1
ligands GDF8 GDF11 Activin A Activin B BMP9 IC 50 ACE-2494/IC 50 ActRIIB-Fc 0 10 20 30 40 50 60 ACE-2494, a Novel GDF Ligand Trap, Increases Muscle Mass upon Systemic Administration in Mice Pearsall RS, Sako D, Liu J, Davies M, Heveron K, Castonguay R, Krishnan L, Troy M, Liharska K, Steeves R, Cannell M, Alimzhanov M, Grinberg A, Kumar R Acceleron Pharma Inc., Cambridge, MA, USA Introduction Myostatin (GDF8), a member of the BMP/TGF-β superfamily of growth factors is a known negative regulator of muscle mass. GDF8 binds to the activin receptor type IIB (ActRIIB) on the cell surface, leading to phosphorylation of SMAD 2/3 proteins and the activation of SMAD- responsive genes. Treatment of GDF8 deficient mice (Mstn-/-) with inhibitors of ActRIIB signaling promotes an additional increase in muscle mass, suggesting that other ligands signaling through the ActRIIB receptor also are negative regulators of muscle mass. Ligands such as GDF11 and activins have been implicated as additional negative regulators of muscle mass that signal through the activin receptor pathway. Trapping of multiple ligands capable of signaling through the ActRIIB receptor is an attractive strategy for the development of therapeutic agents that may benefit patients with muscle weakness. An experimental therapeutic agent, ACE-031, was designed using the ligand- binding portion of ActRIIB to bind and inhibit the multiple ligands capable of signaling through the ActRIIB receptor complex. In preclinical experiments, and in human clinical trials, ACE-031 increased muscle mass, but clinical development was terminated as a consequence of side effects on the vasculature. The vascular effects of ACE-031 are now generally attributed to inhibition of BMP9, another ligand that binds to ActRIIB and primarily regulates development and maintenance of the vascular system. ACE-2494 is a protein-based ligand trap engineered to bind myostatin and other ligands to achieve muscle effects similar to ACE-031 with minimal binding to BMP9. ACE-2494 Ligand Selectivity ActRIIB-Fc ACE-2494 Fig 1. ACE-2494 maintains affinity for GDF8, GDF11 and Activins similarly to ActRIIB-Fc, but shows significantly reduced binding to BMP9. BMP9 Kd 77.2pM GDF8 Kd 52.5pM GDF11 Kd 27.3pM GDF11 Kd 77.5pM Fig 3. ACE-2494 has dose dependent increases in muscle mass comparable to an ActRIIB-Fc ACE-2494 in a novel ligand trap that inhibits multiple negative regulators of muscle growth. Unlike soluble ActRIIB-Fc, ACE-2494 has reduced inhibition of BMP9 which has been implicated in regulation of vascular maturation. Systemic administration of ACE-2494 leads to a significant dose-dependent increase in muscle mass. Gastrocnemius, rectus femoris and pectoralis muscle weights were increased relative to the vehicle control in the 3 and 10 mg/kg dosing cohorts. These increases were comparable to the magnitude of muscle mass increase observed with soluble ActRIIB-Fc. These data suggest that ACE-2494 may be useful as an agent to treat muscle wasting. Activin A Kd 12.7pM Activin A Kd 12.2pM Experiments details: 8 week old male C57BL/6 mice (n=9 per group) were treated with ACE-2494 (3 and 10 mg/kg), ActRIIB-Fc (10 mg/kg) or vehicle (PBS) twice per week by sc injection for 4 weeks. At the end of the treatment the gastrocnemius, rectus, femoris and pectoralis muscles were isolated and weighed. Each muscle weight was normalized to the initial body weight of the animal. Values are expressed as mean % change from vehicle (Figure 3). All muscles were significantly different than the vehicle controls (p≤0.01). Fig 4. Muscle mass increases correlate to an increase in body mass Fig 2. ACE-2494 inhibits GDF8, GDF11, Activin A and Activin B signaling, while inhibition of BMP9 signaling is significantly reduced in a Reporter Gene Assay Gastrocnemius ActRIIB-Fc 10 mg/kg ACE-2494 10 mg/kg ACE-2494 3 mg/kg Muscle Weight/Initial Body Weight (% change from VEH) 0 10 20 30 40 50 60 70 50.8% 53.3% 36.1% Femoris ActRIIB-Fc 10 mg/kg ACE-2494 10 mg/kg ACE-2494 3 mg/kg Muscle Weight/Initial Body Weight (% change from VEH) 0 10 20 30 40 50 60 43.9% 40.9% 24.5% Pectoralis ActRIIB-Fc 10 mg/kg ACE-2494 10 mg/kg ACE-2494 3 mg/kg Muscle Weight/Initial Body Weight (% change from VEH) 0 20 40 60 80 100 51.5% 86.9% 56.7% BMP9 Transient binding Experimental details: SPR experiments were performed using a Biacore T100/T200 biosensor (Biacore/GE Healthcare) at 37°C. ACE-2494 and ActRIIB-Fc were captured on an anti-hFc IgG chip and ligands were injected over the captured test molecule. All experiments were performed in duplicate. Conclusions Experimental details: The ability of ACE- 2494 and ActRIIB-Fc to antagonize SMAD2/3 signaling induced by Activin A, B, GDF8 and GDF11 was tested in a reporter gene assay in A204 cells using the CAGA12 –luciferase reporter gene. The ability of ACE-2494 to inhibit BMP9 signaling was measured in T98G cells using a BRE-luciferase reporter construct. GDF8 Kd 125pM ACE-2494 Increases Muscle Mass In Vivo

Goals and Objectives for New Development Candidatesacceleronpharma.com/.../10/20151001-WMS-2015-Poster...Oct 01, 2015  · ligands GDF8 GDF11 Activin A Activin B BMP9 IC 50 C 50-Fc

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Page 1: Goals and Objectives for New Development Candidatesacceleronpharma.com/.../10/20151001-WMS-2015-Poster...Oct 01, 2015  · ligands GDF8 GDF11 Activin A Activin B BMP9 IC 50 C 50-Fc

ligands

GDF8 GDF11 Activin A Activin B BMP9

IC5

0A

CE

-24

94/IC

50

ActR

IIB

-Fc

0

10

20

30

40

50

60

ACE-2494, a Novel GDF Ligand Trap, Increases Muscle Mass upon Systemic Administration in Mice

Pearsall RS, Sako D, Liu J, Davies M, Heveron K, Castonguay R, Krishnan L, Troy M, Liharska K, Steeves R, Cannell M, Alimzhanov M, Grinberg A, Kumar R

Acceleron Pharma Inc., Cambridge, MA, USA

Introduction • Myostatin (GDF8), a member of the BMP/TGF-β superfamily of growth factors

is a known negative regulator of muscle mass. • GDF8 binds to the activin receptor type IIB (ActRIIB) on the cell surface, leading

to phosphorylation of SMAD 2/3 proteins and the activation of SMAD-responsive genes.

• Treatment of GDF8 deficient mice (Mstn-/-) with inhibitors of ActRIIB signaling promotes an additional increase in muscle mass, suggesting that other ligands signaling through the ActRIIB receptor also are negative regulators of muscle mass. Ligands such as GDF11 and activins have been implicated as additional negative regulators of muscle mass that signal through the activin receptor pathway.

• Trapping of multiple ligands capable of signaling through the ActRIIB receptor is an attractive strategy for the development of therapeutic agents that may benefit patients with muscle weakness.

• An experimental therapeutic agent, ACE-031, was designed using the ligand-binding portion of ActRIIB to bind and inhibit the multiple ligands capable of signaling through the ActRIIB receptor complex. In preclinical experiments, and in human clinical trials, ACE-031 increased muscle mass, but clinical development was terminated as a consequence of side effects on the vasculature. The vascular effects of ACE-031 are now generally attributed to inhibition of BMP9, another ligand that binds to ActRIIB and primarily regulates development and maintenance of the vascular system.

• ACE-2494 is a protein-based ligand trap engineered to bind myostatin and other ligands to achieve muscle effects similar to ACE-031 with minimal binding to BMP9.

ACE-2494 Ligand Selectivity

ActRIIB-Fc ACE-2494

Fig 1. ACE-2494 maintains affinity for GDF8, GDF11 and Activins similarly to ActRIIB-Fc, but shows significantly

reduced binding to BMP9.

BMP9 Kd 77.2pM

GDF8 Kd 52.5pM

GDF11 Kd 27.3pM GDF11 Kd 77.5pM

Fig 3. ACE-2494 has dose dependent increases in muscle mass comparable to an ActRIIB-Fc

• ACE-2494 in a novel ligand trap that inhibits multiple negative regulators of muscle growth.

• Unlike soluble ActRIIB-Fc, ACE-2494 has reduced inhibition of BMP9 which has been implicated in regulation of vascular maturation.

• Systemic administration of ACE-2494 leads to a significant dose-dependent increase in muscle mass. Gastrocnemius, rectus femoris and pectoralis muscle weights were increased relative to the vehicle control in the 3 and 10 mg/kg dosing cohorts. These increases were comparable to the magnitude of muscle mass increase observed with soluble ActRIIB-Fc.

• These data suggest that ACE-2494 may be useful as an agent to treat muscle wasting.

Activin A Kd 12.7pM Activin A Kd 12.2pM

Experiments details: 8 week old male C57BL/6 mice (n=9 per group) were treated with ACE-2494 (3 and 10 mg/kg), ActRIIB-Fc (10 mg/kg) or vehicle (PBS) twice per week by sc injection for 4 weeks. At the end of the treatment the gastrocnemius, rectus, femoris and pectoralis muscles were isolated and weighed. Each muscle weight was normalized to the initial body weight of the animal. Values are expressed as mean % change from vehicle (Figure 3). All muscles were significantly different than the vehicle controls (p≤0.01).

Fig 4. Muscle mass increases correlate to an increase in body mass

Fig 2. ACE-2494 inhibits GDF8, GDF11, Activin A and Activin B signaling, while inhibition of BMP9 signaling is significantly

reduced in a Reporter Gene Assay

Gastrocnemius

ActRIIB

-Fc 1

0 mg/kg

ACE-2494 1

0 mg/kg

ACE-2494 3

mg/kg

Mu

scle

We

igh

t/In

itia

l B

od

y W

eig

ht

(% c

ha

ng

e fro

m V

EH

)

0

10

20

30

40

50

60

70

50.8% 53.3%

36.1%

Femoris

ActRIIB

-Fc 1

0 mg/kg

ACE-2494 1

0 mg/kg

ACE-2494 3

mg/kg

Mu

scle

We

igh

t/In

itia

l B

od

y W

eig

ht

(% c

ha

ng

e fro

m V

EH

)

0

10

20

30

40

50

60

43.9% 40.9%

24.5%

Pectoralis

ActRIIB

-Fc 1

0 mg/kg

ACE-2494 1

0 mg/kg

ACE-2494 3

mg/kg

Mu

scle

We

igh

t/In

itia

l B

od

y W

eig

ht

(% c

ha

ng

e fro

m V

EH

)

0

20

40

60

80

100

51.5%

86.9%

56.7%

BMP9 Transient binding

Experimental details: SPR experiments were performed using a Biacore T100/T200 biosensor (Biacore/GE Healthcare) at 37°C. ACE-2494 and ActRIIB-Fc were captured on an anti-hFc IgG chip and ligands were injected over the captured test molecule. All experiments were performed in duplicate.

Conclusions

Experimental details: The ability of ACE-2494 and ActRIIB-Fc to antagonize SMAD2/3 signaling induced by Activin A, B, GDF8 and GDF11 was tested in a reporter gene assay in A204 cells using the CAGA12 –luciferase reporter gene. The ability of ACE-2494 to inhibit BMP9 signaling was measured in T98G cells using a BRE-luciferase reporter construct.

GDF8 Kd 125pM

ACE-2494 Increases Muscle Mass In Vivo