Exhibit 4.1


 






EXECUTION VERSION


 


VOTING AND SUPPORT AGREEMENT


 


This VOTING AND SUPPORT AGREEMENT (this “Agreement”),
dated as of May 5, 2015, is entered into by and among Alexion Pharmaceuticals, Inc. a Delaware corporation (“Parent”),
Pulsar Merger Sub Inc., a Delaware corporation and a direct wholly owned subsidiary of Parent (“Purchaser”),
and each of the persons set forth on Schedule A hereto (each, a “Stockholder”).  All terms
used but not otherwise defined in this Agreement shall have the respective meanings ascribed to such terms in the Merger Agreement
(as defined below).


 


WHEREAS, as of the date hereof, each Stockholder
is the record and beneficial owner (as defined in Rule 13d-3 under the Exchange Act) of the number of shares of common stock, par
value $0.001 per share of Synageva Biopharma Corp., a Delaware corporation (the “Company”) (the “Company
Common Stock”), set forth opposite such Stockholder’s name on Schedule A (all such shares set forth on Schedule
A next to the Stockholder’s name, in addition to any shares of Company Common Stock acquired in any manner after the
date of this Agreement, being referred to herein as the “Subject Shares”);


 


WHEREAS, concurrently with the execution hereof,
the Company, Parent, Purchaser and Galaxy Merger Sub LLC, a Delaware limited liability company and direct wholly owned subsidiary
of Parent (“Merger Sub 2”, and together with Purchaser, the “Merger Subs”), are entering
into an Agreement and Plan of Reorganization, dated as of the date hereof (as it may be amended from time to time, the “Merger
Agreement”), which provides, among other things, for (a) Purchaser to commence an offer to purchase (subject to the Offer
Conditions (as defined in the Merger Agreement)) all of the issued and outstanding shares of Company Common Stock and, following
completion of the Offer, the merger of Purchaser with and into the Company (the “First Merger”) upon the terms
and subject to the conditions set forth in the Merger Agreement and (b) the Company to convene and hold the Company Stockholder
Meeting for the purpose of obtaining the Company Stockholder Approval and to consummate the First Merger (subject to the conditions
set forth in Article VI of the Merger Agreement) as soon as practicable after the Company Stockholder Approval has been obtained;
and


 


WHEREAS, as a condition to their willingness to
enter into the Merger Agreement, and as an inducement and in consideration for Parent and the Merger Subs to enter into the Merger
Agreement, each Stockholder, severally and not jointly, and on such Stockholder’s own account with respect to the Subject
Shares, has agreed to enter into this Agreement.


 


NOW, THEREFORE, in consideration of the foregoing
and the respective representations, warranties, covenants and agreements set forth below and for other good and valuable consideration,
the receipt and sufficiency of which are hereby acknowledged, the parties hereto, intending to be legally bound, do hereby agree
as follows:


 


ARTICLE I

AGREEMENT TO VOTE


 


1.1.        Agreement
to Vote.  Subject to the terms of this Agreement, each Stockholder hereby irrevocably and unconditionally agrees
that, during the time this Agreement


 




    	 



    	 



    

  


is in effect, at the Company Stockholder Meeting
or any other annual or special meeting of the stockholders of the Company, however called, including any adjournment or postponement
thereof, and in connection with any action proposed to be taken by written consent of the stockholders of the Company, such Stockholder
shall, in each case to the fullest extent that such Stockholder’s Subject Shares are entitled to vote thereon: (a) appear
at each such meeting or otherwise cause all such Subject Shares to be counted as present thereat for purposes of determining a
quorum; and (b) be present (in person or by proxy) and vote (or cause to be voted), or deliver (or cause to be delivered)
a written consent with respect to, all of its Subject Shares (i) for adoption of the Merger Agreement and for the approval
of the transactions contemplated thereby, including the First Merger, (ii) for any proposal to adjourn or postpone the Company
Stockholder Meeting or such other meeting of the Company’s stockholders to a later date if there are not sufficient votes
to adopt the Merger Agreement, (iii) against any action or agreement that would reasonably be expected to (A) result in a
breach of any covenant, representation or warranty or any other obligation or agreement of the Company contained in the Merger
Agreement, or of any Stockholder contained in this Agreement or (B) result in any of the conditions set forth in Annex A or
in Article VII of the Merger Agreement not being satisfied on or before the End Date; (iv) against any change in the Company
Board of Directors, (v) against any Company Takeover Proposal and against any other action, agreement or transaction involving
the Company that is intended, or would reasonably be expected, to impede, interfere with, delay, postpone, adversely affect or
prevent the consummation of the Offer or the Mergers or the other Transactions, including (x) any extraordinary corporate
transaction, such as a merger, consolidation or other business combination involving the Company (other than the Mergers); (y) a
sale, lease, license or transfer of a material amount of assets (including, for the avoidance of doubt, intellectual property rights)
of the Company or any reorganization, recapitalization or liquidation of the Company; or (z) any change in the present capitalization
of the Company or any amendment or other change to the Company Certificate or Company Bylaws; and (vi) in favor of any other matter
necessary to consummate the Transactions.  Subject to the proxy granted under Section 1.2 below, each Stockholder
shall retain at all times the right to vote the Subject Shares in such Stockholder’s sole discretion, and without any other
limitation, on any matters other than those set forth in this Section 1.1 that are at any time or from time to time presented
for consideration to the Company’s stockholders generally.  


 


1.2.       Irrevocable
Proxy.  Solely with respect to the matters described in Section 1.1, for so long as this Agreement has
not been validly terminated in accordance with its terms, each Stockholder hereby irrevocably appoints Parent as its attorney and
proxy with full power of substitution and resubstitution, to the full extent of such Stockholder’s voting rights with respect
to all such Stockholder’s Subject Shares (which proxy is irrevocable and which appointment is coupled with an interest, including
for purposes of Section 212 of the DGCL) to vote, and to execute written consents with respect to, all such Stockholder’s
Subject Shares solely on the matters described in Section 1.1, and in accordance therewith.  Each Stockholder
agrees to execute any further agreement or form reasonably necessary or appropriate to confirm and effectuate the grant of the
proxy contained herein.  Such proxy shall automatically terminate upon the valid termination of this Agreement in accordance
with its terms.  Parent may terminate this proxy with respect to a Stockholder at any time at its sole election by written
notice provided to such Stockholder.


 




    	-2-



    	 



    

  


ARTICLE II

REPRESENTATIONS AND WARRANTIES OF THE STOCKHOLDERS


 


Each Stockholder represents and warrants, on its
own account with respect to the Subject Shares, to Parent and Purchaser as to such Stockholder on a several basis, that:


 


2.1.       Authorization;
Binding Agreement.  If such Stockholder is not an individual, such Stockholder is duly organized and validly
existing in good standing under the Laws of the jurisdiction in which it is incorporated or constituted and the consummation of
the transactions contemplated hereby are within such Stockholder’s entity powers and have been duly authorized by all necessary
entity actions on the part of such Stockholder, and such Stockholder has full power and authority to execute, deliver and perform
this Agreement and to consummate the transactions contemplated hereby.  If such Stockholder is an individual, such Stockholder
has full legal capacity, right and authority to execute and deliver this Agreement and to perform such Stockholder’s obligations
hereunder.  This Agreement has been duly and validly executed and delivered by such Stockholder and constitutes a valid
and binding obligation of such Stockholder enforceable against such Stockholder in accordance with its terms, subject to the effects
of bankruptcy, insolvency, fraudulent conveyance, reorganization, moratorium and other similar Laws relating to or affecting creditors’
rights generally and general equitable principles (whether considered in a proceeding in equity or at law) (the “Enforceability
Exceptions”).  If such Stockholder is married, and any of the Subject Shares of such Stockholder constitute
community property or otherwise need spousal or other approval for this Agreement to be legal, valid and binding, this Agreement
has been duly executed and delivered by such Stockholder’s spouse and, assuming the due authorization,
execution and delivery hereof by Parent and Purchaser, is enforceable against such Stockholder’s spouse in accordance with
its terms, subject to the Enforceability Exceptions.


 


2.2.       Non-Contravention.  Neither
the execution and delivery of this Agreement by such Stockholder nor the consummation of the transactions contemplated hereby nor
compliance by such Stockholder with any provisions herein will (a) if such Stockholder is not an individual, violate, contravene
or conflict with or result in any breach of any provision of the certificate of incorporation or bylaws (or other similar governing
documents) of such Stockholder, (b) require any consent, approval, authorization or permit of, or filing with or notification
to, any supranational, national, foreign, federal, state or local government or subdivision thereof, or governmental, judicial,
legislative, executive, administrative or regulatory authority on the part of such Stockholder, except for compliance with the
applicable requirements of the Securities Act, the Exchange Act or any other United States federal securities laws and the rules
and regulations promulgated thereunder, (c) violate, conflict with, or result in a breach of any provisions of, or require
any consent, waiver or approval or result in a default or loss of a benefit (or give rise to any right of termination, cancellation,
modification or acceleration or any event that, with the giving of notice, the passage of time or otherwise, would constitute a
default or give rise to any such right) under any of the terms, conditions or provisions of any note, license, agreement, contract,
indenture or other instrument or obligation to which such Stockholder is a party or by which such Stockholder or any of its assets
may be bound, (d) result (or, with the giving of notice, the passage of time or otherwise, would result) in the creation or
imposition of any mortgage, lien, pledge, charge, security interest or encumbrance of any kind on any asset of such Stockholder
(other than one created by Parent or Purchaser), or


 




    	-3-



    	 



    

  


(e) violate any order, writ, injunction,
decree, statute, rule or regulation applicable to such Stockholder or by which any of its assets are bound.


 


2.3.       Ownership
of Subject Shares; Total Shares.  Such Stockholder is the record and beneficial owner (as defined in Rule 13d-3
under the Exchange Act) of all such Stockholder’s Subject Shares and has good and marketable title to all such Subject Shares
free and clear of any liens, claims, proxies, voting trusts or agreements, options, rights, understandings or arrangements or any
other encumbrances or restrictions whatsoever on title, transfer or exercise of any rights of a stockholder in respect of such
Subject Shares (collectively, “Encumbrances”), except for any such Encumbrance that may be imposed pursuant
to (a) this Agreement and (b) any applicable restrictions on transfer under the Securities Act or any state securities law (collectively,
“Permitted Encumbrances”).  For the avoidance of doubt, the fact that the Subject Shares are held
in a margin account shall not be deemed to be an Encumbrance hereunder. The Subject Shares listed on Schedule A opposite
such Stockholder’s name constitute all of the shares of “voting stock” of the Company of which such Stockholder
is the “owner” (as such terms are defined in Section 203 of the DGCL) as of the time that the Company Board of Directors
approved the Merger Agreement.


 


2.4.       Voting
Power.  Such Stockholder has full voting power with respect to all such Stockholder’s Subject Shares, and
full power of disposition, full power to issue instructions with respect to the matters set forth herein and full power to agree
to all of the matters set forth in this Agreement, in each case with respect to all such Stockholder’s Subject Shares.  None
of such Stockholder’s Subject Shares are subject to any stockholders’ agreement, proxy, voting trust or other agreement
or arrangement with respect to the voting of such Subject Shares, except as provided hereunder.


 


2.5.       Reliance.  Such
Stockholder understands and acknowledges that Parent and the Merger Subs are entering into the Merger Agreement in reliance upon
such Stockholder’s execution, delivery and performance of this Agreement.


 


2.6.       Absence
of Litigation.  With respect to such Stockholder, as of the date hereof, there are no actions, suits, inquiries,
investigations, proceedings or claims of any nature or subpoenas, civil investigative demands or other requests for information
(each, a “Proceeding”) relating to potential material violations of Law pending against, or, to the knowledge
of such Stockholder, threatened in writing against such Stockholder or any of such Stockholder’s properties or assets (including
any shares of Company Common Stock beneficially owned by such Stockholder) before or by any Governmental Entity that could reasonably
be expected to prevent or materially delay or impair the consummation by such Stockholder of the transactions contemplated by this
Agreement or otherwise materially impair such Stockholder’s ability to perform its obligations hereunder.


 


2.7.       Brokers.  No
broker, finder, financial advisor, investment banker or other person is entitled to any brokerage, finder’s, financial advisor’s
or other similar fee or commission from the Company in connection with the transactions contemplated hereby based upon arrangements
made by or on behalf of such Stockholder.


 




    	-4-



    	 



    

  


ARTICLE III

REPRESENTATIONS AND WARRANTIES OF PARENT AND PURCHASER


 


Parent and Purchaser represent and warrant to
the Stockholders that:


 


3.1.       Organization
and Qualification.  Each of Parent and Purchaser is a duly organized and validly existing corporation in good
standing under the Laws of the state of Delaware.  All of the issued and outstanding capital stock of Purchaser is owned
directly by Parent.


 


3.2.       Authority
for this Agreement.  Each of Parent and Purchaser has all requisite entity power and authority to execute, deliver
and perform its obligations under this Agreement and to consummate the transactions contemplated hereby.  The execution
and delivery of this Agreement by Parent and Purchaser have been duly and validly authorized by all necessary corporate action
on the part of each of Parent and Purchaser, and no other corporate proceedings on the part of Parent and Purchaser are necessary
to authorize this Agreement.  This Agreement has been duly and validly executed and delivered by Parent and Purchaser
and, assuming the due authorization, execution and delivery by the Stockholder, constitutes the legal, valid and binding obligation
of each of Parent and Purchaser, enforceable against each of Parent and Purchaser in accordance with its terms, except as enforceability
may be limited by the Enforceability Exceptions.


 


ARTICLE IV

ADDITIONAL COVENANTS






 


Each Stockholder hereby covenants and agrees that
until the termination of this Agreement:


 


4.1.       No
Transfer; No Inconsistent Arrangements.   Except as provided hereunder or under the Merger Agreement, from
and after the date hereof and until this Agreement is terminated, such Stockholder shall not, directly or indirectly, (i) create
or permit to exist any Encumbrance, other than Permitted Encumbrances, on any of such Stockholder’s Subject Shares, (ii) transfer,
sell, assign, gift, hedge, pledge or otherwise dispose of, or enter into any derivative arrangement with respect to (collectively,
“Transfer”), any of such Stockholder’s Subject Shares, or any right or interest therein (or consent to
any of the foregoing), (iii) enter into any Contract with respect to any Transfer of such Stockholder’s Subject Shares or
any interest therein, (iv) grant or permit the grant of any proxy, power-of-attorney or other authorization or consent in
or with respect to any such Stockholder’s Subject Shares, (v) deposit or permit the deposit of any of such Stockholder’s
Subject Shares into a voting trust or enter into a voting agreement or arrangement with respect to any of such Stockholder’s
Subject Shares, or (vi) take or permit any other action that would in any way restrict, limit or interfere with the performance
of such Stockholder’s obligations hereunder or otherwise make any representation or warranty of such Stockholder herein untrue
or incorrect.  Any action taken in violation of the foregoing sentence shall be null and void ab initio.  Notwithstanding
the foregoing, any Stockholder may Transfer Subject Shares (i) to any member of such Stockholder’s immediate family,
(ii) to a trust for the sole benefit of such Stockholder or any member of such Stockholder’s immediate family, the


 




    	-5-



    	 



    

  


sole trustees of which are such Stockholder or
any member of such Stockholder’s immediate family, (iii) to a charitable organization, including but not limited to, a private
charitable foundation under Section 501(c)(3) of the Internal Revenue Code, or (iv) by will or under the laws of intestacy upon
the death of such Stockholder, provided, that a Transfer referred to in clause (i)
through (iv) of this sentence shall be permitted only if all of the representations and warranties in this Agreement with
respect to such Stockholder would be true and correct upon such Transfer and the transferee agrees in writing, in a manner reasonably
acceptable to Parent, to accept such Subject Shares subject to the terms of this Agreement and to be bound by the terms of this
Agreement and to agree and acknowledge that such person shall constitute a Stockholder for all purposes of this Agreement.  If
any involuntary Transfer of any of such Stockholder’s Subject Shares in the Company shall occur (including, but not limited
to, a sale by such Stockholder’s trustee in any bankruptcy, or a sale to a purchaser at any creditor’s or court sale),
the transferee (which term, as used herein, shall include any and all transferees and subsequent transferees of the initial transferee)
shall take and hold such Subject Shares subject to all of the restrictions, liabilities and rights under this Agreement, which
shall continue in full force and effect until valid termination of this Agreement.  Notwithstanding the foregoing, such
Stockholder may make Transfers of its Subject Shares as Parent may agree in writing in its sole discretion.  


 


4.2.       No
Exercise of Appraisal Rights.  Such Stockholder forever waives and agrees not to exercise any appraisal rights
or dissenters’ rights pursuant to Section 262 of the DGCL or otherwise in respect of such Stockholder’s Subject Shares
that may arise in connection with the Offer and the First Merger.


 


4.3.       Documentation
and Information.  Such Stockholder shall not make any public announcement regarding this Agreement and the transactions
contemplated hereby without the prior written consent of Parent (such consent not to be unreasonably withheld), except as may be
required by applicable Law or in compliance with the rules or regulations of the SEC, any other Government Entity or any stock
exchange as determined in the reasonable discretion of such Stockholder in consultation with its counsel (provided that
reasonable notice of any such disclosure will be provided to Parent).  Such Stockholder consents to and hereby authorizes
Parent and Purchaser to publish and disclose in all documents and schedules filed with the SEC, and any press release or other
disclosure document that Parent or Purchaser reasonably determines to be necessary in connection with the Offer, the First Merger
and any other transactions contemplated by the Merger Agreement, such Stockholder’s identity and ownership of the Subject
Shares, the existence of this Agreement and the nature of such Stockholder’s commitments and obligations under this Agreement,
and such Stockholder acknowledges that Parent and Purchaser will file this Agreement or a form hereof with the SEC or any other
Governmental Entity.  Such Stockholder agrees to promptly give Parent any information it may reasonably require for the
preparation of any such disclosure documents, and such Stockholder agrees to promptly notify Parent of any required corrections
with respect to any written information supplied by such Stockholder specifically for use in any such disclosure document, if and
to the extent that any such information shall have become false or misleading in any material respect.  


 


4.4.       Adjustments.  In
the event of any stock split, stock dividend, merger, reclassification, combination, exchange of shares or the like of the capital
stock of the Company affecting the Subject Shares, the terms of this Agreement shall apply to the resulting securities.  


 




    	-6-



    	 



    

  


4.5.       Waiver
of Certain Actions.  Each Stockholder hereby agrees not to commence or participate in, and to take all actions
necessary to opt out of any class in any class action with respect to, any claim, derivative or otherwise, against Parent, the
Company, the Merger Subs or any of their respective successors (a) challenging the validity of, or seeking to enjoin or delay
the operation of, any provision of this Agreement or the Merger Agreement (including any claim seeking to enjoin or delay the consummation
of the Offer or the Mergers) or (b) alleging a breach of any duty of the Company Board of Directors in connection with the
Merger Agreement, this Agreement or the transactions contemplated thereby or hereby.  


 


4.6.       No
Solicitation.  Each Stockholder shall, and shall cause its Affiliates (which term, solely for purposes of this
Section 4.6, shall be deemed to exclude the Company and its Subsidiaries) and its and their respective directors, officers,
managing partners and employees and their respective agents, financial advisors, investment bankers, attorneys and accountants:
(i) to immediately cease and cause to be terminated any solicitation, encouragement, discussions or negotiations with any
persons (other than Parent) that may be ongoing with respect to a Company Takeover Proposal and (ii) not to, directly or indirectly,
(A) solicit, initiate, knowingly encourage or knowingly facilitate any inquiries regarding, or the making of any proposal
or offer that constitutes, or could reasonably be expected to lead to, a Company Takeover Proposal, (B) engage in, continue
or otherwise participate in any discussions or negotiations regarding, or furnish to any other person any information in connection
with or for the purpose of knowingly encouraging or facilitating, a Company Takeover Proposal (other than, solely in response to
an unsolicited inquiry, to refer the inquiring person to this Section 4.6 and to Section 6.3 of the Merger Agreement and
to limit its conversation or other communication exclusively to such referral), (C) encourage or recommend any other holder of
Company Common Stock to vote against the Transactions (including the First Merger) or to not tender shares of Company Common Stock
into the Offer, or (D) support, recommend, endorse or approve, or propose to support, recommend, endorse or approve, any Company
Takeover Proposal or enter into any letter of intent or similar document, agreement, commitment or agreement in principle relating
to or facilitating a Company Takeover Proposal.  The foregoing notwithstanding, no announcement or disclosure made by,
nor any action taken by, the Board of Directors of the Company (including, without limitation, a Company Adverse Recommendation
Change) shall be deemed to be a breach of this Section 4.6 by any such Stockholder or Affiliate that serves as a director
of the Company so long as such announcement, disclosure or action does not constitute a breach of the Merger Agreement by the Company
or a breach for which the Company was responsible for preventing.


 


4.7.       Registration
Rights.  Between the date of the initial filing of the Offer S-4 (as defined in the Merger Agreement) and the
Closing, Parent and the Stockholders shall use commercially reasonable efforts to negotiate in good faith a usual and customary
registration rights agreement that provides for the registration, for resale on a continuous basis, of all of the equity securities
of Parent owned by the Stockholders and that contains customary provisions related to cooperation, black-out periods and indemnification.  Each
Stockholder acknowledges and agrees that (1) compliance with this Section 4.7 by Parent is not a condition to any other
obligation of any Stockholder contained in this Agreement (including, without limitation, the obligations set forth in Section
1.1), and (2) that no failure of compliance by Parent, nor the failure of the parties to agree to or enter into a registration
rights agreement, shall affect or limit or


 




    	-7-



    	 



    

  


excuse non-performance of any other obligation
of any Stockholder contained in this Agreement (including, without limitation, the obligations set forth in Section 1.1).


 


ARTICLE V

MISCELLANEOUS


 


5.1.       Notices.  All
notices and other communications hereunder shall be in writing and shall be deemed given (a) upon personal delivery to the party
to be notified; (b) when received when sent by email or facsimile by the party to be notified, provided, however,
that notice given by email or facsimile shall not be effective unless either (i) a duplicate copy of such email or facsimile notice
is promptly given by one of the other methods described in this Section 5.1 or (ii) the receiving party delivers a written
confirmation of receipt for such notice either by email or facsimile or any other method described in this Section 5.1;
or (c) when delivered by a courier (with confirmation of delivery); in each case to the party to be notified at the following
address; provided that the notice or other communication is sent to the address, facsimile number or email address set forth
(i) in the case to Parent or Purchaser, to the address, facsimile number or email address set forth in Section 9.7 of the
Merger Agreement and (ii) if to a Stockholder, to such Stockholder’s address, facsimile number or email address set
forth on a signature page hereto, or to such other address, facsimile number or email address as such party may hereafter specify
for the purpose by notice to each other party hereto.


 


5.2.       Termination.  Subject
to the following sentence, this Agreement shall terminate automatically with respect to a Stockholder, without any notice or other
action by any person, upon the first to occur of (a) the valid termination of the Merger Agreement in accordance with its
terms, (b) the First Effective Time, (c) the entry without the prior written consent of such Stockholder into any amendment
or modification to the Merger Agreement that results in a decrease in, or change in the form of the Transaction Consideration or
(d) the mutual written consent of Parent and such Stockholder.  Upon termination of this Agreement, no party shall have
any further obligations or liabilities under this Agreement; provided, however, that (x) nothing set forth in
this Section 5.2 shall relieve any party from liability for any breach of this Agreement prior to termination hereof and
(y) the provisions of this Article V shall survive any termination of this Agreement.


 


5.3.       Amendments
and Waivers.  Any provision of this Agreement may be amended or waived if such amendment or waiver is in writing
and is signed, in the case of an amendment, by each party to this Agreement or, in the case of a waiver, by each party against
whom the waiver is to be effective.  No failure or delay by any party in exercising any right, power or privilege hereunder
shall operate as a waiver thereof nor shall any single or partial exercise thereof preclude any other or further exercise thereof
or the exercise of any other right, power or privilege.


 


5.4.       Expenses.  All
fees and expenses incurred in connection herewith and the transactions contemplated hereby shall be paid by the party incurring
such fees and expenses, whether or not the Offer or the Mergers are consummated.


 


5.5.       Entire
Agreement; Assignment.  This Agreement, together with Schedule A, and the other documents and certificates
delivered pursuant hereto, constitute the


 




    	-8-



    	 



    

  


entire agreement, and supersede all prior agreements
and understandings, both written and oral, among the parties with respect to the subject matter of this Agreement.  This
Agreement shall not be assigned by any party (including by operation of law, by merger or otherwise) without the prior written
consent of the other parties; provided, that Parent or Purchaser may assign any of their respective rights and obligations
to any direct or indirect Subsidiary of Parent, but no such assignment shall relieve Parent or Purchaser, as the case may be, of
its obligations hereunder.


 


5.6.       Enforcement
of the Agreement.  The parties agree that irreparable damage would occur in the event that any Stockholder did
not perform any of the provisions of this Agreement in accordance with their specific terms or otherwise breached any such provisions.  It
is accordingly agreed that Parent and Purchaser shall be entitled to an injunction or injunctions to prevent breaches of this Agreement
and to enforce specifically the terms and provisions of this Agreement in addition to any other remedy to which they are entitled
at law or in equity.  Any and all remedies herein expressly conferred upon Parent and Purchaser will be deemed cumulative
with and not exclusive of any other remedy conferred hereby, or by Law or equity upon Parent or Purchaser, and the exercise by
Parent or Purchaser of any one remedy will not preclude the exercise of any other remedy.


 


5.7.       Jurisdiction;
Waiver of Jury Trial.  


 


(a)          Each
Stockholder (i) consents to submit itself to the exclusive jurisdiction of the Court of Chancery of the State of Delaware
or, solely if such court lacks subject matter jurisdiction, the United States District Court sitting in New Castle County in the
State of Delaware with respect to any dispute arising out of, relating to or in connection with this Agreement or any transaction
contemplated hereby, (ii) agrees that it will not attempt to deny or defeat such personal jurisdiction by motion or other
request for leave from any such court, and (iii) agrees that it will not bring any action arising out of, relating to or in
connection with this Agreement or any transaction contemplated by this Agreement in any court other than any such court.  Each
Stockholder irrevocably and unconditionally waives any objection to the laying of venue of any proceeding arising out of this Agreement
or the transactions contemplated hereby in the chancery courts of the State of Delaware or in any Federal court located in the
State of Delaware, and hereby further irrevocably and unconditionally waives and agrees not to plead or claim in any such court
that any such Proceeding brought in any such court has been brought in an inconvenient forum.  Each Stockholder hereby
agrees that service of any process, summons, notice or document by U.S. registered mail in accordance with Section 5.1 shall
be effective service of process for any proceeding arising out of, relating to or in connection with this Agreement or the transactions
contemplated hereby.


 


(b)          EACH
STOCKHOLDER ACKNOWLEDGES AND AGREES THAT ANY CONTROVERSY WHICH MAY ARISE UNDER THIS AGREEMENT IS LIKELY TO INVOLVE COMPLICATED
AND DIFFICULT ISSUES, AND THEREFORE EACH SUCH PARTY HEREBY IRREVOCABLY AND UNCONDITIONALLY WAIVES ANY RIGHT SUCH PARTY MAY HAVE
TO A TRIAL BY JURY IN ANY LITIGATION arising out of, relating to or in connection with
this Agreement.  EACH STOCKHOLDER CERTIFIES AND ACKNOWLEDGES THAT (I) NO REPRESENTATIVE, AGENT OR ATTORNEY
OF PARENT OR THE MERGER SUBS HAS REPRESENTED, EXPRESSLY OR OTHERWISE, THAT PARENT OR PURCHASER WOULD NOT, IN THE


 




    	-9-



    	 



    

  


EVENT OF LITIGATION, SEEK TO ENFORCE THE FOREGOING
WAIVER, (II) EACH STOCKHOLDER UNDERSTANDS AND HAS CONSIDERED THE IMPLICATION OF THIS WAIVER, (III) EACH STOCKHOLDER MAKES
THIS WAIVER VOLUNTARILY, AND (IV) EACH STOCKHOLDER HAS BEEN INDUCED TO ENTER INTO THIS AGREEMENT BY, AMONG OTHER THINGS, THE
MUTUAL WAIVERS AND CERTIFICATIONS IN THIS SECTION.


 


5.8.       Governing
Law.  This Agreement, and any dispute arising out of, relating to or in connection with this Agreement shall
be governed by and construed in accordance with the Laws of the State of Delaware, without giving effect to any choice or conflict
of Law provision or rule (whether of the State of Delaware or any other jurisdiction) that would cause the application of the Laws
of any jurisdiction other than the State of Delaware.


 


5.9.      Descriptive
Headings.  The descriptive headings herein are inserted for convenience of reference only and are not intended
to be part of or to affect the meaning or interpretation of this Agreement.


 


5.10.    Parties
in Interest.  This Agreement shall be binding upon and inure solely to the benefit of each party hereto, and
nothing in this Agreement, express or implied, is intended to confer upon any other person any rights or remedies of any nature
whatsoever under or by reason of this Agreement.


 


5.11.     Severability.  If
any term or other provision of this Agreement is invalid, illegal or incapable of being enforced by any rule of Law, or public
policy, all other conditions and provisions of this Agreement shall nevertheless remain in full force and effect.  Upon
such determination that any term or other provision is invalid, illegal or incapable of being enforced, the parties hereto shall
negotiate in good faith to modify this Agreement so as to effect the original intent of the parties as closely as possible in a
mutually acceptable manner.


 


5.12.    Counterparts.  This
Agreement may be executed in counterparts, each of which shall be deemed to be an original, but all of which, taken together, shall
constitute one and the same agreement.  This Agreement or any counterpart may be executed and delivered by facsimile
copies or delivered by electronic communications by portable document format (.pdf), each of which shall be deemed an original.


 


5.13.     Interpretation.  The
words “hereof,” “herein,” “hereby,” “herewith” and words of similar import shall,
unless otherwise stated, be construed to refer to this Agreement as a whole and not to any particular provision of this Agreement,
and article, section, paragraph and schedule references are to the articles, sections, paragraphs and schedules of this Agreement
unless otherwise specified.  Whenever the words “include,” “includes” or “including”
are used in this Agreement they shall be deemed to be followed by the words “without limitation.” The words describing
the singular number shall include the plural and vice versa, words denoting either gender shall include both genders and words
denoting natural persons shall include all persons and vice versa.  The phrases “the date of this Agreement,”
“the date hereof,” “of even date herewith” and terms of similar import, shall be deemed to refer to the
date set forth in the preamble to this Agreement.  Any reference in this Agreement to a date or time shall be deemed
to be such date or time in New York City, unless otherwise specified.  The parties have


 




    	-10-



    	 



    

 


participated jointly in the negotiation and drafting of this
Agreement.  In the event an ambiguity or question of intent or interpretation arises, this Agreement shall be construed
as if drafted jointly by the parties and no presumption or burden of proof shall arise favoring or disfavoring any person by virtue
of the authorship of any provision of this Agreement.


 


5.14.     Further
Assurances.  Each Stockholder will execute and deliver, or cause to be executed and delivered, all further documents
and instruments and use its reasonable best efforts to take, or cause to be taken, all actions and to do, or cause to be done,
all things necessary, proper or advisable under applicable Laws and regulations, to perform its obligations under this Agreement.


 


5.15.     No
Agreement Until Executed.  This Agreement shall not be effective unless and until (i) the Company Board
of Directors has approved the Merger Agreement, (ii) the Merger Agreement is executed by all parties thereto and (iii) this
Agreement is executed by all parties hereto.


 


5.16.     Stockholder
Obligation Several and Not Joint.  The obligations of each Stockholder hereunder shall be several and not joint,
and no Stockholder shall be liable for any breach of the terms of this Agreement by any other Stockholder.


 


5.17.     Stockholder
Capacity. No person executing this Agreement who is or becomes during the term hereof a director or officer of the Company
shall be deemed to make any agreement or understanding in this Agreement in such person’s capacity as a director or officer
of the Company.  Each Stockholder is entering into this Agreement solely in such Stockholder’s capacity as the
record holder or beneficial owner of, or as a trust whose beneficiaries are the beneficial owners of, Subject Shares and nothing
herein shall limit or affect any actions taken (or any failures to act) by a Stockholder in such Stockholder’s capacity as
a director or officer of the Company.  The taking of any actions (or any failures to act) by a Stockholder in such Stockholder’s
capacity as a director or officer of the Company shall not be deemed to constitute a breach of this Agreement, regardless of the
circumstances related thereto so long as no such action is or would be a breach or violation of any provision of the Merger Agreement
if taken by an officer or director of the Company acting in such capacity.


 


[Signature Pages Follow]


 




    	-11-



    	 



    

 


The parties are executing this Agreement on the
date set forth in the introductory clause.


 


	 	ALEXION PHARMACEUTICALS, INC.
	 	 	 
	 	By:	/s/ David Hallal
	 	Name:	David Hallal
	 	Title:	CEO
	 	 	 
	 	PULSAR MERGER SUB INC.
	 	 	 
	 	By:	/s/ Scott D. Phillips
	 	Name:	Scott D. Phillips
	 	Title:	President, Treasurer and Secretary


 





[Signature Page to Voting and Support
Agreement] 




    	 



    	 



    

  


	 	667, L.P. ,
	 	 	 
	 	By:  Baker Bros. Advisors LP,
	 	management company and investment adviser to 667, L.P., pursuant to authority granted to it by Baker Biotech Capital, L.P., general partner  to 667, L.P., and not as the general partner.
	 	 	 
	 	By:	/s/ Scott Lessing
	 	Scott Lessing
	 	President
	 	 	 
	 	BAKER BROTHERS LIFE SCIENCES, L.P.
	 	 	 
	 	By:  BAKER BROS. ADVISORS LP,  
	 	management company and investment adviser to Baker Brotheres Life Sciences, L.P.,
    pursuant to authority granted to it by Baker Brothers Life Sciences Capital, L.P., general partner  to Baker Brothers
    Life Sciences, L.P., and not as the general partner.  
	 	 	 
	 	By:	/s/ Scott Lessing
	 	Scott Lessing
	 	President
	 	 	 
	 	14159, L.P.,
	 	 	 
	 	By:  Baker Bros. Advisors LP,
	 	management company and investment adviser to 14159, L.P., pursuant to authority granted to it by 14159 Capital, L.P., general partner  to 14159, L.P., and not as the general partner.
	 	 	 
	 	By:	/s/ Scott Lessing
	 	Scott Lessing
	 	President


 


[Schedule A to Voting and Support Agreement]


 




    	 



    	 



    

  


	 	BAKER BROS. INVESTMENTS, L.P.
	 	 	 
	 	BY:  BAKER BROS. ADVISORS LP,
	 	management company and investment adviser to Baker Bros. Investments, L.P., pursuant to authority granted by Baker Bros. Capital, L.P., general partner to Baker Bros. Investments, L.P., and not as the general partner
	 	 	 
	 	By:	/s/ Scott Lessing
	 	Scott Lessing
	 	President
	 	 	 
	 	BAKER BROS. INVESTMENTS II, L.P
	 	 	 
	 	BY:  BAKER BROS. ADVISORS LP,
	 	management company and investment adviser to Baker Bros. Investments II, L.P., pursuant to authority granted by Baker Bros. Capital, L.P., general partner to Baker Bros. Investments II, L.P., and not as the general partner
	 	 	 
	 	By:	/s/ Scott Lessing
	 	Scott Lessing
	 	President
	 	 	 
	 	BAKER BIOTECH FUND II(A), L.P.,
	 	 	 
	 	By:  Baker Bros. Advisors LP,
	 	management company and investment adviser to Baker Biotech Fund II(A), L.P., pursuant to authority granted to it by Baker Biotech Capital II(A), L.P., general partner  to Baker Biotech Fund II(A), L.P., L.P., and not as the general partner.
	 	 	 
	 	By:	/s/ Scott Lessing
	 	Scott Lessing
	 	President


 


[Schedule A to Voting and Support Agreement]


 




    	 



    	 



    

 


	 	BAKER/TISCH INVESTMENTS, LP.,
	 	 	 
	 	By:  Baker Bros. Advisors LP,
	 	management company and investment adviser to Baker/Tisch Investments, LP pursuant to authority granted to it by Baker/Tisch Capital, L.P., general partner  to Baker/Tisch Investments, LP., and not as the general partner.
	 	 	 
	 	By:	/s/ Scott Lessing
	 	Scott Lessing
	 	President


 


[Schedule A to Voting and Support Agreement]


 




    	 



    	 



    

 


Schedule A


 


	
        Name of Stockholder
	 	
        Number of Shares

        of Company

        Common Stock

	 	 	 
	667, L.P.	 	1,736,065
	 	 	 
	BAKER BROTHERS LIFE SCIENCES, L.P.	 	9,172,521
	 	 	 
	14159, L.P.,	 	211,614
	 	 	 
	BAKER BROS. INVESTMENTS, L.P.	 	165,213
	 	 	 
	BAKER BROS. INVESTMENTS II, L.P.	 	55,479
	 	 	 
	BAKER BIOTECH FUND II(A), L.P. 	 	100,490
	 	 	 
	BAKER/TISCH INVESTMENTS, LP. 	 	206,800


 


[Schedule A to Voting and Support Agreement]