A new referral to the Enlarged Board of Appeal ("EBA") of the European Patent Office ("EPO") seeks clarification on the assessment of partial priority entitlement as well as a statement on the controversy surrounding the so-called "toxic divisional" attack. The referred questions have been published in Board of Appeal Decision T 557/13. At the center of the discussion leading to the referral is decision G 2/98 and the principles laid down by this decision for priority assessment.
Background
The appeal resulted from the opposition division's decision
to revoke European patent EP 0921183, based on the fact that the
claims were not fully entitled to their priority. The granted claim
1 was a generalization of a specific disclosure in the priority
document, and according to the opposition division, claim 1 did not
have the priority date of the parent application. Consequently, the
published parent application constituted prior art only for the
purposes of novelty (Article 54(3) EPC). Hence, the patent under
attack lacked novelty over its own parent application. In the
present decision, the Technical Board of Appeal recognized that the
most important issue to be resolved was whether partial priority
could be claimed for a generic claim.
A core requirement for validly claiming priority is that it has to
be with respect to "the same invention." This concept has
been the subject of extensive analysis and discussion to determine
how similar the disclosure of a later application has to be in
order to be considered "the same invention" as the
earlier application. According to G 2/98, the requirement for
claiming priority of "the same invention" is acknowledged
if the skilled person can derive the subject matter of the claims
directly and unambiguously from the previous application
as a whole.
The principle of "the same invention" also applies to
applications claiming multiple priorities. According to Article
88(2) EPC, second sentence, it is allowed to have "multiple
priorities ... for any one claim." Thus, when evaluating
multiple priorities for the same claim, a distinction has to be
made between the so-called "AND" claims and
"OR" claims.
For example, if an application claims feature A combined with
feature B (A+B), but the priority document discloses only feature
A, then the priority is not valid for the entire claim. If, on the
other hand, the application claims two distinct alternatives,
namely feature A or feature B (A/B), then the claim has
two priority dates—one for feature A (reaching back to the
priority date) and one for feature B (filing date of the subsequent
application). The question is, if the application claims feature C
in a generic term that encompasses feature A (the so-called
"generic OR claim" in the referral), does such claim
enjoy partial priority with respect to the subject matter of
feature A, and is the remaining subject matter entitled only to the
filing date of the subsequent application? For a generic
"OR" claim, the Enlarged Board of Appeal in G 2/98
provided guidance on how Article 88(2) EPC is to be interpreted,
permitting partial priority where "it gives rise to the
claiming of a limited number of clearly defined
alternatives."
However, the criteria established by G 2/98 do not seem to provide
consistent guidance for priority assessment for generic
"OR" claims, and the case law has been developed
divergently in interpretation and application of the criteria. Some
Boards took a "strict" or "literal" approach,
which could lead to denying partial priority, given that the
generic term encompasses a practically unlimited number of
alternatives that are not expressly spelled out. On the other hand,
some Boards took a "generous" or "conceptual"
interpretation, which does not require the "clearly defined
alternatives" to be spelled out in the claim. Rather, it
suffices to be able to conceptually identify a limited number of
such alternatives by comparing the generic "OR" claim
with the priority document. In this way, partial priority may be
acknowledged.
The "strict" approach to partial priority has been used
by some opponents to raise so-called "toxic divisional"
attacks to invalidate a priority claim, whereby an opponent argues
that a family member (a parent or a divisional of the patent at
stake) is novelty destroying under Article 54(3) EPC. The attack
relies on family members with a more specific disclosure according
to the priority document (thus with a valid priority), as compared
to a family member with a generic claim, which is not entitled to
priority. The latter family member loses priority because of the
broader claim, but the more specific disclosure in the former
family member retains priority and so it is, in principle, citable
as prior art under Article 54(3) EPC against the latter family
member. This "toxic divisional" attack has raised much
controversy in recent years.
Not limited to the parent-divisional relationship, similar
objections could also arise where the "colliding"
application is the priority application itself, if the priority
application is a European application that matures to publication,
known as the "toxic priority."
The Referral
In decision T 557/13, published on August 12, 2015, the Technical Board of Appeal referred five questions to the Enlarged Board of Appeal, in order to settle the diverging case law on partial priority assessment. The questions as published are:
- Where a claim of a European patent application or patent encompasses alternative subject-matters by virtue of one or more generic expressions or otherwise (generic "OR"-claim), may entitlement to partial priority be refused under the EPC for that claim in respect of alternative subject-matter disclosed (in an enabling manner) for the first time, directly, or at least implicitly, and unambiguously, in the priority document?
- If the answer is yes, subject to certain conditions, is the proviso "provided that it gives rise to the claiming of a limited number of clearly defined alternative subject-matters" in point 6.7 of G 2/98 to be taken as the legal test for assessing entitlement to partial priority for a generic "OR"- claim?
- If the answer to question 2 is yes, how are the criteria "limited number" and "clearly defined alternative subject matters" to be interpreted and applied?
- If the answer to question 2 is no, how is entitlement to partial priority to be assessed for a generic "OR"-claim?
- If an affirmative answer is given to question 1, may subject-matter disclosed in a parent or divisional application of a European patent application be cited as state of the art under Article 54(3) EPC against subject-matter disclosed in the priority document and encompassed as an alternative in a generic "OR"-claim of the said European patent application or of the patent granted thereon?
The first four questions relate to partial priority, and in
particular how entitlement to partial priority should be assessed
for generic "OR" claims. The questions are intended to
clarify the criteria for priority assessment in cases where the
earlier application discloses a species, and the later application
claims the genus in which that species belongs. For example, can an
application claiming "metal" in general validly claim
priority from an earlier application where only copper has been
disclosed?
If the first question is answered in the negative, i.e., that
partial priority cannot be refused, it would end the referral. If
the answer to the first question is positive, it moves to the
remaining four questions. Should the criteria "it gives rise
to the claiming of a limited number of clearly defined
alternatives" be used for the test (question 2)? If the answer
to question 2 is yes, how are the criteria "limited
number" and "clearly defined alternative subject
matters" to be interpreted and applied (question 3)? If the
answer to question 2 is no, and the G 2/98 criteria are not
applied, then the Enlarged Board should provide new criteria
(question 4).
The fifth question relates to the "toxic divisional"
attack, requesting clarification on the criteria to be applied. In
essence, question 5 asks whether a family member (parent or
divisional) can ever be prior art (novelty-only) according to
Article 54(3) EPC.
Comments
The Enlarged Board is not expected to give its answers until
late 2016, but when issued, they should clarify the concept of
partial priority in Europe and provide some clarification regarding
the relationship between family members with different effective
dates.
However, until the Enlarged Board of Appeal provides its answers,
disclosure of the priority application and the claims of all family
members should be carefully examined before filing a European
divisional application, in order to ensure that no collision among
family member occurs.
The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.