G2_21 and the English Approach to Plausibility.pdf

G2/21 and the English Approach to
Plausibility1
Jane Lambert2
1. Introduction
There is nothing in art 52 (1) EPC that expressly requires an invention to be plausible:
“European patents shall be granted for any inventions, in all fields of technology, provided
that they are new, involve an inventive step and are susceptible of industrial application.”
Nor in s.1 (1) of the Patents Act 1977
“A patent may be granted only for an invention in respect of which the following conditions
are satisfied, that is to say—
(a) the invention is new;
(b) it involves an inventive step;
(c) it is capable of industrial application;
(d) the grant of a patent for it is not excluded by subsections (2) and (3) below;
and references in this Act to a patentable invention shall be construed accordingly.”
But maybe plausibility is implied by the need for an inventive step and industrial application
and/or the requirements of art 83 EPC and s.14 (3) to disclose an invention in a manner that
is sufficiently clear and complete for it to be carried out by a person skilled in the art.
According to Lord Sumption, “The concept
of plausibility originates in the case law of
the EPO as a response to over-broad
claims, in particular claims to whole classes
of chemical compounds supported by a
description which fails to show which
compounds can be expected to work” para
[23] of his judgment in Warner-Lambert
Company LLC v Generics (UK) Ltd (t/a
Mylan) and another [2018] UKSC 56
https://www.bailii.org/uk/cases/UKSC/2018/
56.html
2
Barrister, Second Floor, 2 Snow Hill, Birmingham, B4 6GA, Tel 0121 231 7430 and also at 4-5
Gray’s Inn Square, London, WC1R 5AH, Tel 020, 020 7404 5252, clerks@4-5.co.uk,
https://www.4-5.co.uk, jane.lambert@nipclaw.com, www.nipclaw.com, 07966 373922
1
26 Oct 2023, 09:00 - 10:00
1

2. Case Law of the EPO
(1) In T 0541/96 Zachariah’s Application3
the Board dismissed an appeal against the
refusal of an application for a patent that appeared to be incompatible with the laws of
nature.
Dr Chacko Zachariah applied for a
patent for an Element and energy
production device on 17 Aug 1995. The
gist of the invention was to induce fusion
between light nuclei and heavy unstable
nuclei at low temperatures by means of
an electric field.
The Examining Division rejected his
application on 3 Jan 1996 on the ground
that he had failed to disclose his
invention in a manner that was
sufficiently clear and complete for it to be
carried out by a person skilled in the art.
Dr Zachariah appealed to the Technical
Board of Appeal on 8 May 1996.
By its decision of 7 March 2001, the
Board rejected Dr Zachariah’s appeal. It
upheld the Examining Division’s finding
of insufficiency and added the further
ground of incapability of industrial
application.
The Board said at para 6.1 of its
reasons: “An invention or an application
for a patent for an alleged invention
which would not comply with the
generally accepted laws of physics
would be incompatible with the
requirements of Articles 57 and 83.
because it cannot be used and therefore
lacks industrial application.”
(2) Similarly, in T 1063/06 Reach-through claim/Bayer Schering Pharma AG4
the Board
rejected an appeal from the Examining Division’s refusal of an application that
depended on further developments in the technology to work.
4
https://www.epo.org/en/boards-of-appeal/decisions/t061063ep1
3
https://www.epo.org/en/boards-of-appeal/decisions/t960541eu1
2

“I. A formulation of a claim whereby
functionally defined chemical
compounds are to be found by means of
a new kind of research tool using a
screening method set out in the
description constitutes a reach-through
claim which is also directed to future
inventions based on the one now being
disclosed. As the applicant is entitled to
claim patent protection only for his actual
contribution to the art, it is therefore both
reasonable and imperative to limit the
claim's subject-matter accordingly.
Patent protection under the EPC is not
designed for the purpose of reserving an
unexplored field of research for a
particular applicant, as reach-through
claims do, but to protect factual results of
successful research as a reward for
making concrete technical results
available to the public.
II. A functional definition of a chemical
compound (in this case in a
reach-through claim) covers all
compounds possessing the capability
according to the claim. In the absence of
any selection rule in the application in
suit, the skilled person, without the
possibility of having recourse to his
common general knowledge, must resort
to trial-and-error experimentation on
arbitrarily selected chemical compounds
to establish whether they possess the
capability according to the claim; this
represents for the skilled person an
invitation to perform a research
programme and thus an undue burden
(following T 435/91).”5
(3) In T 0609/02The Salk Institute for Biological Studies v Karo Bio AB and another,6
the
Board ruled that where a new medical use is found for a known compound the
therapeutic effect of that compound must be particularized. Such particulars have to
be given at the time of filing of the application.
6
https://www.epo.org/en/boards-of-appeal/decisions/t020609eu1
5
Taken from the headnote
3

The Salk Institute applied for a patent for
“Methods mediated by the proto-oncogenic
protein complex AP-1,”
The EPO granted a patent for that
invention.
Karo Bio AB and Astra AB brought
opposition proceedings. The Opposition
Division found that claims 1 to 7 could
not be allowed because the specification
did not provide an enabling disclosure.
The Institute appealed. The Board
dismissed the appeal because the
Institute did not justify the assertion that
the invention had the alleged therapeutic
effect.
The catchword states:
“If the description of a patent
specification provides no more than a
vague indication of a possible medical
use for a chemical compound yet to be
identified, later more detailed evidence
cannot be used to remedy the
fundamental insufficiency of disclosure of
such subject-matter.”
(4) According to para 4.1 of Part G of the Rules Common to all Proceedings before the
EPO7
The principle of "free evaluation of evidence" is that there are no rules as to the
types of evidence that are, or are not, admissible. Neither the EPO nor any of the
decisions of the Boards of Appeal sets out formal rules for the evaluation of evidence.
Boards of Appeal and other organs of the EPO may assess whether a fact is
established on a case-by-case basis.
(5) The application of the “free evaluation of evidence” principle was the reason for the
referral to the Enlarged Board of Appeal in G2/21 Syngenta Ltd, v Sumitomo Chemical
Co, Ltd.8
8
https://legacy.epo.org/boards-of-appeal/decisions/pdf/g210002ex1.pdf See also my case note Jane
Lambert Patents and Plausibility - G2/21 Syngenta Ltd v Sumitomo Chemical Co. Ltd. 2 Oct
2023 NIPC Law
https://nipclaw.blogspot.com/2023/10/patents-and-plausibility-g221-syngenta.html
7
https://www.epo.org/en/legal/case-law/2022/clr_iii_g_4_1.html
4

On 1 April 2015 the EPO granted
Sumitomo Chemical Co, Ltd.
(“Sumitomo”) EP 2 484 209 B19
for
“Insecticide compositions”. Essentially
that was a mixture of thiamethoxam and
other compounds in accordance with a
formula disclosed in the specification
that was more potent than any of those
compounds administered on its own
("the invention").
Syngenta Ltd. (“Syngenta”) challenged
the grant under art 99 EPC on all the
grounds in art 100 EPC. The Opposition
Division rejected the opposition,
Syngenta appealed to the Technical
Board of Appeal.
In its interlocutory decision in T 0116/18
Syngenta Ltd. v Sumitomo Chemical Co,
Ltd. of 11 Oct 202110
, the Technical
Board held that there had been sufficient
disclosure of the claimed invention for
the purposes of art 100 (b) EPC. The
only ground on which the grant could be
challenged was art 100 (a) EPC and that
hinged on whether evidence that had
been published after the filing date could
be admitted in evidence.
(6) The Technical Board of Appeal asked the Enlarged Board to answer the following
questions:
“1. Should an exception to the principle of free evaluation of evidence (see
e.g. G 3/97, Reasons 5, and G 1/12, Reasons 31) be accepted in that
post-published evidence must be disregarded on the ground that the proof
of the effect rests exclusively on the post-published evidence?
2. If the answer is yes (the post-published evidence must be disregarded if
the proof of the effect rests exclusively on this evidence), can the
post-published evidence be taken into consideration if, based on the
information in the patent application in suit or the common general
knowledge, the skilled person at the filing date of the patent application in
suit would have considered the effect plausible (ab initio plausibility)?
3. If the answer to the first question is yes (the post-published evidence must
be disregarded if the proof of the effect rests exclusively on this evidence),
can the post-published evidence be taken into consideration if, based on
10
https://legacy.epo.org/boards-of-appeal/decisions/pdf/t180116ex1.pdf
9
https://patentimages.storage.googleapis.com/76/73/0d/7ffd24960748eb/EP2484209B1.pdf
5

the information in the patent application in suit or the common general
knowledge, the skilled person at the filing date of the patent application in
suit would have seen no reason to consider the effect implausible (ab initio
implausibility)?"
(7) The Enlarged Board handed down its decision on 23 March 2023.
The Enlarged Board of Appeal took
question 1 of the Technical Board's
questions first. After reviewing its case
law and the rules of evidence in the
courts of England and Wales, France,
Germany, the Netherlands and
Switzerland the Board held at para 55 of
the reasons that the principle of free
evaluation of evidence qualifies as a
universally applicable principle in
assessing any means of evidence by a
board of appeal. There was one
important exception to this "universally
accepted principle" in that the principle of
free evaluation of evidence does not
exist in England's common law system.
It concluded at para [56] that:
"evidence submitted by a patent
applicant or proprietor to prove a
technical effect relied upon for
acknowledgement of the inventive step
of the claimed subject matter may not be
disregarded solely on the ground that
such evidence, on which the effect rests,
had not been public before the filing date
of the patent in suit and was filed after
that date."
That did not mean that evidence
obtained after publication is
determinative. The Board made clear
that:
“An effect could not be validly used in the
formulation of the technical problem if
the effect required additional information
not at the disposal of the skilled person
even after taking into account the
content of the application in question...."
Even though the Board did not have to
consider questions 2 and 3, it gave the
following additional guidance:
6

"A patent applicant or proprietor may rely
upon a technical effect for inventive step
if the skilled person, having the common
general knowledge in mind, and based
on the application as originally filed,
would derive said effect as being
encompassed by the technical teaching
and embodied by the same originally
disclosed invention."
(8) To understand properly the Board’s decision properly it is necessary to consider that
the EPO’s test for an inventive step is different from the English one. Lord Hodge
pointed out that difference in paras [60] and [61] of his judgment in Actavis Group PTC
EHF and others v ICOS Corporation and another [2019] UKSC 15:11
“[60] In addressing the statutory question of obviousness in section 3 of the
1977 Act it is common for English courts to adopt the so-called
Windsurfing/Pozzoli structure which asks these questions:
‘(1) (a) Identify the notional ‘person skilled in the art’;
(b) Identify the relevant common general knowledge of that person;
(2) Identify the inventive concept of the claim in question or if that cannot
readily be done, construe it;
(3) Identify what, if any, differences exist between the matter cited as forming
part of the ‘state of the art’ and the inventive concept of the claim or the
claim as construed;
(4) Viewed without any knowledge of the alleged invention as claimed, do
those differences constitute steps which would have been obvious to the
person skilled in the art or do they require any degree of invention?
………
61. An alternative approach which the EPO often adopts, is the so called
‘problem-and-solution approach. The EPO has described the approach in
these terms:
‘the Boards of Appeal consistently decide the issue of obviousness on the
basis of an objective assessment of the technical results achieved by the
claimed subject-matter, compared with the results obtained according to
the state of the art. It is then assumed that the inventor did in fact seek to
achieve these results and, therefore, these results are taken to be the
basis for defining the technical problem (or, in other words, the objective) of
the claimed invention. … The next step is then to decide whether the state
of the art suggested the claimed solution of this technical problem in the
way proposed by the patent in suit …’
(Agrevo/Triazoles (above) para 2.4.3)
11
https://www.bailii.org/uk/cases/UKSC/2019/15.html
7

The test is helpfully summarised in the EPO’s Guidelines for Examination
in the EPO (November 2017) (Part G - Chapter VII) para 5:
‘Problem-and-solution approach
In order to assess inventive step in an objective and predictable manner,
the so-called ‘problem-and-solution approach’ should be applied. Thus
deviation from this approach should be exceptional.
In the problem-and-solution approach there are three main stages:
(i) determining the ‘closest prior art’,
(ii) establishing the ‘objective technical problem’ to be solved, and
(iii) considering whether or not the claimed invention, starting from the
closest prior art and the objective technical problem, would have
been obvious to the skilled person.’ ……..”
(9) Finally, the Board made the following observation on plausibility at para [92] of its
decision in Syngenta:
“92 The term “plausibility” that is found in the case law of the boards of appeal
and relied upon by the referring board in questions 2 and 3 of the referral
and the reasons for it, does not amount to a distinctive legal concept or a
specific patent law requirement under the EPC, in particular under Article
56 and 83 EPC. It rather describes a generic catchword seized in the
jurisprudence of the boards of appeal, by some national courts and by
users of the European patent system.”
3. The English Approach
(1) A good place to start is Warner-Lambert Company LLC v Generics (UK) Ltd [2018]
UKSC 56 (118 4 Nov 2018)12
because Lord Sumption said at para [1] of his judgment
in that case that those proceedings raised, for the first time in the courts of the United
Kingdom, the question how the concepts of sufficiency and infringement are to be
applied to a patent relating to a specified medical use of a known pharmaceutical
compound.
(2) The basic facts of Warner-Lambert:
Warner Lambert-Company LLC is a
subsidiary of Pfizer Inc. One of Pfizer's
most successful products is pregabalin
which it markets in the UK under the
trade mark "Lyrica". Pregabalin was
originally used for the treatment of
12
https://www.bailii.org/uk/cases/UKSC/2018/56.html see also my case note The Supreme Court's
Decision on Pregabalin in NIPC Law on 6 Dec 2018
https://nipclaw.blogspot.com/2018/12/the-supreme-courts-decision-on.html
8

epilepsy and similar disorders and it was
protected in this country by European
patent (UK) number 0641330. It was
later found that it could also be used to
alleviate pain. Warner-Lambert applied
for and was granted EP0934061 for that
treatment.
EP 0641330 expired on 17 May 2013
leaving generics manufacturers such as
Mylan (Generics (UK) Ltd) and Actavis
(Actavis Group PTC EHF) free to make
and sell pregabalin for its original use.
The problem for those companies was
that EP 0934061 restricted its use for
pain relief. The corresponding problem
for Pfizer was that doctors prescribed
pregabalin generically for pain relief
which meant that Mylan's or Actavis's
products were likely to be supplied
instead of Pfizer's.
Mylan and Actavis sued Warner-Lambert
for the revocation of EP 0934061 on
grounds of obviousness and insufficiency
while Warner-Lambert sued Mylan and
Actavis for patent infringement. In
Generics (UK) Ltd v Warner-Lambert
Company LLC [2015] EWHC 2548 (Pat)
(10 Sept 2005)13
Arnold J dismissed the
claim for obviousness but revoked
several claims for insufficiency. He also
dismissed the counterclaim.
His judgment was upheld by CA (see
Warner-Lambert Company LLC v
Generics (UK) Ltd (t/a Mylan) and
Others [2016] EWCA Civ 100614
and my
case note The Pregabalin Appeal:
Generics v Warner-Lambert 17 Oct
2016.15
Warner-Lambert appealed to the
Supreme Court against the finding of
insufficiency. The Court dismissed the
appeal
15
https://nipclaw.blogspot.com/2016/10/the-pregabalin-appeal-generics-v-warner.html
14
https://www.bailii.org/ew/cases/EWCA/Civ/2016/1006.html
13
See https://www.bailii.org/ew/cases/EWHC/Patents/2015/2548.html and my case note The
Pregabalin Trial: Generics (UK) Ltd v Warner-Lambert Company LLC 18 Sept, 2015 NIPC Law
https://nipclaw.blogspot.com/2015/09/the-pregabalin-trial-generics-uk-ltd-v.html
9

(3) At para [19] of his judgment in Warner-Lambert, Lord Sumption explained the need for
evidence of effectiveness in second medical use patents:
"[19] …………… Section 14 of the
Patents Act and the corresponding
provisions of the EPC assume that an
invention will be sufficiently disclosed if
the specification enables it to be
“performed”. In the case of a patent for a
new product or process, that assumption
is almost always correct. The skilled
person will discover that it works by
replicating it in accordance with the
specification. But the assumption is not
correct in the case of a second use
patent. The invention is not the
compound or the process of its
manufacture. The skilled person already
knows how to make the product from the
prior art disclosed in the original patent.
The invention consists in the new
purpose for which the product is to be
manufactured. If sections 14 (3) and 72
(1) (c) are read literally and as an
exhaustive statement of the requirement
of sufficiency, all that needs to be
disclosed is the new purpose, which is
enough to enable it to be administered to
a patient suffering from the relevant
condition. The skilled person does not
need to know how or why the invention
works in order to replicate it. The result
would be that the knowledge which
made the identification of the new
purpose inventive need not be disclosed
at all.
[20] The main problem about this result
is that it would enable a patent to be
obtained on a wholly speculative basis.
Without some disclosure of how or why
the known product can be expected to
work in the new application, it would be
possible to patent the manufacture of
known compounds for the purpose of
treating every conceivable relevant
condition without having invented
anything at all, in the hope that trial and
error might in due course show that the
product was efficacious in treating at
least some of them."
10

(4) He proposed a 7-point test of plausibility at para [37] of his judgment which was
adopted by Meade J in Sandoz Ltd v Teva Pharmaceutical Industries Ltd [2022]
EWHC 822 (Pat) (7 April 2022).
(5) Akebia Therapeutics Inc v FibroGen, Inc [2020] EWHC 866 (Pat) (20 April 2020).16
This was a claim by Akebia Therapeutics
Inc. and another to revoke 6 patents held
by FibroGen Inc. on grounds of
obviousness and insufficiency.
FibroGen's exclusive licensee, Astellas
Pharma Inc. brought quia timet
infringement proceedings against
Akebia.
The patents were grouped into 2 families
referred to as Family A and Family B.
The claims were very broad. For
example, claim 1 of EP1463823 B1 was
for:
“Use of a heterocyclic carboxamide
compound selected from the group
consisting of pyridine carboxamides,
quinoline carboxamides, isoquinoline
carboxamides, cinnoline carboxamides,
and beta-carboline carboxamides that
inhibits hypoxia inducible factor (HIF)
prolyl hydroxylase enzyme activity in the
manufacture of a medicament for
increasing endogenous erythropoietin in
the prevention, pretreatment, or
treatment of anemia.”
The proceedings came on before Arnold
LJ sitting as a judge of the Patents
Court.
He held that none of the patents was
obvious but found they were bad for
insufficiency. His finding on insufficiency
was summarized at para [376] of his
judgment:
“Turning to the present case, the patent
is implicitly promising that substantially
all compounds which satisfy the
structural definitions in the claims in
16
https://www.bailii.org/ew/cases/EWHC/Patents/2020/866.html and see also my case note Patents -
Akebia Therapeutics Inc v Fibrogen, Inc. 5 May 2020 NIPC Law
https://nipclaw.blogspot.com/2020/05/patents-akebia-therapeutics-inc-v.html
11

issue will have the claimed therapeutic
efficacy. Otherwise, the skilled team
would be faced with a situation where
the structural definition covers around
10183
compounds (or a little less or even
more), but the specification only
demonstrates that five compounds,
namely Compounds C, E, F, J and K,
satisfy the criteria for therapeutic
efficacy. That would amount to no more
than an invitation to the skilled team to
find the other compounds covered by the
claim which work. It would not involve an
inventive step, because it would not
solve the technical problem of identifying
compounds which have the desired
activity, and it would not sufficiently
disclose the invention, because it would
leave most of the work to the reader.”
(6) FibroGen appealed to the Court of Appeal against the finding of insufficiency
(FibroGen Inc v Akebia Therapeutics Inc [2021] EWCA Civ 1279 (24 Aug 2021). The
CA allowed the appeal for the following reasons.
At para [53] Birss LJ proposed the
following 3-step test to determine
whether an invention was plausible (that
is to say whether it is possible to make a
reasonable prediction that it will work):
“First one must identify what it is which
falls within the scope of the claimed
class. Second one must determine what
it means to say that the invention works.
In other words what is it for? Once you
know those two things, the third step can
be taken: to answer the question
whether it is possible to make a
reasonable prediction the invention will
work with substantially everything falling
within the scope of the claim.”
He referred to that test at para [98]:
“The question is whether it is possible to
make a reasonable prediction the
invention will work with substantially
everything falling within the scope of the
claim, and as I have described, there are
three steps. The judgment does not
approach the question this way, and
instead asks a rolled up question
whether it is plausible that compounds
12

within the structural class will have the
claimed therapeutic efficacy e.g.
paragraph [376], [378] and [380],
concluding that it is not. However,
whether that is the right question
depends on taking the three step
approach I have outlined.”
He applied that test between [99] and
[105] and came up with the following
answers:
He said at [101] “the conclusion at step
one ought to have been that the claimed
compounds are compounds within the
relevant structures which satisfy the in
vitro tests for feature C and the in vivo
animal model tests for feature E.”
As to what it means to say that the
invention works, the answer at [102] was
to treat the CKD form of anaemia.
As to the third step, the question was
whether it is possible to make a
reasonable prediction that compounds
which satisfy the structural features and
which also satisfy the functional features
C and E, will be useful to treat CKD
anaemia (see para [104]). He concluded
at [105] that it was indeed plausible,
(7) Sandoz Ltd and another v Bristol-Myers Squibb Holdings Ireland (Unlimited) Company
[2022] EWHC 822 (Pat) (7 April 2022).17
These were actions by Sandoz Ltd and
Teva Pharmaceutical Industries Ltd for
revocation of EP 1 427 415 B118
on
grounds of lack of plausibility.
Meade J explained at para [10.2] of his
judgment that: "Lack of plausibility is not
a ground for revocation in itself and it
was run both as Agrevo obviousness
and insufficiency. Neither side said it
18
https://patentimages.storage.googleapis.com/8a/0f/2b/1f2922b434af7d/EP1427415B1.pdf
17
https://www.bailii.org/ew/cases/EWHC/Patents/2022/822.html. See also my case note Patents -
Sandoz Ltd v Bristol-Myers Squibb, 28 Aug 2023 NIPC Law
https://nipclaw.blogspot.com/2022/08/patents-sandoz-ltd-v-bristol-myers-squib.html
13

made a difference which head applies,
and I agree in the light of the case law to
which I refer below, in particular
Warner-Lambert and Fibrogen."
He referred in particular to Lord
Sumption’s judgment in Warner-Lambert
and Birss LJ’s three-point test in
FibroGen.
He held that the patent was invalid
because there was no evidence that the
invention had the qualities claimed for it.
Consequently, it could be used as a
therapeutic.
(8) Bristol Myers Squibb appealed unsuccessfully to the Court of Appeal (Sandoz Ltd v
Bristol-Myers Squibb Holdings Ireland Unlimited Company [2023] EWCA Civ 472 (04
May 2023).19
Arnold LJ reviewed Case G 2/21 and
Warner-Lambert Company LLC v
Generics (UK) Ltd (t/a Mylan) and
another [2018] RPC 21, He said that it
was common ground that the majority
judgment in Warner-Lambert was
binding on the Court at least in second
medical use cases, and it had not been
suggested that G 2/21 would justify the
Court in departing from Warner-Lambert
in a second medical use case.
He said at para [92]:
"The fundamental principle is that the
scope of the patent monopoly must be
justified by the patentee's technical
contribution to the art. This remains so
whether the scope of the claim is broad
or narrow. Thus when considering
inventive step it is necessary to consider
what technical problem the claimed
invention solves. If it is not plausible that
the invention solves any technical
problem then the patentee has made no
19
https://www.bailii.org/ew/cases/EWCA/Civ/2023/472.html. See also my case note The Appeal -
Sandoz v Bristol Myers Squibb 25 May 2023 NIPC Law
https://nipclaw.blogspot.com/2023/05/the-appeal-sandoz-v-bristol-myers-squib.html
14

technical contribution and the invention
does not involve an inventive step.
Equally, when considering insufficiency it
is necessary to consider whether the
specification sufficiently discloses the
claimed invention. If it is not plausible
that the invention solves any technical
problem then the patentee has made no
technical contribution and the
specification does not disclose any
invention. It follows that, in order for a
claim to a single chemical compound to
be patentable, the application must
make it plausible, when read in the light
of the skilled person's common general
knowledge, that the compound has the
utility asserted for it. Moreover, it makes
no difference whether the claim
incorporates the use of the compound as
a technical feature or whether the claim
is simply to the compound per se and
the assertion of utility is only to be found
in the specification. This is because, as
explained above, there is no invention in
merely identifying a new chemical
compound; invention can only lie in
identifying its utility."
(9) Gilead Sciences Inc and another v NuCana PLC [2023] EWHC 611 (Pat) (21 March
2023)20
This was an action by Gilead Sciences
Inc. for revocation of EP 2955 190 B1
and EP 3 904 365 B1 for added matter,
implausibility and lack of industrial
applicability. The invention related to
nucleotide derivatives and the treatment
of cancer.
The action came on before Meade J.
Much of the judgment concerned added
matter and other causes of action,
As to the discussion on plausibility the
judge referred to and applied Birss J’s
three-point test:
20
https://www.bailii.org/ew/cases/EWHC/Patents/2023/611.html and see also my case note Patents -
Gilead Sciences Inc v NuCana Plc 11 Oct 2023 NIPC Law
https://nipclaw.blogspot.com/2023/10/patents-gilead-sciences-inc-v-nucana-plc.html
15

In response to a request by Gilead for
further information under CPR Part 18,
NuCana alleged that the technical
contribution of its invention was a new
class of phosphoramidite nucleosides
with cytotoxic activity. After considering
the expert evidence in support of this
allegation, the judge concluded at para
[369] that the skilled team would
positively think that a significant number
of compounds within the claims of the
patents would not have either
“meaningful” cytotoxic activity or activity
at the level of an IC50 of 100µM. The
skilled team would also positively expect
that a significant number of compounds
within the claims of the Patents would
have cytotoxic activity in one of those
senses. However, the skilled team
would be completely unable to predict
what or how many compounds would be
in either of those two categories.
The upshot was that the skilled team
would not think it plausible that
meaningful cytotoxic activity would be
preserved across the range of
possibilities encompassed by the claims
of the patents. They would think that the
effect of the substituents in combination
was unpredictable. They would not be
able to predict how many such
non-working combinations there might
be, but they would not expect them to be
rare one-offs. Since the skilled team
would positively think that a substantial
number of compounds in the claims
would lack activity, it followed that the
patents were invalid for implausibility.
16

G2_21 and the English Approach to Plausibility.pdf

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G2_21 and the English Approach to Plausibility.pdf