Alnylam Highlights Progress on Global Market Access for ONPATTRO (patisiran)

− In the United States, Company Completes Tenth Value-Based Agreement
with Commercial Payers, and Achieves Confirmed Access to ONPATTRO for
Greater than 90 Percent of Covered Lives –

− In Europe, Company Achieves Favorable Health Technology Assessment
Ratings for ONPATTRO in Multiple Countries –

CAMBRIDGE, Mass.–(BUSINESS WIRE)–Alnylam
Pharmaceuticals, Inc. (Nasdaq: ALNY), the leading RNAi therapeutics
company, today announced that it has made substantial progress in the
global commercialization of ONPATTRO for the treatment of the
polyneuropathy of hereditary transthyretin-mediated (hATTR) amyloidosis
in adults. The Company has now completed definitive value-based
agreements (VBAs) with 10 commercial payers in the United States.
Furthermore, greater than 90 percent of U.S. lives across commercial,
Medicare, Medicaid, and other government payer categories are now
confirmed to have access to ONPATTRO if prescribed.

“We’re encouraged by the positive reception for global access to
ONPATTRO from many private and public payers. With 10 VBAs completed
with commercial payers in the U.S., we’re fulfilling our commitment that
ONPATTRO is reimbursed based on its ability to deliver outcomes in the
real-world setting comparable to those demonstrated in clinical trials,”
said Barry Greene, President of Alnylam. “We have also made great
progress advancing pricing and reimbursement procedures with authorities
across Europe. In particular, we’re encouraged by the favorable outcomes
achieved in health technology assessment proceedings in major EU markets
including Germany and France, among others. Overall, our market access
progress in the U.S. and EU is aligned with our commitment to bring
ONPATTRO to patients around the world.”

Alnylam has made significant progress securing access to ONPATTRO for
multiple countries in the EU. The Company remains on track with pricing
and reimbursement procedures in nearly all EU markets, with encouraging
assessment outcomes and ongoing discussions with authorities. Key
updates include:

• Germany: Launched ONPATTRO one month following EC authorization
  (October 2018). Since then, ONPATTRO has become the only product for
  the treatment of hATTR amyloidosis to receive a “considerable benefit”
  rating from the Joint
  Federal Committee (G-BA).
• France: Recognized ONPATTRO as being the only product for the
  treatment of hATTR with a significant public health impact as noted by
  its ASMR
  III and Intêret Santé Publique (ISP) ratings. ONPATTRO is
  currently reimbursed through Temporary Authorization for Use.
• Austria: Achieved access as of October 2018.
• Luxembourg: Achieved access as of October 2018.
• Netherlands: Reached a nationwide agreement to reimburse
  ONPATTRO for all eligible patients through joint negotiations
  coordinated by Zorgverzekeraars Nederland (ZN), the Dutch Association
  of Health Insurers.
• Sweden: Published HTA
  assessment from the Dental and Pharmaceutical Benefits Agency in
  Sweden (TLV) allowing a subsequent ongoing negotiation with the New
  Therapy Council (NT- Council) to allow usage of ONPATTRO within the
  County Councils.

Pricing and reimbursement procedures are progressing in several
additional countries, including the United Kingdom, Italy, Spain,
Portugal, Ireland and key markets in Central and Eastern Europe where
several hATTR endemic regions exist. In addition, authorities have
approved access under specific named patient procedures in several
countries while reimbursement proceedings move forward.

Alnylam remains committed to making ONPATTRO available and reimbursed
worldwide in alignment with its Patient
Access Philosophy, which outlines the Company’s commitment to access
while delivering value to patients, physicians, and payers.

Physicians and patients in the United States can learn more about
Alnylam’s comprehensive patient services by visiting AlnylamAssist.com
or calling 1-833-256-2748.

Visit ONPATTRO.com
for more information, including full prescribing information.

About ONPATTRO^® (patisiran)
Patisiran,
based on Nobel Prize-winning science, is an intravenously administered
RNAi therapeutic targeting transthyretin (TTR) for the treatment of
hereditary ATTR amyloidosis. It is designed to target and silence TTR
messenger RNA, thereby blocking the production of TTR protein before it
is made. Patisiran blocks the production of TTR in the liver, reducing
its accumulation in the body’s tissues in order to halt or slow down the
progression of the disease. In August 2018, patisiran received U.S. Food
and Drug Administration (FDA) approval for the treatment of the
polyneuropathy of hATTR amyloidosis in adults, as well as European
Medicines Agency marketing authorization for the treatment of hATTR
amyloidosis in adults with Stage 1 or Stage 2 polyneuropathy.

Important Safety Information

Infusion-Related Reactions
Infusion-related reactions
(IRRs) have been observed in patients treated with ONPATTRO. In a
controlled clinical study, 19 percent of ONPATTRO-treated patients
experienced IRRs, compared to 9 percent of placebo-treated patients. The
most common symptoms of IRRs with ONPATTRO were flushing, back pain,
nausea, abdominal pain, dyspnea, and headache.

To reduce the risk of IRRs, patients should receive premedication with a
corticosteroid, paracetamol, and antihistamines (H1 and H2 blockers) at
least 60 minutes prior to ONPATTRO infusion. Monitor patients during the
infusion for signs and symptoms of IRRs. If an IRR occurs, consider
slowing or interrupting the infusion and instituting medical management
as clinically indicated. If the infusion is interrupted, consider
resuming at a slower infusion rate only if symptoms have resolved. In
the case of a serious or life-threatening IRR, the infusion should be
discontinued and not resumed.

Reduced Serum Vitamin A Levels and Recommended Supplementation
ONPATTRO
treatment leads to a decrease in serum vitamin A levels. Supplementation
at the recommended daily allowance (RDA) of vitamin A is advised for
patients taking ONPATTRO. Higher doses than the RDA should not be given
to try to achieve normal serum vitamin A levels during treatment with
ONPATTRO, as serum levels do not reflect the total vitamin A in the body.

Patients should be referred to an ophthalmologist if they develop ocular
symptoms suggestive of vitamin A deficiency (e.g. night blindness).

Adverse Reactions
The most common adverse reactions
that occurred in patients treated with ONPATTRO were respiratory-tract
infection (29 percent) and infusion-related reactions (19 percent).

About LNP Technology
Alnylam has licenses to Arbutus
Biopharma LNP intellectual property for use in RNAi therapeutic products
using LNP technology.

About RNAi
RNAi (RNA interference) is a natural cellular
process of gene silencing that represents one of the most promising and
rapidly advancing frontiers in biology and drug development today. Its
discovery has been heralded as “a major scientific breakthrough that
happens once every decade or so,” and was recognized with the award of
the 2006 Nobel Prize for Physiology or Medicine. By harnessing the
natural biological process of RNAi occurring in our cells, a new class
of medicines, known as RNAi therapeutics, is now a reality. Small
interfering RNA (siRNA), the molecules that mediate RNAi and comprise
Alnylam’s RNAi therapeutic platform, function upstream of today’s
medicines by potently silencing messenger RNA (mRNA) – the genetic
precursors – that encode for disease-causing proteins, thus preventing
them from being made. This is a revolutionary approach with the
potential to transform the care of patients with genetic and other
diseases.

About Alnylam Pharmaceuticals
Alnylam (Nasdaq: ALNY) is
leading the translation of RNA interference (RNAi) into a 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/ocular diseases. Based on Nobel Prize-winning
science, RNAi therapeutics represent a powerful, clinically validated
approach for the treatment of diseases with high unmet need. ONPATTRO^®
(patisiran) is the first-ever RNAi therapeutic approved by the U.S. FDA
for the treatment of the polyneuropathy of hereditary
transthyretin-mediated (hATTR) amyloidosis in adults and by the EMA for
the treatment of hATTR amyloidosis in adults with stage 1 or stage 2
polyneuropathy. Alnylam has a deep pipeline of investigational
medicines, including six product candidates in Phase 3 studies. 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.
Headquartered in Cambridge, MA, Alnylam employs over 1,000 people
worldwide. For more information, please visit www.alnylam.com
and engage with us on Twitter at @Alnylam
or on LinkedIn.

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 availability and reimbursement for ONPATTRO in multiple
geographies around the world, 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, 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.

Contacts

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

Josh Brodsky
(Investors)
617-551-8276