Corporate Overview

June 9, 2017

Jefferies Conference

Douglas M. Fambrough, CEO

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Forward-looking statements

This information may contain projections and other forward‐looking statements regarding future events, including regarding Dicerna’s technology platform, product candidates, preclinical and clinical pipeline and milestones, regulatory objectives, market opportunities, and intellectual property. Such statements are predictions only and are subject to risks and uncertainties that could cause actual events or results to differ materially. These risks and uncertainties include, among others, the cost, timing and results of preclinical studies and clinical trials and other development activities; the unpredictability of the duration and results of regulatory review of New Drug Applications and Investigational NDAs; market acceptance for approved products and innovative therapeutic treatments; competition; the possible impairment of, inability to obtain and costs of obtaining intellectual property rights; and possible safety or efficacy concerns, general business, financial and accounting risks and litigation. More information concerning Dicerna and such risks and uncertainties is available on its website and in its press releases, and in its public filings with the U.S. Securities and Exchange Commission.

Dicerna is providing this information as of its date and does not undertake any obligation to update or revise it, whether as a result of new information, future events or circumstances or otherwise. Additional information concerning Dicerna and its business may be available in press releases or other public announcements and public filings made after the date of this information.

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GalXC technology provides a solid foundation for building value

About Dicerna

Dicerna Facts

• Founded in 2007 based on proprietary RNAi technology

• Ticker: DRNA

• Based in Cambridge, MA, with approximately 50 employees

• ~$100 million current cash

• Subcutaneously delivered drugs for liver gene silencing

• Infrequent dosing, potentially quarterly or less frequently

Rare Diseases

Chronic Liver Diseases

Cardiovascular Diseases

Liver Infectious Diseases

• Broad therapeutic applicability

Discovering New Pharmaceuticals with RNAi

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How GalXC Silences Liver Genes

Passenger strand

Guide strandGalNAc-conjugated

tetraloop

Delivered via subcutaneous injection

Long duration of action

Extensively demonstrated in monkeys

Very well tolerated, high therapeutic index

Easy to manufacture

Proprietary IP

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Delivering RNAi-based breakthrough therapies to improve lives

Portfolio Development Strategy for GalXC

• Dicerna development programs – rare diseases

Genetically and molecularly defined diseases with high unmet need and efficient development paths

Fibrotic liver disease

Chronic Liver Diseases

Hyper-cholesterolemia

(PCSK9)

Cardiovascular Diseases

Chronic hepatitis B infection

Liver Infectious DiseasesPrimary

Hyperoxaluria

Rare Diseases• Partnering focused efforts – large population size disorders

Where subcutaneous RNAi presents a compelling commercial profile

The scope of the RNAi liver opportunity supports multiple successful entrants

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GalXC Development Pipeline

STAGES OF DEVELOPMENT

Dicerna has developed an extensive library of GalXC molecules across our Tx areas with high potency in rodents, ready for optimization and full candidate qualification.

PRODUCT CANDIDATE INDICATION

DCR-PHXC Primary Hyperoxaluria

DCR-undisclosed Rare Disease

DCR-HBV Hepatitis B Virus

DCR-PCSK9 Hypercholesterolemia

DCR-undisclosed Cardiovascular

DCR-undisclosed Chronic Liver Disease

Dicerna program

Dicerna program

To be partnered at or before POCTo be partnered at or before POC

Partnering opportunity

Partnering opportunity

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Will oversee all Dicerna development programs

Dicerna Welcomes Dr. Ralf Rosskamp as Chief Medical Officer

• Extensive record of successful drug development– Pre-clinical through NDA approval– Rare diseases and large population diseases

• Successful NDA Approvals– NatPara – hypoparathyroidism (NPS Pharmaceuticals)– Simcor – cholesterol control (Kos Pharmaceuticals)– Apidra – rapid acting insulin (Aventis)– Lantus – basal insulin (Aventis)

• Notable prior positions– Chief Medical Officer – Summit Therapeutics– VP Global Clinical Development – NPS Pharmaceuticals– EVP Research and Development – Kos Pharmaceuticals

Dicerna Rare Disease Programs:Primary Hyperoxaluria Type 1

Undisclosed Target

9CONFIDENTIAL

From genetic mutation to outcomes

Primary Hyperoxaluria Type 1 (PH1)

Abnormal liver metabolism produces excess oxalate which is concentrated in the renal filtrate (Cochat, 2013)

Calcium oxalate crystals form, inducing nephrolithiasis & nephrocalcinosis (Cochat, 2013)

Subsequent decline in kidney function results in systemic oxalosis(Cochat 2013)

Median age of onset of kidney failure is 23 yrs (van der Hoeven, 2012)

Patients then require intensive daily dialysis while awaiting a dual liver-kidney transplant (Hoppe, 2012)

Children have poorer transplant outcomes vs. non-PH patients (Harambat, 2012)

Photographs reprinted by permission from Macmillan Publishers Ltd: Nature Reviews Nephrology 8 (2012) pg. 467

Bone Bone & Kidney

Skin Kidney

Eye

Systemic oxalosis in PH1

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Epidemiology

Primary Hyperoxaluria Type 1

~2,000

Ad

ult

20

+

34%

Juve

nile

10

-19

Late

Ch

ild 5

-9

18%18%

Earl

y C

hild

0-4

30%

PH1 is an ultra rare disease

P. Cochat et al. 2013. NEJM 369;7; Hopp et al, 2015 JASN ePub; http://www.rarekidneystones.org/hyperoxaluria; http://www.oxaleurope.org http://www.rarekidneystones.org/hyperoxaluria/physicians.html; Tang 2014, Kidney International

Estimated prevalence & genotypic incidence:1-3 cases per million pop (diagnosed today in EU countries)1 case per ~150,000 births (based on disease allele frequency)

683 PH1 ptsJuly 2015

Over 1,000 PH1 patients in two registries

Median age of diagnosis is 12 years

330 PH1 ptsJuly 2015

Potential for Accelerated Approval

Urinary oxalate excretion rate of >2 mmol/1.73m2/24hr associated with a significantly lower rate of end stage renal disease (ESRD)

Analysis of Urinary Risk Factors for ESRD among Patients with Primary Hyperoxaluria, Zhao, F. et al., J. Am. Soc. Neph, vol 25 Abstract suppl. (TH-PO310)

Nearly 15k eligible patients worldwide in peak year of sales (2027)

How large is the addressable market?

Predicted incidence based on US allele freq. of 6.6 per million (Hopp 2015), adjusted for PH1 lifespan (~65 yrs. (Mandrile 2014) which is ~81% of normal). ME/Africa is doubled due consanguinity (estimate); may actually be as high as 10x. Assumes that van der Hoeven 2012 (Netherlands) represents max possible diagnosed prevalence, which is functionally similar to penetrance; after adjusting for consanguinity in Netherlands, diagnosed prevalence is 2.6 per M.

Country

US 917

EU28 1,347

LATAM 1,097

ME/Africa 3,357

AZ/NZ 86

Canada 104

China 3,714

India 3,905

Japan 319

So. Korea 137

14,982

Eligible Pts. ('27)

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HAO1 silencing generates the expected urinary oxalate reduction and urinary glycolate increase

GalXC HAO1 is Efficacious in the Mouse Genetic Model of PH1

0 1 2 3 4 5 6 7

0

2 0 0

4 0 0

6 0 0

8 0 0

1 0 0 0

W e e k s

Ox

ala

te

/Cr

ea

tin

in

e (m

g/g

)

1 m g / k g

3 m g / k g

0 1 2 3 4 5 6 7

0

3 0 0

6 0 0

9 0 0

1 2 0 0

1 5 0 0

1 8 0 0

2 1 0 0

2 4 0 0

2 7 0 0

3 0 0 0

W e e k s

Ur

in

e G

ly

co

la

te

(m

g/g

Cre

ati

nin

e/2

4 h

r)

1 m g / k g

3 m g / k g

Oxalate Reduction

A single SC dose of GalXC HAO1 produced strong effects on urinary biomarkers in Agxt-/- PH1 disease model mice

Glycolate Elevation

dose

disease oxalate level

normal oxalate level

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DCR-PHXC precursor in long-term non-human primate studies at 2 mg/kg and 4 mg/kg

Multi-Month Duration for DCR-PHXC Lead in Non-Human Primates

• ~90% average gene silencing with both 2 mg/kg and 4 mg/kg dose levels

• 2-3 month duration of full gene silencing effect with 4 mg/kg dosing

• gene silencing duration suggests 2 mg/kg monthly or 4 mg/kg quarterly dosing intervals will be efficacious in patients

Multi-Dose Regimens in Non-Human Primates

ongoing

to 7.5

months

Dicerna has generated comparable non-human primate data with GalXC molecules against 7 different genes

Last DoseFirst Dose

Months

2 mpk QMx4

Dosing

Regimens: Multi-dose Tx Regimens

Last

Dose

4 mpk QMx4

Four Monthly Doses with Washout

First

Dose

%

UD

T#

1m

RN

A

Re

ma

in

in

g

(r

el

t

o

pr

e-

do

se

)

0 1 2 3 4 5 6

0

2 5

5 0

7 5

1 0 0

1 0

% m

RN

A R

em

ain

ing

(relto

pre

-dose) *

*includes one value of 163%

washout

monthly

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DCR-PHXC Primary Hyperoxaluria Development Plan

DCR-PHXC Development

• IND/CTA late 2017

• Expected POC ~end of Q3 2018

• Endpoints:

- Urine & plasma biomarkers

- Safety & tolerability

- Pharmacokinetics

• PHYOS observational study underway, establishing disease baseline and progression characteristics

• DCR-PHXC will have an IND/CTA filing in late 2017

• Dicerna’s prior IV-administered clinical program, DCR-PH1, has validated disease pathway biology in patients

Dosing Regimen: Single ≤1 subcutaneous injection

PHYOS

• Natural history and clinical course of patients with PH1

• Urine & plasma biomarkers

• Quality-of-life and economic burden of disease

• 20 patients enrolled to date

Dicerna Large Population Disease Programs:HBV

PCSK9

Dicerna’s strategy is to work with partners to develop therapies for large patient populations

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Over 250 million people are chronically infected worldwide. GalXC-HBV IND filing around end of 2018.

HBV: GalXC May Play a Key Role in Establishing a Functional Cure

Pre-S1,

pre-S2

and S

Polymerase

X gene

Pre-Core

& Core

Organization of the HBV Genome:

One GalXC molecule and can be used to target the whole virus

W e e k s

% P

las

ma

HB

sA

g

(re

l to

da

y -

1,

+/-

SE

M)

0 1 2 3 4 5 6

0 .0 1

0 .1

1

1 0

1 0 0

S e q u e n c e 2 1

S e q u e n c e 1 8

S e q u e n c e 1

S P ro to ty p e

P B S

S e q u e n c e 3

Greater than 3 Log reduction in HBsAg after GalXC-HBV treatmentSingle 3 mg/kg subcutaneous injection

One Dose3 mg/kg

BLOQ (2/4)

BLOD (4/4)

HBsAg is below the limit of detection in 4 out of

4 animals (ongoing until HBsAg rebound)

BLOD (4/4)

2-log

3-log

*For BLOD samples, the highest theoretical value is displayed

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Unmet medical need to reduce recurrent CV events in statin-refractory CVD patients

GalXC PCSK9: Atherosclerotic Cardiovascular Disease

23M (2/3) without CVD 12M (1/3) with CVD1,2,3

Addressable U.S. Patient Population:

> 4.5M (>37%) CVD patients not at LDL

goal of 70 mg/dL on statin alone4

35M statin treated patients in U.S. with hypercholesterolemia1,2

Competition:Market Opportunity:

PCSK9 GalXC is being developed for the $10B+ statin-refractory CVD market with the goal of improved convenience and adherence (less frequent dosing) compared to mAbs.

1. Qiuping Gu, et al. NCHS Data Brief. 2014, No. 177.2. CDC. Age and Sex Composition in the United States, 2012.3. CDC. Summary Health Statistics: National Health Interview Survey 2014.4. Wiviott SD, et al. J Am Coll Cardiol. 2005;46(8):1411-14165. Cannon CP, et al. NEJM. 2015; 372 (25).

6. Eliano PN, et al. Annals of Internal Medicine. 2015; 163 (1).7. Unpublished data. Alnylam Pharmaceuticals; 11.11.15 Press Release.

Results derived from non-human primate testing of a non-optimized GalXC molecule

Testing of optimized molecules is on-going

LDL-C reduction and duration levels for the non-optimized GalXC molecule appears comparable to existing siRNA product in development at an equivalent dose

GalXC PCSK9 LDL-C Reduction:

L D L -C

S tu d y D a y

%

LD

L-C

L

ow

erin

g

(re

lati

ve

to

pre

-ble

ed

)

2 0 4 0 6 0 8 0 1 0 0 1 2 0

100

80

60

40

20

0

-203 .0

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Delivering RNAi-based breakthrough therapies to improve lives

Our Vision for GalXC

• Powerful Capability – durable, specific liver gene silencing

• Expansive Opportunity – multiple gene targets across four disease areas

Fibrotic liver disease

Chronic Liver Diseases

Hyper-cholesterolemia

(PCSK9)

Cardiovascular Diseases

Chronic hepatitis B infection

Liver Infectious Diseases

Primary Hyperoxaluria

Rare Diseases

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Key Milestones

2017 GalXC Subcutaneous Platform Milestones

• Multiple GalXC candidate declarations and data sets

• IND/CTA filing for first indication: DCR-PHXC for Primary Hyperoxaluria

2018 GalXC Subcutaneous Platform Milestones

• DCR-PHXC clinical proof of concept

• File additional GalXC INDs for second rare disease program and HBV

GalXC technology provides multiple

partnering opportunities

Investment Highlights and Key Milestones

Investment Highlights

• Proprietary RNAi technology (GalXC) expected to yield tangible therapeutic benefits and ease of administration

• Applicable to a broad range of diseases

• Full pipeline aimed at:

– Internal development for smaller patient population disorders

o Primary Hyperoxaluria

o Other rare diseases

– Partnership opportunities for large population disorders

o Hepatitis B Virus

o Cardiovascular Disease

o Chronic Liver Disease

• Strong intellectual property position

• Proven management team