©2019 DICERNA

June 4, 2019

Corporate OverviewJefferies Global Healthcare Conference

©2019 DICERNA

This presentation includes forward-looking statements. Forward-looking statements are subject to risks and uncertainties that could cause actual resultsto differ materially from those expressed or implied in such statements. Examples of forward-looking statements include, among others, statements wemake regarding: (i) the therapeutic and commercial potential of DCR-PHXC, DCR-HBVS and the GalXC™ platform; (ii) research and development plans andtimelines related to DCR-PHXC, DCR-HBVS and GalXC; and (iii) the potential of Dicerna’s technology and drug candidates in the Company’s research anddevelopment pipeline. The process by which an early stage investigational therapy such as DCR-PHXC and an early stage platform such as GalXC couldpotentially lead to an approved product is long and subject to highly significant risks. Applicable risks and uncertainties include those relating to Dicerna’sclinical research and other risks identified under the heading "Risk Factors" included in the Company’s most recent Form 10-K filing and in other futurefilings with the Securities and Exchange Commission. These risks and uncertainties include, among others, the cost, timing and results of preclinicalstudies and clinical trials and other development activities; the likelihood of Dicerna’s clinical programs being executed within timelines provided andreliance on the Company’s contract research organizations and predictability of timely enrollment of subjects and patients to advance Dicerna’s clinicaltrials; the potential for future data to alter initial and preliminary results of early stage clinical trials; the unpredictability of the duration and results ofthe regulatory review of Investigational New Drug Applications (NDAs) and Clinical Trial Applications that are necessary to continue to advance andprogress the Company’s clinical programs and the regulatory review of NDAs; market acceptance for approved products and innovative therapeutictreatments; competition; the possible impairment of, inability to obtain and costs of obtaining intellectual property rights; and possible safety or efficacyconcerns that could emerge as new data are generated in R&D, general business, financial and accounting risks and litigation.

Dicerna is providing this information as of this 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 otherpublic announcements and public filings made after the date of this information.

Dicerna™, GalXC™, and PHYOX™ are trademarks of Dicerna Pharmaceuticals, Inc.

Forward-looking Statements

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©2019 DICERNA

Build a fully integrated company by developing innovative RNAi-based therapies for high unmet medical needs and broadly capture the value of our GalXC platform

Vision Strategy

• Build Value in rare diseases by independently developing and commercializing programs with high value and high probability of success

• Capture Value in common diseases by developing select programs through clinical proof-of-concept before seeking development and commercialization partners

• Enhance Value by partnering with therapeutic field leaders on discovery stage programs

Dicerna Vision and Strategy: Driving RNAi Therapies Forward for Patients

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• Proprietary, patented RNA interference technology

• Objectively excellent pharmaceutical properties

- Subcutaneously delivered → convenient administration

- Long duration of action → convenient regimens

- High target specificity → predictable activity

- High therapeutic index → broad applicability

• Potential to extend the GalXC platform to diverse tissues beyond the liver

The Foundation of Our Value

Dicer substrate (DsiRNA) RNAi trigger

GalNAc targetingligands

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CANDIDATE INDICATION RESEARCH PRECLINICAL CLINICAL POCTRIALS

REGISTRATION TRIALS PARTNER

DCR-PHXC Primary Hyperoxaluria —

DCR-HBVS Hepatitis B Virus —

DCR-undisclosed Rare Disease —

DCR-undisclosed Undisclosed —

DCR-LIV1 NASH Boehringer Ingelheim

DCR-LIV2 NASH Boehringer Ingelheim

DCR-CM1 Cardiometabolic Lilly

DCR-CM2 Cardiometabolic Lilly

DCR-CM3 Cardiometabolic Lilly

DCR-NEURO1 Neurodegeneration Lilly

DCR-NEURO2 Neurodegeneration Lilly

DCR-PAIN1 Pain Lilly

DCR-PAIN2 Pain Lilly

DCR-COMP1 Complement-mediated Alexion

DCR-COMP2 Complement-mediated Alexion

Dicerna Development Pipeline

ORPHAN PREVALENT5

©2019 DICERNA

Primary Hyperoxaluria

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Disease Progression of PH Type 1 (PH1)

A family of rare, inherited, liver metabolic disorders resulting in oxalate overproductionPrimary Hyperoxaluria (PH)

Abnormal liver metabolism produces excess oxalate

Calcium oxalate crystals form in the kidneys

Decline in kidney function results in systemic oxalosis

Median age of onset of kidney failure is mid-20s

Patients require intensive daily dialysis while awaiting a liver-kidney transplant

PH Type 1: Most serious form of PHMedian age of kidney failure mid-20sSystemic oxalosis

PH Type 2: Very serious, chronic stones with significant risk of kidney failure

PH Type 3: Chronic stones, especially in youth

Peroxisome

Oxalate

GO

Primary hyperoxaluria 1

Glycolate

Glyoxylate

Primary hyperoxaluria 2 & 3

Glycine

LDH DCR-PHXC

AGT

HEPATOCYTE

GRHPR

Glyoxylate

Glycolate

Mitochondria

PathwayInputs

HOGA1 2 3

DCR-PHXC, under evaluation for the treatment of all forms of PH, silences LDHA, the final common pathway of oxalate production

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A two-part, single-ascending dose study (ClinicalTrials.gov: NCT03392896)

• Cohort 1 (1.5 mg/kg):- 3/5 participants’ 24Hr Uox values reached near-normalization (<0.6 and ≥0.46

mmol/24Hr) at one or more post-dose time points- Mean maximal 24Hr Uox reduction = 51% (range: 28%-72%)

• Cohort 2 (3.0 mg/kg):- 4/5 participants’ 24Hr Uox values have reached normalization (<0.46 mmol/24Hr)

at one or more post-dose time points- Mean maximal 24Hr Uox reduction = 71% (range: 62%-80%)

• Cohort 3 (6.0 mg/kg):- As of March 14, 2019 data cut, 3 participants have 24Hr Uox results- Mean maximal 24Hr Uox reduction = 76% (range: 58%-100%)- One participant in this cohort reached normalization at one or more post-dose

time points- Two participants are still in follow-up, as their 24Hr Uox has not yet returned to

within 80% of the lowest baseline 24Hr Uox measurement

*Results based on availability of data as of March 14, 2019**These data were presented at the German Society of Pediatric Nephrology Meeting on March 28, 2019

PHYOX™1: An Ongoing Phase 1 Study of DCR-PHXC in PH1 and PH2

Group A: Healthy volunteers• 25 healthy volunteers• Randomized 3:2 DCR-PHXC to placebo• 5 cohorts: 0.3, 1.5, 3.0, 6.0, 12.0 mg/kg• 5 subjects per cohort• Group A is complete

Group B: PH Patients• 18 PH1 and PH2 patients, open-label

Genetically confirmed diagnosis Uox ≥0.7mmol/24hr eGFR ≥30mL/min/1.73m2

• PH1 cohorts: 1.5, 3.0, 6.0 mg/kg• Mixed PH1 & PH2 cohort: variable dosing• 18 patients dosed as of today

(15 PH1, 3 PH2)

PHYOX1: A Placebo-Controlled, Single-Blind, Single-Center Phase 1 Study in Healthy Volunteers and Open-Label Multi-Center Study in Patients With Primary Hyperoxaluria (PH) to Evaluate the Safety, Tolerability, Pharmacokinetics and Pharmacodynamics of Single Ascending Doses of DCR-PHXC Solution for Injection (Subcutaneous Use)

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PHYOX – PH1 ONLY: PD and safety/tolerability results lay groundwork for pivotal trialPHYOX1: Uox Reduction in Patients After a Single Dose

Mean 24Hr Oxalate Over Time, Following Single Administration of DCR-PHXC

Mean Oxalate-to-Creatinine Ratio Over Time, Following Single Administration of DCR-PHXC

Most data points taken from 2 or fewer participants*Results based on availability of data as of March 14, 2019.

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8/13 patients achieve normalization or near-normalization; 8/13 with >50% Uox reductionScreening to Maximum Observed Reduction in Uox

Observed Uox Values (µmol/24hr)Screening to Maximal Reduction

% Reduction in UoxMaximal Reduction vs. Screening

Screening Maximal Reduction0

500

1000

1500

2000

2500

3000

Uox

(µm

ol/2

4hr)

<460normal

≥460 and <600near-normal

Screening Maximal Reduction0

10

20

30

40

50

60

70

80

90

100

% C

hang

e*Results based on availability of data as of March 14, 2019**These data were presented at the German Society of Pediatric Nephrology Meeting on March 28, 2019

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Coordinated program of Phase 2 pivotal trial and additional supportive trials

• PHYOX2 (PIVOTAL TRIAL): Double-blind, randomized, placebo-controlled trial (2:1 randomization) in approx. 36 patients with PH1 and PH2 (Q2 2019 initiation). Convenient, monthly fixed-dose regimen, enabling pre-filled syringes or autoinjectors at or shortly after product launch.

• PHYOX3 (ROLL-OVER STUDY): Patients from PHYOX trials may be re-enrolled into a long-term, multi-dose open-label extension trial, allowing readout of multi-dose data (Q2 2019 initiation)

• PH3 Patient Trial: Open-label study in approximately 10 patients with PH3

• ESRD Patient Trial: Single-dose trial in adults with end stage renal disease (ESRD) to determine PK

• Pediatric Trial: Open-label study in children (below age 6)

• Additional trials exploring dosing paradigms are also anticipated

DCR-PHXC: Moving into Regulatory Approval Trial in Q2 2019

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DCR-PHXC significantly expands to the patient pool compared to PH1-specific therapyDCR-PHXC is the Only RNAi Drug Candidate in Development for All PH Types

The Genetics of PH Current Diagnosis Rates

PH1 PH2 PH3

Genetic prevalence(per million) 8.23 5.08 12.58

US 2,681 1,655 4,098

EU 2,607 1,609 3,986

Total Potential Patients 5,288 3,264 8,084

PH1 PH2 PH3

Hoppe et al 2003 (US) 20.5% 3.8% Unknown

Hoppe et al 2005 (Germany) 20.3% 2.0% Unknown

OxalEUROPE 23.2% 4.0% Unknown

We anticipate that diagnostic rates will increase with an available effective treatment, especially for PH2

Epidemiology, diagnostic and uptake models developed Dicerna estimate peak sales between $500M and $1B

Pediatr Nephrol. 2003 Oct;18(10):986-91Am J Nephrol. 2005 May-Jun;25(3):276-81Am J Nephrol. 2005; 25:290-296

J Am Soc Nephrol. 2015 Oct;26(10):supp, and applied to population sizes

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Chronic Hepatitis B Virus Infection

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• Massive worldwide economic burden: ~257 million chronically infected (WHO)

• >10th leading cause of death worldwide: 887,000 in 2015 (WHO)

• Asymptomatic during the acute infection phase: just 9% of all HBV infections were diagnosed in 2015, and just 8% of those diagnosed were on treatment (WHO)

• Responsible for 80% of primary liver cancers

• Current treatments are rarely effective in achieving functional cures

Hepatitis B: A Severe, Global Unmet Medical Need

Electron micrograph of HBV showing infectious viral particles (~42 nm) and non-infectious subviral “decoy” particles (~22 nm) and filaments

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Organization of the HBV genome enables effective RNAi targeting of multiple viral functions GalXC RNAi May Play a Key Role in Establishing a Functional HBV Cure

• Functional Cure of chronic HBV is currently the best treatment outcome

• Defined by the lack of detectable HBsAg in serum (often associated with seroconversion to anti-HBsAg+)

• Interferons and NUCs are the only approved therapies, but offer very low functional cure rates

Current HBV Therapies Are Insufficient

The Promise of RNAi for HBV

• RNAi can simultaneously inhibit multiple viral activities due to overlapping transcripts

• RNAi can target viral transcripts and pgRNA from cccDNA and integrated genomes

DCR-HBVS Has Entered Clinical Development• Healthy volunteer dosing underway

• First chronic HBV patient dosing expected Q2 2019

3,221

EcoRI

preS1, preS2

and S

Polymerase

X gene

preCore,Core

1,376

2,856

834

1,6221,816

1,873

2,458

2,309

P gene: Polymerase. Viral genome production

S gene: Surface protein. HBsAg,

hepatocyte entry and immune decoy

X gene: Epigenetic

maintenance of viral genome

C gene: Core protein. Capsid

assembly; E antigen secretion

DCR-HBVS target site

Overlapping mRNAs and protein-coding regions enable targeting multiple HBV genes and proteins with a single GalXC trigger

AAAAA

Region of viral genome conservation

Viral mRNA transcript

Viral genome

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Driven by striking pharmacodynamic differences between targeting in the S versus X ORFsSingle Dose HBsAg Reduced to Below Lower Level of Detection in Preclinical Study

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• GalXC-HBVS: ≥3.9 log reduction, long duration of activity • X gene targeted: 3.0 log reduction, shorter duration of activity

• Immunohistochemical staining of mouse liver sections for HBV Core Protein (HBc) reveals extreme differences in subcellular localizationof HBc in the HDI-HBV plasmid model

• These results have been reproduced using alternative guide strand sequences (i.e., different mRNA binding sites) for both GalXC-HBVS and GalXC-HBVX

Time (days)

%HB

sAg

+/-

SEM

(Nor

mal

ized

to d

0)

-1 0 1 2 3 4 5 6 7 8 9 10 11 120.001

0.01

0.1

1

10

100

2/3 BLOQ 3/3 BLOQ

Vehicle Control

X Gene targeted treatment

GalXC-HBVS

3 mg/kg qWx3

HDI-HBV Plasmid Model (cccDNA-dependent)

HDI-HBV

Vehi

cle

Ctl.

GalX

C-HB

VS

HDI-HBV

X ta

rget

ed

Time (weeks)

©2019 DICERNA

Includes placebo-controlled studies in both NUC-naïve and NUC-experienced patientsDCR-HBVS Clinical Program for Proof of Concept

Three Part Study in Healthy Volunteers and Chronic HBV Patients

• Group A: Single-dose-ascending dose study, placebo-controlled, in 30 healthy volunteers- 5 dose cohorts: 0.1, 1.5, 3.0, 6.0, 12.0 mg/kg

• Group B: Single-dose study, placebo-controlled, in eight patients with NUC-naïve chronic hepatitis B- 1 dose cohort at 3.0-mg/kg

- Introduction of NUCs after 12 weeks

• Group C: Multiple-dose-ascending dose study, placebo-controlled, in 18 NUC-experienced chronic hepatitis B patients- 3 dose cohorts: 1.5, 3.0, and 6.0 mg/kg, 4 monthly doses, in parallel to Group A after 2nd cohort complete

- Patients with HBsAg seroclearance will be followed up for seroconversion (anti-HBsAg)

Study Launched in Q1 2019

• Filed Clinical Trial Application (CTA) with the New Zealand Medicines and Medical Devices Safety Authority (MedSafe) and the Health and Disability Ethics Committee (HDEC). Further CTA submissions in Asia-Pacific planned

• Dosed first healthy volunteer in January 2019 and first patient dosed in May 2019

• Interim data expected in Q4 2019

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Selected Dicerna GalXC™ ProgramsCollaborations With Lilly, Alexion and Boehringer Ingelheim

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Realizing Value Through Strategic Collaborations

Developing GalXC™ candidates with established pharmaceutical partners• Lilly: cardiometabolic, neurodegenerative and pain targets• Alexion: complement pathway targets• Boehringer Ingelheim: NASH targets

Expanding the range of the GalXC technology platform to go beyond liver tissue• Neural tissues: exclusive collaboration with Lilly to develop RNAi neural delivery

technology; Dicerna retains right to select rare diseases for Dicerna development

• Cardiometabolic tissue: non-exclusive collaboration with Lilly

Providing resources to drive our strategic programs• $252 million in upfront and option payments and equity at a premium among

the three collaborations

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Dicerna drivesto market

We seek to generate value across the full spectrum of GalXC clinical applicationsElements of Portfolio Strategy

Primary Hyperoxaluria

Undisclosed indication

ORPHAN DISEASE

Strategic Programs Partnered ProgramsHighest

ResourceInvestment

LowerResource

Investment

Dicerna drivesto clinical POC

Hepatitis BVirus

Undisclosed indication

COMMON DISEASE

Dicerna discoversPartner develops

COMMON DISEASE

Dicerna discoversPartner develops

AlexionCollaboration

DCR-COMP1DCR-COMP2

ORPHAN DISEASE

Key ValueDrivers

AdditiveValue

Lilly & BoehringerCollaborations

DCR-LIV1DCR-LIV2

DCR-CM1DCR-CM2DCR-CM3

DCR-NEURO1DCR-NEURO2

DCR-PAIN1DCR-PAIN2

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Building Value, Capturing Value, Enhancing Value

Advance DCR-PHXC for the treatment of primary hyperoxaluria (PH) Initiate PHYOX2, a pivotal multi-dose, double-blind, randomized, placebo-controlled trial Initiate PHYOX3, a long-term, multi-dose, open-label roll-over extension trial Report longer-term clinical data from PHYOX3

Advance DCR-HBVS for the treatment of patients with chronic hepatitis B virus (HBV) Dose first healthy volunteer in Phase 1 trial Dose first patient with non-cirrhotic chronic HBV in Phase 1 trial Report proof-of-concept data

Advance investigational GalXC™ therapy for the treatment of an undisclosed rare disease File clinical trial application

Achieve anticipated corporate milestones Evolve Board composition and expand leadership team to support continued growth

2019 Milestones

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