Arrowhead Pharmaceuticals : American Diabetes Association (ADA) 84th Scientific Sessions View Presentation

Liver-specific silencing of INHBE with ARO-INHBE, an siRNA therapeutic, for metabolic diseases

Michelle Ngai, Feng Liu, Puhui Li, Xiaokai Li, Cole Christy, Holly Hamilton, Maria Afrazi, Pierce Sullivan, Tao Pei, James Hamilton, Zhi-Ming Ding

Arrowhead Pharmaceuticals Inc., Madison, WI, USA

Poster # 1626-P

INTRODUCTION

PHARMACOLOGICAL STUDIES OF INHBE siRNA IN RODENT MODELS

INHBE silencing in the db/db mouse model results in an

improvement in body composition

• Incretin-based therapies are powerful and effective for obesity

and metabolic outcomes, but significant loss of lean mass and

adverse GI events at high dose levels has prompted the

Knockdown of hepatic INHBE mRNA expression with surrogate RNAi-trigger results in an improved body composition

with 1) BW suppression, 2) fat mass loss, 3) lean mass retention

Saline

Body Weight

4

0

INHBE (9 mpk)

Tirzepatide (0.48 mpk)

INHBE (9 mpk) + Tirzepatide (0.48 mpk)

Body Composition

40

32.08

100000

AUC of oGTT

✱

✱✱✱

ns

identification of a novel mechanism of action

• Large-scale human genetic studies support an association

between pLOF INHBE variants and 1) reduced WHRadjBMI, 2)

improved metabolic profile including lower TG, higher HDL, and

INHBE expression

expression	2.0
1.5	1.00
HBE	1.0

▪ DIO mice were

administered with saline

(weekly), mouse

surrogate ARO-INHBE (9

Body Composition by DEXA

	35			Saline
	30
	26.08	27.37	INHBE
(g)	25	23.01	21.42	Tirzepatide
20	17.80

ngecha	2	0
BW%		0
- 2	0	8	1	5	2	2	2	9	3	6	4	3	5	0	5	7	6	4
		1
	- 4	0

	30		24.17	24.80	24.81				80000
)(g Mass		23.72	24.21	21.96
			(OGTT)AUC
20			17.61				60000
							40000
10							20000
	0								0
		Fat Mass		Lean Mass

Saline	INHBE	Tirzepatide INHBE +
	(9 mpk)	(0.48 mpk) Tirzepatide
		(0.48 mpk)

reduced fasting glucose levels

• Activin E signaling regulates adipose lipid storage and

mobilization

• Activin E levels are elevated in individuals with obesity, insulin

resistance, and NAFLD

• siRNA targeting hepatic INHBE has potential to be a novel

therapeutic for metabolic diseases

AIM

• Evaluate the potential therapeutic benefits of INHBE silencing in

obese and diabetic mouse models with a mouse surrogate of

mIN										0.37
0.5
Relative
						0.06
0.0
		Saline		INHBE		Tirzepatide
						(9 mpk)		(0.48 mpk)
				Body Weight
100		Saline			INHBE	Tirzepatide
change	75
50
25
BW
0
%
1	2	3	4	5	6	7	8	9 10 11 12 13 14 15 16
	-25
	-50

mpk, weekly), or

tirzepatide (0.48 mpk,

daily)

▪ n=10 for each treatment

group

▪ INHBE mRNA expression

reduced by ~95%

▪ INHBE silencing led to a

19% suppression of body

weight compared to

saline controls

Mass	15
	10
	5	3.35
	0
		Fat Mass	Lean Mass

• Body composition analysis through DEXA imaging indicates a 26% loss of fat mass and preservation

of lean mass with INHBE silencing

• Weekly SC dosing of mouse surrogate ARO-INHBE in db/db mice (n=10 per treatment group) resulted in: 1) 15% suppression in BW compared to the saline group, 2) 26% loss of fat mass, 3) lean mass retention, 4) lack of improvement in oGTT

PHARMACODYNAMIC STUDY OF ARO- INHBE IN CYNOMOLGUS MONKEYS

ARO-INHBE 3 mpk SC

Liver biopsy

ARO-INHBE

• Evaluate the pharmacodynamic effects of ARO-INHBE in

cynomolgus monkeys

Impact on glycemic control is mild based on oGTT, fasting

glucose, fasting insulin, and HOMA-IR indicators

AUC of oGTT

Fasting Glucose

INHBE KD improves catecholamine sensitivity, increasing

lipid mobilization and oxidation

NEFA	β-hydroxybutyrate

Day -7 Day 1 Day 15 Day 29 Day 57 Day 85

METHODS

Rodent studies

• Diet-induced obese (DIO) and db/db mouse models

		✱✱✱				500
	80000	ns		glucosesting Fa		400
			g/dL)(m levels
(OGTT)AUC	60000			300
40000			200
20000			100
	0						0
	Saline	INHBE	Tirzepatide				Saline	INHBE	Tirzepatide
	80	Fasting Insulin				20	HOMA-IR	D-5
Fasting insulin (ng/mL)	60						15		D29
						D57
				IR-HOMA
40				10		D85
20				5
	0						0
	Saline	INHBE	Tirzepatide				Saline	INHBE	Tirzepatide

2.5	ns
2.0

mmol/L	1.5
	1.0
	0.5
	0.0
		Saline		INHBE
	14	pgWAT
levels	12
mRNA	10
8
Relative	6
4
	2
	0
	Adrb3	Atgl	Cgi-58	Hsl	Fabp4

	2.5		✱✱
mmol/L	2.0
1.0
	1.5
	0.5
	0.0
		Saline		INHBE
	8		iWAT
levels
6
mRNA
4
Relative
2
	0
	Adrb3	Atgl	Cgi-58	Hsl	Fabp4

Expression	7)ARL1,-D	1.5
1.00
RelativeNHBEI	(Normalizedto	1.0
0.5	0.32	0.32		0.33
					0.17
		0.0
		D-7	D15	D29	D57	D85

▪	After a single 3 mpk SC dose, hepatic INHBE mRNA expression
	was reduced by ~70% (n=3; n=2 on D57 and D85)
▪	Knockdown was maintained through D85 with a second dose

• Dosing regimen: weekly 9 mpk subcutaneous (SC) dosing of

mouse surrogate ARO-INHBE; daily 0.48 mpk tirzepatide as

benchmark; co-treatment of weekly INHBE (9 mpk) and daily

• Animals were fasted for 6 hours prior to glucose homeostasis analysis

• INHBE KD animals treated with CL316,243 (1 mpk, IP) had increased circulating ketone levels and expression of lipolytic genes relative to control group

on D29

tirzepatide (0.48 mpk)

• Body weight, body composition (lean versus fat mass) via Dual X-

ray Absorptiometry (DEXA) scans, glucose homeostasis (fasting

Increased lipid mobilization with INHBE silencing does not

lead to liver steatosis

Co-treatment of tirzepatide with INHBE siRNA allows use of lower tirzepatide dose for similar therapeutic effect in DIO mice

CONCLUSIONS

glucose, insulin, HOMA-IR, oGTT), lipid metabolism (non-

esterified fatty acids, beta-hydroxybutyrate) assessed at various

points over the course of the studies

Non-human primate study

• Cynomolgus monkeys (n=3) received 2 SC doses (D1 and D29) of ARO-INHBE at 3 mpk
• Liver biopsies were collected for INHBE mRNA expression via qRT-PCR

Saline	INHBE RNAi
	▪ H&E staining of the
	liver indicate there is
	less fat accumulation
	in DIO mice treated
	with INHBE RNAi

change%BW

60		Saline		INHBE (9 mpk)		Tirzepatide (0.21 mpk)

Co-treat (9 mpk + 0.14 mpk)

40

20

0
8	15	22	29	36	43	50	57	64	71	78	85
-20

-40

-60

• Co-treatedDIO mice (n=10 per treatment group) were administered 9 mpk mouse surrogate ARO-INHBE weekly and 0.14 mpk tirzepatide daily
• Co-treatedmice showed similar levels of %BW change as mice treated with a higher dose level of tirzepatide

• ARO-INHBEis a potent RNAi therapeutic capable of silencing hepatic INHBE mRNA expression
• Pre-clinicalstudies with a mouse surrogate of ARO-INHBE in DIO and db/db models indicate that INHBE KD potentially leads to a suppression in body weight gain, loss of fat mass, and preservation of lean mass likely due to the increased lipolysis
• Co-treatmentof tirzepatide with INHBE RNAi has the potential to allow for the use of a lower tirzepatide dose without compromising

the therapeutic effect