EXHIBIT 99.1

 Alnylam Pharmaceuticals Reports First Quarter 2007 Financial Results

     - Product Pipeline, Revenues and Cash Position Significantly
                     Strengthened Year-Over-Year -


    CAMBRIDGE, Mass.--(BUSINESS WIRE)--May 9, 2007--Alnylam
Pharmaceuticals, Inc. (Nasdaq: ALNY), a leading RNAi therapeutics
company, today reported its consolidated financial results for the
quarter ended March 31, 2007 and company highlights.

    "We have made important advancements already this year, and
anticipate continued progress on many fronts in the months to come,"
said John Maraganore, Ph.D., President and Chief Executive Officer of
Alnylam. "In particular, we have advanced our development pipeline
year to date. Our lead program, ALN-RSV01, an RNAi therapeutic for the
treatment of RSV infection, is advancing towards Phase II studies that
hold the potential of demonstrating human proof of concept as measured
by anti-viral activity. We also advanced ALN-VSP01, a new development
program for the treatment of liver cancers and potentially other solid
tumors. Further, we continued to advance the science of RNAi towards
its broad therapeutic applications, as evidenced by our presentations
at top-tier scientific meetings and publications in peer-reviewed
journals, as well as executing on our business strategies and building
on our leading intellectual property position."

    Cash, Cash Equivalents and Marketable Securities

    At March 31, 2007, Alnylam had cash, cash equivalents and
marketable securities of $204.5 million, compared to $217.3 million at
December 31, 2006 and $132.3 million at March 31, 2006.

    Net Loss

    The net loss according to accounting principles generally accepted
in the U.S. (GAAP) for the quarter ended March 31, 2007 was $21.6
million, or $0.58 per share (including a one-time non-cash license fee
of $7.9 million and a cash license fee of $0.4 million which totaled
$0.22 per share, and $2.2 million, or $0.06 per share of non-cash
stock-based compensation expense), compared to $8.9 million, or $0.30
per share (including $2.4 million, or $0.08 per share of non-cash
stock-based compensation expense), in the first quarter of 2006. The
company's increase in net loss is primarily a result of a license fee
the company paid in its common stock to Tekmira Pharmaceuticals
Corporation (formerly Inex Pharmaceuticals Corporation) and a related
cash license fee during the first quarter of 2007, in exchange for the
worldwide exclusive license to Tekmira's liposomal delivery
formulation technology for the discovery, development, and
commercialization of RNAi therapeutics, as well as the expansion of
the technology research and manufacturing alliance on lipid-based
delivery technology.

    Revenues

    Revenues in the first quarter of 2007 were $7.2 million, compared
to $5.7 million during the first quarter of 2006. Included in revenues
in the first quarter of 2007 were $4.1 million of expense
reimbursement and amortization revenues related to the company's
collaborations with Novartis, and $3.1 million of expense
reimbursement and amortization revenues from Biogen Idec, Merck, the
National Institutes of Health (NIH) for Ebola, research reagent and
services licensees, and other sources. Revenues in the first quarter
of 2006 were comprised of $5.2 million of expense reimbursement and
amortization revenues related to the company's Novartis collaborations
as well as an aggregate of $0.5 million of expense reimbursement and
amortization revenue received from Merck, research reagent and
services licensees, and other sources.

    Research and Development Expenses

    Research and development (R&D) expenses were $26.7 million in the
first quarter of 2007, including $1.2 million of non-cash stock-based
compensation, compared to $11.7 million in the first quarter of 2006,
which included $1.5 million of non-cash stock-based compensation. The
increase in R&D expenses was primarily due to a non-cash license fee
of $7.9 million to Tekmira that the company paid in its common stock
as well as a related cash license fee of $0.4 million, as discussed
above. The increase was also due to the planned increase in clinical
trial expenses in support of Alnylam's clinical program for
respiratory syncytial virus (RSV) infection related to its ongoing
Phase I inhalation trial, as well as its experimental infection study.
Also contributing to the increase were higher manufacturing and
external service costs associated with the company's pre-clinical
programs for the treatment of hypercholesterolemia and liver cancer,
as well as costs related to an increase in R&D headcount over the past
year to support the company's expanding pipeline and alliances.

    General and Administrative Expenses

    General and administrative (G&A) expenses were $4.5 million in the
first quarter of 2007, including $1.0 million of non-cash stock-based
compensation, compared to $3.8 million in the first quarter of 2006,
which included $0.8 million of non-cash stock-based compensation. The
increase in G&A expenses was primarily due to higher professional
service fees as a result of increased business activities.

    2007 Financial Guidance

    Alnylam expects that its cash, cash equivalents and marketable
securities balance will be greater than $180.0 million at December 31,
2007.

    "Our first quarter financial performance reflects a particularly
active and productive period at Alnylam, as we advanced our
proprietary and partnered programs, including our lead RNAi
therapeutic, ALN-RSV01 for the treatment of RSV, as well as ALN-PCS01
for the treatment of hypercholesterolemia," stated Patricia Allen,
Vice President, Finance and Treasurer at Alnylam. "Although there will
be variability in R&D expenses and revenues from quarter to quarter,
we expect to maintain a solid financial profile with a strong revenue
base as a result of our existing and more recent collaborations,
balanced with planned investments in advancing our pipeline. We remain
on track to achieve our cash guidance for the remainder of the year as
we execute on our scientific, clinical, and business objectives for
2007."

    First Quarter 2007 and Recent Corporate Highlights

    Product Pipeline and Scientific Leadership Highlights

    --  Continued Progress with Development of ALN-RSV01 for RSV
        Infection. Alnylam is conducting an experimental infection
        study with ALN-RSV01, an RNAi therapeutic for the treatment of
        RSV infection. Results from Part I of this study were
        presented at the recent Pediatric Academic Societies' Annual
        Meeting and demonstrated the establishment of a safe and
        reliable RSV infection of the upper respiratory tract in adult
        volunteers. In the second quarter, Alnylam intends to advance
        to the second part of this study in a Phase II trial that is
        designed to evaluate safety and tolerability, as well as to
        demonstrate anti-viral activity with ALN-RSV01 treatment. Data
        from this study is expected in the second half of the year.
        Alnylam's Phase I inhalation trial with ALN-RSV01 is still
        actively enrolling and data from this safety trial is also
        expected in the second half of the year.

    --  Expanded Development Pipeline. At the recent American
        Association for Cancer Research meeting, Alnylam expanded its
        pipeline with the announcement of another development program.
        The company will be advancing ALN-VSP01, a systemically
        delivered RNAi therapeutic for the treatment of liver cancers
        and potentially other solid tumors, towards the clinic and
        expects to file an investigational new drug application (IND)
        for this program in 2008. ALN-VSP01 is comprised of two
        siRNAs, each targeting a distinct and well-validated gene in
        the growth and proliferation of tumors: VEGF (vascular
        endothelial growth factor) and KSP (kinesin spindle protein).
        In addition, the company has a goal of filing two INDs in 2007
        from its development pipeline.

    --  Advanced Additional Programs as Reported at Scientific
        Meetings. Alnylam had a significant presence at the Keystone
        Symposium on RNAi and microRNAs (miRNAs), which was co-chaired
        by Alnylam's President and Chief Executive Officer. Updates
        from the company's programs at this top-tier meeting included:

        -- New non-human primate data indicating a nearly one-month
           durability of RNAi-mediated silencing of a liver-expressed
           gene after a single dose of our systemically delivered RNAi
           therapeutic;
        -- Data from Alnylam's hypercholesterolemia program using
           ALN-PCS01 delivered systemically and targeting PCSK9,
           demonstrating duration of effect in a rodent model; and
        -- In the neurodegenerative disease area, data from the
           company's Huntington's disease program, which showed both
           reduction of neuronal pathology and an improvement in
           abnormal behavior with administration of a huntingtin-
           specific siRNA.

    --  Continued Leadership with microRNAs. With researchers at
        Stanford University, Alnylam published results of a study in
        the journal Cell on the role of miRNAs in immunity. In
        addition, Alnylam scientists and collaborators published new
        results with antagomirs in Nucleic Acids Research that further
        characterized the attributes required for developing
        miRNA-targeted drugs and may facilitate future studies to
        silence miRNAs in clinically relevant settings.

    Business Execution Highlights

    --  Increased Commitment to Delivery Technologies for RNAi
        Therapeutics. Alnylam signed an agreement with the
        Massachusetts Institute of Technology (MIT) Center for Cancer
        Research to sponsor a five-year research program focused on
        the delivery of RNAi therapeutics. Robert Langer, an Institute
        Professor at MIT and Daniel Anderson of the MIT Center for
        Cancer Research, are the co-investigators of the research
        program.

    --  Expanded Leading Position for Systemic Delivery of RNAi
        Therapeutics. Alnylam obtained a worldwide exclusive license
        to Tekmira's liposomal delivery formulation technology for the
        discovery, development, and commercialization of RNAi
        therapeutics. The companies also expanded their technology
        research and manufacturing alliance on lipid-based delivery
        technology.

    --  Continued Leveraging of Intellectual Property (IP) for
        Near-Term Value Creation. Alnylam continues to leverage its IP
        position for near-term value. This was done recently with
        options to InterfeRx(TM) licenses with Tekmira as part of the
        companies' collaboration, and a license of the Kreutzer-Limmer
        patent family to Bio-Rad for the research reagent market.

    Intellectual Property (IP) Leadership Highlights

    --  United States Patent and Trademark Office (USPTO) Allowed
        Claims in Key miRNA Patent. The USPTO allowed claims in a
        patent application that covers miRNAs and therapeutic
        molecules that target these miRNAs. The USPTO issued a "Notice
        of Allowance" for patent application 10/490,955, which is
        derived from the "Tuschl III" patent series licensed
        co-exclusively to Alnylam and Isis Pharmaceuticals, Inc. for
        miRNA therapeutics on a worldwide basis through an agreement
        with Max-Planck-Innovation GmbH, the licensing agent for the
        Max Planck Society.

    --  USPTO Allowed Claims in Patent Covering Lipid-Based Delivery
        of RNAi Therapeutics. The USPTO allowed claims in a patent
        application that covers nucleic acid-lipid compositions,
        including cationic liposomes, a family of specialized lipid
        molecules which enable the delivery of oligonucleotides,
        including siRNAs. The USPTO issued a "Notice of Allowance" for
        patent application 09/431,594, which is derived from the
        "Wheeler" patent series and includes a number of patents
        licensed exclusively to Tekmira through agreements with the
        University of British Columbia, and which Tekmira has
        exclusively licensed to Alnylam for RNAi therapeutics.

    --  USPTO Issued Patent for AML-1/MTG8 Fusion Gene. The USPTO
        issued to Alnylam a composition of matter patent (U.S. Patent
        No. 7,196,184) covering an siRNA for inhibiting expression of
        the AML-1/MTG8 fusion gene.

    --  Intellectual Property Office of Singapore Issued Tuschl II
        Patent. A patent from Alnylam's exclusively held "Tuschl II"
        patent series was issued by the Intellectual Property Office
        of Singapore. The issued patent (No. 96891) broadly covers
        methods of making siRNAs with or without chemical
        modifications required to introduce drug-like properties in
        RNAi therapeutics for any and all disease targets in mammalian
        cells.

    Organizational Highlights

    --  Expanded Management Team. Alnylam appointed Eric Raichle to
        the position of Vice President, Human Resources. Mr. Raichle
        joins Alnylam from Alkermes, Inc. and has over 20 years of
        global human resources experience focusing on employee
        relations, talent management and compensation.

    --  Developed Board of Directors. Alnylam elected Victor Dzau,
        M.D. to its Board of Directors. Dr. Dzau is Chancellor for
        Health Affairs at Duke University, and President and Chief
        Executive Officer of the Duke University Health System. He is
        also the James B. Duke Professor of Medicine and Director of
        Molecular and Genomic Vascular Biology at Duke. Peter Barrett,
        Ph.D., of Atlas Venture intends to resign from Alnylam's Board
        of Directors when his term expires at the company's 2007
        Annual Meeting of Stockholders on June 1, 2007. Atlas Venture
        was an early venture investor in Alnylam, and Dr. Barrett has
        served as a member of the company's Board since its inception
        in 2002. Dr. Barrett has elected to resign in order to focus
        on his private portfolio companies.

    Conference Call Information

    Alnylam will host a conference call at 4:30 p.m. ET on May 9, 2007
to discuss 2007 first quarter financial results and recent corporate
developments. The call may be accessed by dialing 800-573-4840
(domestic) or 617-224-4326 (international) five minutes prior to the
start time and providing the passcode 95409631.

    A replay of the call will be available from 6:30 p.m. ET on May 9,
2007 until May 16, 2007. To access the replay, please dial
888-286-8010 (domestic) or 617-801-6888 (international), and provide
the passcode 55487707. A live audio webcast of the call will also be
available on the "Investors" section of the company's website,
www.alnylam.com. An archived webcast will be available on the
company's website approximately two hours after the event and will be
archived for 14 days thereafter.

    About RNA Interference (RNAi)

    RNA interference (or RNAi) is a naturally occurring mechanism
within cells for selectively silencing and regulating specific genes.
The discovery of RNAi has been widely acknowledged as a major
breakthrough in biology, and the technology was recognized for its
potential broad impact in medicine with the award of the 2006 Nobel
Prize for Physiology or Medicine. Since many diseases are caused by
the inappropriate activity of specific genes, the ability to silence
genes selectively through RNAi has accelerated the understanding of
these genes and their related pathways. Additionally, RNAi could
provide a new way to treat a wide range of human diseases. RNAi is
induced by small, double-stranded RNA molecules. One method to
activate RNAi is with chemically synthesized small interfering RNAs,
or siRNAs, which are double-stranded RNAs that are targeted to a
specific disease-associated gene. The siRNA molecules are used by the
natural RNAi machinery in cells to cause targeted gene silencing.

    About Alnylam

    Alnylam is a biopharmaceutical company developing novel
therapeutics based on RNA interference, or RNAi. The company is
applying its therapeutic expertise in RNAi to address significant
medical needs, many of which cannot effectively be addressed with
small molecules or antibodies, the current major classes of drugs.
Alnylam is building a pipeline of RNAi therapeutics; its lead program
is in Phase I human clinical trials for the treatment of respiratory
syncytial virus (RSV) infection. RSV infects nearly every child at
least once by the age of two and accounts for more than 125,000
hospitalizations annually in the U.S. pediatric population. RSV
infection also poses a great risk to the elderly and other adults with
compromised immune systems. The company's leadership position in
fundamental patents, technology, and know-how relating to RNAi has
enabled it to form major alliances with leading companies including
Merck, Medtronic, Novartis, and Biogen Idec. The company, founded in
2002, maintains global headquarters in Cambridge, Massachusetts, and
has an additional operating unit in Kulmbach, Germany. For more
information, visit www.alnylam.com.

    Alnylam Forward-Looking Statements

    Various statements in this release concerning our future
expectations, plans, and prospects, including, without limitation,
statements related to clinical development plans for ALN-RSV01,
ALN-VSP01, ALN-PCS01 and our other product candidates, the filing of
an IND for ALN-VSP01 and our other product candidates and projections
for the amount and sufficiency of cash, cash equivalents and
marketable securities, constitute forward-looking statements for the
purposes of the safe harbor provisions under The Private Securities
Litigation Reform Act of 1995. Actual results may differ materially
from those indicated by these forward-looking statements as a result
of various important factors, including risks related to: our approach
to discover and develop novel drugs, which is unproven and may never
lead to marketable products; our ability to fund and the results of
further pre-clinical and clinical trials; obtaining, maintaining and
protecting intellectual property utilized by our products; our ability
to enforce our patents against infringers and to defend our patent
portfolio against challenges from third parties; our ability to obtain
additional funding to support our business activities; our dependence
on third parties for development, manufacture, marketing, sales, and
distribution of products; the successful development of our product
candidates, all of which are in early stages of development; obtaining
regulatory approval for products; competition from others using
technology similar to ours and others developing products for similar
uses; our dependence on collaborators; and our short operating
history; as well as those risks more fully discussed in the "Risk
Factors" section of our most recent report on Form 10-K on file with
the Securities and Exchange Commission. In addition, any
forward-looking statements represent our views only as of today and
should not be relied upon as representing our views as of any
subsequent date. We do not assume any obligation to update any
forward-looking statements.

                    Alnylam Pharmaceuticals, Inc.
           Unaudited Consolidated Statements of Operations
                (In thousands, except per share data)

- ----------------------------------------------------------------------
                                            Three Months Three Months
                                                Ended        Ended
                                              March 31,    March 31,
                                                2007         2006
- ----------------------------------------------------------------------
Net revenues from research collaborators          $7,217       $5,717
- ----------------------------------------------------------------------
Operating expenses:
  Research and development (1)                    26,671       11,706
  General and administrative (1)                   4,540        3,808
- ----------------------------------------------------------------------
    Total operating expenses                      31,211       15,514
- ----------------------------------------------------------------------
    Loss from operations                         (23,994)      (9,797)
- ----------------------------------------------------------------------
Other income (expense):
  Interest income                                  2,690        1,260
  Interest expense                                  (286)        (238)
  Other expense, net                                 (55)         (85)
- ----------------------------------------------------------------------
    Total other income (expense)                   2,349          937
- ----------------------------------------------------------------------
Net loss                                        $(21,645)     $(8,860)
- ----------------------------------------------------------------------

Net loss per common share:
Net loss per common share - basic and
 diluted                                          $(0.58)      $(0.30)
- ----------------------------------------------------------------------
Weighted average common shares - basic and
 diluted                                          37,376       30,028
- ----------------------------------------------------------------------

(1) Non-cash stock-based compensation
 expense included in these amounts are as
 follows:
    Research and development                      $1,156       $1,530
    General and administrative                     1,004          845
- ----------------------------------------------------------------------

                    Alnylam Pharmaceuticals, Inc.
           Unaudited Condensed Consolidated Balance Sheets
                            (In thousands)

- ----------------------------------------------------------------------
                                                March 31, December 31,
                                                  2007       2006
- ----------------------------------------------------------------------
Cash, cash equivalents and marketable securities $204,466    $217,260
Collaboration receivables                           4,393       3,829
Prepaid expenses and other current assets           1,057       1,695
Property and equipment, net                        12,527      12,173
Long-term restricted cash                           2,313       2,313
Intangible and other assets                         2,584       2,736
- ----------------------------------------------------------------------
Total assets                                     $227,340    $240,006
- ----------------------------------------------------------------------
Other current liabilities                         $13,599     $11,781
Deferred revenue                                   15,554      17,930
Notes payable, net of current portion               5,065       5,919
Deferred rent                                       3,095       3,202
Total stockholders' equity                        190,027     201,174
- ----------------------------------------------------------------------
Total liabilities and stockholders' equity       $227,340    $240,006
- ----------------------------------------------------------------------

    This selected financial information should be read in conjunction
with the consolidated financial statements and notes thereto included
in the Company's Annual Report on Form 10-K which includes the audited
financial statements for the year ended December 31, 2006.


    CONTACT: Alnylam Pharmaceuticals, Inc.
             Cynthia Clayton, 617-551-8207
             Director, Investor Relations and Corporate Communications
             OR
             Patricia Allen, 617-551-8362
             Vice President, Finance and Treasurer