robust knock down of toxic human
TRANSCRIPT
Joachim, living with DM1
The FORCETM Platform Achieves
Robust Knock Down of Toxic Human
Nuclear DMPK RNA and Foci Reduction
in DM1 cells and in Newly Developed
hTfR1/DMSXL Mouse Model
STEFANO ZANOTTI, PH.D.
ASGCT ANNUAL MEETING | MAY 14, 2021
Forward-Looking Statements
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This presentation contains forward-looking statements that involve substantial risks and uncertainties. All statements, other than statements of historical facts,
contained in this presentation, including statements regarding Dyne Therapeutics, Inc.’s (the “Company”) strategy, future operations, prospects, plans and
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statements, and you should not place undue reliance on these forward-looking statements. Actual results or events could differ materially from the plans,
intentions and expectations disclosed in these forward-looking statements as a result of various important factors, including: uncertainties inherent in the
identification and development of product candidates, including the conduct of research activities, the initiation and completion of preclinical studies and clinical
trials; uncertainties as to the availability and timing of results from preclinical studies; the timing of and our ability to submit and obtain regulatory approval for
investigational new drug applications; whether results from preclinical studies will be predictive of the results of later preclinical studies and clinical trials; the
Company’s ability to obtain sufficient cash resources to fund the Company’s foreseeable and unforeseeable operating expenses and capital expenditure
requirements; the impact of the COVID-19 pandemic on the Company’s business and operations; as well as the risks and uncertainties identified in Dyne’s
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LINKER
Clinically validated, enables
precise conjugation of multiple
payloads to a single Fab
Cytoplasmic
localization
Nuclear
localization
PAYLOAD
Modularity enables rational
selection of payload to target
the genetic basis of disease
ASO siRNA
ANTIBODY
Proprietary Fab targets TfR1
to enable muscle delivery
Adapted from: Ohrt et al: NAR , 2006, v.34, p.1369
Dyne FORCE Platform: Modern Oligo Therapeutics for Muscle Diseases
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• Myotonia
• Muscle weakness
• Cardiac arrhythmia
• Pulmonary abnormalities
MBNL
proteins
Sequestered
ActivatedCELF1
proteins
FORCE designed to address the
genetic basis of disease by
targeting toxic nuclear DMPK RNA
CpG islands
DMPK
3” UTR
479bp449bp
DNA Triplet Repeats
Toxic RNA Forms Foci
RNA Binds Splicing Proteins
Clinical Presentation
Nucleus
Toxic RNA is unable
to leave the nucleus,
sequesters MBNL
and forms foci
Toxic DMPK
mRNA
Sequestered MBNL
Cytoplasm
CTCF CTCFCTG exp DHS
DMPK SIX5DMWD
FORCE Targets the Genetic Basis of DM1
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RNaseH1
Normal DMPK mRNA is
able to leave the nucleus
Toxic DMPK mRNA
is unable to leave
the nucleus
Toxic RNA sequesters
MBNL and forms foci
Nucleus
Cell Membrane
ASO
ASO binds RNA
RNaseH1 cleaves RNA
MBNL is released
to restore splicing
in the nucleusCytoplasm
Endosome
TfR1
FORCE
FORCE Targets Toxic Nuclear DMPK RNA
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6
FORCE Conjugate Demonstrated Dose-dependent DMPK KD, Splicing Correction, and Foci Reduction in DM1 Myotubes with 380 CTG Repeats
Note: Data are mean ±SD; n = 4
PBS 14 45 1500.0
1.0
2.0
3.0
4.0
BIN
1 E
xon 1
1 Inclu
sio
n v
s. P
BS
FORCE (nM ASO)
PBS 14 45 1500
20
40
60
80
100
120
Foci A
rea/N
ucle
ar
Are
a %
vs. P
BS
FORCE (nM ASO)
Nucleus
Foci
PBS FORCEPBS 14 45 150
0.00
0.25
0.50
0.75
1.00
1.25
DM
PK
vs. P
BS
FORCE (nM ASO)
FISH with CAG PNA probe
DMPK mRNA KD by qPCR BIN1 splicing correction by qPCR Toxic DMPK foci KD
150 nM ASO
(CUG)380
5’ 3’Human DMPK mRNA
PBS 45 150 5000.00
0.25
0.50
0.75
1.00
1.25
DM
PK
vs. P
BS
FORCE (nM ASO)
DMPK mRNA KD by qPCR
PBS 45 150 5000
1
2
3
BIN
1 E
xon 1
1 Inclu
sio
n v
s. P
BS
FORCE (nM ASO)
BIN1 splicing correction by qPCR
PBS 45 150 5000
20
40
60
80
100
120
Foci A
rea/N
ucle
ar
Are
a %
vs. P
BS
FORCE (nM ASO)
Toxic DMPK foci KD
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Nucleus
Foci
FISH with CAG PNA probe
PBS FORCE
500 nM ASO
(CUG)2,600
5’ 3’Human DMPK mRNA
FORCE Conjugate Demonstrated Dose-dependent DMPK KD, Splicing Correction, and Foci Reduction in DM1 Myotubes with 2,600 CTG Repeats
Note: Data are mean ±SD; n = 4
hTfR1/DMSXL Mice: Innovative Model to Evaluate FORCE Conjugate Pharmacodynamics By Measuring Toxic Human Nuclear DMPK KD
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hTfR1
hTfR1/DMSXL
(CUG)1,000+
5’ 3’
Note: DMSXL mice first described in PLOS Genetics 2012, 8(11):e1003043
Human DMPK mRNA
DMSXL
mDMPK
Fully human
FORCE
conjugate
ASO
hTfR1
mDMPKNucleus
hDMPKASO
1,000+ CUG
repeats
Cytoplasm
• Expresses human TfR1 receptor, enabling use
of human TfR1-targeting Fabs
• Underestimates potency, expressing >10 times
less human toxic DMPK vs. mouse DMPK
Uptakes human TfR1
targeting Fabs
Expresses human toxic
DMPK
FORCE Conjugate Demonstrated Robust Toxic Human DMPK KD in hTfR1/DMSXL Mice after 14 Days
PBS FORCE0.0
0.5
1.0
1.5
Tibialis Anterior
DM
PK
vs. P
BS
****
54% KD
PBS FORCE0.0
0.5
1.0
1.5
Gastrocnemius
DM
PK
vs. P
BS
**
39% KD
PBS FORCE0.0
0.5
1.0
1.5
Heart
DM
PK
vs. P
BS
****
60% KD
PBS FORCE0.0
0.5
1.0
1.5
Diaphragm
DM
PK
vs.
PB
S
***
56% KD
9Note: Data are mean ±SD; n = 6 – 9; **p < 0.01,***p < 0.001, ****p < 0.0001, significant by t-test
hTfR1/DMSXL
d0
d7
d14
IV Dose 10 mg/kg ASO
IV Dose 10 mg/kg ASO
Analysis
FORCE Conjugate Demonstrated Robust Toxic Human DMPKmRNA and Foci KD in the Heart of hTfR1/DMSXL Mice
10Note: 10 mg/kg ASO d0 and d7, analyzed d14; data are mean ±SD; n = 6 – 9; ****p < 0.0001, significant by t-test. Representative images of heart sections stained by RNAscope
PBS FORCE
Toxic human DMPK foci
Nuclei
DMPK mRNA KD by qPCR
DM
PK
vs.
PB
S
DMPK foci reduction in the heart by in situ hybridization
Single Dose of FORCE Conjugate Achieved Sustained Toxic Human DMPK KD at Week 4 in hTfR1/DMSXL Mice
PBS FORCE0.0
0.5
1.0
1.5
Tibialis Anterior
DM
PK
vs. P
BS
**
46% KD
PBS FORCE0.0
0.5
1.0
1.5
Gastrocnemius
DM
PK
vs. P
BS
**
42% KD
PBS FORCE0.0
0.5
1.0
1.5
Heart
DM
PK
vs. P
BS
**
46% KD
PBS FORCE0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
Diaphragm
DM
PK
vs. P
BS
51% KD
11Note: Data are mean ±SD; n = 6; **p < 0.01, significant by t-test
hTfR1/DMSXL
Wk0
Wk4 Analysis
IV Dose 10 mg/kg ASO
Conclusions
• FORCE is designed to address the genetic basis of DM1 by targeting toxic
nuclear DMPK RNA
• These new data demonstrated that a fully human FORCE conjugate can:
▪ Correct the DM1 phenotype of patient-derived myoblast cultures with a range of repeats,
including those representative of severe DM1
▪ Reduce toxic nuclear human DMPK foci in cardiac muscle of hTfR1/DMSXL mice
▪ Lead to sustained KD of toxic nuclear human DMPK in hTfR1/DMSXL mice after a single
dose
• These data strongly support further development of our DM1 therapeutic
candidate, including a planned clinical study
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Acknowledgements
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Dyne:
▪ Ryan Russo
▪ Lydia Schlaefke
▪ Cody Desjardins
▪ Scott Hildebrand
▪ Nelson Hsia
▪ John Najim
▪ Mo Qatanani
▪ Qifeng Qiu
Collaborators:
▪ Genevieve Gourdon
Institut de Myologie
Paris, France
▪ Brendan Quinn
▪ Kim Tang
▪ Tim Weeden
▪ Irene Wen
▪ Monica Yao
▪ Romesh Subramanian
▪ Oxana Beskrovnaya