The Wall Street Analyst Forum’s 17th Annual Analyst Conference

Forward Looking Statements…Forward Looking Statements…

During this presentation, our remarks will include forward-looking statements. These statements are neither promises nor guarantees, but involve risks and uncertainties that could cause actual results to differ materially from those anticipated or indicated. Any forward-looking statements should be considered in light of such risks and uncertainties including, without limitation, those detailed in the Company's filings with the SEC, including those discussed in the prospectus supplement.

Our Current MissionOur Current Mission

“To eradicate mortality from colorectal cancer through

early detection using applied genomics”

The Promise of EXASThe Promise of EXAS

• Large unmet medical market

• No controversy- early detection provides less costly treatment & saves lives

• Pre-Gen-Plus is first “average risk” marketed genomics diagnostic for CRC

• Molecular biology & mutations associated with CRC are well known

• Ability to detect these mutations in stool, which provides us with a biological advantage

• PreGen-Plus is the most accurate non-invasive diagnostic available

Five-year Survival Rate for CRCFive-year Survival Rate for CRC

Two-thirds of Patients are Diagnosed Too Late

Early DiagnosisEarly Diagnosis Late DiagnosisLate Diagnosis

0

25

50

75

100

0

25

50

75

100

Dukes A Dukes B Dukes C Dukes D

37% of Patients 63% of Patients

80%

55%

10%

95%

A Success and a FailureA Success and a Failure

Source: World Health Organization, American Cancer Society

1950 1960 1970 1980 1990 2000

FOBTColo Flex Sig

Screening Colo

Pap

ColorectalCervical

0

10,000

50,000

60,000

40,000

Colorectal vs. Cervical Cancer Death Estimates

The Opportunity in CRCThe Opportunity in CRC

0

20

40

60

80

100

2002 2003 2004 2005

20% Screened20% Screened

80% Unscreened80% Unscreened

People Over the Age of 50 Should Be Screened Regularly

Increases by 4 Million Each YearIncreases by 4 Million Each Year

People Over 50(Millions)

A New Genetic ModelA New Genetic Model

Validation of PreGen PlusValidation of PreGen Plus

• PreGen-Plus is a single test comprised of 23 molecular markers of CRC

• PreGen-Plus has significant clinical publications– Gastroenterology (2000,04, and 04)– Clinical Colorectal Cancer (2003)– New England Journal of Medicine (2004)– Journal of Molecular Diagnostics 2004

• Blue Shield California Technology Assessment

• Patients are more compliant– Single whole stool specimen – No bowel preparation – No medication or dietary restrictions – No sample manipulation

Clinical Utility = f (A x C x D)Clinical Utility = f (A x C x D)

Accuracy Compliance

Distribution / Access

FOBT

Flex Sig

Colonoscopy

PreGen-Plus™

Develop Cancer Specific Non-Invasive Assay

Demonstrate Superiority to Already Recommended Screening Modality in Average Risk Population (MCS)

Introduce Commercial Assay-PreGen-Plus™ through LabCorp

• Product Adoption/Guideline Inclusion/Payor Policy

Our Short Term Strategy

Observations & Confirmations

Observations & Confirmations

The Importance of Guideline InclusionThe Importance of Guideline Inclusion

Multi-Society Task Force/ACSMulti-Society Task Force/ACS

• 13 State Mandates

• NCQA/HEDIS Guidelines

• Requirement for self insured

• Positive impact on payors

• Will tip the scales for some doctors

How to get into GuidelinesHow to get into Guidelines

RequirementsRequirements

• Peer reviewed studies to prove equality/superiority

• Acceptability to patients

• Comparable or lower complication rates & costs

• Feasibility in general clinical practice

• Thought leader support

• Demand

GeneralGeneral

• 50% reduction in age-adjusted cancer mortality rates

• 25% reduction in age-adjusted cancer incidences rates

American Cancer Society2015 Challenge GoalsAmerican Cancer Society2015 Challenge Goals

Colorectal CancerColorectal Cancer

• Increase to 75% the proportion of people over the age of 50 years who have CRC screening consistent with ACS guidelines

– e.g., FOBT, flex sig, DCBE, colonoscopy

ReduceCancerReduceCancer

IncreaseScreeningIncrease

Screening

PayorsPayors

Managed Care / Self-Insured EmployersManaged Care / Self-Insured Employers

• Clinical Studies

• Thought Leaders

• Provider Pressure

• Membership Demand

• Cost Effectiveness

• NCQA/HEDIS Guidelines

EXAS Value Drivers EXAS Value Drivers

• Guideline Inclusion

• Payor Policy Decisions

• Strong Development Strategy– Improved Assay for CRC

– Assay for Pre-Cancer

Applied Research Applied Research

• Stage I√ Develop Cancer Specific Assay √ Demonstrate Superiority to Already Recommended Screening

Modality in Average Risk Population (MCS)√ Introduce Commercial Assay through partner– Guideline Inclusion

• Stage II – Increase Performance

• Cancer• Adenomas

– Decrease Cost

• Stage III– Apply Assay to Platform

• Kit Development

Development Strategy

Assay Improvements (Stage II)

• Increase DNA Yield– Effipure DNA Prep.

• Sample Handling– Stabilize Sample During Collection Method

• Marker Reformulation– De Novo Mutation Scanning (e.g. APC MCR)– Hypermethylation– Cancer Detection– Pre-Cancer Detection

Next GenerationAssay performanceTumor tissue analysis

Next GenerationAssay performanceTumor tissue analysis

Cancer tissues analyzed 94 94Assay positive samples 68 72.3% 88 93.6%

(95% CI) (62.2-81.1%) (86.6-97.6%)

Adenoma tissues analyzed 50 50Assay positive samples 31 62.0% 46 92.0%

(95% CI) (47.2-75.4%) (80.8-97.8%)

V1 assay V2 assay

The FutureThe Future

Other Screening Opportunities

More Depth in Colorectal Cancer

Expanding Internationally

The Wall Street Analyst Forum’s 17th Annual Analyst Conference