Full Judgment Text
$~
* IN THE HIGH COURT OF DELHI AT NEW DELHI
Reserved on: 20 December 2025
Pronounced on: 12 January 2026
+ FAO(OS) (COMM) 120/2025, CM APPL. 44383/2025, CM
APPL. 44386/2025 & CM APPL. 44388/2025
ZYDUS LIFESCIENCES LIMITED .....Appellant
Through: Dr. Abhishek Manu Singhvi
and Mr. Dayan Krishnan, Sr Advs. with Mr.
Adarsh Ramanujan, Ms. Bitika Sharma, Ms
Vrinda Pathak, Mr. P.S. Manjunathan, Mr
Rajnish Kumar, Ms. Aakashi Lodha, Mr.
Shreedhar Kale, Mr. Parth Singh, Mr.
Chanan Parwani and Mr. Rishi Agrawala,
Advs.
versus
E. R. SQUIBB AND SONS, LLC & ORS. .....Respondents
Through: Mr. Sandeep Sethi, Sr. Adv.,
Mr. Pravin Anand, Ms. Archana Shanker,
Ms. Prachi Agarwal, Mr. Devinder Singh
Rawat, Ms. Elisha Sinha, Mr. Manan
Mondal, Mr. Krisna Gambhir, Ms. Shreya
Sethi, Advs.
CORAM:
HON'BLE MR. JUSTICE C. HARI SHANKAR
HON'BLE MR. JUSTICE OM PRAKASH SHUKLA
JUDGMENT
% 12.01.2026
C. HARI SHANKAR, J.
A Prefatory Note summarizing the judgment in conspectus
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1. This appeal throws up issues, for consideration, which are of
fundamental importance, not merely as legal principles relating to the
patent regime, but also vitally of public interest.
2. The impugned order restrains the appellant from manufacturing
or releasing, in the market, its product ZRC 3276, which is an anti-
cancer drug and is essential for treatment of a wide variety of life-
threating carcinomas, on the premise that the product infringes the
respondent’s patent. According to the appellant, treatment, using the
appellant’s product, would be 70% cheaper than treatment using the
respondent’s patented drug 5C4.
3. The Supreme Court has, in its decisions in Ramnik Lal Bhutta
1
v. State of Maharashtra and Raunaq International v. I.V.R.
2
Construction Ltd , held that, while considering pleas for injunction or
stay, public interest is also a consideration to be borne in mind, apart
from the classical troika of a prima facie case, balance of convenience
and irreparable loss.
4. That said, we have no doubt about the fact that the mere fact
that the injuncted product is a life saving drug is no absolute armour
against injunction. Products which infringe patents of others cannot be
permitted to circulate in the market. Intellectual property rights are
entitled to protection.
1
(1997) 1 SCC 134
2
(1999) 1 SCC 492
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5. This case, however, is peculiar, as there is admittedly no
mapping of the appellant’s product ZRC 3276 onto the claims in the
respondent’s suit patent at any stage. Injunction has, therefore, been
granted without any product-to-claim mapping.
6. The impugned order seeks to justify this course of action on the
ground that the suit is a quia timet action, instituted in anticipation of
future infringement and that, therefore, as the appellant’s product is
not commercially available, no product-to-claim mapping is possible.
3
7. Rule 3(A)(ix) of the High Court of Delhi Rules Governing
4
Patent Suits, 2022 specifically requires product-to-claim mapping as
one of the necessary ingredients of a patent infringement suit.
However, the impugned judgment holds that the words “to the extent
possible”, in Rule 3A may, in a quia timet action, justify doing away
with the requirement of product-to-claim mapping altogether.
5
8. This is of vital importance, as Section 48 of the Patents Act,
1970 confers, on the holder of a registered patent, the exclusive right
to prevent third parties from using, offering, selling or importing that
3
A. Plaint:
The Plaint in an infringement action shall, to the extent possible, inter alia , contain a description of
the following:
*
(ix) Precise claims versus product (or process) chart mapping including claim chart
mapping through standards;
4
“the DHC Patent Suits Rules” hereinafter
5
48. Rights of patentees .—Subject to the other provisions contained in this Act and the conditions
specified in Section 47, a patent granted under this Act shall confer upon the patentee—
( a ) where the subject-matter of the patent is a product, the exclusive right to
prevent third parties, who do not have his consent, from the act of making, using, offering
for sale, selling or importing for those purposes that product in India;
( b ) where the subject-matter of the patent is a process, the exclusive right to
prevent third parties, who do not have his consent, from the act of using that process, and
from the act of using, offering for sale, selling or importing for those purposes the product
obtained directly by that process in India:
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product in India, without consent of the patentee. The issue of
whether, in the absence of any mapping of the defendant’s product to
the plaintiff’s granted claim in the suit patent, the defendant’s product
can be said to be that product , therefore, requires serious
consideration. Especially so as the product is a life-saving drug needed
for cancer therapy.
9. The learned Single Judge holds that, even in the absence of
product-to-claim mapping, the fact that the appellant’s product is in
fact the product claimed in the suit patent stands prima facie
established through other material.
10. Pared down to essentials, the suit patent claims an isolated
monoclonal antibody, through two indicia, which are that (i) the
antibody “ binds specifically to human Programmed Death (PD-1)”,
and (ii) the antibody comprises chains consisting of amino acids in
specified sequences.
11. PD-1 is a protein found in the human body, of the CD 28
family. Antibodies are also proteins. Every protein consists of amino
acids in a particular unique sequences.
12. There is no dispute that the appellant’s product binds not only to
PD-1, but also to other proteins of the CD 28 family . The learned
Single Judge holds that the word “specifically” does not mean
“exclusively”, and that binding with other proteins of the CD 28
family is not, therefore, a factor which would take the appellant’s
product ZRC 3276 outside the scope of the suit patent.
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13. We are unable, for reasons which this judgment would disclose
in detail, to agree with this finding, on facts or in law. The respondent
has itself , while responding to pre-grant objections, explained the
expression “specifically” as meaning that there should be no
statistically significant binding with other proteins of the CD 28
family. Statistically significant binding, as per the respondent itself in
the said response, is binding with a ‘p’ factor of less than 0.05. The
‘p’ binding factor of the appellant’s ZRC 3276 is of the range of
0.0001. Given the standards suggested in this regard by the
respondent itself, we find that ZRC 3276, in fact, did have statistically
significant binding with other CD 28 family proteins.
14. The impugned judgment, however, does not advert to this
aspect at all, despite noting the appellant’s contention in that regard.
15. Impugned judgment proceeds on the basis of product-to-product
mapping
15.1 In fact, submitted the appellant, the respondent’s 5C4 product
itself did not conform to the granted claim in the suit patent, as it, too,
had a ‘p’ binding factor of much less than 0.05. The learned Single
Judge has held that, as ZRC 3276 and 5C4 were both revealed, on
testing, to bind comparably to CD 28 proteins other than PD-1, ZRC
3276 mapped onto the suit patent.
15.2 This is, to our mind, fundamentally flawed, as it would envisage
a product-to-product mapping, whereas patent infringement is to be
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assessed on the basis of a product-to-claim mapping. In fact, the
position would be that neither ZRC 3276, nor 5C4, would actually
map onto the granted claim in the suit patent.
16. On the second aspect of the claim in the suit patent, of amino-
acid sequencing, the learned Single Judge observes that (i) the
appellant had sought exemption from detailed drug control research on
the ground that ZRC 3276 is a biosimilar of Nivolumab which was,
therefore, the “reference biologic” of ZRC 3276, (ii) 5C4, which was
the claimed antibody in the suit patent, had the same amino acid
sequencing as in Nivolumab and (iii) biosimilars had necessarily to
have the same amino acid sequencing. Once, therefore, as its
biosimilar, ZRC 3276 had the same amino acid sequencing as
Nivolumab, and 5C4 also had the same amino acid sequencing as
Nivolumab, the corollary would be that ZRC 3276 and 5C4 have the
same amino acid sequences. If a equals b, and c equals b, holds the
learned Single Judge, a must necessarily equal c.
17. It is in premise (iii) of this reasoning that, to our mind, the
learned Single Judge has erred. There is nothing, in the impugned
judgment, to indicate, as an inflexible principle, that biosimilars have
the same amino acid sequencing.
18. Apart from this “biosimilar analysis”, there is nothing, in the
impugned judgment, to sustain the prima facie finding that ZRC 3276
has the same amino acid sequences as 5C4. Indeed, there could be
none, as there has never been, at any stage, mapping of the appellant’s
ZRC 3276 product to the respondent’s granted claim in the suit patent.
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19. To our mind, while precise product-to-claim mapping, as
envisaged by Rule 3(A)(ix) of the DHC Patent Suit Rules may, in a
given case, suffice to establish a prima facie case of infringement, the
collateral material, on the basis of which the learned Single Judge has
proceeded, in the absence of any product-to-claim mapping, raise, at
the best, issues which are highly arguable, and would require expert
evidence. We are, therefore, unable to satisfy ourselves that, on this
material, the learned Single Judge was justified in entirely injuncting
the appellant from releasing its product in the market.
20. Rather, given the fact that the product is a life saving drug
needed for cancer therapy, and keeping in mind the pre-eminent
consideration of public interest, we are of the opinion that the interests
of justice would adequately have been subserved if the appellant were
to be directed to maintain and file, with this Court, periodical accounts
of the amounts earned through sale of the appellant’s product, so as to
secure the respondent in the event of its succeeding in the suit.
21. Besides, the suit patent expires on 2 May 2026. Thereafter,
there can be no embargo on anyone marketing the patented drug. The
only issue is, therefore, whether the appellant’s product should be
made available to the public for the next four months. Given the
nature of the product, and applying the principle of balance of
convenience, too, the interests of justice would require the appellant to
be bound down to maintain accounts of the realizations from the sale
of its product till the expiry of the suit patent, rather than depriving the
ailing public of access to the product.
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Facts
22. With that prefatory note, we proceed to the facts.
23. The rival products are proteins. Proteins consist of amino acid
sequences. Paras 23 to 31 of the impugned judgment set out, with
lucid clarity, the science of the suit patent, and we can do no better
than to reproduce the said paragraphs, verbatim:
“23. The white blood cells (“WBCs”) in our blood are divided
into five types, one of them being, lymphocytes. Lymphocytes are
immune cells which are prepared in our bone marrow, and are
found in the blood and lymph tissue. Lymphocytes further consist
of B-lymphocytes (B-cells) and T-lymphocytes (T-cells).
24. B-cells are the ones responsible for producing antibodies.
Antibodies are Y-shaped proteins that protect us when an unwanted
foreign substance enters our body. They are produced by our
immune systems to neutralise pathogens such as bacteria, virus,
etc. In the event that such a pathogen enters our body, it stimulates
our immune system to produce antibodies that bind with a unique
molecule of the pathogen, called an antigen.
25. The ‘Y’-shaped structure of an antibody contains two
‘Heavy’ and two ‘Light’ chains. The variable region in each heavy
and light chain, responsible for generating antigen-binding site of
the antibody, are termed Complementarity Determining Regions -
CDRs, which are immunoglobulin (Ig) hypervariable domains.
Thus, the CDRs are responsible for binding to the target antigen.
The variable regions of both the heavy chain and the light chain
have three CDRs each and these CDRs are specific to an antibody
for binding to an antigen. General structure of an antibody, is
represented in the following manner:
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26. The antibodies present in our body are basically proteins.
Proteins in turn are made up of amino acids which are small
molecules that are the building blocks of proteins. There are 20
amino acids commonly found in the protein present in our body.
The amino acids present in our body are represented by standard
codes. The unique arrangement of amino acids is called an amino
acid sequence.
27. Further, the T-cells in our WBCs are responsible for the
identification and destruction of abnormal/infected cells. They
have CD-28 proteins, which signal the immune system if a cell is
normal or abnormal. When T-cells receive this signal, the immune
system attacks the abnormal cells. One important CD-28 protein on
T-cells is called Programmed Death 1, i.e., PD-1, which helps in
identification of abnormal cells.
28. PD-1 has two ligands, i.e., PD-L1 (Programmed Death-
Ligand 1) and PD-L2 (Programmed Death-Ligand 2). PD-L1 and
PD-L2 are proteins which are located on the surface of normal
cells. In a healthy human body, once PD-1 binds with either of its
ligands, it essentially signals to the T-cell to tolerate those normal
cells, and not attack them. Thus, engagement of PD-1 with either
of its two ligands suppresses immune system responses in case of
healthy normal cells.
29. However, cancer cells also have PD-L1 on their surface and
have the potential to impair PD-1's ability to send signals to the T-
cell. Therefore, when PD-1 on our T-cell binds to the PD-L1 ligand
on a cancerous cell, it deactivates the PD-1 on the T-cell. When
PD-1 is inactive, T-cells do not attack the cancer cells.
30. Thus, to prevent this binding between PD-1 and PD-L1 on
a cancer cell, monoclonal antibodies have been developed in order
to allow the immune system to recognise and destroy cancer cells.
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Monoclonal antibodies are man-made antibodies which are created
artificially in laboratories and are designed to act like human
antibodies for specific purposes. As the name suggests, they are a
single kind of antibody that bind to a single target receptor/antigen
or ligand.
31. The suit patent, i.e., Nivolumab, is one such monoclonal
antibody, which is an anti-PD-1 antibody, also called ‘5C4’
antibody. In other words, Nivolumab binds with the PD-1 protein
on our T-cell, which prevents PD-1 from binding itself with PD-L1
ligand on a cancer cell. This ensures that our T-cells are not
rendered inactive and the immune system is able to identify the
cancer cell and act accordingly
.”
24. The suit patent
6
24.1 The respondent is the holder of Indian Patent No. IN 340060 ,
titled “Human Monoclonal Antibodies to Programmed Death 1 (PD-1)
for use in treating Cancer”. Claims 1, 3 and 7 in the suit patent read
thus:
“1. An isolated monoclonal antibody or an antigen-binding
portion thereof that binds specifically to human Programmed
Death (PD-1), comprising:
a) a heavy chain CDR1 consisting of the amino acid
sequence set forth in SEQ ID NO: 18;
b) a heavy chain CDR2 consisting of the amino acid
sequence set forth in SEQ ID NO: 25;
c) a heavy chain CDR3 consisting of the amino acid
sequence set forth in SEQ ID NO: 32;
d) a light chain CDR1 consisting of the amino acid
sequence set forth in SEQ ID NO: 39;
e) a light chain CDR2 consisting of the amino acid
sequence set forth in SEQ ID NO: 46; and
f) a light chain CDR3 consisting of the amino acid
sequence set forth in SEQ ID NO: 53.
6
“IN’060”, also referred to as “the suit patent” hereinafter
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*
3. The monoclonal antibody or antigen-binding portion
thereof, as claimed in claim 1, which comprises:
a) a heavy chain variable region comprising the amino
acid sequence set forth in SEQ ID NO: 4; and
b) a light chain variable region comprising the amino
acid sequence set forth in SEQ ID NO: 11.
*
7. A composition comprising the monoclonal antibody or
antigen-binding portion thereof as claimed in any one claims 1-6
and a pharmaceutically acceptable carrier.”
24.2 Clearly, therefore, the claims in the suit patent consists of two
main features; firstly, the fact that it “binds specifically to PD-1” and,
secondly, that it consists of the specified amino acid sequences.
24.3 The antibody 5C4, or Nivolumab, is marked by the respondent
® ®
outside India as Opdivo , and in India as Opdyta .
25. Concept of infringement in the Patents Act
25.1 The Patents Act is a peculiar statute, in the intellectual property
firmament. Unlike other intellectual property statutes, it does not
define “infringement”, though it refers to it. Section 48, however,
refers to the rights of patentees, and, for want of any other definition,
one presumes that infraction of those rights amounts to infringement.
Particularly so, as Section 49, which follows, sets out circumstances
which do not amount to infringement.
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25.2 In the case of a product patent, therefore, Section 48 confers, on
the patentee, exclusive right to prevent third parties from making,
using, offering, selling or importing that product in India, without
consent of the patentee. “That product”, obviously, refers to the
product which is subject matter of the patent. It is for this reason that
mapping of the product to the granted claim in the patent becomes
indispensable, for it is only then that it can be said that the product in
which the defendant is dealing is the product which is subject matter
of the plaintiff’s patent.
25.3 That said, “mapping” is not a word of art; it merely implies
identification of the product in which the defendant is dealing as the
product of which the plaintiff holds the patent, and nothing else. Any
method by which this can be established would suffice, to constitute
“mapping”.
25.4 What is of the essence, however, is that the essential features of
the patented claim must be found to exist in the infringing product.
Minor “workshop improvisations” cannot mitigate infringement. It is
for this reason that the doctrine of equivalents has been formulated.
The extent to which this doctrine would apply in the case of chemical
or pharmaceutical patents is, however, to our mind, seriously
disputable. Ultimately, the outcome of the lis would turn on whether
the product of the defendant is the product claimed in the plaintiff’s
patent.
26. The impugned judgment
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26.1 We are restricting our observations and findings, qua the
impugned judgment, to the issues on which we feel that a case for
interference, even within the limited parameters of para 14 of Wander
7
Ltd v. Antox India (P) Ltd , is made out. On other issues, though
contentions were advanced by both sides, we are of the view that any
interference by us would amount to our substituting our view for the
view of the learned Single Judge, which Wander does not permit.
26.2 On infringement – The “biosimilar” approach
26.2.1 The impugned order, admittedly, does not proceed on the basis
of any mapping of the appellant’s product to the Claims in the suit
patent. The learned Single Judge holds that, as the suit was in the
nature of a quia timet action, and commercial release of the appellant’s
product in the market had been injuncted by order dated 8 May 2024,
no product, which could be mapped on to the suit patent, was
available. The impugned order proceeds, therefore, on the basis of an
“indirect mapping” basis, through the following steps:
(i) The amino acid sequence of the respondents’ 5C4
antibody mapped onto the amino acid sequence of INN
Nivolumab.
(ii) The appellant’s ZRC 3276 claimed to be a biosimilar of
INN Nivolumab.
7
1990 Supp SCC 727
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(iii) Biosimilars necessarily had to have the same amino acid
sequence.
(iv) Ergo, the amino acid sequence of ZRC 3276 and 5C4 was
necessarily the same.
26.2.2 There are, in our view, clear logistical difficulties in accepting
this method of mapping.
26.2.3 Qua Step (i)
26.2.3.1 We may commence our analysis from step (i), i.e. the
“mapping” of 5C4 onto INN Nivolumab. In this regard, Para 93 of
the impugned judgment reads thus:
“93. Further, the plaintiffs have done complete mapping of the
suit patent with Nivolumab as contained in INN, which is
reproduced as under:
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26.2.3.2 The learned Single Judge holds that the respondents did
“complete mapping” of the suit patent with Nivolumab as given in
INN. Inasmuch as Nivolumab is the INN assigned name to one of the
exemplified products in the suit patent itself, we fail to understand the
concept of “mapping” of the suit patent onto INN Nivolumab. True,
Claim 1 in the suit patent could cover a wide variety of proteins,
containing the amino acid sequences indicated therein, depending on
the other amino acids contained in the entire protein chain. Each,
however, is an exemplified product in the suit patent, which includes
Nivolumab. The claims in the suit patent were, therefore, bound to
map onto INN Nivolumab.
26.2.3.3 In this context, before proceeding to other aspects of
indirect mapping, we may reproduce paras 42 to 44 of the impugned
judgment, thus:
“42. As noted above, antibodies are proteins that protect us
when an unwanted substance enters the body. All antibodies are
constructed in the same way. As per the suit patent, Nivolumab is a
PD-1 blocking antibody for treatment of cancer. It has specific
amino acid sequences of heavy and light chains of an antibody
termed as the ‘5C4 antibody’, which contains six CDRs. Changes
have been made in the amino acid sequencing, which has resulted
in creation of the suit patent, Nivolumab, i.e., monoclonal anti-PD-
1 antibody for treatment of cancer. Three changes have been made
in the sequencing of amino acid in the heavy chain variable and
three changes have been made in the sequencing of amino acid in
the light chain variable, totalling to six changes.
43. The changes, as made by the plaintiffs, in the amino acid
sequencing in the heavy chain variable region and light chain
variable region, which is reflected in red colour, is reproduced as
under:
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b. SEQ ID No. 11 (light chain variable region)
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44. The six separate changes in the amino acid sequencing, as
done by the plaintiffs, are reproduced as under:
“27. …………
a. SEQ ID No. 18 (heavy chain CDR 1)
b. SEQ ID No. 32 (heavy chain CDR 2)
c. SEQ ID No. 32 (heavy chain CDR 3)
d. SEQ ID No. 39 (light chain CDR 1)
e. SEQ ID No. 46 (light chain CDR 2)
f. SEQ ID No. 53 (light chain CDR 3)
26.2.3.4 We have gone through the pleadings in detail, but find no
reference to any “changes” made by the respondent in amino acid
sequencing. The learned Single Judge, therefore, appears to have
proceeded on the premise that the respondent had carried out changes
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in the amino acid sequencing, which does not appear to be correct.
Indeed, if there were in fact changes in the amino acid sequencing,
there would have had to be an “unchanged” amino acid sequence.
There is none.
26.2.3.5 What the respondents appear, instead, to have claimed, in
the suit patent, is any isolated monoclonal antibody which has, in the
various heavy chain and light chain CDRs, amino acids in the claimed
sequences at any point, and which bind specifically to PD-1.
26.2.3.6 Once this is understood, the principle of “mapping” of
the 5C4 antibody onto INN Nivolumab becomes meaningless, as it is
no more, and no less, than mapping onto oneself. Nivolumab is, even
as per the respondent, the INN nomenclature of the 5C4 antibody,
containing the amino acid sequences claimed in Claims 1 (a) to (f). It
is not as though there was any pre-existing INN Nivolumab onto
which 5C4 mapped; indeed, had there been, the suit patent would
itself become vulnerable to invalidity for lack of inventiveness.
26.2.3.7 The first step of the “indirect mapping” analysis of the
learned Single Judge, therefore, really does not advance the discussion
to any meaningful extent.
26.2.4 Qua step (ii)
26.2.4.1 On this, there can be no cavil, as the appellants, in fact,
claimed ZRC 3276 to be a biosimilar of Nivolumab.
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26.2.4.2 But what follows?
26.2.5 Qua step (iii)
26.2.5.1 The learned Single Judge, thereafter, proceeds on a
premise that all biosimilars would have identical amino acid
sequences. The impugned judgment, to our mind, does not support
such a finding.
26.2.5.2 As this is the very basis of the “indirect mapping”,
following which the learned Single Judge has returned a finding of
infringement, it assumes stellar importance.
26.2.5.3 The issue of whether a biosimilar product can, on that
basis alone, be said to be infringing of the reference biologic, appears
to us to be extremely thorny. If the impugned judgment is accepted,
every biosimilar product would, on that basis alone, infringe the
patent claimed by the reference biologic.
26.2.5.4 As we have already noted, the Claims in the suit patent,
which are alleged to be infringed, have, as their distinguishing
features, their “specific” binding to the PD-1, and the amino acid
sequencing in their chains. The learned Single Judge holds that,
having claimed itself to be biosimilar to INN Nivolumab, the amino
acid sequences of ZRC 3276 and Nivolumab were necessarily
identical.
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26.2.5.5 There is, however, in the impugned judgment, no
material on the basis of which such a finding could be arrived at. In
para 81, the learned Single Judge has quoted the following definition
of “Similar Biologic Product” in the Similar Biologic Guidelines
issued by the Department of Biotechnology, Government of India:
“A Similar Biologic product is that which is similar in terms of
quality, safety and efficacy to an approved Reference Biological
product based on comparability.”
Thus, biologics are similar only in quality, safety and efficacy . The
definition in the Similar Biologic Guidelines does not state that they
have identical amino acid sequencing, or are similar in other respects.
26.2.5.6 The learned Single Judge also refers to para 6.3.2 (i) of
the Similar Biologic Guidelines under the head “Product
Characterization”, which reads:
“6.3.2 Product Characterization
*
i. Structural and Physicochemical Properties: The
analysis of physicochemical characteristic should include
determination of primary and higher order structure of the
drug substance and the product along with other significant
physicochemical properties. The target amino acid
sequence of the Similar Biologic should be confirmed and
is expected to be the same as for the Reference Biologic.
Analytical methods that are used (including Biological and
functional assays) should have acceptable precision and
accuracy. In cases, where post translational modifications
are taking place, these modifications need to be identified
and quantified. In case any significant differences are
found, these should be scientifically justified and critically
examined in preclinical studies and clinical trials.”
(Emphasis supplied)
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26.2.5.7 Immediately following the reproduction of this extract,
the impugned judgment observes:
“84. Thus, in bio-similar drugs, the efficacy and amino acid
sequencing, is also similar, however, chemically, the said drugs
would be different .”
(Emphasis supplied)
This observation, even by itself, throws the entire reliance, by the
learned Single Judge, on the “biosimilarity” between ZRC 3276 and
Nivolumab, as a basis to arrive at a finding of infringement, seriously
disputable.
26.2.5.8 In the first place, what is needed is not similarity of
amino acid sequencing, but identity . Else, the Court would have to
assess the degree of dissimilarity and hold that, despite there being
dissimilarity, ZRC 3276 infringes the suit patent.
26.2.5.9 Secondly, if the amino acid sequencing is identical, it is
not possible to understand how chemically the products would be
different, as the impugned judgment itself holds that each amino acid
sequence is unique to a particular protein.
26.2.5.10 Thirdly, if the products are chemically different, it is
again highly arguable as to whether they can be said to map on to one
another. Or as to whether, if Nivolumab maps on to the claims in the
suit patent, ZRC 3276 can also be said to do so. In any case, once the
impugned judgment that biosimilar products can be chemically
different – in fact, it asserts that they would be chemically different –
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it is impossible to understand how Section 48(1) of the Patents Act
would at all apply, as it employs the expression “ that product”.
26.2.5.11 The learned Single Judge proceeds to presume that para
12 of the Note submitted by the appellant sufficed to prima facie
establish the similarity in the amino acid sequencing of ZRC 3276 and
Nivolumab. Para 12 read thus:
“12. The Defendant’s product can certainly be called a
biosimilar of “Nivolumab”. A product can be called Nivolumab so
long as it comprises the specific sequence of amino acids
mentioned in the “WHO Drug Information” document. However,
claim 1 of the suit patent has an added limitation over and above
such sequences, i.e., the product having such sequences must be
isolated and bind specifically to PD-1. Defendant’s product does
not fulfil this additional requirement of claim 1 of the suit patent.”
The learned Single Judge regards the italicized sentences in the above
extracted para 12 as establishing, prima facie , similarity in the amino
acid sequencing of Nivolumab and ZRC 3276.
26.2.5.12 There is, to our mind, no such premise, which can
legitimately be drawn. Para 12, to the extent emphasized, merely
states that (i) ZRC 3276 is a biosimilar of Nivolumab (which cannot
be, and is not, in dispute) and (ii) a product can be called Nivolumab
if it comprises the specific sequence of amino acids mentioned in the
WHO Drug Information document. There is, therefore, no admission
that the amino acid sequence in ZRC 3276 is the same as that in the
suit patent.
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26.2.5.13 It cannot, therefore, to our mind, be regarded, merely on
the basis of the fact that the respondent had claimed its product to be
biosimilar to Nivolumab, that it mapped onto the suit patent.
26.3 Extending the mapping controversy
26.3.1 We are also of the view that the impugned judgment does
not entirely appreciate, or address, the issue raised by the appellants,
in their written statement, on the aspect of erroneous or incomplete
mapping.
26.3.2 The written statement averred, inter alia , as under:
“12. The underlying suit has been filed by the Respondents
alleging that the Appellant's similar biologic/biosimilar of
NIVOLUMAB infringes the patent IN 340060 (IN'060). The
Respondents' case is based inter alia on the premise that
NIVOLUMAB is covered in the scope of the suit patent IN 060, and
that the mere fact of applying for a similar biologic of the said
drug by the Appellant would amount to an admission of
infringement. The Respondents have produced a 'claim mapping'
with the present suit, which allegedly maps the claims of the suit
patent with the INN of Nivolumab as given by the WHO, however
what has been mapped is only the 6 CDR sequences, while the rest
of the claim is ignored . For ease of reference, the claim 1 of the suit
patent is reproduced below:
Claim 1:
1. An isolated monoclonal antibody or an antigen-
binding portion thereof that binds specifically to human
Programmed Death (PD-1), comprising:
a) a heavy chain CDR1 consisting of the amino acid
sequence set forth in SEQ ID NO: 18.
b) a heavy chain CDR2 consisting of the amino acid
sequence set forth in SEQ ID NO: 25.
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c) a heavy chain CDR3 consisting of the amino acid
sequence set forth in SEQ ID NO: 32,
d) a light chain CDR1 consisting of the amino acid
sequence set forth in SEQ ID NO: 39,
e) a light chain CDR2 consisting of the amino acid
sequence set forth in SEQ ID NO: 46, and
f) a light chain CDR3 consisting of the amino acid
sequence set forth in SEQ ID NO: 53.
*
15. The Appellants have argued that the mere manufacture of a
bio-similar of Nivolumab can never amount to patent infringement
or an admission thereof, since the test for patent infringement is
claim-to-product comparison, while the test for assessment of bio-
similar is based on a product-to-product comparison . Further there
is no justification about the grounds that led the Respondents to
believe that the biosimilar employed by the Appellant is the same
as the suit patent, since the suit patent is not for NIVOLUMAB but
for an 'isolated monoclonal antibody that 'binds specifically to PD-
1'. In the claim mapping done by the Respondents, the 6 CDR
sequences have been mapped with the INN of Nivolumab,
however, the features of 'isolated' and 'binding specifically to PD-1'
have not been mapped . This incomplete mapping is a glaring error
since the Appellant's case of noninfringement is premised on the
fact that Appellant's bio-similar is not 'isolated' and 'does not bind
specifically to PD-1' but also to other members of the CD-28
family.
16. It is further relevant to note that the 'Similar Biologics'
guidelines 2016 gauges 'similarity' in terms of 'safety, efficacy and
quality' and makes no reference to patent infringement. In fact, the
guidelines provide a caveat that they are not meant to substitute or
rephrase the Drugs and Cosmetics Act, 1940 or rules thereunder. It
is a settled law that there is no patent linkage in India, and
therefore, the mere fact of applying for a similar biologic cannot
lead to a finding of patent infringement. The Appellant had placed
on record experimental data to show that the Respondents' own
product was not isolated and displayed binding to other members
of the CD-28 family, thereby confirming that the Appellant's
product is a bio-similar of the Respondents product, but is not
infringing the claims of the suit patent.”
(emphasis supplied)
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26.3.3 Following this, it was pointed out, in the written
statement, that, even in the submissions made by the respondent
during prosecution proceedings preceding registration of IN’060, the
respondent had sought to distinguish the prior art antibodies on the
8
ground that as the ‘p’ value in the test antibody wells, for binding
with CD 28 protein family members, was less than 0.05, it was
statistically significant. The relevant paragraphs from the
respondent’s submissions read thus:
“с. Dr. Madamwar's arguments do not refute conclusions
regarding cross-reactivity. Rather than discussing the actual results,
Dr. Madamwar focuses on the scale of absorbance as depicted in
graphs of the different antibody-binding (i.e., a y-axis with a
maximum value of 0.15 or 0.08) that is lower than the scale
depicted for the PD-1 binding experiment (i.e., a y-axis with a
maximum value of 2.0).
d. But the scale of each graph is irrelevant in view of the fact
that each of those experiments showed statistically significant
binding by the test prior art antibodies to members of the CD28
family of proteins relative to a control antibody. The absorbance
levels charted are the raw output from the assays, and the bars
represent the average of three individual measurements with the
standard deviation shown by the error bars. Statistical analysis of
those results with the Student's T Test indicated that in each case,
the value in the test antibody wells was significantly higher than
the IgG isotype control (p < 0.05). And thus there was significant
specific binding by each prior art antibody to each CD28 family
member tested.”
26.3.4 The appellant pointed out, in its written statement, that
independent third party studies by the Sardar Patel University revealed
that the ‘p’ value, qua binding with members of the CD 28 family
other than PD-1, was less than 0.0001, which was statistically
significant, both in the case of ZRC 3276 as well as in the case of
5C4. This, it was submitted, clearly indicated that ZRC 3276 did not
8
probability
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map onto the claims in the suit patent. Para 18 of the appeal
memorandum reads thus:
“18. In view of the above, the Appellant conducted experiments
in-house and also engaged an independent third party, i.e. Sardar
Patel University, to show that the antibody of the Appellants' bio-
similar shows statistically significant binding to other members of
the CD-28 family. As per the experiment reports, "p" value of the
Appellants antibody was <0.0001, which is "statistically
significant" by Respondents' own admission. Further, to clarify that
the product of the Appellant can be a bio-similar of the
Respondents' product, while falling outside the scope of the suit
patent, the Appellant also conducted the same tests on the
Respondents' product, which resulted in the conclusion that the
Respondent's product also displayed statistically significant
binding to other members of the CD-28 family. In view of the test
reports, it was pleaded that since the Appellants product binds to
other members of the CD-28 family, the said product is non-
infringing, and is in fact following the prior art. Further, since the
Respondents' product also binds to other members of the CD-28
family, the product of the Appellant and the Respondent are bio-
similars.”
26.3.5 This submission of the appellant is also specifically noted
in para 16.3 of the impugned judgment, thus, albeit without reference
to the ‘p’ numbers:
“16.3 It is the plaintiffs’ case that the claim scope of the suit
patent is limited to only those antibodies which bind to PD-1 with
no binding or statistically insignificant binding with other receptors
in the CD-28 family. The defendant’s product does not fulfil this
limitation and thus, is not infringing the suit patent. Further, in the
defendant’s product there is statistically significant binding,
therefore, the defendant is following the prior art.”
What was taken was, therefore, a Gillette defence, pleading that
antibodies with statistically insignificant binding to non-PD-1
antibodies were known in the prior art and that, therefore, ZRC 3276
merely followed prior art, and did not infringe the suit patent.
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26.3.6 There is, however, no finding, in the impugned judgment,
on this argument of the appellant.
26.3.7 In fact, the impugned judgment overlooks this aspect of
the matter altogether, as it merely concentrates on the higher binding
specificity of the antibodies with the PD-1 ligand, as compared to
binding with other proteins of the CD-28 family. The charts on which
the impugned judgment itself relies, in para 101 to 105, clearly
indicate considerable binding of the antibodies with other proteins of
the CD-28 family which cannot, viewed any which way, be regarded
as “statistically insignificant”.
26.3.8 The fact that the respondent had obtained registration of
the suit patent by pleading novelty, originality, and lack of anticipation
vis-à-vis prior art on the ground that there was no statistically
significant binding vis-à-vis non-PD-1 proteins, and had set a ‘p’ value
of less than 0.05 as demonstrating statistically significant binding, has
been totally overlooked by the learned Single Judge. Having obtained
registration of the suit patent on this representation, the respondents
were bound thereby.
26.3.9 Claim 1 in the suit patent professes, as it most particular
feature, “(binding) specifically to human PD-1”. “Specifically”,
plainly etymologically understood, would imply exclusivity. Even if
one were to regard the interpretation, by the impugned judgment, of
the expression “specifically” as not being amenable to interference in
appeal given the Wander principles, the understanding of the
expression in the pre-grant proceedings, and the explanation tendered
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by the respondent in that regard, could not have been ignored,
especially as prior art patents, which also claimed anti-PD-1
antibodies, were set up against the claim of the respondent, and the
respondent bypassed the challenge by adopting a stand that there was
no “statistically significant” binding, in the claim in the suit patent,
with non-PD-1 antibodies of the CD 28 family. Once, therefore, the
litmus test to determine statistical significance had been cited, by the
respondent itself, before the Registrar, as a ‘p’ value of less than 0.05,
the prima facie inexorable sequitur would be that antibodies with ‘p’
values of 0.05 would not map onto the claims in the suit patent.
26.3.10 Had this aspect been addressed by the learned Single
Judge, and a plausible view taken thereon, we would have had to test
the amenability of the view to interference on the Wander touchstone.
However, the complete want of consideration, by the learned Single
Judge, of this aspect, is, to our view, fatal to the impugned order.
26.4 Impugned judgment proceeds on product-to-product mapping
26.4.1 Instead of proceeding on the basis of the admitted
standard of statistical significance [of a ‘p’ factor being less than
0.05], the impugned judgment returns a finding of infringement on the
basis of a product-to-product mapping , which is ex facie unacceptable
in law as a basis to determine patent infringement. This is clear from
para 106 of the judgment, which reads thus:
106. The aforesaid test results to determine the binding
®
specificity of Opdivo , the product of the plaintiffs, and ZRC-
3276, the product of the defendant, clearly demonstrate that both
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®
Opdivo and ZRC-3276, are anti-PD-1 antibodies, that bind with
PD-1 with high specificity than the other CD-28 family receptors,
and do not bind substantially with human CD-28/CTLA4 or ICOS
receptors.”
26.4.2 The error into which the impugned judgment is apparent
from the opening sentence in the next paragraph (para 107), which
reads:
“107. Considering the aforesaid test results filed by the
®
defendant, it is apparent that both the products, i.e., Opdivo of the
plaintiffs and ZRC-3276 of the defendant, fall within the scope of
the claims of the suit patent.”
In arriving at this conclusion, we are of the respectful view that the
learned Single Judge erred. The highest that the test results would
reveal is that the respondent’s 5C4 and the appellants’ ZRC 3276
mapped onto each other – which, too, may be disputable. They
cannot, in any case, make out a case of mapping onto the suit patent,
which, in fact, they do not, as the ‘p’ factor was less than 0.0001 in
both cases.
26.5 Absence of product-to-claim mapping – The duty of the Court
26.5.1 In a case as involved as this, we are of the opinion that it
would be erroneous to injunct the appellant from releasing its product
in the market without any product-to-claim mapping with the suit
patent. While product-to-claim mapping may not be a cast-in-iron
imperative in every case, in its absence, there must be overwhelming
circumstantial material to indicate that the defendant’s product maps
onto the suit patent. There must be, in a manner of speaking, a
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continuous and unbroken chain of circumstances to that effect. There
is no room for assumption and presumption.
26.5.2 This would be additionally so in a case such as the
present, when the injunction that is sought is against the release, in the
market, of a life giving therapeutic preparation, especially where it is
to treat an ailment such as cancer. Courts owe a debt to society. Public
interest is, as held in Ramnik Lal Bhutta and Raunaq International ,
also a pre-eminent consideration while deciding whether to grant, or
not to grant, an absolute interlocutory injunction.
26.5.3 Courts have to be acutely conscious of their duties in
such matters. The tightrope is shaky, and walking it is not always an
enviable enterprise. Our oath of office, however, obligates us to do so
and, while doing so, we have to bear in mind our duty to the teeming
citizenry of this country who may be in dire need of the therapy, the
release of which a plaintiff seeks to injunct.
26.5.4 There is, at the same time, also a pre-eminent element of
public interest in ensuring protection of valuable patents, which not be
forgotten. If Courts are to swing to the other extreme, and openly
allow circulation, in the market, of drugs which infringe valuable
pharmaceutical patents, the incentive to invent would be altogether
lost, which might result in ebbing the stream at the source. There
would be no incentive to expend valuable time, energy and often
cripplingly huge financial resources in inventing a new and more
efficacious drug, if one is not ensured of patent protection as available
in law.
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26.5.5 As we said, the tightrope is shaky, and walking it often an
ordeal. Perhaps, the Court can hardly ever rest content in the
conviction that it has fulfilled its task appropriately, much less
adequately.
26.5.6 Where, however, a clear cut case of patent infringement,
within the meaning of Section 48, is made out, on the basis of
product-to-claim mapping , and there is no credible challenge made out
to the validity of the asserted suit patent, the Court has to protect the
patentee from infringement. On that, to our mind, there can be no
compromise.
26.5.7 Where, however, no product-to-claim mapping has been
attempted, and the Court is relying on other collateral material, that
material, to our mind, has to be so conclusive, even at the prima facie
stage, as to indicate that the defendant’s product is that product of
which the plaintiff holds the patent, before its dissemination to the
public can be restrained.
26.5.8 Where the issue is triable, or involves complicated
technical issues which would appropriately need a trial, then, in our
opinion, where the product in question is a life-saving drug, the Court
has to err in favour of public interest, and ensure securing of the
plaintiff’s interest by alternate methods, short of making the drug
unavailable to the public during the entire period for which the suit
would remain pending. Withholding such therapy from the public can
cause untold and irreparable prejudice to lakhs of lives, and it is,
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therefore, only where the Court is in possession of irrefutable material
to indicate that a patented product is being released in the market
without permission of the patentee, in breach of Section 48, that an
injunction can issue.
26.5.9 Tested on this crucible, we are of the opinion that, in the
present case, the issues which have persuaded the learned Single
Judge to restrain the appellant from manufacturing or releasing ZRC
3276 in the market do not make out such a clear prima facie case as
would justify the injunction. The issues are extremely technical, and
would clearly require expert technical evidence to be led before even a
prima facie view can be taken.
26.5.10 We are additionally persuaded in the view we take as the
suit patent, in any event, expires on 2 May 2026, after which the
respondent cannot, in any case, injunct the appellant from releasing its
product in the market.
Conclusion
27. In these circumstances, we are of the opinion that the interests
of justice would be adequately subserved if the impugned judgment is
modified by vacating the injunction granted by the impugned
judgment and requiring the appellant, instead, to file, with the
Registry of this Court and an advance copy to the respondent, audited
accounts of the amounts earned by the appellant by sale of the
allegedly infringing product, till the expiry of the suit patent. As a
period of hardly four months remains till the suit patent expires, this
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arrangement would, to our mind, protect the interests of both sides and
would also ensure that the availability of the appellant’s product to the
public, who may be in need of it, is not restrained any further.
28. The impugned judgment stands modified accordingly.
29. The appeal is allowed to the aforesaid extent with no orders as
to costs.
C. HARI SHANKAR, J.
OM PRAKASH SHUKLA, J.
JANUARY 12, 2026
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