Double Patenting at the EPO by leader6


									                        Double Patenting at the EPO

I.         Summary

Recent case law confirms that patents granted on parent and divisional applications cannot contain
claims of identical scope, and potentially restricts the ability to claim subject matter in a divisional
European patent application that is wholly encompassed within, or wholly encompasses, the claims of
its parent.

II.   Enlarged Board of Appeal endorses prohibition on double patenting under the
European Patent Convention (EPC)

The EPC has no express provisions prohibiting double patenting, but it has long been considered an
“accepted principle in most patent systems” that two patents cannot be granted to the same applicant
for one invention (Guideline C-IV, 7.4) and this has been endorsed by the Enlarged Board of Appeal
in Decision G01/05 of 28 June 2007, which says “the principle of prohibition of double patenting exists
on the basis that an applicant has no legitimate interest in proceedings leading to the grant of a
second patent for the same subject matter if he already possesses one granted patent therefor
(Reasons, para. 13.4, and also Decision G1/06 of the same date, Reasons, para. 13.4).

Subsequently, in Decision T 0307/03, the Board of Appeal found basis for the prohibition in Article 60
EPC which states "The right to a European patent shall belong to the inventor or his successor in
title".1 From this the Board concludes that the inventor (or his successor in title) has a right to the
grant of one and only one patent from the European Patent Office for a particular invention as
defined in a particular claim.2 Once a patent has been granted to the inventor (or his successor in
title) this right to a patent has been “exhausted”, and the European Patent Office is entitled to refuse to
grant a further patent to the inventor (or his successor in title) for the subject-matter for which he has
already been granted a patent.

The decision is open to severe criticism. Its basis is very unsound. It compares poorly with US
statutory double-patenting based on 35 USC 101 that says "whoever invents . . . shall have a patent"
and it does not take into account the positive decision by the drafters of the legislation not to include a
double patenting provision.3

This heralds a potential a volt-face by the EPO. Earlier Decision T587/98 found no express or implicit
provision in the EPC prohibiting the presence in a divisional application of an independent claim -
explicitly or as a notional claim arrived at by partitioning of an actual claim into notional claims reciting
explicit alternatives - which is related to an independent claim in the parent application in such a way
that the 'parent' claim includes all the features of the 'divisional' claim combined with an
additional feature. The Board in Decision T587/98 said any contrary conclusion “would require a

   Identically worded under the EPC 1973 and 2000 - in German "Das Recht auf das europäische Patent steht dem
Erfinder oder seinem Rechtsnachfolger zu." and in French "Le droit au brevet européen appartient à l'inventeur ou à
son ayant cause."
     In re Zickendraht, 319 F.2d 225, 232, 138 USPQ 22, 27 (CCPA 1963)
  Travaux Préparatoires 1969, BR/7 e/69, p. 8 point 17. For further criticism of the decision, reference can be made to
comments by Derk Visser at and to “It is a
truth universally acknowledged” or “Double patenting and the EPC” D. Harrison & T. Bremi, EPI 2/09, 64,68.
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legal basis”. Such a basis has now been identified, allowing the EPO to close the door on double

II.1    A much more strict regime

The question in T307/03 arose in appeal from examination of a divisional application, where a patent
had been granted on the parent application. (The parent patent was undergoing opposition, and
appeal proceedings were pending.) The applicant sought to amend the claims of the divisional
application to correspond exactly to the subject-matter of claim 3 when dependent on claim 1 of the
patent granted on the parent application. This was not allowed.

On its face, this is not necessarily new law (see below), but the applicant also put forward an Auxiliary
Request which was almost identical to claim 3 of the parent patent, but omitted a certain feature.4 This
placed the Auxiliary Request on all-fours with earlier cases such as T372/88 . . in which the parent
claims called for A+B and the divisional claims called for A+C. The Board said:

           The claim they are now seeking would be re-patenting the subject-matter of claim
           3 of the parent application as granted, and seeking protection for additional
           subject-matter, namely where the water-soluble alcohol is not aliphatic.

           This Board considers that the double patenting objection can be raised where
           subject-matter of the granted claim is encompassed by the subject-matter of the
           claim later put forward. The Board cannot regard the extent of double patenting
           here as something that can be ignored as de minimis, given that the subject
           matter which would be double patented is stated to be the preferred way of
           carrying out the invention of the present application.

Accordingly, this Board considers it is not enough to compare the features of the overlapping claims in
a purely formulaic manner, but consideration needs to be given to the importance of the features to
“the invention”. The reference to “de minimis” double patenting must contemplate the circumstance
where the area of overlap is trivial. Beyond that, there is presumably a degree of overlap that is more
than trivial but is permissible. In this case, the Board did not need to consider whether the additional
feature of claim 3 [of the parent] made a significant contribution to the claim of the divisional5 - the
question was irrelevant because the claim was already granted, but it seems they took the view that
the feature of “aliphatic” in the alcohol complexing agent did not significantly contribute to the claim of
the parent, so that removal and replacement of that feature with an unrelated feature in the divisional
was insignificant.

What if the parent did not include dependent claim 3?                 Would it have been permissible as an
independent claim in the divisional? Maybe.

II.2    Double patenting is an “evil” that exists once one of the patents is granted, but not

In a reply to a question (which for the sake of discussion we shall consider to be obiter), the Board in
T307/03 advised the proprietor that it would make no difference if they agreed to abandon the
European patent granted on the parent application. The Board took the view that once the earlier

  The invention related to an improved double metal cyanide complex catalyst. In claim 1 of the Main Request it
included a complexing agent which was a water-soluble aliphatic alcohol, but in the Auxiliary Request, this was
broadened to any water-soluble alcohol.

  Claim 3 placed an upper limit on the surface area of the catalyst – a surface area of less than 30 m2/g. The patent
application does not appear to indicate any advantage to this lower limit, it merely asserts that conventional DMC
compounds have higher surface areas.

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patent has been granted the double patenting objection exists “irrespective of the fate of the granted
patent.” The Board described it as “one of the potential evils” of double patenting that the proprietors
of the granted patent sought to defend a claim that should properly be in the appeal proceedings
on the granted patent. To allow the patent proprietors to abandon the granted patent, but continue
with some of the same claims in the pending divisional application would lengthen the time until a final
decision is reached and involve more instances of the EPO. Also the so-far successful opponents to
the patent granted on the parent application would not have a position as parties in proceedings on the
divisional application.

In contrast, where pending applications are concerned, a more recent decision (T 0114/06 of 22 July
2008) ruled out double patenting where the parent application had been withdrawn before grant. It
would indeed be very onerous if withdrawal of a pending parent application in favour of a pending
divisional application carried the risk that the subject matter was irrevocably abandoned. This confirms
earlier case law such as T441/92 of 10 March 1995.

II.3      A Maverick Decision?

Decision T307/03 came out in 2007 amid a drive within the EPO to clamp down on the freedom to use
the divisional procedures afforded by the EPC. This was in part triggered by the Enlarged Board of
Appeal comments in Decisions G001/05 and G001/066 earlier that year, and led to the President
submitting draft amendments to Rule 36 the following year.7 In submitting those rule changes the
President wrote “there is a trend for divisional applications to be used to ‘duplicate’ proceedings . . . ,
and for applicants to pursue the divisional application instead of ‘the more proper course’ of appealing
a subsequent negative decision [in the parent application]”. The President perceived problems in
terms of duplication of work at the EPO and legal uncertainty for third parties. All these issues arise in
the double patenting situation in T307/03.

The Board in T307/03 could have resolved these perceived problems by simply deferring any decision
pending the outcome of appeal proceedings in the parent patent. Instead they chose a different route.
The decision may me viewed as an aberration by a maverick board, but pending further decisions we
must live with the possibility of it being accepted more widely.

II.4      Will the Guidelines have to be revised?

Guideline C-IV 7.4 says: “It is permissible to allow an applicant to proceed with two applications having
the same description where the claims are quite distinct in scope and directed to different
inventions.” Does this Guideline mean that the claims must have mutual non-overlap, or can the
distinction in scope extend to the claims of one application encompassing those of the other?

Decisions G1/05 and G1/06 give authority for the “established practice” of the EPO although not in the
exact words of the Guideline. The decisions say “the Enlarged Board finds nothing objectionable in
the established practice of the EPO that amendments to a divisional application are objected to and
refused when the amended divisional application claims the same subject-matter as a pending parent
application or a granted parent patent.”8 This can be read two ways. It can be read as an
endorsement of Guideline C-IV 7.4 and indeed Guideline C-VI 9.1.6. Or it can be read in its own
terms, viz. that the critical question is that the parent and divisional must not claim the same subject
matter. Perhaps the two readings of the decision are the same.

  The Enlarged Board said “what applicants consider a legitimate exploitation of the procedural possibilities afforded by
the EPC others consider an abuse in relation to the law as they think it ought to be rather than as it is”.
 Derk Visser takes the view that these words are an “oversight” -
double-patenting.html - but this is unlikely and they cannot in any case be ignored.
HCD 28 July 2009
What is the test for claiming “the same subject matter”? Is it, for example, the test of Guideline C-IV
7.4 (distinct in scope and directed to different inventions) or is it some other test, such as the
“same invention” test of Decision G2/98 (in which the invention claimed is compared with the invention
disclosed in an application for which priority is claimed to determine if it is “directly and
unambiguously derivable”)?

The question of “permissible” overlap in the A+B and A+C sense has never been purely formulaic
(although some of the early decisions tend to give that impression). Guideline C-VI 9.1.6 sets forth a
“general rule” that one application may claim its own subject-matter in combination with that of the
other application, but this rule is not without qualification. The next sentence very much limits the
contemplated scope of the rule. It says “if the parent and divisional applications claim separate and
distinct elements A and B respectively which function in combination, one of the two applications
may also include a claim for A plus B”. Note also that the Guidelines do not permit both of the
applications to have claims to A+B, and if it were not for the claim broadening issue (the removal of the
word “aliphatic”), Decision J307/03 could be read as saying no more than this.

II.5    How much overlap is permitted? How much non-overlap is necessary?

Clearly the situation where each of A and B stands alone as a patentable invention is at one end of the
extreme of what is permissible, i.e. the non-overlapping subject matter is new and inventive in its own
right. Also at this end of the extreme is the situation in which the overlap is minor and the non-overlap
is substantial (though not necessarily new and inventive in its own right). Decision T1391/07 is such a
case. In this case the scope of protection notionally conferred by present claim 1 would partially
overlap with that of the granted parent patent but this did not prejudice the grant of a patent. The
Board said:

           The practice of prohibition of "double patenting" is confined to patents and
           applications directed to the same invention as defined by the subject-matter of
           the corresponding claims and is therefore confined to claims conferring notionally
           the same scope of protection, the Board sees no basis for extending this
           practice to cover claims not defining the same subject-matter but
           conferring . . . a scope of protection overlapping with each other only
           partially in the sense that some, but not all of the embodiments notionally
           encompassed by one of the claims would also be encompassed by the other one
           of the claims. In particular, the lack of legitimate interest of an applicant in
           obtaining two patents for the same subject-matter invoked by the Enlarged Board
           of Appeal in decisions G 1/05 and G 1/06 in endorsing the above mentioned
           practice cannot be invoked in the case in which the scopes of protection
           conferred by the respective subject-matters overlap only partially with each
Guideline C-VI, 9.1.6 discusses overlap more generally, saying:

           The parent and divisional applications . . . must not contain claims of
           substantially identical scope, [and] that one application must not claim the
           subject-matter claimed in the other, even in different words. The difference
           between the claimed subject-matter of the two applications must be clearly

In the case of the double metal cyanide complex catalyst (Decision T307/03), there were clearly
distinguishable differences in the scope of wording of the parent and divisional claims, but not
necessarily in the subject matter falling within the respective scopes. The differences in scope, though
distinguishable, were evidently not considered substantial.

Accordingly, Decision T307/03 is consistent with the Guidelines and is consistent with Decision
T80/98, in which “care was taken to ensure that the subject-matter of the divisional application differed
HCD 28 July 2009
from that of the parent application”, however it is at odds with Decision T587/98, which says: “Claims
to A and AB in successive applications are typical ... and ... this kind of ‘overlap’ is not prohibited under
the EPC”, and is possibly at odds with Decision T118/91 in which the board stated that it could “find
nothing to support the contention that features forming part of the subject-matter of the divisional
application could not be the subject of a dependent claim in the parent application”, except that in the
latter case the Board was satisfied that double patenting had been eliminated by extensive restriction
of the claims of the divisional application.

It is worth noting that the Board in T587/98 explicitly refused to concern itself with whether the
difference amounted to an obvious variant, saying it would appear invidious to make a distinction
between copending applications in an Article 54(3) EPC relationship and divisional applications in this
respect. That decision explains why it concerns itself only with whether there is a difference between
the inventions (in the nature of a “novelty test”). Provided there is such a difference, it did not matter
whether it has independent inventiveness or solves a different problem. That issue is once again in
the forefront.

III.     Conclusion

It seems the Guidelines stand up to scrutiny in the light of the new case law,9 but that Decision
T587/98 is now in doubt (the Board in T307/03 clearly said they were not following T587/98).

Accordingly, a divisional application can claim subject matter that is wholly encompassed within the
claims of its parent (or vice-versa), provided that the claims - independent and dependent claims - are
distinct in scope, but the distinction must be more than trivial. It is, of course, sufficient if the non-
overlapping subject matter can stand alone as new and inventive, but once a patent has been granted,
the proprietor cannot necessarily patent subject matter that amounts to an obvious variant of a broader
claim of an issued patent having the same priority date. Whether the distinction is sufficient to justify a
second patent will depend on the circumstances of the case or will depend on further clarifying case
law or a referral to the Enlarged Board of Appeal to clarify any divergence in the existing case law.

For the present, at least one Examiner has confirmed to us that there is no change of policy in the
Examining Divisions and that, in line with earlier Decision T587/98, policy continues to be very
“applicant friendly”.

 Others say that Decision T587/93 throws doubt on the correctness of the Guidelines (Harrison & Bremi supra at 66)
and that T307/03 is wrongly decided and lacking basis (supra at 68), so the Guidelines should be reined in to say no
more than is said in T587/98.
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