In T 2129/14, the EPO Boards of Appeal applied the exception to the prohibition of reformatio in peius established in G 1/99 to allow the patentee, as respondent, to make an amendment which extended the scope of protection of the patent in question compared to the scope of protection maintained by the Opposition Division.

The prohibition of reformatio in peius set out in G 9/92 is the principle that in appeal proceedings a decision must not be reached which puts a sole appellant in a worse position than if they had not appealed. Thus, where a patent is maintained in amended form by an Opposition Division and only the opponent appeals the decision, the patentee, as respondent, cannot amend the claims such that the scope of the patent after appeal proceedings is broader than after opposition proceedings.

An exception to this principle was set out in G 1/99, wherein the Enlarged Board of Appeal held that such an amendment could be made where the patent would otherwise have to be revoked as a direct consequence of an inadmissible amendment held allowable by the Opposition Division. The Board set out three sequential conditions the patentee must meet when filing requests to rectify the inadmissible amendment:

  1. introduce one or more originally disclosed feature(s) which limit the scope of the patent as maintained;
  2. if (1) is not possible, introduce one or more originally disclosed feature(s) which extend the scope of the patent as maintained, within the limits of Article 123(3) EPC which states that an amendment cannot broaden the scope of the patent as granted;
  3. if neither (1) nor (2) is possible, delete the inadmissible amendment, within the limits of Article 123(3) EPC

Thus, a broadening amendment relative to claims allowed in opposition proceedings may be allowed where it is not possible to rectify the situation by further limiting the scope of the claims.

In T 2129/14, Smith and Nephew appealed a decision of the Opposition Division upholding EP1418973 to KCI Licensing in amended form. The patentee did not appeal. The patent concerned a system for stimulating the healing of tissue by applying negative pressure to a wound site comprising, inter alia, a canister, a means for applying negative pressure, two hydrophobic filters and an odor vapor filter. Claim 1 of the patent as maintained by the Opposition Division, which formed the main request on appeal, corresponded to claim 1 of the patent as granted with the additional requirement that “the hydrophobic filter is attached to the canister, the odor vapor filter is attached to the hydrophobic filter, and the further hydrophobic filter is attached to the odor vapor filter”.

The Board of Appeal held this amendment to be unallowable because the sole basis for the amendment in the application as filed was Figure 1, which depicted the device only schematically and did not directly and unambiguously disclose that the odor filter was “attached” to the hydrophobic filters within the meaning of the claim. The amendment was therefore found to constitute added matter in contravention of Article 123(2) EPC. Claim 1 of the first auxiliary request included the same disputed feature and so was also unallowable.

In claim 1 of the second auxiliary request this disputed feature had been deleted. Instead claim 1 specified that the two hydrophobic filters were “an integral part of the canister” and that the odor vapor filter was “interposed between” the two hydrophobic filters. Claim 1 of the second auxiliary request therefore covered systems in which the odor vapor filter was not attached to the hydrophobic filters, extending protection with respect to the patent as maintained by the Opposition Division.

The inadmissible amendment held allowable by the Opposition Division and deleted in the second auxiliary request concerned four elements of the system – the two hydrophobic filters, the odor vapor filter and the canister – and the relationship between them. The Board of Appeal considered each of these in turn vis-à-vis the conditions for an allowable exception established in G 1/99. The requirement that each of the two hydrophobic filters were an integral part of the canister was considered to imply a more specific relationship between these features than had been specified in the deleted feature, thereby limiting the scope and falling within the first condition.

The Board held that the requirement for the odor vapor filter to be interposed between the two hydrophobic filters did not imply any form of attachment between the odor vapor filter and the hydrophobic filters and thus extended the scope of the patent as maintained by the Opposition Division. The Board went on to decide, however, that in the original application there was no disclosure of any form of attachment between these features and so it would have been impossible to satisfy the first condition of the exception. The amendment therefore validly fell within the second condition and so was allowable.

Claim 1 of the patent as maintained by the Opposition Division also required the odor vapor filter and the canister to be indirectly attached via the first hydrophobic filter. In claim 1 of the second auxiliary request this feature had simply been deleted. In relation to this amendment the Board held that no part of the original application disclosed any form of direct or indirect attachment of the odor vapor filter to the canister and so the introduction of an originally disclosed feature was not possible. In this case therefore neither the first nor the second condition of the exception could be satisfied and so the deletion validly fell within the third condition. The Board therefore found the second auxiliary request allowable in view of the exception to the prohibition of reformatio in peius and the patent was maintained in a form broader than that maintained by the Opposition Division.

For opponents considering appealing an Opposition Division decision to maintain a patent in amended form, the outcome in T 2129/14 underlines the risk that, even as sole appellant, you may potentially be adversely affected by the outcome of the appeal. Whilst the G 1/99 conditions allowing a broadening amendment apply only exceptionally, it is worthwhile considering whether they could apply when deciding whether or not to include an added matter attack when filing an appeal.

From the point of view of the patentee, it is advisable to appeal an Opposition Division decision to maintain your patent in amended form if you wish to reserve the right to broaden the claim scope in appeal proceedings, since the exception to the prohibition of reformatio in peius is only applicable in a very limited set of circumstances.