ANTISENSE TECHNOLOGY EVOLUTION OF ANTISENSE CHEMISTRY

EVOLUTION OF ANTISENSE MECHANISMS

EXPLOSION OF ANTISENSE TARGETS BROUGHT BY THE GENETIC REVOLUTION

CHEMISTRY, MECHANISMSAND TARGETS

Antisense Technology – The Third Drug Discovery Platform

For diseases where targets are inaccessible with traditional approaches

Productivity of current approaches does not meet the need

Cost of drug discovery & failure rate of current approaches is high

Why is another drug discovery platform needed?

Platform technologies need to combine all the elements necessary to create rapidly & e�ciently a stream of new products

Isis has successfully generated a large pipeline of �rst-in-class antisense drugs, each unique to a speci�c RNA target & each to treat a disease where there are patients with signi�cant unmet

medical needs

Proteins are Made from Genes via mRNA

Small Molecules & Biologics Target Proteins

Antisense Drugs Target RNA, not ProteinsAntisense Targets – Unlimited Possibilities The Genomic Era Dramatically Increased

the Number of Potential Drug Targetsfor Antisense Technology

The RNA WorldThe Universe of Antisense Drug Targets is Expanding

Drug Discovery & DevelopmentStrategy

Understanding How Antisense Drugs Work Antisense Mechanisms of Action Spinal Muscular Atrophy: An Example of a Severe DiseaseTreatable with a Splicing Modulatory Antisense Drug

First-Generation Chemistry(Phosphorothioate, PS)

Second-Generation Chemistry(2’-Methoxyethyl, MOE)

First Demonstration of Generation 2.5 PotentialPotent Activity of STAT3 Inhibitor

in Human Tumor XenograftsGeneration 2.5 Chemistry(IScEt)

How Understanding MechanismHas Shaped

the Future of Antisense DrugsAttributes of Antisense Drugs

Creating Signi�cant Competitive Advantagefor the Platform

Three Drug Discovery Platforms

Antisense Platform TechnologySaves Time & Cost with Higher Success Rate

to Clinical Trials

How Antisense Technology Supports Our Business StrategyAntisense Platform Attributes

Identify the receptors that distribute antisense drugs to the target tissues

Determine how antisense drugs enter the cells in the target tissue

Determine how antisense drugs distribute to & bind the RNA receptor in the cell

Understand the mechanisms of action responsible for the reduction of the receptor RNA

Understand the mechanisms of unwanted e�ects

Natural nucleic acids (RNA & DNA) bind speci�cally to each other, but have �aws as drug molecules

Rapidly degraded in animals

Very poor distribution to tissues

The pharmaceutical industry has addressed these issues with other natural products using medicinal chemistry for over 100 years

Broaden therapeutic applications

Expand routes of delivery

Improve therapeutic index through increased potency & improved tolerability

Advance the chemistry platform

Control the technology through patents

To date more than 12 di�erent antisense mechanisms of actionhave been characterized

Spinal Muscular Atrophy (SMA) is caused by loss of a gene called SMN-1

Humans have a second copy of the gene that produces a defective protein due to an RNA splicing defect

Our antisense drug corrects the splicing disorder resulting in the production of a fully

functional protein

Generation 2.5 Drugs & Cancer

What Does the Future Look Like?

Rapidly incorporate Generation 2.5 chemistry to develop a broad preclinical pipeline of antisense drugs against targets involved in numerous

aspects of tumor biology

Understanding the mechanisms that distribute antisense drugs from the site of administration to the target receptor (RNA) in cells will result in the design of better antisense drugs

“A scienti�c milestone of enormous proportions, the sequencing of the human genome will impact all of us in diverse ways–from our views of ourselves as human beings to new paradigms in medicine.” Science Magazine - Feb. 2001

Gene mRNA

Transcription Translation

DISEASE

SMALL MOLECULE DRUGS (TRADITIONAL APPROACH)

BIOLOGICS

NO DISEASE

NO DISEASE

Disease-Causing Protein

Gene mRNA

Transcription

No Translation of Disease-Causing

Protein

NO DISEASE

ANTISENSE DRUGS(Oligonucleotides)

Attribute Small Molecules Biologics Antisense

History 1850s to present 1920s to present 1990s to present

Molecular weight 200-500 6,000 to >150,000 5,000 to 7,000

Identification of clinical candidate

Random screening Focused screening Rationally designed

Probability of identifying drug candidate

Low-~5% Moderate-~50% High-~90%

Routes of administration

Oral, injectable, inhaled

Injectable Injectable, inhaled, orally feasible

Platform Efficiencies Small Molecules Biologics Antisense

Discovery process - ++ +++

Pharmacology - ++ +++

Toxicology - ++ +++

Manufacturing - - +++

Routes of administration

+++ - ++

Only Direct Route from Genes to Drugs

Uniquely specific & broadly applicable

Efficient Discovery & Early Development

Dramatically reduced cost & increased success in R&D

Investment Amortized Across the Entire Pipeline

Chemistry, manufacturing,formulation & analytical methods

Generate an Evergreen Pipeline

Robust, diversified pipeline growing by 3-5 new drugs per year

Breadth of Opportunities

CMC Investments

Preclinical Development

Idea to Phase 1

TOX/PK

SMALL MOLECULE DRUGS

Only “druggable” targets

Unique investments required for each drug

~10% probability of reaching clinical trials

Cost $40-100M

Time 7-10 yrs

FTE/yr 20-40

Unique for each drug

ANTISENSE DRUGS

All genes Major tissues Most diseases - proven efficacy& safety in humans

Investments amortize over entire pipeline

~90% probability of reaching clinical trials

Time 2-5 yrs

Cost $5-10M

FTE/yr 3-5

Similar for all drugs No drug interactions

Specificity Selectively target a single gene product

Broad Applicability Ability to approach inaccessible targets

Rational Design Similar distribution & metabolism = common & predictable safety profile

Efficiency Cost & development time advantages

Lessons learned translated to future drugs

Manufacturing Simple & cost effective process

CHEMISTRY

MECHANISM

TARGETS

nucleus

nuclear envelope

cytosol

cell membrane

ANTISENSE DRUGS

mRNA

Antisense Strand

AntisenseStrand

Modulation of Splicing: An Example of a Novel Antisense Mechanism

CytoplasmNucleus

DNA

Introns

ExonsIntron

Exon 3‘5‘

mRNA

Cell Membrane

DNA RNA

Drug Properties (Example: Fomivirsen)

Potency 1,200 to 3,500 mg/week

Dose Frequency Daily to 3x/week

Cost of Therapy Between branded small molecules & antibodies

Routes of Administration

IV, enema & intravitreal

Chemistry Attributes

Adds stability

Improves distribution to tissues

Drug Properties (Example: Mipomersen)

Potency ~50 to 400 mg/week

Dose Frequency Weekly to monthly

Cost of Therapy Competitive with upper end of branded small molecules

Routes of Administration

SC, IV, inhalation, topical & intrathecal

Chemistry Attributes

Increases potency

Further increases stability

Reduces non-specific toxicities

Drug Properties

Potency <5 to 40 mg/week(10-fold )

Dose Frequency Weekly to monthly

Cost of Therapy >3-fold less costly

Routes of Administration

Same + potential of oral

Chemistry Attributes

Improves potency & therapeutic index

Expands range of targets & tissues

Increased patient convenience in dosing (including potentially oral)

The human genome (3 billion base pairs)

Most of the genome is transcribed into RNA (Directly targetable with antisense)

Coding RNAs (2-3% of genome)

Proteins

Non-coding RNA (all other RNAs including

microRNAs & long non-coding RNAs)

Novel Genetic-Based Targets

ANTISENSE DRUG DISCOVERY

Potential ToIdentify Sensitive

Patient Populations

Avoid Small Molecule

Competition

Early Clinical Readouts

Consistent With PK/PD (Distribution)

Compatible With Infrequent Injections

BiologicallyValidated Targets

Unmet Medical Need

Enhanced Commercial Potential

Increased potency

New mechanisms

Improved tolerability

Broadened therapeutic applications

Augmented patient coverage

Creating Antisense Drugs of the FutureInvestments in Antisense Technology

LIVER

SPLEEN

FAT

BONE MARROW

KIDNEYS

ISIS SMNRx Increases Survivalin a Mouse Model of SMA

ISIS SMNRx Improves Muscle Healthin a Mouse Model of SMA

ASO

-A

Know

n Bi

olog

ical

Tar

gets

Year

Genomic Revolution

Addition of non-coding RNAs

Gene mRNA

DISEASETranscription Translation

Disease-Causing Protein

SMN-2 Gene

1 2 2 3 4 5 6 8 SMN-2 mRNA

1 2 2 3 4 5 6 7 8

C to T

Defective Protein, missing exon 7

SMN-2 Gene

1 2 2 3 4 5 6 8 SMN-2 mRNA

1 2 2 3 4 5 6 7 8

C to T

Functional Protein

7

ASO

0

400

800

1200

1600

2000

10 15 20 25 30 35

Tum

or S

ize

(mm

3 )

Days after tumor inoculation

Saline ISIS-STAT3Rx, 25 mg/kg

p=0.001

STAT3

GAPDH

Saline ISIS-STAT3Rx

Generation 2.5 drug inhibits production of STAT3 protein

Human Breast Cancer Xenograft

Pipeline PARTNERED

PRECLINICAL PHASE I PHASE II PHASE III COMMERCIAL

BMS-PCSK9Rx CAD

PCSK9

ISIS-CRPRx CAD/Inflammation/Renal

CRP

ISIS FXIRx Clotting Disorders

Factor XI

ISIS-APOCIIIRx High Triglycerides

apoC-III

MIPOMERSEN High Cholesterol

apoB

ISIS-PTP1BRx Diabetes PTP-1B

ISIS-GCCRRx Diabetes GCCR

ISIS-GCGRRx Diabetes GCGR

ISIS-FGFR4Rx Obesity FGFR4

ISIS-SGLT2Rx Diabetes SGLT2

ISIS-STAT3Rx Cancer STAT3

OGX-011 Cancer clusterin

LY2181308 Cancer survivin

ISIS-EIF4ERx Cancer eIF-4E

OGX-427 Cancer Hsp27

ISIS-SOD1Rx ALS

SOD1

ISIS-TTRRx TTR Amyloidosis

TTR

ISIS-SMNRx Spinal Muscular Atrophy

SMN2

ATL1103 Acromegaly

GHr

ALICAFORSEN Ulcerative Colitis

ICAM-1 *Named Patient Supply

iCo-007 Ocular Disease

C-raf kinase

ACHN-490 Severe Bacterial Infection

Aminoglycoside

ATL1102 MS

VLA-4

EXC 001 Local Fibrosis

CTGF

CARDIOVASCULAR

METABOLIC

CANCER

SEVERE & RARE/ NEURODEGENERATIVE

INFLAMMATION & OTHER VITRAVENE®

CMV Retinitis CMV

ASO A, 2 µg, n=12, 22d

ASO A, 4 µg, n=24, 25d

Untreated SMA, n=19, 15d

Mismatch, 4 µg, n=18, 16d

ASO A, 8 µg, n=18, 25d

Antisense: A Technology Platform