Discovery and optimization of novel piperazines as potent inhibitors of fatty acid synthase (FASN)

Article abstract of DOI:10.1016/j.bmcl.2019.02.012

The discovery, structure-activity relationships, and optimization of a novel class of fatty acid synthase (FASN) inhibitors is reported. High throughput screening identified a series of substituted piperazines with structural features that enable interactions with many of the potency-driving regions of the FASN KR domain binding site. Derived from this series was FT113, a compound with potent biochemical and cellular activity, which translated into excellent activity in in vivo models.

Full text of DOI:10.1016/j.bmcl.2019.02.012

Accepted Manuscript
Discovery and Optimization of Novel Piperazines as Potent Inhibitors of Fatty
Acid Synthase (FASN)
Matthew W. Martin, David R. Lancia Jr., Hongbin Li, Shawn E.R. Schiller,
Angela V. Toms, Zhongguo Wang, Kenneth W. Bair, Jennifer Castro, Shawn
Fessler, Deepali Gotur, Stephen E. Hubbs, Goss S. Kauffman, Mark Kershaw,
George P. Luke, Crystal McKinnon, Lili Yao, Wei Lu, David S. Millan
PII:
S0960-894X(19)30088-5
https://doi.org/10.1016/j.bmcl.2019.02.012
BMCL 26292
DOI:
Reference:
To appear in:
Bioorganic & Medicinal Chemistry Letters
Received Date:
Revised Date:
Accepted Date:
15 January 2019
5 February 2019
10 February 2019
Please cite this article as: Martin, M.W., Lancia, D.R. Jr., Li, H., Schiller, S.E.R., Toms, A.V., Wang, Z., Bair, K.W.,
Castro, J., Fessler, S., Gotur, D., Hubbs, S.E., Kauffman, G.S., Kershaw, M., Luke, G.P., McKinnon, C., Yao, L.,
Lu, W., Millan, D.S., Discovery and Optimization of Novel Piperazines as Potent Inhibitors of Fatty Acid Synthase
(
FASN), Bioorganic & Medicinal Chemistry Letters (2019), doi: https://doi.org/10.1016/j.bmcl.2019.02.012
This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers
we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and
review of the resulting proof before it is published in its final form. Please note that during the production process
errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Bioorganic & Medicinal Chemistry Letters
Discovery and Optimization of Novel Piperazines as Potent Inhibitors of Fatty
Acid Synthase (FASN)
a,
a
b
a
a
Matthew W. Martin, David R. Lancia, Jr., Hongbin Li, Shawn E. R. Schiller, Angela V. Toms,
a
a
a
a
a
b
Zhongguo Wang, Kenneth W. Bair , Jennifer Castro, Shawn Fessler, Deepali Gotur, Stephen E. Hubbs,
Goss S. Kauffman, Mark Kershaw, George P. Luke, Crystal McKinnon, Lili Yao, Wei Lu
b
b
b
a
b
a,†
,
and David
a,‡
S. Millan
a
FORMA Therapeutics, 500 Arsenal Street, Suite 100, Watertown, MA 02472, USA
FORMA Therapeutics, 35 Northeast Industrial Road, Branford, CT 06405, USA
b
ARTICLE INFO
ABSTRACT
Article history:
Received
Revised
Accepted
Available online
The discovery, structure-activity relationships, and optimization of a novel class of fatty
acid synthase (FASN) inhibitors is reported. High throughput screening identified a
series of substituted piperazines with structural features that enable interactions with
many of the potency-driving regions of the FASN KR domain binding site. Derived
from this series was FT113, a compound with potent biochemical and cellular activity,
which translated into excellent activity in in vivo models.
Keywords:
Fatty acid synthase, FASN, de novo lipogenesis,
oncology, piperazines
Fatty acid synthase (FASN) is a key enzyme in the de novo
lipogenesis (DNL) pathway, catalyzing the synthesis of palmitate
and coenzyme A (CoA) from malonyl-CoA and acetyl-CoA. Most
normal human tissues preferentially use dietary lipids for synthesis
of new structural lipids, and de novo fatty-acid synthesis is usually
suppressed, with FASN expression maintained at low levels. By
contrast, in cancer cells, the supply of cellular fatty acids is highly
dependent on the de novo synthesis with the expression of many
of these key enzymes being elevated. As such, FASN is highly
expressed in many cancers, including glioblastoma, prostate,
ovarian, breast, endometrial, thyroid, colorectal, bladder, lung,
thyroid, oral, head and neck, hepatocellular, pancreatic, gastric
compound 1 was a selective inhibitor of the ketoreductase (KR)
6
,11,12
domain of FASN (see Supplementary Material).
Synthesis
and screening of the individual enantiomers of 1 identified the (R)-
isomer (2) as the more potent isomer (IC50 = 1.1 µM) with the
corresponding (S)-isomer (3) showing significantly less activity
(IC50 >50 µM). Compound 2 also had robust microsomal stability
when screened in mice (100% remaining after 30-minute
incubation), providing an excellent starting point for compound
optimization.
1
carcinomas, melanoma, and soft tissue sarcomas. Therefore,
FASN has been emerged as an attractive therapeutic target for
2
–10
cancer drug discovery and development efforts.
Figure 1. Structure and activity of initial HTS hit
We initiated efforts to identify a novel and potent inhibitor of
FASN as a potential cancer therapeutic. A high throughput screen
of our compound collection was conducted against full length
human FASN recombinant enzyme. In this assay, the production
of coenzyme A was measured by the formation of a fluorescent
CPM-CoA conjugate from the non-fluorescent reagent 7-
diethylamino-3-(4’-maleimidyl-phenyl)-4-methylcoumarin
With the aryl acyl group at N4 and the polar alkyl acyl group at
N1, these compounds were amenable to further optimization by
taking advantage of Suzuki cross-couplings and subsequent
amide-forming reactions. In the absence of any structural
information at the outset, a ligand-based compound design
approach was undertaken. Initial efforts were focused on two
fronts: (1) varying the “left-hand side” (LHS) (as drawn) of the
molecule while maintaining the local environment provided by the
carbonyl and THF-oxygens and (2) optimizing the biaryl group on
the “right-hand side” (RHS) of the molecule.
(CPM). Substituted piperazines, such as the racemic compound 1,
were discovered as active FASN inhibitors (IC50 = 1.14 µM) with
drug-like properties (LE = 0.29, LipE = 4.0) suitable for follow-up
(
Figure 1). Further biochemical characterization suggested
—
——

Corresponding author. Tel.: +1-857-209-2357; e-mail: mmartin@formatherapeutics.com
Current Address: KSQ Therapeutics, 610 Main Street, Cambridge, MA 02139, USA
Current Address: Foghorn Therapeutics, 100 Binney Street, Suite 610, Cambridge, MA 02142, USA
†
‡

Table 1 summarizes our exploration of the N1 amide. We
sought to identify alternative groups that could maintain the key
interactions while removing the stereogenic center. A variety of
cycloalkyl systems were explored, with a distinct preference for
small rings. The importance of the oxygen was confirmed, as
removal resulted in almost complete loss of activity (e.g. 4). We
next explored the possibility of moving the oxygen out of the ring.
Hydroxycyclopentyl analog 5 showed no significant activity (IC50
variety of 6,5- and 6,6-heteroaromatic ring-containing compounds
were synthesized. As exemplified by indole analogs 13 and 14,
pyrazole 15, benzothiazole 16, as well as isoquinoline 18 and
quinolines 19 and 20, the introduction of polarity resulted in as
much as a 10-fold improvement in potency in the biochemical
assay, as well as improved properties (LipE ~ 6).
In addition to the enzymatic assay, the cellular activities of the
1
4
compounds were also measured by two cell assays. In the C-
acetate incorporation assay, BT474 human breast cancer cells
>
50 µM), whereas hydroxycyclobutyl analog 6 (IC50 = 1.8 M)
was equipotent with the original THF analog 2.
Hydroxycyclopropyl analog 7 showed the most promise with
improvements in both potency (IC50 = 350 nM) and drug-like
properties (LipE 5.3 vs 4.3 for 2) while maintaining excellent
microsomal stability. Finally, we explored opening the cycloalkyl
ring (e.g. 8); however, this change also resulted in a large loss in
potency, showing the importance of the cyclopropyl ring. The
combination of promising potency and drug-like properties, as
well as the removal of the stereogenic center (thus avoiding any
possibilities of epimerization or scrambling of stereochemistry in
subsequent steps), made the hydroxycylopropyl group a desirable
option, and this group was utilized in subsequent analogs.
1
4
14
converted C-acetate to C-acetyl-CoA, which was subsequently
assembled into newly synthesized radiolabeled palmitate by
cellular FASN enzyme. Therefore, this assay measured the ability
of FASN inhibitors to block FASN activity in a cellular context.
In the second cellular assay, the proliferation of PC3 human
prostate cancer cells were maintained in growth media
supplemented with 10% lipid-reduced serum (LRS) in the
presence of FASN inhibitor. Under LRS condition, PC3 growth
has been shown to be dependent on DNL. Hence, this assay
monitored functional consequence of FASN inhibition on cancer
cells. As shown in Table 2, improvements in enzyme potency
translated into improved cellular activity.
Table 1. Exploration of the N1 Amide
Based on its promising drug-like properties (LipE 6.4) and
good in vitro ADME properties, 18 was studied in a mouse oral
PK study. Unfortunately, the compound showed very little oral
exposure (AUC0-8h= 0.1 M*h) after a 5 mg/kg oral dose in mice
with clearance much greater than would be expected from the
moderate metabolic stability observed for the compound in mouse
liver microsomes.
FASNa
IC50 (M)
MLMb
R
LipEc
4.3
(% 30 min)
Low oral exposures were found in several other compounds
possessing similar nitrogen-containing heterocycles, such as
indole 13, benzothiazole 16, and quinoline 19 (data not shown).
One factor in this low exposure was hypothesized to be
metabolism derived from aldehyde oxidase (AO), a cytosolic
enzyme expressed primarily in the liver that can hydroxylate
2
3
1.1
50
100
65
2.6
1.2
1
3,14
adjacent to an aromatic nitrogen.
To test this theory, attention
was turned to the less potent phenyl analog 9 (FASN IC50 = 110
nM), featuring a di-substituted aromatic ring instead of a nitrogen-
containing heterocycle. When dosed orally in mice at 5 mg/kg, 9
exhibited reasonable drug levels (AUC0-8h= 47.6 M*h). To
further understand this issue, several compounds were also
screened in mouse hepatocytes as well as mouse S9 fraction (a
liver fraction containing microsomal and cytosolic enzymes,
including AO, capable of phase 1 and 2 metabolism) to determine
if a better in vitro to in vivo correlation could be identified (see
Supplementary Data). Indeed, these measures did correlate much
better with in vivo results, further supporting the hypothesis. At
this stage, it was unclear if AO would be relevant in the human
system, and therefore removing this liability became an area of
focus.
4
5
6
7
8
50
50
2.2
4.0
5.3
2.7
1.8
0.35
35
85
95
99
Several compounds containing bicyclic heteroaromatic rings
were then synthesized, each lacking an oxidizable CH bond
adjacent to the nitrogen of the heterocycle (e.g. 22-24). Among
these, benzoxazole analog 22 was a compound with excellent
potency (FASN IC50 = 50 nM, PC3 proliferation IC50 = 15 nM,
aIn vitro enzymatic potency was measured using a CPM assay with
full-length recombinant human FASN enzyme. Reported as mean of
b
at least two separate assay runs. Mouse liver microsome stability
expressed as percent remaining after 30-minute incubation.
14
BT474 C incorporation IC50 = 100 nM), low intrinsic clearance
c
Lipophilic efficiency = pIC50(FASN)–clogP.
(~7 µL/min/mg in human and mouse microsomes), and overall
excellent drug-like properties (LipE 5.9). When dosed at 5 mg/kg
PO in mice, this compound provided excellent oral exposure
Our attention then turned to optimization of the biaryl right
hand side of the molecule. Initial efforts focused on substituting
the second aryl ring to alter the electronics. As shown in Table 2,
the incorporation of electron-withdrawing groups (e.g. 9-11)
afforded modest increases in potency with little impact on other
properties of the molecule. In contrast, the addition of electron
donating groups, such as in 12, exhibited decreased potency. We
also examined the impact of heterocyclic substituents, and a
(AUC0-8h= 28.7 M*h). Unfortunately, this compound was not
well tolerated, with an MTD of less than 5 mg/ kg in mice (single
dose).

Table 2. Exploration of the Aryl substituent
FASNa
IC50 (M)
PC3b
IC50 (M)
14C BT474c
IC50 (M)
MLMd
(% 30 min)
Solubilitye
(M)
R
clogPf
2.0
LipEg
5.0
9
0.11
0.11
0.31
3.1
0.146
0.138
0.336
0.158
4.96
92
66
69
33
43
67
1
0
1
2
2.1
4.9
1
1
1.7
4.8
1.7
3.8
13
14
15
16
17
18
0.016
0.012
0.026
0.032
0.142
0.013
0.004
0.018
0.019
55
81
89
88
60
45
60
3
1.5
1.9
1.2
2.0
1.2
1.5
6.3
6.0
6.4
5.9
4.9
6.4
0.012
0.017
0.142
0.013
79
95
92
77
0.011
0.257
0.011
19
20
21
0.010
0.032
>5
0.012
0.101
>125
86
79
89
82
71
95
1.5
1.6
0.5
6.5
5.9
4.8
0.002
22
23
24
0.054
0.057
0.033
0.015
0.214
0.025
0.101
0.067
0.070
109
84
83
18
1.3
1.8
1.9
6.0
5.4
4.8
20
0.3
a
In vitro enzymatic potency was measured using a CPM assay with full-length recombinant human FASN enzyme. Reported as mean of
b
at least two separate assay runs. Anti-proliferative activity assessed in PC3 cells. Reported as mean of at least two separate assay runs.
c
14
The C BT474 assay measured the potency of FASN inhibitors in blocking FASN activity as measured in BT474 cells. Reported as mean
d
of at least two separate assay runs. Mouse liver microsome stability expressed as percent remaining after 30-minute incubation.
e
f
g
Kinetic solubility at pH=7.4. Calculated logP value. Lipophilic efficiency = pIC50 (FASN) – clogP.
To verify the binding mode and potentially aid in optimization carbonyl of the hydroxycyclopropylamide and the KR domain
of this lead series, an X-ray crystal structure of 22 bound to a
ΨME-ΨKR-KR tridomain FASN construct was solved to 2.26 Å
resolution (Figure 2). The compound binds to the active site of the
KR domain near the interface with the ΨKR domain. A network
of key hydrogen bond interactions forms between the hydroxyl and
active site residues (Ser2021, Gln2031, Tyr2034). A pi interaction
is also observed between the cyclopropyl group and the
nicotinamide moiety of the NADPH cofactor, confirming the
importance of the cyclopropyl ring. The angle formed by the amide
bond between the piperazine and the phenyl places the phenyl and

benzoxazole ring system in a narrow hydrophobic channel. The
benzoxazole fills a flexible pocket at the interface of the KR and
ΨKR domains. The pocket is lined with a mixture of rigid
hydrophobic residues (Phe2019, Pro1264, Leu1265, Val2022) and
flexible basic residues (His1263, Arg1462, Arg2026). The
residues present in this pocket explain the SAR preference for
heteroaromatic rings that could interact both hydrophobically and
through hydrogen bonding to the basic residues. The benzoxazole
in 22 fulfills these interactions including a through water
interaction to Gly2027.
The initial promising potency and PK properties of 22, coupled
with the structural insights obtained from the crystal structure,
guided further optimization (Table 3). We sought to mitigate the
potential toxicity of the benzoxazole series by blocking the sites
para to the anilino nitrogen and phenolic oxygen, areas known to
15
form reactive metabolites.
Thus, 5- and 6-substituted
benzoxazoles were examined (e.g. 25-27, FT113). Introduction of
chloro- and fluoro-substitution had minimal effect on potency
and the overall physicochemical properties. However, some
decrease in solubility was observed for the chloro analogs. Fluoro
analogs 27 and FT113 were ultimately identified as the
compounds with the best balance of potency and
physicochemical properties, and both were advanced to in vivo
studies.
The pharmacokinetic properties of fluoro-benzoxazoles 27 and
FT113 were assessed in mice. Upon oral dosing at 5 mg/kg in
female Balb/c nude mice, a stark contrast was observed. 5-
Fluorobenzoxazole analog 27 was not tolerated, displaying acute
toxicity after a single 5 mg/kg dose.
In contrast, 6-
fluorobenzoxazole FT113 showed no acute toxicity and provided
excellent exposure when dosed orally at 5 mg/kg (AUC0-8h = 46

M*h, see Table 4). These findings suggest blocking of the 6-
position is important to the prevention of potentially reactive
metabolites. The PK properties of FT113 were further profiled in
rats. Upon oral dosing at 5 mg/kg in male Sprague-Dawley rats,
FT113 displayed excellent exposure (AUC0-24h = 440 M*h, see
Table 4) and bioavailability (84%).
Figure 2. Co-crystal structure of 22 (2.26 Å) bound to ΨME-ΨKR-
KR tridomain FASN construct (PDB code: 6NNA)
Table 3. Optimization of the Benzoxazole substituent
FASNa
IC50 (M)
PC3b
IC50 (M)
14C BT474c
IC50 (M)
MV-411d
IC50 (M)
MLMe
(% 30 min)
Solubilityf
(M)
R
clogPg
LipEh
25
26
27
0.069
0.097
0.192
0.049
0.029
0.052
0.136
0.104
0.061
85
92
93
6
7
1.8
1.8
1.3
5.4
5.3
5.4
30
FT113
0.213
0.047
0.090
0.026
100
39
1.3
5.4
a
In vitro enzymatic potency was measured using a CPM assay with full-length recombinant human FASN enzyme. Reported as mean of
b
at least two separate assay runs. Anti-proliferative activity assessed in PC3 cells. Reported as mean of at least two separate assay runs.
c
14
The C BT474 assay measured the potency of FASN inhibitors in blocking FASN activity as measured in BT474 cells. Reported as mean
d
of at least two separate assay runs. Anti-proliferative activity assessed in MV-411 cells. Reported as mean of at least two separate assay
e
f
runs. Mouse liver microsome stability expressed as percent remaining after 30-minute incubation. Kinetic solubility at pH=7.4.
g
h
Calculated logP value. Lipophilic efficiency = pIC50 (FASN) – clogP.
a
Table 4. Pharmacokinetic Profile of FT113 after oral dosing
Dosed p.o. in female Balb/c nude mice (n=6). Dosing formulation:
b
PEG400/Ethanol (9:1). Dosed p.o. in male Sprague Dawley rats (n=3).
Dosing formulation: PEG400/Ethanol (9:1).
Dose
mg/kg)
t
(h)
max
C
(M)
max
AUC0-8h
(M*h)
Bioavailability
(%F)
Species
Mousea
(
(
5
2
8.4
46
95
We investigated the in vivo potency of compound FT113 in
mouse models subcutaneously xenografted with human cancer
cell line MV-411. When the tumor size reached 130-140 mm , the
xenografted mice were randomized based on tumor size into four
groups (N=4 mice/group) and received vehicle (9:1 (v/v)
PEG400/ethanol), or 5, 25, or 50 mg/kg of FT113 twice daily for
Dose
mg/kg)
t
max
C
(M)
max
AUC0-24h Bioavailability
(M*h)
Species
Ratb
3
(h)
(%F)
5
3
33
440
84

1
6 days. At 4 hour post last dose, the mice were euthanized and
synthesis. We also thank Viva Biotech (Shanghai) Ltd. for the
FASN co-crystal structure with compound 22.
the malonyl-CoA (FASN substrate) in xenograft tumor samples
was measured by LC-MS. FT113 treatment showed dose-
dependent increase of malonyl-CoA concentration in tumors in
treated vs. vehicle groups, indicating FASN inhibition in the tumor
tissue (Figure 3). In addition, treatment with 25 and 50 mg/kg of
FT113 achieved 32 % and 50% tumor growth inhibition,
respectively, vs. the vehicle group after 16-day treatment (data
not shown), suggesting that FASN inhibitors could hold promise
for activity against cancer and, as such, merit further study.
Supplementary Material
Supplementary material associated with this article (including
details of the in vitro FASN enzyme and cellular assays; the MV-
4
11 xenograft mouse model; FASN protein expression,
purification, crystallization, and X-ray structure solution; as well
as experimental procedures for the synthesis of compound FT113)
can be found in the online version.
*
**
1
000
*
1
00
e
g
g
g
l
k
k
k
/
c
/
/
i
g
g
g
h
e
m
m
m
V
5
5
0
2
5
Figure 3. MalonylCoA levels in MV-411 mouse xenograft model.
Athymic nude mice (n=4) were treated b.i.d. with FT113 for 16
days at the indicated doses. Tumors were collected 4 h post last
dose and MalonylCoA levels were measured by LC-MS. Error bars
represent +/- SEM. P values of * indicates p < 0.05; *** indicates
p < 0.0005, as determined by one-way ANOVA vs. vehicle control.
Scheme 1. Synthesis of 2-arylisoindoline-4-carboxamides. Reagents
FT113 was synthesized from readily available starting
materials according to the concise route illustrated in Scheme 1.
Condensation of methyl 4-(chlorocarbonyl)benzoate (28) with 2-
amino-5-fluorophenol (29) in the presence of methane sulfonic
acid provided 2-arylbenzoxazole 30 in 66% yield. Saponification
with lithium hydroxide yielded carboxylic acid 31, which was
reacted with tert-butyl piperazine-1-carboxylate under standard
amide coupling conditions to afford piperazine amide 32 in 56%
overall yield. Removal of the Boc-protecting group with
hydrochloric acid provided piperazine 33 as its hydrochloride salt
in near quantitative yield. Subsequent treatment of 33 with 1-
hydroxycyclopropane-1-carboxylic acid under amide coupling
conditions afforded the desired product FT113 in 47% yield.
and conditions: (a) methanesulfonic acid, 1,4-dioxane, 100 °C, 24 h,
66%; (b) LiOH, 1,4-dioxane, H
butylpiperazine-1-carboxylate, EDC·HCl, HOBt, NMM, DMF, 4 h,
56 %; (d) HCl, Et O, 18 h, 98%; (e) 1-hydroxycyclopropane-1-
2
O, rt, 5 h, 100%; (c) tert-
2
carboxylic acid, EDC·HCl, HOBt, NaOH EtOH, 24 h, 47 %.
References and notes
1. Menendez JA, Lupu R. Fatty acid synthase and the lipogenic phenotype
in cancer pathogenesis. Nat Rev Cancer. 2007;7(10):763-777.
doi:10.1038/nrc2222
2
.
Kridel SJ, Lowther WT, Pemble CW. Fatty acid synthase inhibitors: new
directions for oncology. Expert Opin Investig Drugs. 2007;16(11):1817-1829.
doi:10.1517/13543784.16.11.1817
3
.
Kridel SJ. Orlistat Is a Novel Inhibitor of Fatty Acid Synthase with
Antitumor Activity. Cancer Res. 2004;64(6):2070-2075. doi:10.1158/0008-
In summary, we have described the discovery of a novel series
of piperazines as potent FASN inhibitors. Systematic SAR
exploration allowed for the rapid identification of the optimal
groups necessary for efficient binding. This led to the discovery
of compound FT113, which had the best balance of potency and
in vitro and in vivo PK/PD properties, enabling its use as a tool to
develop POC in models of DNL driven disease. Upon daily
dosing, compound FT113 demonstrates significant increases in
malonylCoA concentrations as well as tumor growth inhibition.
5
4
472.CAN-03-3645
Vázquez MJ, Leavens W, Liu R, et al. Discovery of GSK837149A, an
.
inhibitor of human fatty acid synthase targeting the β-ketoacyl reductase
reaction. FEBS J. 2008;275(7):1556-1567. doi:10.1111/j.1742-
4658.2008.06314.x
Oslob JD, Johnson RJ, Cai H, et al. Imidazopyridine-Based Fatty Acid
5
.
Synthase Inhibitors That Show Anti-HCV Activity and in Vivo Target
Modulation. ACS Med Chem Lett. 2013;4(1):113-117. doi:10.1021/ml300335r
6
.
Hardwicke MA, Rendina AR, Williams SP, et al. A human fatty acid
synthase inhibitor binds β-ketoacyl reductase in the keto-substrate site. Nat
Chem Biol. 2014;10(9):774-779. doi:10.1038/nchembio.1603
7
.
Ventura R, Mordec K, Waszczuk J, et al. Inhibition of de novo Palmitate
Acknowledgments
Synthesis by Fatty Acid Synthase Induces Apoptosis in Tumor Cells by
Remodeling Cell Membranes, Inhibiting Signaling Pathways, and
Reprogramming Gene Expression. EBioMedicine. 2015;2(8):808-824.
doi:10.1016/j.ebiom.2015.06.020
We thank Hien Diep for in vitro ADME support, Scot Mente
for statistical analysis and helpful discussions, and Mark Tebbe
and James Loch for contributions to compound design and

8
.
Angeles TS, Hudkins RL. Recent advances in targeting the fatty acid
biosynthetic pathway using fatty acid synthase inhibitors. Expert Opin Drug
Discov. 2016;11(12):1187-1199. doi:10.1080/17460441.2016.1245286
9
.
Buckley D, Duke G, Heuer TS, et al. Fatty acid synthase - Modern tumor
cell biology insights into a classical oncology target. Pharmacol Ther.
February 2017. doi:10.1016/j.pharmthera.2017.02.021
1
0. Lu T, Schubert C, Cummings MD, et al. Design and synthesis of a series
of bioavailable fatty acid synthase (FASN) KR domain inhibitors for cancer
therapy. Bioorg Med Chem Lett. 2018;28(12):2159-2164.
doi:10.1016/j.bmcl.2018.05.014
1. Maier T, Leibundgut M, Ban N. The Crystal Structure of a Mammalian
Fatty Acid Synthase. Science. 2008;321(5894):1315-1322.
doi:10.1126/science.1161269
2. Weissman KJ. Taking a Closer Look at Fatty Acid Biosynthesis.
ChemBioChem. 2008;9(18):2929-2931. doi:10.1002/cbic.200800671
3. Pryde DC, Dalvie D, Hu Q, Jones P, Obach RS, Tran T-D. Aldehyde
oxidase: an enzyme of emerging importance in drug discovery. J Med Chem.
1
1
1
2
1
010;53(24):8441-8460. doi:10.1021/jm100888d
4. Pryde DC, Tran T-D, Jones P, et al. Medicinal chemistry approaches to
avoid aldehyde oxidase metabolism. Bioorg Med Chem Lett. 2012;22(8):2856-
2
1
860. doi:10.1016/j.bmcl.2012.02.069
5. Plampin JN, Cain CK. Synthesis of Metabolic Products of
Benzoxazoles1. J Med Chem. 1963;6(3):247-248. doi:10.1021/jm00339a006

Discovery and Optimization of Novel
Piperazines as Potent Inhibitors of
Fatty Acid Synthase (FASN)
a,*
a
Matthew W. Martin, David R. Lancia, Jr.,
b
a
Hongbin Li, Shawn E. R. Schiller, Angela V.
Toms, Zhongguo Wang, Kenneth W. Bair ,
Jennifer Castro, Shawn Fessler, Deepali Gotur,
Stephen E. Hubbs, Goss S. Kauffman, Mark
a
a
a
a
a
a
b
b
b
b
a
Kershaw, George P. Luke, Crystal McKinnon,
b
a
a
Lili Yao, Wei Lu
,
and David S. Millan
aFORMA Therapeutics, 500 Arsenal Street, Suite
1
00, Watertown, MA 02472, USA
b
FORMA Therapeutics, 35 Northeast Industrial
Road, Branford, CT 06405, USA
Highlights




Identified novel and potent inhibitors of
FASN KR domain
Synthesis and structure activity
relationships of compounds are reported
FT113 displays excellent cellular activity
and pharmacokinetic properties
FT113 is a valuable tool to develop POC
models of DNL driven disease