CONFIDENTIAL 1

Development of an Investigational

RNAi Therapeutic Targeting Glycolate

Oxidase for the Treatment of Primary

Hyperoxaluria Type 1

David V. Erbe, PhD

September 5, 2015

CONFIDENTIAL 2

Statement of Conflict of Interest: The speaker is

an employee of Alnylam Pharmaceuticals.

CONFIDENTIAL 3

RNAi Therapeutics

A New Class of Innovative Medicines

• Harness the natural pathway, mediated by

small interfering RNA or “siRNA”, to

therapeutically silence any gene

◦ Distinct mechanism of action vs. other drug

classes

– Catalytic gene silencing

• GalNAc-siRNA conjugates for efficient

delivery to hepatocytes through ASGPR

◦ Permits subcutaneous dosing with a wide

therapeutic index

◦ “Enhanced stabilization chemistry” used to

significantly improved potency and durability

• Clinically validated platform with human

Proof-of-Concept in multiple programs

ASGPR

(pH>5)

GalNAc-siRNA

conjugate

Clathrin-coated pit

Clathrin-coated vesicle

Endosome

Recycling

ASGPR

mRNA

Nucleus

Target

protein

RISC

Adapted from Essentials of Glycobiology (2009)

CONFIDENTIAL 4

CONFIDENTIAL 5

Primary Hyperoxaluria Type 1 (PH1)

Summary

• Rare, devastating disease due to excessive overproduction of oxalate

by the liver ◦ Deficiency of alanine-glyoxlyate aminotransferase (AGT)

◦ Prevalence of 6-7 per million, higher in some populations globally

◦ Calcium oxalate crystals deposit in kidneys, inflammation & fibrosis, nephrolithiasis

• Chronic kidney disease develops, leading to end-stage-renal-disease for

the majority (nearly 100% lifetime risk) ◦ Median age at diagnosis of 5 yrs; onset of ESRD - 24 yrs for males, 27 for females

• Once renal function is compromised, progressive systemic oxalate

deposition can then lead to severe illness and death ◦ Heart, CNS, skin, retina, joints, bone marrow

• The only effective treatment is dual liver-kidney transplantation ◦ No approved pharmacological interventions

N Engl J Med 2013; 369:649-58 Nephrol Dial Transplant 2012; 27:3855-62 Nat Rev Nephrol 2012; 8:467-75

Kidney Int advance online publication 2 July 2014; doi: 10.1038/ki.2014.222

J Am Soc Nephrol 2015. doi: 10.1681/ASN.2014070698

“As the liver is the only organ responsible for glyoxylate detoxification by

AGT, the excessive production of oxalate will continue as long as the native

liver is left in place.” - OxalEurope

CONFIDENTIAL 6

Glycolate Oxidase (GO) Knockdown to Starve

Substrate for Oxalate Synthesis in PH1

Am J Physiol 2004; 287:C1359-65 J Med Genet 2014; 51:526-9

11th Annual PH Workshop, June 27-29, 2014, Chicago, IL

PH1 PH1

ALN-GO1

• Human GO deficiency well tolerated provides validation through increased glycolate excretion ◦ 8-yr old boy with homozygous GO loss-of-function identified by Dr. Yaacov

Frishberg

◦ 20x increase in glycolate, normal oxalate, normal kidneys, no nephrocalcinosis

• GO deficient mice also validate therapeutic approach (Dr. Eduardo Salido)

◦ Breeding with PH1 disease mice (AGT deficient) substantially resolves Uox levels

Um

ol/2

4hr

Urinary Oxalate (Uox)

CONFIDENTIAL 7

ALN-GO1 in Normal and Diseased Mice Potent mRNA Silencing, Substantial Efficacy with Durability

day 10 sac

PB

S 10 3 1

0.3

0.1

0 .0

0 .5

1 .0

1 .5

A L N -6 5 5 8 5 (m g /k g )

Mo

us

e H

AO

1 m

RN

A,

Re

lati

ve

to

PB

S=

1

PB

S 10 3 1

0.3

0.1

0

1 0 0

2 0 0

3 0 0

A L N -6 5 5 8 5 (m g /k g )

Mo

us

e

Se

ru

m

Gly

co

late

,

M

HA

O1

mR

NA

(re

lati

ve t

o P

BS

) S

eru

m g

lyc

ola

te (

uM

)

ALN-GO1 (mg/Kg)

Uri

ne

Gly

co

late

(m

g/g

Cre

atin

ine

/24

hr)

Uri

ne

Ox

ala

te

(mg

/g C

rea

tin

ine

/24

hr)

Normal mice (single dose) PH1 mice (single dose)

In collaboration with University of Alabama, Birmingham

Weeks

0 1 2 3 4 5 6 7

Weeks

0 1 2 3 4 5 6 7

CONFIDENTIAL 8

ALN-GO1 Substantially Lowered Urinary

Oxalate in Rat PH1 Model

0

500

1000

1500

0 7 14 21 28 35

1% EG + AGXT LNP + PBS

1% EG + AGXT LNP + 3mg/kg

1% EG + AGXT LNP + 1mg/kg

1% EG + AGXT LNP + 0.3mg/kg

Uri

ne O

xala

te

(mg/g

Cre

atinin

e/2

4 h

r)

Day ALN-GO1

Veh

3 mg/kg ALN-GO1

1 mg/kg ALN-GO1

0.3 mg/kg ALN-GO1

Note: >95% HAO1 mRNA

silencing at all doses

Vehicle treated

Oxalate decreased up to 98% following weekly dosing

CONFIDENTIAL 9

Single, Low Dose ALN-GO1 in PH1 Rats

Demonstrates substantial potential for efficacy

1:1 Relationship of Oxalate Lowering to HAO1 mRNA Silencing

0

200

400

600

800

1000

1200

1400

1600

1800

-1 1 3 5 7 9 11 13 15

Day

PBS

0.3 mg/Kg

0.1 mg/Kg

0.03 mg/Kg

0.01 mg/Kg

Uri

ne

Ox

ala

te

(mg

/g C

reatin

ine/2

4 h

r)

ALN-GO1

CONFIDENTIAL 10

ALN-GO1 in Non-human Primates (ongoing)

Up to 99% silencing of HAO1 mRNA in non-human primates

Potent mRNA Silencing, Expected Increases in Serum Glycolate

Grou

p #

Dose

Level

(mg/kg)

Dose

Frequency

1 Veh qMx6

2 0.25

qWx8

3 1

4 1

qMx6 5 2

6 4

7 2 → 1 qWx4 → qMx5

0

50

100

150

Day 29

m R

N A

, R

e l a

t i v

e t

o P

B S

HAO1 mRNA -2 0 0 2 0 4 0 6 0 8 0 1 0 0

0

2 0

4 0

6 0

8 0

D a y

Se

ru

m G

lyc

ola

te,

M

G r. 1

G r. 2

G r. 3

G r. 4

G r. 5

G r. 6

G r. 7

CONFIDENTIAL 11

ALN-GO1

• Pre-clinical data summary

◦ Potent, durable silencing of HAO1 mRNA across species

– Translates into expected increases in serum glycolate in healthy animals

◦ Profound lowering of urinary oxalate in animal models of PH1

– 1:1 relationship of oxalate lowering to mRNA silencing

• Next steps

◦ Plan to file CTA in late 2015 and start Phase 1 study in early 2016 to study

safety, along with impact on glycolate and oxalate metabolism

– Pre-clinical durability supports monthly, and potentially quarterly, subcutaneous dosing

• Acknowledgments

Summary, Next Steps, & Acknowledgments

Alnylam Pharmaceuticals

Abigail Liebow

Stu Milstein

Satya Kuchimanchi

Kevin Fitzgerald

William Querbes

Rachel Meyers

University of Alabama, Birmingham

Xingsheng Li

Sonia Fargue

Ross Holmes

John Knight