Shire Completes Acquisition of Dyax

    Lexington, Mass. - January 22, 2016 - Shire plc (LSE: SHP, NASDAQ: SHPG) today
    announced that it has completed its acquisition of Dyax Corp. (NASDAQ: DYAX) in
    an all-cash transaction valued at approximately $5.9 billion, comprised of
    $37.30 in cash per Dyax share. Dyax shareholders may receive additional value
    through a non-tradable contingent value right (CVR) that will pay $4.00 in cash
    per Dyax share upon approval of DX-2930 for HAE, representing a potential
    additional $646 million in aggregate contingent consideration.

    Shire's Chief Executive Officer, Flemming Ornskov, MD, MPH, commented:

    "We are excited to complete the acquisition of Dyax and look forward to working
    alongside their very talented and committed team to address significant unmet
    patient need around the world. The addition of Kalbitor and DX-2930 to our
    portfolio strengthens our leadership position in HAE and, along with the
    commercial and research and development expertise at Dyax, is a clear strategic
    fit for us that advances our position as the global leader in rare diseases. We
    are confident that our patients, particularly those with HAE, will be served
    for many years to come."

    For further information please contact:

    Investor Relations                                                            
                                                                                  
    Matt Osborne                          mattosborne@shire.com +1 781 482 9502   
                                                                                  
    Sarah Elton-Farr                      seltonfarr@shire.com  +44 1256 894157   
                                                                                  
    Media                                                                         
                                                                                  
    Michele Galen                         mgalen@shire.com      +1 781 482-1867   

    NOTES TO EDITORS

    About Shire

    Shire enables people with life-altering conditions to lead better lives.

    Our strategy is to focus on developing and marketing innovative specialty
    medicines to meet significant unmet patient needs.

    We focus on providing treatments in Rare Diseases, Neuroscience,
    Gastrointestinal and Internal Medicine and are developing treatments for
    symptomatic conditions treated by specialist physicians in other targeted
    therapeutic areas, such as Ophthalmics.

    www.shire.com

    Forward-Looking Statements

    Statements included herein that are not historical facts, including without
    limitation statements concerning our proposed business combination with Baxalta
    Incorporated ("Baxalta") and the timing and financial and strategic benefits
    thereof, our 20x20 ambition that targets $20 billion in combined product sales
    by 2020, as well as other targets for future financial results, capital
    structure, performance and sustainability of the combined company, the combined
    company's future strategy, plans, objectives, expectations and intentions, the
    anticipated timing of clinical trials and approvals for, and the commercial
    potential of, inline or pipeline products are forward-looking statements. Such
    forward-looking statements involve a number of risks and uncertainties and are
    subject to change at any time. In the event such risks or uncertainties
    materialize, Shire's results could be materially adversely affected. The risks
    and uncertainties include, but are not limited to, the following:

      * the proposed combination with Baxalta may not be completed due to a failure
        to satisfy certain closing conditions, including any shareholder or
        regulatory approvals or the receipt of applicable tax opinions;
       
      * the businesses may not be integrated successfully, such integration may be
        more difficult, time-consuming or costly than expected, or the expected
        benefits of the transaction may not be realized;
       
      * disruption from the proposed transaction may make it more difficult to
        conduct business as usual or maintain relationships with patients,
        physicians, employees or suppliers;
       
      * the combined company may not achieve some or all of the anticipated
        benefits of Baxalta's spin-off from Baxter International, Inc. ("Baxter")
        and the proposed transaction may have an adverse impact on Baxalta's
        existing arrangements with Baxter, including those related to transition,
        manufacturing and supply services and tax matters;
       
      * the failure to achieve the strategic objectives with respect to the
        proposed combination with Baxalta may adversely affect the combined
        company's financial condition and results of operations;
       
      * products and product candidates may not achieve commercial success;
       
      * product sales from ADDERALL XR and INTUNIV are subject to generic
        competition;
       
      * the failure to obtain and maintain reimbursement, or an adequate level of
        reimbursement, by third-party payers in a timely manner for the combined
        company's products may affect future revenues, financial condition and
        results of operations, particularly if there is pressure on pricing of
        products to treat rare diseases;
       
      * supply chain or manufacturing disruptions may result in declines in revenue
        for affected products and commercial traction from competitors; regulatory
        actions associated with product approvals or changes to manufacturing
        sites, ingredients or manufacturing processes could lead to significant
        delays, an increase in operating costs, lost product sales, an interruption
        of research activities or the delay of new product launches;
       
      * the successful development of products in various stages of research and
        development is highly uncertain and requires significant expenditures and
        time, and there is no guarantee that these products will receive regulatory
        approval;
       
      * the actions of certain customers could affect the combined company's
        ability to sell or market products profitably, and fluctuations in buying
        or distribution patterns by such customers can adversely affect the
        combined company's revenues, financial condition or results of operations;
       
      * investigations or enforcement action by regulatory authorities or law
        enforcement agencies relating to the combined company's activities in the
        highly regulated markets in which it operates may result in significant
        legal costs and the payment of substantial compensation or fines;
       
      * adverse outcomes in legal matters and other disputes, including the
        combined company's ability to enforce and defend patents and other
        intellectual property rights required for its business, could have a
        material adverse effect on the combined company's revenues, financial
        condition or results of operations;
       
      * Shire is undergoing a corporate reorganization and was the subject of an
        unsuccessful acquisition proposal and the consequent uncertainty could
        adversely affect the combined company's ability to attract and/or retain
        the highly skilled personnel needed to meet its strategic objectives;
       
      * failure to achieve the strategic objectives with respect to Shire's
        acquisition of NPS Pharmaceuticals Inc. or Dyax Corp. ("Dyax") may
        adversely affect the combined company's financial condition and results of
        operations;
       
      * the combined company will be dependent on information technology and its
        systems and infrastructure face certain risks, including from service
        disruptions, the loss of sensitive or confidential information,
        cyber-attacks and other security breaches or data leakages that could have
        a material adverse effect on the combined company's revenues, financial
        condition or results of operations;
       
      * the combined company may be unable to retain and hire key personnel and/or
        maintain its relationships with customers, suppliers and other business
        partners;
       
      * difficulties in integrating Dyax or Baxalta into Shire may lead to the
        combined company not being able to realize the expected operating
        efficiencies, cost savings, revenue enhancements, synergies or other
        benefits at the time anticipated or at all; and
       
        other risks and uncertainties detailed from time to time in Shire's, 
        Dyax's or Baxalta's filings with the Securities and Exchange Commission
        ("SEC"), including those risks outlined in Baxalta's current Registration
        Statement on Form S-1, as amended, and in "Item 1A: Risk Factors" in
        Shire's Annual Report on Form 10-K for the year ended December 31, 2014.
       
        All forward-looking statements attributable to us or any person acting on
        our behalf are expressly qualified in their entirety by this cautionary
        statement. Readers are cautioned not to place undue reliance on these
        forward-looking statements that speak only as of the date hereof. Except to
        the extent otherwise required by applicable law, we do not undertake any
        obligation to republish revised forward-looking statements to reflect
        events or circumstances after the date hereof or to reflect the occurrence
        of unanticipated events.