  United States Court of Appeals
      for the Federal Circuit
                ______________________

         MERCK SHARP & DOHME CORP.,
               Plaintiff-Appellant

                           v.

       AMNEAL PHARMACEUTICALS LLC,
              Defendant-Appellee
            ______________________

                      2017-1560
                ______________________

    Appeal from the United States District Court for the
District of Delaware in No. 1:15-cv-00250-SLR-SRF,
Judge Sue L. Robinson.
                ______________________

               Decided: February 9, 2018
                ______________________

   NICOLAS BARZOUKAS, Reed Smith LLP, Houston, TX,
argued for plaintiff-appellant. Also represented by
JOSHUA DAVIS, LISA M. THOMAS.

    THOMAS J. MELORO, Willkie Farr & Gallagher LLP,
New York, NY, argued for defendant-appellee. Also
represented by DEVON EDWARDS, MATTHEW S. FREIMUTH,
MICHAEL JOHNSON.
                ______________________
2        MERCK SHARP & DOHME CORP.    v. AMNEAL PHARM. LLC



Before TARANTO, CLEVENGER, and STOLL, Circuit Judges.
STOLL, Circuit Judge.
    Merck Sharp & Dohme Corp. (“Merck”) owns U.S.
Patent No. 6,127,353, which claims mometasone furoate
monohydrate, the active ingredient in Merck’s Nasonex®
nasal product. Amneal Pharmaceuticals LLC (“Amneal”)
submitted an Abbreviated New Drug Application
(“ANDA”) to the U.S. Food & Drug Administration
(“FDA”) seeking approval to market a generic mometa-
sone furoate nasal spray. Merck filed an infringement
suit in the District of Delaware alleging that Amneal’s
proposed ANDA product would infringe the ’353 patent if
approved by the FDA.
    Following a bench trial, the district court found that
Merck failed to prove by preponderant evidence that
Amneal’s ANDA product will infringe the ’353 patent. On
appeal, Merck argues that the district court abused its
discretion by not compelling Amneal to produce additional
samples of its ANDA product for testing before trial.
Merck also argues that the district court’s noninfringe-
ment finding must be reversed because it was not based
on Amneal’s final commercial product. Merck also chal-
lenges the district court’s fact-finding that a Raman
spectroscopy three-peak analysis was required to confirm
the infringing form of mometasone furoate in Amneal’s
product.
    For the reasons explained below, we conclude that the
district court did not abuse its discretion in denying
Merck’s request for additional samples and a new trial.
Further, we hold that the district court did not err in
finding that Merck failed to demonstrate that Amneal’s
ANDA product, which formed the basis for the district
court’s noninfringement finding, was not representative of
Amneal’s final commercial product. Finally, we conclude
that the district court did not clearly err in finding that
MERCK SHARP & DOHME CORP.   v. AMNEAL PHARM. LLC         3



three Raman peaks were required to prove infringement.
Accordingly, we affirm.
                      BACKGROUND
    In the early 1980s, Merck scientists discovered and
synthesized the corticosteroid anhydrous mometasone
furoate or “MFA.” After initial setbacks with dissolving
MFA in water and pharmaceutical compositions, Merck
discovered a solvent that eventually allowed it to develop
MFA for the treatment of psoriasis.
     In the late 1980s, Merck sought to further develop
MFA into nasal formulations. That research led to the
discovery of a polymorph of MFA, mometasone furoate
monohydrate, also referred to as “MFM.” MFM and MFA
differ in that every molecule of MFM is associated with
water, whereas no water is present in the crystal lattice
structure of MFA. These differences cause conformational
changes to the solid crystal lattice structure in the two
crystalline forms. In certain aqueous suspensions, MFM
is the more stable polymorphic form.
    The discovery of MFM led to the development of
Merck’s Nasonex® nasal product, which is approved for
the treatment of perennial allergic rhinitis, seasonal
allergic rhinitis, nasal polyps, and congestion associated
with nasal symptoms of allergic rhinitis. The ’353 patent
claims MFM and pharmaceutical compositions comprising
MFM.
    In November 2014, Amneal filed ANDA No. 207989,
seeking approval to market a generic mometasone furoate
nasal spray comprising MFA (as opposed to MFM) as the
active ingredient. In February 2015, Amneal sent Merck
a notice letter, informing Merck of its ANDA filing and
certifying that its proposed product would not infringe the
’353 patent and that the ’353 patent was invalid. As a
result, in March 2015, Merck filed an infringement suit
against Amneal asserting claims 1, 6, and 9–12 of the ’353
4        MERCK SHARP & DOHME CORP.    v. AMNEAL PHARM. LLC



patent. Merck alleged that although Amneal’s ANDA
product contained MFA, its ANDA product would convert
to the infringing MFM form over time. Thus, the issue of
infringement before the district court was whether Am-
neal’s ANDA product would contain any patented MFM
during Amneal’s product’s two-year shelf-life.
    Relevant to the issues in this case, Amneal manufac-
tured three 100 kilogram ANDA submission batches
(“Exhibit Batches”) of its proposed ANDA product and
provided the FDA data on those samples. Amneal pro-
duced samples of the Exhibit Batches to Merck. Although
Amneal also gave the FDA data on samples from a 1,000
kilogram commercial-sized batch (“Commercial 157
Batch”), Amneal did not produce those samples to Merck.
As a result, Merck moved to compel production of the
Commercial 157 Batch samples, which the district court
ordered on November 24, 2015.
    On December 10, 2015, the district court ordered that
the case would be stayed unless Amneal filed a declara-
tion attesting that the Exhibit Batch samples provided to
Merck were representative of Amneal’s commercial ANDA
product. The district court further ordered “Amneal [to]
immediately make available to Merck samples of any
further representative commercial batches sent to the
FDA.” J.A. 82. On December 21, 2015, Amneal filed a
declaration, representing that its Exhibit Batch samples
were representative of its commercial ANDA product.
Amneal’s declaration indicated, however, that Amneal
amended its ANDA to change its commercial batch size
from 1,000 kg to 100 kg and would manufacture its com-
mercial ANDA products using the same formulation and
manufacturing process as the Exhibit Batch samples
provided to Merck. Based on this amendment, the district
court later excluded the Commercial 157 Batch samples
from trial, concluding that Amneal “has identified the
Exhibit Batches as its Generic Product to the FDA and
there is no credible indication that [Amneal] could realis-
MERCK SHARP & DOHME CORP.   v. AMNEAL PHARM. LLC          5



tically use the [Commercial] 157 Batch manufacturing
process instead.” J.A. 149.
    Because Amneal’s ANDA specification allowed for a
maximum bulk suspension hold of up to four days, the
FDA required Amneal to complete a bulk-hold study, in
which Amneal’s commercial batch would be held for a
four-day period before being packaged into nasal spray
bottles. On January 11, 2016, Amneal manufactured
another 100 kilogram commercial batch for the bulk-hold
study (“Batch 16001”). Amneal drew samples from the
batch on the first day (“Day 1 Batch”) and again on the
fourth day (“Day 4 Batch”). Before sampling the Day 4
Batch, Amneal additionally mixed the batch at 840 revo-
lutions per minute (“RPM”) for 30 minutes. After the
bulk-hold study was completed, Amneal again mixed the
Batch 16001 mixture and bottled it for storage, re-
designating the batch as “Batch 16001A” (hereinafter
referred to as the “A Batch”). On February 29, 2016,
Amneal responded to the FDA, providing data on samples
from the Day 1 and Day 4 Batches from the requested
bulk-hold study. Amneal did not provide the FDA data on
samples from the A Batch.
    On January 12, 2016 and February 11, 2016, Amneal
produced samples from the Day 1 Batch to Merck, indicat-
ing that they were representative of Amneal’s finished
commercial product. On March 10, 2016, Amneal com-
pleted its document production to Merck, which included
its February 29, 2016 response to the FDA providing the
results of the bulk-hold study. On April 25, 2016, Amneal
served a rebuttal expert report on infringement, in which
Amneal’s expert opined regarding samples from the Day 4
Batch. Merck represents that this was the first time it
became aware of the Day 4 and A Batch samples.
    This led to a discovery dispute close to trial regarding
whether samples of Amneal’s Day 1 Batch were repre-
sentative of Amneal’s final commercial product and
6         MERCK SHARP & DOHME CORP.   v. AMNEAL PHARM. LLC



whether Amneal should have produced the Day 4 and
A Batch samples. On May 9 and 13, 2016—six weeks
before trial—Merck sought emergency relief from the
district court, arguing that Amneal should have produced
samples from the Day 4 and A Batches. Merck argued
that because the Day 4 and A Batches underwent addi-
tional mixing, which can promote conversion of MFA to
the infringing MFM form, Amneal should have produced
samples from those batches for testing. Amneal argued
that additional samples would have been cumulative of
the Day 1 Batch samples already produced and main-
tained its representation that the Day 1 Batch samples
were representative of its ANDA product. The parties
and the district court recognized the link between the
requested production and the trial date: the upcoming
trial would have to be materially postponed if the Day 4
and A Batch samples were produced and Merck were
given a full opportunity to test those samples before trial.
    Following two discovery hearings on the issue, the
district court became aware of Amneal’s discovery viola-
tion and acknowledged that ideally Amneal should have
produced samples of the Day 4 and A Batches. The
district court determined, however, that it did not have
enough information at the time to determine whether the
Day 4 and A Batch samples were materially different
from the Day 1 Batch samples. The district court con-
cluded that it was “not persuaded sitting right here that
mixing [] makes a substantive difference, and if it doesn’t,
then it doesn’t matter that Amneal didn’t give [Merck] a
sample of both [the Day 4 and A Batches] . . . [and] only
gave [Merck the Day 1 Batch].” J.A. 128 at 27:7–12. The
district court did not compel Amneal to produce the
additional samples. Nor did the court postpone trial.
Instead, the district court gave Merck the opportunity to
prove at trial that the Day 4 and A Batch samples were
substantively different than the Day 1 Batch samples and
MERCK SHARP & DOHME CORP.   v. AMNEAL PHARM. LLC          7



warned Amneal that it was at risk of incurring costs if
Merck prevailed on the issue.
    At trial, Merck’s expert, Dr. Matzger, testified that he
tested samples of Amneal’s ANDA product using Raman
spectroscopy. 1 Dr. Matzger tested samples of Amneal’s
Exhibit Batches and did not identify any MFM crystals.
But Dr. Matzger also tested samples from the Day 1
Batch and testified that he identified a single Raman
peak at 1709 cm-1, which is characteristic of MFM.
Dr. Matzger testified that although he tested the Exhibit
and Day 1 Batch samples, he would have preferred to test
samples of Amneal’s Day 4 and A Batches because they
underwent additional mixing and thus were more repre-
sentative of the final ANDA product.
    Amneal’s expert, Dr. Marquardt, testified that
Dr. Matzger misinterpreted the data as identifying MFM
in Amneal’s Day 1 Batch samples and opined that MFM
was not present in Amneal’s final ANDA product.
Dr. Marquardt further opined that three Raman peaks
were required to confirm the presence of MFM rather
than a single Raman peak. Amneal’s other expert, Dr.
Rogers, disagreed with Dr. Matzger’s opinion regarding
the relevance of the Day 4 and A Batches. Dr. Rogers
opined that the likelihood of conversion of MFA to MFM
was merely theoretical and unlikely due to the high
energy required to convert between forms.
    Based on this competing testimony regarding sample
production and whether the Day 1 Batch samples were
representative of Amneal’s ANDA product, the district
court summarized the parties’ positions and its fact-
findings as follows:


   1    Raman spectroscopy is a vibrational spectroscopy
technique. A laser is used to generate a Raman spectrum,
which indicates the vibrational modes of molecules and
can be used to differentiate crystalline forms.
8         MERCK SHARP & DOHME CORP.    v. AMNEAL PHARM. LLC



        The parties dispute whether Amneal should
    have provided samples from [the Day 4 and A
    Batches] (“additional samples”) to Merck. Amneal
    asserts that the additional samples would be cu-
    mulative to those provided ([the Day 1 Batch] and
    the Exhibit Batches). Merck requests that the
    court conclude that the additional samples would
    have contained MFM because of the additional
    mixing. From the expert testimony, the court
    concludes that generally additional (or faster)
    mixing tends to promote conversion of MFA to
    MFM. Neither party, however, has offered a
    quantification of how the additional (or faster)
    mixing might affect the dissolution of MFA, or the
    nucleation and crystal growth of MFM in Am-
    neal’s ANDA product . . . . The expert testimo-
    ny—that conversion is system-dependent and the
    additional mixing performed on Batch 16001 like-
    ly would have promoted conversion—renders any
    conclusion regarding [the Day 4 and A Batches]
    theoretical. On the evidence presented, the court
    concludes that Merck has not demonstrated that
    the additional samples would yield different re-
    sults. Consequently, the court denies Merck’s al-
    ternative request for the production of [the Day 4
    and A Batch] samples and a new trial.
Merck Sharp & Dohme Corp. v. Amneal Pharm. LLC, 235
F. Supp. 3d 625, 631–32 (D. Del. 2017) (“District Court
Decision”) (footnotes omitted).
    Regarding infringement, the district court credited
Amneal’s expert that three Raman peaks were required to
identify MFM in Amneal’s ANDA product. As a result,
the district court “assign[ed] little weight to Dr. Matzger’s
identification of MFM based on a single peak . . . .” Id. at
636. The district court concluded that based on the “lack
of MFM in the Exhibit Batches and opposing conclusions
on the same testing of the [Day 1 Batch],” Merck failed to
MERCK SHARP & DOHME CORP.   v. AMNEAL PHARM. LLC          9



carry its burden of proving by a preponderance of the
evidence that MFM is present in Amneal’s ANDA product.
Id. at 637–38.
   Merck appeals. We have jurisdiction pursuant to
28 U.S.C. § 1295(a)(1).
                             I.
    We start our analysis with the district court’s discov-
ery ruling. We review the district court’s denial of addi-
tional discovery under regional circuit law. Digeo, Inc. v.
Audible, Inc., 505 F.3d 1362, 1370 (Fed. Cir. 2007). The
Third Circuit will not disturb a denial of additional dis-
covery absent an abuse of discretion and “a showing of
actual and substantial prejudice.” Anderson v. Wachovia
Mortg. Corp., 621 F.3d 261, 281 (3d Cir. 2010).
    The district court’s standing discovery order required
Amneal to “immediately make available to Merck samples
of any further representative commercial batches sent to
the FDA.” J.A. 82 (emphasis added). Amneal, however,
did not produce samples of its Day 4 Batch that it submit-
ted to the FDA, in violation of the discovery order. Merck
argues that the district court abused its discretion by not
compelling Amneal to produce samples of its Day 4 and
A Batches and by not postponing trial.
    The question before us is a close one. Amneal’s failure
to abide by the standing discovery order resulted in a trial
situation that was less than ideal. Because Amneal did
not produce samples of the Day 4 and A Batches, the
district court faced a very difficult situation a mere six
weeks prior to trial. The district court held two hearings
in which it tried to ascertain whether the Day 4 and
A Batches were materially different from the produced
Day 1 Batch samples. After concluding that Merck had
not shown that the Day 1 Batch samples were insufficient
to represent Amneal’s finished ANDA product, the district
court decided to proceed to trial, but also allowed Merck
10        MERCK SHARP & DOHME CORP.   v. AMNEAL PHARM. LLC



the opportunity to present evidence on the issue at trial.
The question on appeal is thus whether the district court
abused its discretion in choosing this particular approach
as opposed to ordering additional discovery and delaying
trial. We hold that it did not.
    The district court took adequate steps to ensure that
proceeding with trial would not prejudice Merck. Because
the court allowed Merck the opportunity to prove at trial
that the Day 4 and A Batch samples were different than
the Day 1 Batch samples for purposes of infringement, we
cannot say that Merck was prejudiced by the district
court’s decision to proceed to trial. The district court’s
offer to Merck was not illusory. At trial, Merck attempted
to prove that mixing promotes conversion of MFA to MFM
such that the additional mixing of Amneal’s Day 4 and
A Batches would likely convert the MFA to MFM.
    Merck’s expert, Dr. Matzger, testified that he per-
formed a thermodynamic stability study, which demon-
strated the conversion of MFA to MFM. In the study,
Dr. Matzger added MFM to Amneal’s Exhibit Batch of
MFA. Dr. Matzger then subjected the mixture to vigorous
shaking (at 500 RPM) for 27 days and sampled the mix-
ture at various stages during the shaking. Dr. Matzger
testified that at the end of the 27-day process, the mixture
converted to MFM. He also testified that he “intentional-
ly added [MFM] so that the conversion could take place
with both forms present, and so [he] wouldn’t know if
[MFM] would become present or when it would become
present if [he] hadn’t added it.” J.A. 166 at 63:6–12.
    Additionally, Dr. Matzger testified at trial that he was
aware of Amneal’s Day 4 and A Batches and that he
would have preferred to test samples of those batches
because they were “more representative” of Amneal’s final
product in that they went through additional mixing.
J.A. 178 at 111:6–25. Based on his analysis of the addi-
tional mixing steps, Dr. Matzger stated that he would
MERCK SHARP & DOHME CORP.    v. AMNEAL PHARM. LLC         11



have expected to find MFM in the Day 4 and A Batch
samples.
    Merck’s other expert, Dr. Trout, also opined that gen-
erally additional mixing increases the likelihood of poly-
morphic conversion to MFM. Dr. Trout testified that
additional vigorous mixing on an industrial scale imparts
more energy into the system, which increases the likeli-
hood of polymorphic conversion. Dr. Trout admitted,
however, that this conversion concept was based on
general chemical, thermodynamic, and kinetic principles
and that to determine whether conversion occurs in a
given sample, the sample would need to be tested. But
Dr. Trout did not test Amneal’s product, including the
Day 1 Batch samples.
    Amneal’s expert, Dr. Rogers, disagreed that the
amount of mixing Amneal did to arrive at the Day 4 and
A Batch samples would have increased the likelihood of
conversion. Dr. Rogers testified that Dr. Trout’s opinion
was based on a scientific reference involving a different
drug, which did not provide any relevant information on
MFM or MFA. Dr. Rogers also testified that increased
mixing does not necessarily result in increased polymor-
phic conversion. Finally, Dr. Rogers explained his view
that conversion of MFA in Amneal’s ANDA product would
be difficult due to the high energy required to convert to
MFM.
    In light of the competing evidence in the record before
us, we discern no clear error in the district court’s finding
that the trial evidence failed to demonstrate that the
MFA in Amneal’s product would have converted to MFM
based on Amneal’s additional mixing. As the district
court found, Merck presented little more than theoretical
evidence to show that the Day 4 and A Batch samples
would be more likely to undergo conversion than the
Day 1 Batch samples. Merck’s evidence merely supported
that MFA could convert to MFM by additional mixing.
12        MERCK SHARP & DOHME CORP.   v. AMNEAL PHARM. LLC



Merck made no attempt to prove that Amneal’s product
would convert simply by the additional mixing Amneal
performed on the produced Day 1 samples. While Merck’s
expert, Dr. Matzger, attempted to show conversion from
MFA to MFM in the Exhibit Batch samples produced by
Amneal, he did so by, among other steps, adding MFM to
the Exhibit Batch samples and mixing for 27 days. As the
district court explained, Dr. Matzger’s study was “not
representative of the ANDA product (because of the
addition of MFM) and did not measure the effect of mix-
ing speed or time on the rate of conversion.” District
Court Decision, 235 F. Supp. 3d at 631.
     We reject Merck’s argument that it could not prove
conversion without testing the Day 4 and A Batch sam-
ples. Merck had samples of Amneal’s Exhibit and Day 1
Batches, but made no attempt to experiment with Am-
neal’s ANDA product to demonstrate conversion by addi-
tional mixing and passage of time alone, let alone by
matching the mixing, in both speed and duration, that
Amneal carried out to arrive at the Day 4 and A Batch
samples. For example, Merck could have tested whether
mixing an MFA solution (e.g., the Day 1 Batch solution)
at 840 RPM for 30 minutes (the additional mixing steps of
the Day 4 or A Batches) would result in conversion of
MFA to MFM. Based on such lack of conclusive evidence,
we cannot say that the district court clearly erred in
finding that Merck failed to show that the Day 4 and
A Batch samples would have differed from the Day 1
Batch samples. We are not “left with a definite and firm
conviction that the district court was in error” to overturn
its fact-finding. Alza Corp. v. Mylan Labs., Inc., 464 F.3d
1286, 1289 (Fed. Cir. 2006).
    We recognize, as did the district court, that it would
have been better for the process if Amneal had provided
samples of the Day 4 and A Batches. Uncertainties in
pharmaceuticals provide sufficient reason for ANDA filers
to produce samples that are provided to the FDA for
MERCK SHARP & DOHME CORP.   v. AMNEAL PHARM. LLC         13



which they seek approval, as Amneal had been ordered to
do. In this case, however, we hold that the district court
did not err given the steps it took to allow Merck to prove
that Amneal’s discovery violation was prejudicial.
                            II.
     Having concluded that the district court did not abuse
its discretion in denying discovery of the Day 4 and
A Batch samples, we next turn to Merck’s argument that
the district court erred in relying on Amneal’s Day 1
Batch samples to find that Amneal will not infringe the
’353 patent. Following a bench trial, we review the dis-
trict court’s conclusions of law de novo and its fact-
findings for clear error. Golden Blount, Inc. v. Robert H.
Peterson Co., 365 F.3d 1054, 1058 (Fed. Cir. 2004). The
ultimate determination of infringement is a question of
fact, which we review for clear error. Id. A fact-finding is
clearly erroneous if the court “is left with a definite and
firm conviction that the district court was in error.” Alza,
464 F.3d at 1289.
    Merck argues that the district court’s finding of non-
infringement must be reversed as a matter of law because
the district court improperly based its noninfringement
finding on Amneal’s intermediate product (the Day
1 Batch samples) rather than its final, commercial-sized
product (the A Batch samples). In this regard, Merck
argues that the proper adjudication of an ANDA in-
fringement inquiry must focus on what will be or is likely
to be sold. Merck avers that Amneal’s A Batch samples
were the only final commercial ANDA product and thus
should have been the focus of the infringement question.
As Merck posits the argument, “[a]lthough the district
court’s error started as a discovery dispute, the district
court’s failure to recognize the proper subject of the in-
fringement inquiry according to 35 U.S.C. § 271(e)(2) and
this [c]ourt’s precedent resulted in a complete misapplica-
14        MERCK SHARP & DOHME CORP.    v. AMNEAL PHARM. LLC



tion of law under the Hatch-Waxman Act’s framework.”
Appellant Br. 37.
    As we explained above, Merck was allowed an oppor-
tunity to prove at trial that samples of the Day 4 and
A Batches would have materially differed from the Day 1
Batch samples. But Merck failed to do so. Based on the
lack of conclusive evidence that Amneal’s additional
mixing would have caused conversion in the Day 4 and
A Batches, we cannot say that the district court erred in
finding that Amneal’s Day 1 Batch samples were ade-
quate to represent Amneal’s final ANDA product for
purposes of determining infringement.
    We do not agree with Merck that our law requires
otherwise. In arguing that only the A Batch samples
should have been the focus of infringement, Merck seeks
to impose a heightened evidentiary standard in ANDA
cases not supported by our case law. We agree with
Merck that infringement under 35 U.S.C. § 271(e)(2)
“must focus on what the ANDA applicant will likely
market if its application is approved . . . .” Glaxo, Inc. v.
Novopharm, Ltd., 110 F.3d 1562, 1569 (Fed. Cir. 1997).
But we have not said that the proof of infringement in the
ANDA context must necessarily be based on any particu-
lar sample. To the contrary, we have “endorsed the
district court’s reference to relevant evidence, including
biobatch data and actual samples of the proposed generic
composition that the ANDA filer had submitted to the
FDA.” Ferring B.V. v. Watson Labs, Inc.-Fla., 764 F.3d
1401, 1409 (Fed. Cir. 2014). Regardless of the type of
sample (e.g., commercial or batch), the critical inquiry is
whether it is representative of what is likely to be ap-
proved and marketed.
    Here, we disagree with Merck that Amneal’s Day 1
Batch samples were merely an intermediate product and
not representative of its final commercial product. Am-
neal represented to the FDA and the district court that its
MERCK SHARP & DOHME CORP.   v. AMNEAL PHARM. LLC        15



Day 1 Batch samples were representative of its ANDA
product. Moreover, we note that Amneal’s ANDA specifi-
cation allows up to a four-day batch-hold period. Thus,
samples drawn from the Day 1 Batch met Amneal’s
ANDA specification and thus represented its ANDA
product.
    Merck’s reliance on Ferring is misplaced. In Ferring,
we held that infringement could not be based on Watson’s
uncoated tablets, but rather had to be based on the “final,
coated commercial . . . tablets for which Watson sought
and was granted FDA approval to market as a generic
version . . . .” 764 F.3d at 1409. In so holding, we empha-
sized the fact that Watson could not sell uncoated tablets
because they did not comply with Watson’s ANDA specifi-
cation. Id. Here, however, Amneal’s Day 1 Batch sam-
ples comply with its specification, and despite Merck’s
insistence that the A Batch samples are the most repre-
sentative of Amneal’s final product, Merck concedes that
no data on the A Batch samples was submitted to the
FDA for approval. See Oral Arg. at 10:00–10:35. Thus,
we conclude that the district court did not err in relying
on Amneal’s Day 1 Batch samples. 2




   2     In addition to finding that Amneal’s Day 1 Batch
samples did not infringe, the district court also supported
its noninfringement finding on the lack of MFM found in
Amneal’s Exhibit Batch samples. Merck argues that the
district court also erred in relying on the Exhibit Batch
samples because the Exhibit Batches were not manufac-
tured according to Amneal’s ANDA specification. We
need not resolve this issue because we conclude that the
district court did not clearly err in relying on the Day 1
Batch samples to conclude that Amneal does not infringe.
16       MERCK SHARP & DOHME CORP.    v. AMNEAL PHARM. LLC



                           III.
    We also discern no clear error in the district court’s
fact-finding of noninfringement. Although Dr. Matzger
testified that he identified a single Raman peak charac-
teristic of MFM in Amneal’s Day 1 Batch samples, his
testimony was rebutted. Amneal’s expert, Dr. Marquardt,
opined that Dr. Matzger misinterpreted his data and
testified that MFM was not present in the Day 1 Batch
samples. Dr. Marquardt also disagreed that a single
Raman peak was sufficient to distinguish between MFA
and MFM. The district court found Amneal’s expert
evidence “at least as consistent and credible” as Merck’s
expert and concluded that Merck failed to prove infringe-
ment by preponderant evidence. District Court Decision,
235 F. Supp. 3d at 637. Because its noninfringement
finding is supported by the record, we conclude that the
district court did not clearly err in its noninfringement
finding.
    On appeal, Merck argues that the district court clear-
ly erred in finding that three Raman peaks were required
to confirm the presence of MFM in Amneal’s ANDA
product. Specifically, Merck argues that the district court
ignored Amneal’s admission to the FDA that a single peak
at 1705 cm-1 is sufficient to identify MFM. Merck also
references portions of Amneal’s ANDA suggesting that
the Raman spectra peaks at 1705 cm-1 and 1725 cm-1 are
quick references to distinguish between MFM and MFA.
Merck further cites the deposition testimony of one of
Amneal’s scientists who testified that Amneal would look
for the 1705 cm-1 peak for MFM and the 1725 cm-1 peak
for MFA.
    The district court heard testimony from Amneal’s
expert, Dr. Marquardt, however, that although a single
peak can be used at times, three Raman peaks are typi-
cally used to absolutely confirm the presence of molecules
in complex mixtures like MFM. Because the district
court’s finding that three Raman peaks were required to
MERCK SHARP & DOHME CORP.    v. AMNEAL PHARM. LLC         17



identify MFM is supported by Dr. Marquardt’s testimony,
we conclude that the district court did not clearly err in so
finding.
     In concluding that three Raman peaks were required,
the district court also noted that the district court in
Schering Corp v. Apotex Inc., No. 09-6373, 2012 WL
2263292 (D.N.J. June 15, 2012), likewise concluded that
three peaks were required to confirm MFM. Schering
dealt with a similar generic version of Nasonex® manufac-
tured by Apotex, which also comprised MFA. The district
court there addressed the same issue of whether a single
peak or three peaks were required to identify MFM.
Schering involved Merck’s same expert, Dr. Matzger. In
Schering, the district court gave Dr. Matzger’s evidence
“little weight because it [did] not identify three peaks,”
and concluded that Apotex did not infringe. Id. at *10.
The three-peak issue was raised on appeal to this court,
and we affirmed the district court’s judgment without
opinion. See Merck Sharp & Dohme Corp. v. Apotex Inc.,
517 F. App’x 939 (Fed. Cir. 2013).
     Merck suggests that the district court improperly re-
lied on Schering to find that three peaks were required to
confirm the presence of MFM in Amneal’s ANDA product.
We disagree. While the district court noted the holding in
Schering, it is clear from the district court’s opinion that
it independently relied on Dr. Marquardt’s credible testi-
mony that three peaks were required. Based on this
record, we see no clear error in the district court’s fact-
finding that three peaks were required and that Amneal’s
ANDA product will not infringe.
                       CONCLUSION
   We have considered the parties’ remaining arguments
and find them unpersuasive. For the foregoing reasons,
we affirm.
                       AFFIRMED
18        MERCK SHARP & DOHME CORP.   v. AMNEAL PHARM. LLC



                          COSTS
     Costs to Appellee.
