use of a straw man did not render the opposition inadmissible unless "the involvement of the opponent is to be regarded as circumventing the law by abuse of process.

The Opposition Division may do so "if there are clear reasons to believe that such grounds are relevant and would in whole or in part prejudice the maintenance of the European patent", the underlying aim being to avoid "the maintenance of European patents which are invalid".

[29] Thus, in view of the grounds of opposition, and in view for instance of a prior art document introduced into the proceedings by the opponent, the proprietor may amend the patent, i.e. the description, claims, and drawings thereof,[28] although amendments may not be filed as of right at any stage during the opposition proceedings.

[39] The list of public oral proceedings in opposition before the EPO is available on its web site.

[41] A decision is usually pronounced at the end of the oral proceedings, with reasons to follow in writing.

The EPO decision does not create an estoppel precluding a subsequent challenge by an unsuccessful opponent at the national level (at least before the English courts).

The same is not true for infringement proceedings, upon which national courts and the UPC exercise exclusive jurisdiction.

Each party to the opposition proceedings normally bears the costs it has incurred, unless the Opposition Division (or, in appeal proceedings, the Board of Appeal under Rule 100(1) EPC[54]), for reasons of equity, orders a different apportionment of costs.

[55] For example, in case T 1306/05, a highly relevant document had been lately filed, without any valid justification, by the opponent during the oral proceedings before the Board of Appeal, thus rendering useless both the oral proceedings and the patent proprietor preparation thereto.

[63][64] Under Article 105 EPC, any third party may intervene in ongoing opposition proceedings after the 9-month opposition period has expired, if the third party proves that "(a) proceedings for infringement of the same patent have been instituted against him, or (b) following a request of the proprietor of the patent to cease alleged infringement, the third party has instituted proceedings for a ruling that he is not infringing the patent.

[67] The so-called notice of intervention must inter alia be filed within three months of the date on which proceedings referred to in Article 105 are instituted.

An intervention may be based on any ground for opposition under Article 100 EPC, and the intervener may also introduce new facts and arguments, which can therefore not be regarded as late filed.

[45] The opposition rate (i.e. the number of oppositions filed per 100 granted patents) before the EPO is consistently higher in the closest available proxy for the pharmaceutical sector than it is in organic chemistry and in all sectors (overall EPO average).

[45] Filing an opposition before the EPO is reportedly relatively affordable, "as the cost varies between €6000 and €50,000 (including patent lawyers’ fees)"[51] (as of 2009).

[53] If a party files an opposition to a European patent with the EPO, that party may in most countries (except in Germany[80]) also, in parallel, initiate a revocation action (also called "nullity action" or "validity proceedings") against the same patent before a national court (or the UPC).

In such a case, the national court (or the UPC) may, at least in England, exercise its discretion to either Further, the rules and practice differ from country to country in relation to infringement proceedings before national courts or the UPC in parallel to pending EPO opposition proceedings.

"For example, as of 2008, Belgium and France will stay the main proceeding until a final decision has been reached by the EPO whereas in Germany, Italy, the Netherlands and in the United Kingdom such a stay is not automatic and in most cases the courts will continue the proceedings notwithstanding the opposition.