Prosecuting patent applications at the European Patent Office (EPO) can often be tricky in terms of what amendments can be made after filing. The EPO is well known for its strict approach to “added matter” and applicants can come unstuck when trying to amend the claims to overcome prior art or when altering the claim scope to focus on a particular embodiment.
The legal basis for the permissibility of amendments is found in Article 123 EPC and particularly Article 123(2) EPC which states:
“The European patent application or European patent may not be amended in such a way that it contains subject-matter which extends beyond the content of the application as filed”.
Amendments which can be at risk of being deemed to add matter can fall into several categories, which are defined by EPO Board of Appeal case law. One of these categories relates to so-called selections from multiple lists and particularly selecting one or more features from multiple lists. A recent decision from the EPO Board of Appeal has again reiterated how strictly the EPO approaches amendments involving features taken from multiple lists.
In T1809/20, the Board ruled that amendments made to claim 1 violated Article 123(2) EPC and thus the patent was revoked for adding matter. The patent in question was EP2513134 owned by Novartis.
Claim 1 of the Main Request read as follows:
1. A method of producing a purified protein of interest antibody, antibody fragment, or Fc fusion protein, using an affinity chromatography (AC) matrix to which the protein of interest antibody, antibody fragment, or Fc fusion protein is bound, the method comprising:
(a) Loading a mixture comprising the antibody, antibody fragment, or Fc fusion protein, or Fc fusion protein onto the AC matrix; and
(b) Washing the AC matrix with one or more a wash solutions comprising both (i) arginine, or an arginine derivative selected from the group consisting of acetyl arginine, N-alpha-butyroyl-arginine, agmatine, arginic acid and N-alpha-pyvaloyl-arginine, at a concentration in a range of 0.05-0.85 M, and (ii) a nonbuffering [sic] salt prior to elution of the protein of interest at a concentration in a range of 0.1-2.0M, wherein the pH of the wash solution is greater than 8.0, and wherein the wash solution removes impurities from the AC matrix; and
(c) Eluting the antibody, or antibody fragment, or Fc fusion protein, from the AC matrix;
with the proviso that if a purified Fc fusion protein is produced, the AC matrix is selected from the group consisting of a Protein A column, a Protein G column, a Protein A/G column and a Protein L column.
(strikethrough represents deleted text, underline represents addition)
The Appellant Opponents argued that the claim as granted comprised multiple selections e.g. (i) the type of protein to be purified, (ii) the concentration of arginine or arginine derivative, (iii) concentration of non-buffering salt and (iv) the pH of the wash solution being greater than 8.0.
In terms of (i) the type of protein (i.e. an antibody, antibody fragment or Fc fusion protein), this subject matter found basis in two separate parts of the description. The Board ruled that selecting antibodies and antibody fragments from a list of proteins from one disclosure of the application and selecting Fc fusion protein from another list in a different section of the disclosure added matter.
The amendment to specify the concentration of arginine or arginine derivative in claim 1 was also ruled to add matter. The concentration of “between 0.05 and 0.85M” was selected from a list of three ranges, of which it was not the most preferred range.
The concentration range of the non-buffering salt in the wash solution was the broadest range disclosed. Consequently, the Board ruled that the broadest range could not be considered the preferred range.
Finally, the Board ruled that the selection of a pH greater than 8.0 of the wash solution was also the broadest range and therefore could not be considered a preferred range. Although there were a number of disclosures of a pH greater than 8.0, other higher pHs were disclosed as preferable ranges in the application as filed.
The Board also referred to the Examples and considered that there was no pointer therein to the particular combination of features introduced into claim 1. This was despite the concentration values of the arginine/ arginine derivatives and non-buffering salt used in the Examples falling within the claimed range, since they also fell within a narrower disclosed range.
Thus, the Board ruled that the multiple selection of features which were deemed to disclosed at different levels of preference in the application as filed resulted in the claim adding matter.
An auxiliary request was also considered in which claim 1 was amended to specify:
(1) the antibody fragment comprised an Fc region;
(2) the wash solution comprised arginine at a concentration of 0.1-0.5M;
(3) the non-buffering salt was at a concentration of 0.5-1.5M; and
(4) the pH of the wash solution is in a range of about 8.5-9.5.
The AC matrix was also specified as a Protein A column.
The Board ruled that the Auxiliary Request also added matter since whilst Example 6 gave a pointer to the combination of features (2) and (4), it did not provide a pointer to (3) as the three values of salt concentration in Example 6 also fell into a disclosed broader range and so neither could be considered the preferred range.
The decision in T1809/20 again highlights the EPO’s rigid stance on what constitutes allowable amendments. T1809/20 is just one of several decisions from the EPO Boards of Appeal which have ruled that multiple selections are not permitted unless there is a clear pointer to the combination of features.
EPO Boards of Appeal have even ruled that combining features present in dependent claims from filing in an amendment to an independent claim may add matter if there is no pointer elsewhere in the application as filed to the specific combination (see e.g. T1137/21). The fact that the features were deemed significant enough to be placed in a dependent claim was not a sufficient pointer to avoid adding matter. The number of selections made and the number of alternatives within each selection play a role in whether or not the amendment will be considered to add matter.
The language used in a patent specification to describe specific embodiments may also be important. In T1925/22 the Board ruled that the term “optionally” did not provide a pointer to a preferred embodiment. Contrary to some of the comments made by the Board in T1809/20, the Board in T1925/22 decided that narrowest disclosed range was not necessarily the most preferred and therefore there was no pointer to this narrow range.
Case law which may be helpful when faced with an objection that an amendment is an unallowable selection from multiple lists include T615/95, in which deletion of one group from each of three lists of R groups was considered allowable on the basis that the amendment did not single out a new combination or selection. In addition, in T1506/13 deletion of genes from a list of genes was deemed allowable if the deletion maintained a generic group and did not lead to a particular combination. Thus, it may be possible to restrict protection via amendment but not create a new technical contribution. Another decision which went the way of the Patentee is T1621/16 in which the Board opined that amendments based on multiple selections from lists of converging alternatives may be allowable as long as the combination is not associated with an undisclosed technical contribution and the combination should be supported by a pointer in the application as filed. Such pointers may be provided by the Examples or by specific embodiments of the application.
If you would like any further information on the treatment of amendments at the European Patent Office, please contact one of the Secerna attorneys docketing@secerna.com
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