Alnylam and Regeneron Announce Broad Collaboration to Discover, Develop and Commercialize RNAi Therapeutics Focused on Ocular and Central Nervous System (CNS) Diseases

− Companies to Also Jointly Advance Select Number of Preclinical
Disease Programs with Targets Expressed in the Liver and Treatments for
C5 Complement-Mediated Diseases –

− Regeneron to Invest $800 million Through Upfront Cash and Equity
Investment in Alnylam, with up to Additional $200 Million in Potential
Near-Term Milestones –

− Alnylam to Host Conference Call Today, Monday, April 8^th
at 8:30 am ET –

CAMBRIDGE, Mass. & TARRYTOWN, N.Y.–(BUSINESS WIRE)–Alnylam
Pharmaceuticals, Inc. (Nasdaq:ALNY), the leading RNAi therapeutics
company, and Regeneron Pharmaceuticals, Inc. (NASDAQ: REGN), announced
today a collaboration to discover, develop and commercialize new RNA
interference (RNAi) therapeutics for a broad range of diseases by
addressing disease targets expressed in the eye and central nervous
system (CNS), in addition to a select number of targets expressed in the
liver. The collaboration will leverage both companies’ scientific and
technological expertise and will build on Alnylam’s recent preclinical
data showing potent and highly durable delivery of RNAi therapeutics to
achieve target gene silencing in the eye and CNS. The collaboration will
also benefit from Regeneron’s industry-leading VelociSuite^®
technologies and capabilities from the Regeneron Genetics Center (RGC).

Under the terms of the alliance, Alnylam will work exclusively with
Regeneron to discover RNAi therapeutics for eye and CNS diseases.
Regeneron will lead development and commercialization for all programs
targeting eye diseases, with Alnylam entitled to potential milestone and
royalty payments. The companies will jointly advance and alternate
leadership on CNS programs, with the lead party retaining global
development and commercial responsibility. For CNS programs, both
companies will have the option at candidate selection to participate
equally in potential future profits of programs led by the other party.

The collaboration also includes a select number of RNAi therapeutic
programs designed to target genes expressed in the liver, which can
influence a wide variety of diseases throughout the body. These programs
include a planned joint effort evaluating anti-C5 antibody-siRNA
combinations for C5 complement-mediated diseases including evaluating
the combination of Regeneron’s pozelimab (REGN3918), currently in Phase
1 development, with Alnylam’s cemdisiran, currently in Phase 2
development. Alnylam will retain control of cemdisiran monotherapy
development, and Regeneron will lead combination development. The
parties will equally share investment and potential future profits on
the monotherapy program, and Alnylam will receive royalties on any
potential combination product sales. For all other alliance liver
programs, the parties will alternate leadership and participate equally
in potential profits. The companies will continue their previously-announced
collaboration to identify RNAi therapeutics for the chronic liver
disease nonalcoholic steatohepatitis (NASH) based on novel RGC findings.
Alnylam retains broad global rights to all of its other unpartnered
liver-directed clinical and preclinical pipeline programs.

“At Regeneron we believe the best use of our resources is to invest in
potentially game-changing science that will yield innovative medicines
for patients with serious diseases. This collaboration couples proven
and emerging RNAi technology, which holds important promise in many
diseases, with Regeneron’s world-leading genetics research and target
discovery engine,” said George D. Yancopoulos, M.D., Ph.D., President
and Chief Scientific Officer of Regeneron. “This collaboration enables
us to reach targets inside the cell complementing our expertise in
antibodies, which are ideal for extracellular targets and those on the
cell surface. Through the RGC and our other research groups, we are
already identifying additional targets that may be well-suited for
RNAi-based drug development, particularly in the eye and CNS.”

“This new industry-leading alliance is aimed at realizing what we
believe to be a significant opportunity for RNAi therapeutics as
potentially transformative medicines for ocular and CNS diseases. We are
thrilled to collaborate with Regeneron, a like-minded science-based
organization, to significantly accelerate our efforts to bring RNAi
therapeutics to patients,” said John Maraganore, Ph.D., Chief Executive
Officer of Alnylam. “Importantly, the alliance structure enables Alnylam
to continue to build its industry-leading pipeline of RNAi therapeutics
while retaining significant product rights. In addition, the near-term
payments under this new agreement will strengthen Alnylam’s balance
sheet with over $2 billion in pro forma cash upon closing of the
transaction, supporting our global efforts to develop and commercialize
multiple products as potentially breakthrough medicines and advance our
profile toward sustainable profitability.”

Regeneron has agreed to make a $400 million upfront payment to Alnylam
and to purchase $400 million of Alnylam equity at a price per share of
$90.00 (4.44 million common shares), based on the volume-weighted
average price over the last fifteen-trading-day period. Alnylam is
eligible to receive up to an additional $200 million in milestone
payments upon achievement of certain criteria during early clinical
development for the eye and CNS programs. The companies plan to advance
programs directed to 30 targets and introduce many into clinical
development during the initial five-year discovery period, which
includes an option to extend. For each program, Regeneron will provide
Alnylam with $2.5 million in funding at program initiation and an
additional $2.5 million at lead candidate identification, translating to
the potential for approximately $30 million in annual discovery funding
to Alnylam as the alliance reaches steady state. The alliance and
equity-related agreements are subject to customary closing conditions
and clearances, including clearance under the Hart-Scott Rodino
Antitrust Improvements Act.

Alnylam, alongside multiple other leading life sciences companies, is
also a member of Regeneron’s pre-competitive consortium to sequence the
DNA of 500,000 individuals in the UK Biobank health resource and
subsequently make the data publicly available to the global research
community.

Alnylam Conference Call Information

Alnylam Management will discuss this collaboration via conference call
on Monday, April 8, 2019 at 8:30 am ET. A webcast presentation will also
be available on the Investors page of the Company’s website, www.alnylam.com.
To access the call, please dial 800-289-0438 (domestic) or 323-794-2423
(international) five minutes prior to the start time and refer to
conference ID 2197882. A replay of the call will be available beginning
at 11:30 am ET on the day of the call. To access the replay, please dial
888-203-1112 (domestic) or 719-457-0820 (international) and refer to
conference ID 2197882.

About Alnylam Pharmaceuticals

Alnylam (Nasdaq: ALNY) is leading the translation of RNA interference
(RNAi) into a whole new class of innovative medicines with the potential
to transform the lives of people afflicted with rare genetic,
cardio-metabolic, hepatic infectious, and central nervous system
(CNS)/ocular diseases. Based on Nobel Prize-winning science, RNAi
therapeutics represent a powerful, clinically validated approach for the
treatment of a wide range of severe and debilitating diseases. Founded
in 2002, Alnylam is delivering on a bold vision to turn scientific
possibility into reality, with a robust discovery platform. Alnylam’s
first U.S. FDA-approved RNAi therapeutic is ONPATTRO^® (patisiran)
lipid complex injection available in the U.S. for the treatment of the
polyneuropathy of hereditary transthyretin-mediated (hATTR) amyloidosis
in adults. In the EU, ONPATTRO is approved for the treatment of hATTR
amyloidosis in adults with stage 1 or stage 2 polyneuropathy. Alnylam
has a deep pipeline of investigational medicines, including five product
candidates that are in late-stage development. Looking forward, Alnylam
will continue to execute on its “Alnylam 2020” strategy of building a
multi-product, commercial-stage biopharmaceutical company with a
sustainable pipeline of RNAi-based medicines to address the needs of
patients who have limited or inadequate treatment options. Alnylam
employs over 1,000 people worldwide and is headquartered in Cambridge,
MA. For more information about our people, science and pipeline, please
visit www.alnylam.com
and engage with us on Twitter at @Alnylam
or on LinkedIn.

About Regeneron Pharmaceuticals, Inc.

Regeneron (NASDAQ: REGN) is a leading biotechnology company that invents
life-transforming medicines for people with serious diseases. Founded
and led for 30 years by physician-scientists, our unique ability to
repeatedly and consistently translate science into medicine has led to
seven FDA-approved treatments and numerous product candidates in
development, all of which were homegrown in our laboratories. Our
medicines and pipeline are designed to help patients with eye disease,
heart disease, allergic and inflammatory diseases, pain, cancer,
infectious diseases and rare diseases.

Regeneron is accelerating and improving the traditional drug development
process through our proprietary VelociSuite^® technologies,
such as VelocImmune^® which produces optimized
fully-human antibodies, and ambitious research initiatives such as the
Regeneron Genetics Center, which is conducting one of the largest
genetics sequencing efforts in the world.

For additional information about the company, please visit www.regeneron.com
or follow @Regeneron on Twitter.

Alnylam Forward-Looking Statements

Various statements in this release concerning Alnylam’s future
expectations, plans and prospects, including, without limitation,
Alnylam’s views with respect to the potential of RNAi therapeutics to
achieve target gene silencing in the CNS and eye, Regeneron’s
participation in the development and commercialization of RNAi
therapeutics directed to CNS, eye and a select number of liver targets,
as well as the planned joint effort evaluating an anti-C5 antibody-siRNA
combination as well as a monotherapy approach, the parties plans to
advance 30 targets and file multiple Investigational New Drug
Applications during the discovery period, Alnylam’s expectations
regarding funding for each program under the collaboration at various
stages of development, its expectations regarding the receipt of upfront
cash and an equity investment, as well as potential development,
regulatory and sales milestones and royalties from Regeneron, its
expectations regarding available cash for its operations through
multiple product launches, and expectations regarding its “Alnylam 2020”
guidance for the advancement and commercialization of RNAi therapeutics,
constitute forward-looking statements for the purposes of the safe
harbor provisions under The Private Securities Litigation Reform Act of
1995. Actual results and future plans may differ materially from those
indicated by these forward-looking statements as a result of various
important risks, uncertainties and other factors, including, without
limitation: Alnylam’s ability to discover and develop novel drug
candidates and delivery approaches; successfully demonstrate the
efficacy and safety of its product candidates; the pre-clinical and
clinical results for its product candidates, which may not be replicated
or continue to occur in other subjects or in additional studies or
otherwise support further development of product candidates for a
specified indication or at all; actions or advice of regulatory
agencies, which may affect the design, initiation, timing, continuation
and/or progress of clinical trials or result in the need for additional
pre-clinical and/or clinical testing; delays, interruptions or failures
in the manufacture and supply of its product candidates; Regeneron’s
ability to successfully advance and develop programs targeting eye
diseases, resulting in the potential payment of milestones and royalties
to Alnylam; the parties ability to successfully develop and
commercialize CNS programs; obtaining, maintaining and protecting
intellectual property; Alnylam’s ability to enforce its intellectual
property rights against third parties and defend its patent portfolio
against challenges from third parties; obtaining and maintaining
regulatory approval, pricing and reimbursement for products; progress in
establishing a commercial and ex-United States infrastructure,
successfully launching, marketing and selling its approved products
globally; Alnylam’s ability to successfully expand the indication for
ONPATTRO in the future; competition from others using technology similar
to Alnylam’s and others developing products for similar uses; Alnylam’s
ability to manage its growth and operating expenses, obtain additional
funding to support its business activities, and establish and maintain
strategic business alliances and new business initiatives; Alnylam’s
dependence on third parties for development, manufacture and
distribution of products; the outcome of litigation; the risk of
government investigations; and unexpected expenditures; as well as those
risks more fully discussed in the “Risk Factors” filed with Alnylam’s
most recent Annual Report on Form 10-K filed with the Securities and
Exchange Commission (SEC) and in other filings that Alnylam makes with
the SEC. In addition, any forward-looking statements represent Alnylam’s
views only as of today and should not be relied upon as representing its
views as of any subsequent date. Alnylam explicitly disclaims any
obligation, except to the extent required by law, to update any
forward-looking statements.

Regeneron Forward-Looking Statements and Use of Digital Media

This press release includes forward-looking statements that involve
risks and uncertainties relating to future events and the future
performance of Regeneron Pharmaceuticals, Inc. (“Regeneron” or the
“Company”), and actual events or results may differ materially from
these forward-looking statements. Words such as “anticipate,” “expect,”
“intend,” “plan,” “believe,” “seek,” “estimate,” variations of such
words, and similar expressions are intended to identify such
forward-looking statements, although not all forward-looking statements
contain these identifying words. These statements concern, and these
risks and uncertainties include, among others, the nature, timing, and
possible success and therapeutic applications of Regeneron’s or its
collaborators’ products, product candidates, and research and clinical
programs now underway or planned, such as the RNA interference programs
discussed in this press release (including programs evaluating anti-C5
antibody-siRNA combinations for C5 complement-mediated diseases and RNAi
therapeutics for the chronic liver disease nonalcoholic
steatohepatitis); the extent to which the results from the research and
development programs conducted by Regeneron or its collaborators
(including based on the collaboration discussed in this press release)
may be replicated in other studies and lead to therapeutic applications;
the potential for any license or collaboration agreement, including
Regeneron’s agreements with Sanofi, Bayer, and Teva Pharmaceutical
Industries Ltd. (or their respective affiliated companies, as
applicable), as well as Regeneron’s collaborations with Alnylam
Pharmaceuticals, Inc. discussed in this news release, to be cancelled or
terminated without any product success; the likelihood, timing, and
scope of possible regulatory approval and commercial launch of
Regeneron’s late-stage product candidates and new indications for
marketed products; unforeseen safety issues resulting from the
administration of products and product candidates in patients, including
serious complications or side effects in connection with the use of
Regeneron’s or its collaborators’ product candidates in clinical trials;
ongoing regulatory obligations and oversight impacting Regeneron’s
marketed products, research and clinical programs, and business,
including those relating to patient privacy; determinations by
regulatory and administrative governmental authorities which may delay
or restrict Regeneron’s or its collaborators’ ability to continue to
develop or commercialize products and product candidates; competing
drugs and product candidates that may be superior to Regeneron’s or its
collaborators’ products and product candidates; uncertainty of market
acceptance and commercial success of Regeneron’s or its collaborators’
products and product candidates and the impact of studies (whether
conducted by Regeneron or others and whether mandated or voluntary) on
the commercial success of Regeneron’s or its collaborators’ products and
product candidates; the ability of Regeneron to manufacture and manage
supply chains for multiple products and product candidates; the ability
of Regeneron’s collaborators, suppliers, or other third parties (as
applicable) to perform manufacturing, filling, finishing, packaging,
labeling, distribution, and other steps related to Regeneron’s products
and product candidates; the availability and extent of reimbursement of
the Company’s products from third-party payers, including private payer
healthcare and insurance programs, health maintenance organizations,
pharmacy benefit management companies, and government programs such as
Medicare and Medicaid; coverage and reimbursement determinations by such
payers and new policies and procedures adopted by such payers;
unanticipated expenses; the costs of developing, producing, and selling
products; the ability of Regeneron to meet any of its financial
projections or guidance and changes to the assumptions underlying those
projections or guidance; and risks associated with intellectual property
of other parties and pending or future litigation relating thereto,
including without limitation the patent litigation and other related
proceedings relating to EYLEA^® (aflibercept) Injection, and
Dupixent^® (dupilumab) Injection, and Praluent^®
(alirocumab) Injection, the ultimate outcome of any such proceedings,
and the impact any of the foregoing may have on Regeneron’s business,
prospects, operating results, and financial condition. A more complete
description of these and other material risks can be found in
Regeneron’s filings with the U.S. Securities and Exchange Commission,
including its Form 10-K for the year ended December 31, 2018. Any
forward-looking statements are made based on management’s current
beliefs and judgment, and the reader is cautioned not to rely on any
forward-looking statements made by Regeneron. Regeneron does not
undertake any obligation to update publicly any forward-looking
statement, including without limitation any financial projection or
guidance, whether as a result of new information, future events, or
otherwise.

Regeneron uses its media and investor relations website and social media
outlets to publish important information about the Company, including
information that may be deemed material to investors. Financial and
other information about Regeneron is routinely posted and is accessible
on Regeneron’s media and investor relations website (http://newsroom.regeneron.com)
and its Twitter feed (http://twitter.com/regeneron).

Contacts

Alnylam Pharmaceuticals, Inc.
Christine Regan Lindenboom
(Investors
and Media)
617-682-4340

Josh Brodsky
(Investors)
617-551-8276

Regeneron Investor Relations
Mark Hudson
Tel: +1 (914)
847-3482
[email protected]

Regeneron Media Relations
Hala Mirza
Tel: +1 (914)
847-3422
[email protected]