Dicerna™ Reports First Quarter 2019 Financial and Operating Results and Provides Corporate Update

— Initiated Screening of Participants to Enroll in the PHYOX™2 Phase
2 Pivotal Trial of DCR-PHXC for the Treatment of Primary Hyperoxaluria
(PH) and Announced Updated Data from Ongoing PHYOX1 Phase 1 of DCR-PHXC –

— Dosed First Healthy Volunteer in Phase 1 Clinical Trial of DCR-HBVS
for Treatment of Chronic Hepatitis B Virus (HBV) Infection –

— Advanced Boehringer Ingelheim Collaboration with Exercise of Option
for Second Hepatic Disease Target for Non-Alcoholic Steatohepatitis
(NASH) and Other Chronic Liver Diseases —

— Management to Host Conference Call Today at 4:30 p.m. ET —

CAMBRIDGE, Mass.–(BUSINESS WIRE)–Dicerna™
Pharmaceuticals, Inc. (Nasdaq: DRNA) (the “Company” or “Dicerna”), a
leading developer of investigational ribonucleic acid interference
(RNAi) therapeutics, today reported financial and operating results for
the first quarter ended March 31, 2019.

“During the first quarter we were very pleased to report several
important milestones for our lead GalXC™ program, DCR-PHXC, currently in
development for primary hyperoxaluria, as well as other pipeline
programs. In addition, we made strategic progress in augmenting our
board of directors and management team with talented, experienced
industry experts,” said Douglas M. Fambrough, Ph.D., president and chief
executive officer of Dicerna. “Specifically, we announced encouraging
updated data demonstrating utility of DCR-PHXC from our PHYOX1 Phase 1
clinical trial at the German Society of Pediatric Nephrology 50^th
Annual Meeting in March. Based on these data, we began screening
participants for our PHYOX2 Phase 2 pivotal trial for DCR-PHXC. We also
advanced our Phase 1 DCR-HBVS program for the treatment of chronic
hepatitis B virus infection by dosing our first healthy volunteer in the
trial.”

“We are encouraged that Boehringer Ingelheim elected and is moving
forward with a second GalXC compound against a hepatic target in the
chronic liver disease space. Our recent strategic alliances with Alexion
and Lilly are off to a strong start, as we have initiated nine
early-stage discovery programs to generate GalXC molecules against both
liver and neurological targets. Our ability to simultaneously drive
discovery in these collaborative programs demonstrates the efficiency,
robustness, and reproducibility of our GalXC discovery and optimization
methods. We expect 2019 to be a year of execution for Dicerna, and we
look forward to achieving key milestones in the second quarter, as we
expect to dose the first patients in PHYOX2, PHYOX3 and our DCR-HBVS
program and submit a clinical trial application for our second rare
disease program.”

First Quarter 2019 Achievements

Clinical

• Initiated screening to enroll participants in the PHYOX2 Phase 2
  multi-dose, double-blind, randomized, placebo-controlled pivotal trial
  of DCR-PHXC.
• Announced updated data from ongoing PHYOX1 Phase 1 clinical trial
  demonstrating utility of lead compound DCR-PHXC in treating primary
  hyperoxaluria Type 1 (PH1) and Type 2 (PH2). Data showed significant
  substantial post-dose reductions in 24-hour urinary oxalate levels in
  adult and adolescent study participants with PH1 and PH2.
  • Updated data for DCR-PHXC in 25 adult healthy volunteers (HVs) and
    18 participants (15 adults and three adolescents [participants
    12-17 years old]) with PH1 (n=15) and PH2 (n=3) were presented in
    a poster on March 28 at the German Society of Pediatric Nephrology
    50^th Annual Meeting in Cologne, Germany.
  • The results (as of March 14, 2019) show that a single dose of
    3.0-mg/kg of DCR-PHXC brought urinary oxalate levels into the
    normal range (defined as 24-hour excretion <0.46 mmol) at one or
    more post-dose time points in four of five participants with PH1,
    including a mean maximal reduction of 24-hour urinary oxalate of
    71% for the cohort. A single 1.5-mg/kg dose led to
    near-normalization (defined as 24-hour excretion <0.6 and ≥0.46
    mmol) in three of five participants with PH1 dosed at this level,
    including a mean maximal reduction in urinary oxalate of 51% for
    the cohort. Among the three participants with PH1 dosed at
    6.0-mg/kg, the mean maximal reduction in urinary oxalate was 76%.
    One participant in this cohort reached normalization and a second
    reached near-normalization, at one or more post-dose time points;
    one has not reached Day 57 and the other is still in follow-up and
    may not yet have reached maximal 24-hour urinary oxalate reduction.
  • Investigators reported that DCR-PHXC was generally well-tolerated
    in HVs and participants with PH. As of a data cut on March 14,
    2019, four serious adverse events have occurred in three
    participants, though none were deemed related to the study drug.
    Nine participants (27%) dosed with DCR-PHXC experienced mild or
    moderate injection site reactions, all of which resolved without
    intervention within 96 hours.
• Achieved agreement on the primary endpoint for the PHYOX2 pivotal
  clinical trial, which is enrolling patients with PH1 and PH2, and
  alignment with the FDA regarding the path to full approval for the
  treatment of patients with PH1, as conveyed during a recent FDA Type A
  meeting.
• Dosed first HV in the multi-dose, double-blind, randomized,
  placebo-controlled Phase 1 clinical trial of DCR-HBVS, studying the
  Company’s investigational GalXC-based therapy for the treatment of
  chronic HBV infection in adults.
• Continued to advance internal development of the wholly-owned
  undisclosed program for a second rare disease involving the liver.

Collaborations

• Triggered $5 million payment from Boehringer Ingelheim International
  GmbH (BI) upon exercise of option for second hepatic disease target
  under research and license agreement.
  • The collaboration, established in October 2017, aims to discover
    and develop novel GalXC RNAi therapeutics for the treatment of
    chronic liver diseases, with an initial focus on NASH.
  • Dicerna is eligible to receive development and commercial
    milestone payments, and royalties on worldwide net sales.

Business Highlights

• Strengthened board of directors with addition of Marc Kozin, formerly
  vice-chair and head of healthcare, LEK Consulting, and Anna
  Protopapas, president and chief executive officer of Mersana
  Therapeutics, Inc.
  • J. Kevin Buchi, former chief executive officer of Cephalon, Inc.
    and TetraLogic Pharmaceuticals Corp., was appointed as board chair.
• Fortified leadership team to support Dicerna’s continued growth with
  the strategic hires of Regina DeTore Paglia as senior vice president
  of human resources and Hardean Achneck, M.D., as vice president, head
  of medical development.

Upcoming Regulatory and Clinical Milestones

• Dose first patient in PHYOX2, a multi-dose, double-blind, randomized,
  placebo-controlled pivotal trial of DCR-PHXC for the treatment of all
  forms of PH expected in the second quarter of 2019.
• Dose first patient in PHYOX3, the long-term, multi-dose open-label,
  roll-over extension initially for our Phase 1 study for the treatment
  of PH expected in the second quarter of 2019.
• Dose first patient in the Phase 1 clinical trial of DCR-HBVS for the
  treatment of patients with chronic HBV expected in the second quarter
  of 2019.
  • The Company anticipates human proof-of-concept data from the first
    cohort to be available in the fourth quarter of 2019
• Submit a CTA in the second quarter of 2019 for the Company’s
  undisclosed second rare disease program to initiate clinical trials.

Financial Condition and Operating Results for the First Quarter of
2019

• Cash Position – As of March 31, 2019, Dicerna had $371.2
  million in cash, cash equivalents and held-to-maturity investments,
  which included $94.5 million in net proceeds received in the first
  quarter of 2019 from our collaborations, as compared to $302.6 million
  in cash, cash equivalents and held-to-maturity investments as of
  December 31, 2018. Additionally, the Company had $3.5 million and $0.7
  million of restricted cash equivalents as of March 31, 2019 and
  December 31, 2018, respectively, which reflects collateral securing
  the Company’s lease obligations.
• Revenue – Dicerna recognized $3.1 million of revenue
  associated with its collaboration agreements with Lilly, Alexion and
  BI during the first quarter ended March 31, 2019 compared with $1.5
  million in the same period in 2018.
• Research and Development (R&D) Expenses – R&D expenses were
  $21.6 million in the first quarter ended March 31, 2019, as compared
  to $9.9 million for the same period in 2018. The increase, as compared
  to the same period in 2018, was primarily due to increased direct R&D
  expenses and an increase in employee-related expenses due to an
  increase in headcount necessary to support our growth.
• General and Administrative (G&A) Expenses – G&A expenses
  were $9.7 million for the first quarter ended March 31, 2019, as
  compared to $4.3 million for the same period in 2018. The increase is
  predominantly related to increases in employee-related expenses,
  including stock-based compensation expense, as well as an increase in
  general and business development consulting expense.
• Litigation Expenses – There were no litigation expenses in the
  first quarter ended March 31, 2019, as compared with $3.2 million in
  the first quarter of 2018. Litigation expense was solely related to
  trade secret litigation that was settled in the second quarter of 2018.
• Net Loss – Net loss was $26.2 million, or $0.38 per share, for
  the first quarter ended March 31, 2019, as compared to $15.6 million,
  or $0.30 per share, for the same period in 2018. The increase for the
  three months ended March 31, 2019 was driven by the increase in
  operating expenses.

Guidance

• Dicerna believes that its current cash, cash-equivalents and
  held-to-maturity investments will be sufficient to fund the execution
  of its current clinical and operating plan beyond 2020, which includes
  advancing DCR-PHXC through late-stage clinical development and
  regulatory filing, completing proof-of-concept studies of DCR-HBVS in
  participants with HBV, and advancing the Company’s undisclosed rare
  disease program through initial clinical studies. This estimate
  assumes no new funding from additional collaboration agreements or
  from external financing events and no significant unanticipated
  changes in costs and expenses.
• Dicerna expects its overall R&D expense to continue to increase for
  the foreseeable future, primarily as the Company completes clinical
  manufacturing activities, increases clinical and non-clinical
  development activities associated with its lead product candidates,
  and continues activities under the Lilly, Alexion and BI agreements.

Conference Call

Management will host a conference call at 4:30 p.m. ET today to review
Dicerna’s first quarter 2019 financial results and provide a general
business update. The conference call can be accessed by dialing (855)
453-3834 or +1 (484) 756-4306 (international) and referencing conference
ID 4749943 prior to the start of the call. The call will also be webcast
via the Internet and will be available under the “Investors & Media”
section of the Dicerna website, www.dicerna.com.
A replay of the call will be available approximately two hours after the
completion of the call and will remain available for seven days. To
access the replay, please dial (855) 859-2056 or (404) 537-3406 and
refer to conference ID 4749943. The webcast will also be archived on
Dicerna’s website.

About Dicerna™ Pharmaceuticals, Inc.

Dicerna™ Pharmaceuticals, Inc., is a biopharmaceutical company focused
on the discovery and development of innovative, subcutaneously delivered
RNAi-based therapeutics for the treatment of diseases involving the
liver, including rare diseases, chronic liver diseases, cardiovascular
diseases and viral infectious diseases. Dicerna is leveraging its
proprietary GalXC™ RNAi technology platform to build a broad pipeline in
these core therapeutic areas, focusing on target genes where connections
between these genes and diseases are well understood and documented.
Dicerna intends to discover, develop and commercialize novel
therapeutics either on its own or in collaboration with pharmaceutical
partners. Dicerna has strategic collaborations with Eli Lilly and
Company, Alexion Pharmaceuticals, Inc. and Boehringer Ingelheim
International GmbH. For more information, please visit www.dicerna.com.

About GalXC™ RNAi Technology Platform

GalXC™ is a proprietary technology platform invented by Dicerna to
discover and develop RNAi-based therapies designed to silence
disease-driving genes in the liver. Compounds produced via GalXC are
intended to be broadly applicable across multiple therapeutic areas
involving the liver, including rare diseases, chronic liver diseases,
cardiovascular diseases and viral infectious diseases. Using GalXC,
Dicerna scientists attach N-acetylgalactosamine sugars directly to the
extended region of the Company’s proprietary RNAi molecules, yielding
multiple proprietary conjugate delivery configurations. Many of the
conjugates produced via GalXC incorporate a folded motif known as a
tetraloop in the extended region. The tetraloop configuration, which is
unique to Dicerna’s GalXC compounds, allows flexible and efficient
conjugation to the targeting ligands, and stabilizes the RNAi duplex
which the Company believes will enable subcutaneous delivery of its RNAi
therapies to hepatocytes in the liver, where they are designed to
specifically bind to receptors on target cells, potentially leading to
internalization and access to the RNAi machinery within the cells. The
technology may offer several distinct benefits, as suggested by strong
preclinical data. The benefits seen in preclinical studies include:
potency that is on par with or better than comparable platforms, highly
specific binding to gene targets, long duration of action and an
infrequent subcutaneous dosing regimen.

Cautionary Note on Forward-Looking Statements

This press release includes forward-looking statements. Such
forward-looking statements are subject to risks and uncertainties that
could cause actual results to differ materially from those expressed or
implied in such statements. Examples of forward-looking statements
include, among others, statements we make regarding: (i) the therapeutic
and commercial potential of DCR-PHXC, DCR-HBVS and the GalXC™ platform;
(ii) research and development plans and timelines related to DCR-PHXC,
DCR-HBVS and GalXC; and (iii) the potential of Dicerna’s technology and
drug candidates in the Company’s research and development pipeline. The
process by which an early stage investigational therapy such as DCR-HBVS
and an early stage platform such as GalXC could potentially lead to an
approved product is long and subject to highly significant risks.
Applicable risks and uncertainties include those relating to Dicerna’s
clinical research and other risks identified under the heading “Risk
Factors” included in the Company’s most recent Form 10-Q or 10-K filing
and in other future filings with the Securities and Exchange Commission.
These risks and uncertainties include, among others, the cost, timing
and results of preclinical studies and clinical trials and other
development activities; the likelihood of Dicerna’s clinical programs
being executed on timelines provided and reliance on the Company’s
contract research organizations and predictability of timely enrollment
of subjects and patients to advance Dicerna’s clinical trials; the
potential for future data to alter initial and preliminary results of
early stage clinical trials; the unpredictability of the duration and
results of the regulatory review of Investigational New Drug
Applications (NDAs) and CTAs that are necessary to continue to advance
and progress the Company’s clinical programs and the regulatory review
of NDAs; market acceptance for approved products and innovative
therapeutic treatments; competition; the possible impairment of,
inability to obtain and costs to obtain intellectual property rights;
and possible safety or efficacy concerns that could emerge as new data
are generated in R&D, general business, financial and accounting risks
and litigation. The forward-looking statements contained in this press
release reflect Dicerna’s current views with respect to future events,
and Dicerna does not undertake and specifically disclaims any obligation
to update any forward-looking statements.Dicerna™, GalXC™, and PHYOX™
are trademarks of Dicerna Pharmaceuticals, Inc.

DICERNA PHARMACEUTICALS, INC.
SELECTED FINANCIAL INFORMATION (UNAUDITED)
Condensed Consolidated Balance Sheets				March 31, 2019				December 31, 2019
(In thousands)
Cash and cash equivalents				$	160,141			$	54,239
Held-to-maturity investments				211,063				248,387
Contract receivables				—				100,000
Other current assets				2,160				2,888
Right-of-use asset				3,047				—
Property and equipment, net				3,971				2,718
Restricted cash equivalents				3,544				744
Other noncurrent assets				63				65
Total Assets				$	383,989			$	409,041
Accounts payable				$	4,958			$	5,013
Accrued expenses and other current liabilities				8,196				9,649
Litigation settlement payable				—				10,500
Current portion of deferred revenue				59,784				68,893
Lease liability, current portion				1,750				—
Deferred revenue, net of current portion				128,295				114,293
Lease liability, noncurrent				1,378				—
Total stockholders’ equity				179,628				200,693
Total Liabilities and Stockholders’ Equity				$	383,989			$	409,041
Common stock outstanding				68,288,906				68,210,742

DICERNA PHARMACEUTICALS, INC.
SELECTED FINANCIAL INFORMATION (UNAUDITED)
Condensed Consolidated Statements of Operations					Three Months Ended March 31, 2019				Three Months Ended March 31, 2018
(In thousands, except per share data)
Revenue from collaborative arrangements					$	3,107			$	1,545
Operating expenses:
Research and development					21,603				9,893
General and administrative					9,676				4,335
Litigation expense					—				3,184
Total operating expenses					31,279				17,412
Loss from operations					(28,172		)		(15,867		)
Interest income					2,018				288
Net loss					$	(26,154	)		$	(15,579	)
Net loss per share – basic and diluted					$	(0.38	)		$	(0.30	)
Weighted average common shares outstanding – basic and diluted					68,259				51,723

Contacts

Investors:
Stern Investor Relations, Inc.
Kendra Packard,
212-362-1200
Kendra.packard@sternir.com

Media:
SmithSolve
Alex Van Rees, 973-442-1555 ext. 111
alex.vanrees@smithsolve.com