IP Cases & Articles

Permissible Amendments And Sufficiency

Several decisions recently added to the EPO database of Board of Appeal decisions1 have been selected for review. They collectively provide some insight into the way the Boards are considering the question of permissible amendments and sufficiency.

Added matter

T-759/10 provides further guidance of the fact that the previously accepted unwritten understanding that one could, even without specific basis, amend the term ‘comprising’ in a claim to ‘consisting essentially of…’, is now a thing of the past. Previous to this decision, T-472/88 and T-975/94 had confirmed the unwritten understanding whereas T-868/04, T-903/09 and T-725/08 provided an indication that the ‘understanding’ was misplaced.

In T-759/10 this amendment had been made to overcome prior art. The specification had specific basis for the composition ‘comprising’ or in the alternative ‘consisting of’ the claimed texturizing agents. Despite the appellant’s (patentee’s) arguments that ‘comprising’ encompassed the alternative expressions ‘comprising’, ‘consisting of’ and ‘consisting essentially of’ and therefore by itself already provided a sufficient basis for ‘consists essentially of’, the Board concluded that each clearly had an alternative technical meaning. Thus, as T-472/88 provided the well-understood meaning of ‘consisting essentially of’, this specific meaning did not have basis in the specification and its inclusion was therefore impermissible. The appellant additionally argued that the general and specific examples showed that the claimed texturizing agents could be used in an unpurified form which was commensurate with ‘consisting essentially of’ but this too was not accepted by the Board.

Referral to the Enlarged Board was refused as, despite the existence of conflicting decisions (as set out above), the Board explained that these arose from the intervening decisions of the Enlarged Board of Appeal in G2/98 and G1/03. These decisions clearly establish that the test for priority (same invention), novelty and amendment is identical ie, clear and unambiguous. There was therefore no need for a referral – things had moved on.

The clear message for all applicants is to ensure that the fall-back positions of ‘consisting essentially of’ and ‘consisting of’ are clearly included as alternative embodiments in both priority applications and final specifications.

Added matter was also the main consideration in T-0197/08 where the amendment of ‘active ingredient’ to ‘sole active ingredient’ was considered permissible even though the specific phrase did not have literal basis in the application as filed. Here the Board took the view that although the specific compound was just one of many described in the specification, monotherapy as well as combination therapy were described. Looking at the examples where single agents were administered in the biological examples and formulation examples each contained a single agent, the Board concluded that it would be clearly understood that monotherapy was contemplated and most probably preferred. This was sufficient basis for the amendment.

This decision is in some way consistent with a decision from the end of 2011 (T-1188/10) where the only basis for the claimed range of preservative was the upper and lower amounts used in the examples. Here the claimed range was 0.006% to 0.015% and the only specific basis in the description was 0.0001% to 1%. The Board looked at the examples and concluded that as the preservation effect appeared to be generally applicable to a range of foods and bacteria, the upper and lower amounts used could be taken from the examples and combined to form a range. Both these decisions demonstrate the willingness of the Board to consider the examples and not just conclude that they are specific to the particular conditions described but can be extended to a generalisation.


Moving on to sufficiency, the Boards of Appeal have provided some guidance as to when the argument “the skilled person cannot determine when he infringes” is actually relevant. The patent in T-593/09 had been revoked as being insufficient for that reason – the claimed parameter of “low temperature crystallisation” (LTC) could not be determined and therefore the Opposition Division concluded that as an infringement determination could not be made the patent was insufficient. On appeal, the end result was the same (patent revoked as being insufficient) but for a subtly different reason.

There was much debate as to whether there was sufficient detail in the specification or within the common general knowledge to enable the skilled person to measure this parameter. The deficiency lay in the absence of the heating rate required when conducting differential scanning calorimetry (DSC) as variance in the rate of heating was known to affect the measured LTC. The Board concluded that the inability to measure the parameter and therefore be able to reproduce the technical teaching of the patent rendered it insufficient. The Board continued to state that the ‘infringement test’ was only applicable when considering Art 84 EPC (clarity, not available as a ground of opposition) and referred to T-1062/98 as basis for this. Several decisions on sufficiency that appeared to rely on this test were dismissed as the test was not the sole reason for reaching such a conclusion. Regarding sufficiency of a vague parameter the Board concluded:

What is decisive for establishing insufficiency within the meaning of Article 83 EPC is whether the parameter, in the specific case, is so ill-defined that the skilled person is not able, on the basis of the disclosure as a whole and using his common general knowledge, to identify (without undue burden) the technical measures (eg, selection of suitable compounds) necessary to solve the problem underlying the patent at issue.

Result to be achieved

There are many applications directed to and patents even granted to claims that appear to be directed to a ‘result to be achieved’. An excellent example of this arose in T-1751/07, a decision relevant to the pharmaceutical industry. The claim was directed to a controlled release composition (tablet/capsule) where the drug was present as nanoparticles together with a surface stabiliser in a polymer matrix;

“wherein controlled release refers to therapeutically effective release of the drug in a patient for a time period ranging from 2 to 24 hours”

The Board concluded that that this phrase raised significant areas of ambiguity:

  • Was release prior to the second hour permissible?
  • Did the therapeutic effect have to exist for the whole period of 2-24 hours?
  • Did it matter when the therapeutic level was reached as long as it was maintained for 2-24 hours?
  • What if drug release or the drug level remained unchanged after 24 hours?

In short, the definition was so ambiguous that to grant the claim as such would be unreasonable. This is not to say that claims to a ‘result to be achieved’ are impressible per se, but the decision clearly demonstrates the Board’s insistence that as the claim could not be clearly understood, it must be refused as lacking clarity.