sig-018: novel encapsulated non-viral cell-based therapy
TRANSCRIPT
SIG-018: Novel Encapsulated Non-Viral Cell-Based Therapy for
MPS II
MARISSA DONOVAN, PHD
SIGILON THERAPEUTICS, CAMBRIDGE, MA, USA
254
Marissa Donovan Disclosures•Employed by Sigilon Therapeutics, Inc.
•Has stock ownership in Sigilon Therapeutics, Inc.
MPS II (Hunter Syndrome)•MPS II (Hunter Syndrome) is caused by deficiency of the lysosomal enzyme iduronate 2-sulfatase (IDS) leading to GAG accumulation in multiple tissues and organs
•The accumulation results in a complex array of progressive, multi-organ, clinical manifestations with ~2/3 of the patients presenting with CNS involvement
•Approved treatments include enzyme replacement therapy, with gene therapies under investigation
HYPOTHESIS: Sustained therapeutic effect can be achieved by administration of hIDS-secreting allogeneic human cells shielded within spheres designed to avoid immune rejection and pericapsular fibrotic overgrowth (PFO) in the patient
Scarpa Gene Reviews 2018
Allogeneic Cell-Based Therapy: Challenges•Biomaterials can physically protect the cells but they themselves activate foreign body response resulting
in pericapsular fibrotic overgrowth (PFO)
Normal
Range
fibrosis of
capsules
immune rejection of
implanted rat cells
Rat islets, encapsulated in alginates
Rat islets, not encapsulated
Adapted from Lim Science 1980
Sigilon data on file
10X
fibrous tissue formation
immune cell adhesion
40X
Non-Viral Cell-Based Engineered Platform•This non-viral, cell-based, modular platform
was designed to address both challenges:
Bochenek Nat Biomed Eng 2018
Carmona ISTH 2020
Barney ASGCT 2020
No PFO observed
after 180 days
Empty spheres were
administered to the
non-human primates
intraperitoneally via
laparoscopic
procedure.
Cell-to-cell interaction
and rejection
Physical shield
(2-compartment,
modified alginate
sphere)
Pericapsular fibrotic
overgrowth (PFO)
Small-molecule
conjugated alginate
in outer layer
SIG-018: Encapsulated Non-Viral Cell-Based Platform
Inner Compartment:• genetically modified human
cells that express hIDS
• modified alginate designed to
optimize cell function
Outer Layer:• modified alginate chemically
linked to small molecule to
minimize PFO
1.5 mm
Bright field microscope image of a typical sphere
Bochenek Nat Biomed Eng 2018
Barney ASGCT 2020
• The shielded spheres are placed in the peritoneal space where they can absorb nutrients while the
released therapeutic protein can enter the blood compartment
SIG-018: Development Path
SIG-018
0
50
100
150
200
ng
hID
S/s
ph
ere
/day
2. Evaluate secreted hIDS
biochemical characteristics
& in vitro functionality
4. Evaluate hIDS production
from spheres
5. Implant in Ids-/- mice3. Encapsulate engineered cells1. Engineer cells to express hIDS
hIDSGenomic DNA
hIDS
Muenzer Acta Paediatrica 2002
JAX stock #024744
©ATCC
Comparison of hIDS Produced From Engineered Allogeneic Cells to Commercial Idursulfase
0 1 2 3
0
500
1000
1500
2000
Km: hIDS from cell media vs idursulfase
4-Methylumbellifery-α-L-Iduronide, [mM]
RF
U
Idursulfase
hIDS
hIDS cell media idursulfase untreated
0
200
400
600
800
Equivalent GAG lowering in MPS II fibroblasts
by hIDS from cell media vs commercial idursulfase
Tota
l H
S, n
g/m
g p
rote
in
ns
hIDS cell media idursulfase
0
10
20
30
Equivalent uptake by MPS II fibroblasts
of hIDS from cell media vs commercial idursulfase
% u
pta
ke
by
MP
SII
fib
rob
last ns
Secreted hIDS Idursulfase
Km (mM) 1.89 ± 0.20 2.01 ± 0.26
hIDS Levels and Heparan Sulfate (HS) Reduction in MPS II Mice Plasma
Day 7 Day 14 Day 21 Sham
0
50
100
150
200
250
Plasma total heparan sulfate (HS)
ng
HS
/mL
pla
sm
a
as %
of
sh
am
****
**
0 5 10 15 20
0
5
10
15
20
25
Plasma hIDS levels
ng
hID
S/m
L p
lasm
a
imp
lan
t Days
HS heparan sulfate; Each time point, n=4; Each dose level, n=4; Sham, n=16; **** p<0.001; *** p<0.001; ** p<0.01; * p<0.05; n.s. p>0.05
hIDS is detectable in MPS II KO mouse plasma resulting
in significant HS reduction at all timepoints
Heparan Sulfate (HS) Reduction With Low Dose of SIG-018 Across Tissues in MPS II Mice
1 week 2 weeks 3 weeks 4 weeks Sham
0
2
4
6
8
1050
100
150
ng
HS/m
g t
ota
l p
rote
in
as
% o
f sh
am
****
**** ********
1 week 2 weeks 3 weeks 4 weeks Sham
0
50
100
150
ng
HS/m
g t
ota
l p
rote
in
as
% o
f sh
am
**
**** *******
1 week 2 weeks 3 weeks 4 weeks Sham
0
50
100
150
ng
HS/m
g t
ota
l p
rote
in
as
% o
f sh
am
****
********
****
1 week 2 weeks 3 weeks 4 weeks Sham
0
50
100
150
ng
HS/m
g t
ota
l p
rote
in
as
% o
f sh
am
******** **** ****
Liver Kidney Spleen Heart
Lung Plasma
1 week 2 weeks 3 weeks 4 weeks Sham
0
50
100
150
ng
HS/m
g t
ota
l p
rote
in
as
% o
f sh
am
********
****
****
1 week 2 weeks 3 weeks 4 weeks Sham
0
50
100
150
200
250
ng
HS/m
L p
lasm
a
as
% o
f sh
am
****
** **
1 week 2 weeks 3 weeks 4 weeks Sham
0
200
400
600
ng
HS/m
g c
rea
tin
ine
as
% o
f sh
am
Urine
HS heparan sulfate; Each time point, n=4; Sham, n=16; **** p<0.001; *** p<0.001; ** p<0.01; * p<0.05; n.s. p>0.05
4-week treatment with SIG-018 demonstrated reduction of
HS across MPS II KO mouse tissues
Dose Response PD Study in MPS II Mice
L M H Sham
0
5
1050
100
150
ng
HS/m
g t
ota
l p
rote
in
as
% o
f sh
am
**** ********
L M H Sham
0
50
100
150
ng
HS/m
g t
ota
l p
rote
in
as
% o
f sh
am
****
*****
L M H Sham
0
50
100
150
200
ng
HS/m
g t
ota
l p
rote
in
as
% o
f sh
am
*** **
L M H Sham
0
50
100
150
ng
HS/m
g t
ota
l p
rote
in
as
% o
f sh
am
***
*****
L M H Sham
0
50
100
150
ng
HS/m
g t
ota
l p
rote
in
as
% o
f sh
am
***
**
***
L M H Sham
0
50
100
150
ng
HS/m
L p
lasm
a
as
% o
f sh
am
****
**
****
HS heparan sulfate; L Low Dose; M Medium Dose; H High Dose; Each dose level, n=4; Sham, n=4; **** p<0.001; *** p<0.001; ** p<0.01; * p<0.05; n.s. p>0.05
Liver Kidney Spleen
Heart Lung Plasma
After one week SIG-018 reduces HS build-up across MPS II mouse tissues at the lowest dose level
ConclusionsThis modular platform can be applied across a range of chronic diseases
◦ SIG-001, product that utilizes the same technology platform, is currently being studied in the first-in-
human clinical trial in patients with severe or moderately severe hemophilia A (NCT04541628)• Iduronate 2-sulfatase produced by the engineered cells has similar biochemical characteristics
as recombinant protein
• Encapsulated engineered cells (SIG-018) produced active human iduronate 2-sulfatase
• MPS II KO mice treated with SIG-018 showed continuous levels of active hIDS in plasma resulting
in sustained reduction of accumulated substrate in multiple tissues
• Administration of various doses of SIG-018 demonstrated good correlation with substrate
reduction
• Ongoing work is addressing CNS access
• Data supports transition of SIG-018 into the next phase of preclinical development
SIG-018 Team:Drew Tietz, Marissa Donovan, Erika Pearson, Brian Fluharty,
Devyn Smith, Elina Makino
Thank you for your attention!
PLEASE VISIT OUR POSTERS:
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• 192 (MPS VI)