EMPLOYMENT AGREEMENT
This EMPLOYMENT AGREEMENT (the “Agreement”) dated as of June 11, 2017 by and
between Alexion Pharmaceuticals, Inc., a Delaware corporation (the “Company”),
and Paul J. Clancy (the “Employee”).
WITNESSETH
WHEREAS, the Company agrees to employ the Employee, subject to the terms and
conditions contained in this Agreement; and
WHEREAS, the Employee agrees to accept employment with the Company, subject to
the terms and conditions contained in this Agreement.
NOW, THEREFORE, in consideration of the premises and the mutual covenants and
agreements herein contained, the parties hereto agree as follows:
1.    Employment Duties and Acceptance.
a.The Company hereby employs the Employee, for the Term (as hereinafter
defined), to render full-time services to the Company as Executive Vice
President, reporting to the Chief Executive Officer of the Company. Effective
July 31, 2017, the Employee shall be appointed the Company’s Executive Vice
President and Chief Financial Officer, and shall perform such duties
commensurate with such office or other office as the Employee shall reasonably
be directed by the Company to perform. The Employee hereby accepts such
employment and agrees to render the services described above.
b.During the Term, the Employee shall devote his full business time and his best
efforts, business judgment, skill and knowledge exclusively to the advancement
of the business and interests of the Company and its Affiliates and to the
discharge of his duties and responsibilities hereunder. Notwithstanding anything
to the contrary herein, although the Employee shall provide services as a full
time employee, it is understood that the Employee, with consent of the Chief
Executive Officer, may (1) have non full-time academic appointments; (2)
participate in professional activities; (3) publish academic articles; and (4)
participate in community and/or philanthropic activities (collectively,
“Permitted Activities”); provided, however, that such Permitted Activities do
not materially interfere with the Employee’s duties to the Company.
2.    Term of Employment.
The term of the Employee’s employment under this Agreement shall commence as of
July 10, 2017 (the “Effective Date”) and shall end on the third anniversary
thereof, unless sooner

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terminated pursuant to Section 6, 7 or 8 of this Agreement. Notwithstanding the
foregoing, unless notice is given by the Employee or the Company at least sixty
(60) days prior to the expiration of the Term of this Agreement (or at least
sixty (60) days prior to the expiration of any extension hereof), the Term of
the Agreement shall be automatically extended by one (1) year from the date it
would otherwise end (whether upon expiration of the original Term or any
extension(s) thereof), unless sooner terminated pursuant to Section 6, 7 or 8
hereof. The term of this Agreement as from time to time extended or renewed is
hereafter referred to as “the Term of this Agreement” or “the Term”.
3.    Compensation and Benefits.
a.As compensation for services to be rendered pursuant to this Agreement, the
Company agrees to pay the Employee, during the Term, an annual base salary of
$900,000.00 as adjusted from time to time, which base salary as so adjusted,
shall be not less than the Employee’s base salary in effect on the Effective
Date (the “Base Salary”), payable in accordance with its regular payroll
practices. The Employee’s Base Salary hereunder shall be reviewed at least
annually thereafter during the Term of the Agreement for increase at the
discretion of the Company.
b.The Company agrees that the Employee shall be eligible for an annual
performance bonus from the Company with respect to each fiscal year of the
Company that ends during the Term, pursuant to the Company’s management
incentive bonus program in effect from time to time (such plan, as so in effect,
the “Bonus Plan”). The Employee’s target bonus under the Bonus Plan will be 70%
of the Base Salary. The actual amount of any such bonus payable to the Employee
under the Bonus Plan shall be determined by the Board of Directors of the
Company (the “Board”) or the Compensation Committee thereof (the “Committee”)
and paid by the Company in accordance with the terms of the Bonus Plan, subject
to the Employee’s remaining employed on the date that bonuses are paid under the
Bonus Plan, except as otherwise expressly provided herein.
c.The Employee shall be eligible to receive the equity incentive awards
described in the Company’s Offer Letter to the Employee dated June 1, 2017 (the
“Offer Letter”) according to its terms. Additionally, the Employee shall be
eligible to receive stock-based awards under the equity incentive plan or
program maintained by the Company as in effect from time to time (such plan, as
so in effect, the “Equity Plan”) in the discretion of the Board or the
Committee. Any such stock-based award will be subject to the terms of the Equity
Plan, the terms of the award agreement evidencing such stock-based award, and
such other restrictions and limitations as are generally applicable to shares of
the Company’s common stock or Company employees or otherwise imposed by law.
d.The Company shall pay or reimburse the Employee for all reasonable, customary
and necessary business expenses actually incurred or paid by the Employee during
the Term in the performance of services under this Agreement, subject to travel
and other policies and such

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reasonable substantiation and documentation as may be required by the Company
from time to time, provided that (i) the amount of expenses eligible for
reimbursement during any calendar year may not affect the expenses eligible for
reimbursement in any other taxable year, (ii) reimbursement is made not later
than December 31 of the calendar year following the calendar year in which the
expense was incurred, and (iii) the right to reimbursement is not subject to
liquidation or exchange for any other benefit.
e.During the Term, the Employee shall be eligible to participate in all employee
benefit plans from time to time in effect for employees of the Company
generally, except to the extent such plans are duplicative of benefits otherwise
provided under this Agreement (e.g., a severance pay plan). Participation in
such employee benefit plans will be subject to the terms of the applicable plan
documents and generally applicable Company policies, as the same may be in
effect from time to time, and any other restrictions or limitations imposed by
law
f.For 2017 only, the Employee shall be eligible for paid vacation of eight weeks
and two personal days. Beginning January 1, 2018 and for the duration of the
Term, the Employee shall be eligible for paid vacation of four weeks and two
personal days per calendar year taken in accordance with applicable Company
policy.
e.On the first regular payroll date following the Effective Date, the Employee
will be advanced the gross amount of $500,000.00, subject to taxes and other
withholdings, as a sign-on wage advance. The Employee shall be required to repay
the full gross amount of such payment to the Company if this Agreement is
terminated under Sections 6(c) or 7(a) hereof prior to the first anniversary of
the Effective Date; and the Employee shall be required to repay 50% of the gross
amount of such payment to the Company if this Agreement is terminated under
Sections 6(c) or 7(a) hereof between the first and second anniversaries of the
Effective Date.
4.Confidentiality.
The Employee acknowledges and agrees that he is bound by the terms and
conditions of the Proprietary Information and Inventions Agreement separately
entered into with the Company (the “Proprietary Information and Inventions
Agreement”). Notwithstanding any other provision of this Agreement, the Employee
shall continue to be bound by the terms of such Proprietary Information and
Inventions Agreement which shall survive the termination of this Agreement in
accordance with its terms.
5.Non-Competition, Non-Solicitation and Non-Disparagement.
a.During the Term, the Employee shall not (1) provide any services, directly or
indirectly, to any other business or commercial entity without the consent of
the Company, which may be withheld in the Company’s sole discretion, or (2)
participate in the formation of any business or commercial entity without the
consent of the Company, which may be withheld in the Company’s sole discretion;
provided, however, that nothing contained in this Section 5(a)

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shall be deemed to prohibit the Employee from acquiring, solely as an
investment, shares of capital stock (or other interests) of any corporation (or
other entity) not exceeding 2% of such corporation’s (or other entity’s) then
outstanding shares of capital stock and provided, further, that nothing
contained herein shall be deemed to limit the Employee’s Permitted Activities
pursuant to Section 1(b).
b.Upon a termination of the Employee’s employment by the Company for any reason
other than pursuant to Section 6(a) or Section 6(b), or upon a termination of
the Employee’s employment by the Employee for any reason, following such
termination of employment and during the Restricted Period, the Employee shall
not, directly or indirectly, whether as owner, partner, investor, consultant,
agent, employee, co-venturer, or otherwise, compete with the Company or any of
its Affiliates, or undertake any planning for any business competitive with the
Company or any of its Affiliates (a “Competing Organization”). Specifically, but
without limiting the foregoing, during the Restricted Period the Employee will
not: (1) provide any services directly or indirectly, whether as an employee or
independent contractor or otherwise, whether with or without compensation, to
any other business or commercial entity in the United States that is competitive
with all or any portion of the business of the Company or its Affiliates; (2)
participate in the formation of any business or commercial entity in the United
States that is competitive with all or any portion of the business of the
Company or its Affiliates, (3) directly or indirectly seek to employ, any person
employed by the Company or any of its Affiliates anywhere in the world, or
otherwise encourage or entice any such person to leave such employment; (4)
solicit or encourage any independent contractor providing services to the
Company or any of its Affiliates anywhere in the world to terminate or diminish
its relationship with the Company or its Affiliates; or (5) solicit or encourage
any customer, consultant, or vendor of the Company or its Affiliates anywhere in
the world, to terminate or diminish its relationship with the Company or its
Affiliates; provided, however, that nothing contained in this Section 5(b) shall
be deemed to prohibit the Employee from acquiring, solely as an investment,
shares of capital stock (or other interests) of any corporation (or other
entity) not exceeding 2% of such corporation’s (or other entity’s) then
outstanding shares of capital stock and provided, further, that nothing
contained herein shall be deemed to limit Employee’s Permitted Activities
pursuant to Section 1(b). This Section 5(b) shall be subject to written waivers
that may be obtained by the Employee from the Company. For purposes of this
Section 5(b), an entity shall be deemed to be a Competing Organization if, as of
the date that the Employee leaves employment with the Company (the “Separation
Date”), it is engaged in the Company’s “Field of Interest,” which is hereby
defined to include all businesses of the Company related to the following areas:
(i) complement inhibition or inhibitors; (ii) diseases for which the Company has
marketed products as of the Separation Date; (iii) diseases or targets for which
the Company has a product candidate in clinical development as of the Separation
Date; (iv) diseases or targets for which the Company has a pre-clinical product
candidate as of the Separation Date, provided that the Competing Organization
has either a marketed product or a product candidate that is under active
development or testing for the same disease or target; and (v) companies,
technologies or therapeutic areas that, to Employee’s knowledge, the Company
either is

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evaluating or has evaluated for business development purposes within the 12
months preceding the Separation Date.

c.At no time during the Term of this Agreement or thereafter, regardless of the
reason for termination, will Employee knowingly make any written or verbal
untrue statement that disparages the Company, its Affiliates, its business, its
management, or its products in communications with any customer, client or the
public. The employee will, furthermore, not otherwise do or say anything that
could disrupt the good morale of employees of the Company or any of its
Affiliates, or that harms the interests or reputation of the Company or any of
its Affiliates.

d.Nothing in this Agreement or the Proprietary Information and Inventions
Agreement limits, restricts, or in any other way affects the Employee’s
communicating with any governmental agency or entity, or communicating with any
official or staff person of a governmental agency or entity, concerning matters
relevant to the governmental agency or entity.

e.The Employee acknowledges that he has read and considered all the terms and
conditions of this Agreement, including the restraints imposed upon him pursuant
to Sections 5(a)-(c) above. The Employee agrees without reservation that these
restraints are necessary for the reasonable and proper protection of the Company
and its Affiliates, and are reasonable in respect to subject matter, length of
time, and geographic area. If the Employee commits a breach, or threatens to
commit a breach, of any of the provisions of this Section 5, the Company shall
have the right and remedy to have the provisions of this Agreement specifically
enforced by any court having equity jurisdiction, it being acknowledged and
agreed that any such breach or threatened breach will cause irreparable injury
to the Company and that money damages may not provide an adequate remedy to the
Company. The Employee therefore agrees that the Company, in addition to any
other remedies available to it, shall be entitled to preliminary and permanent
injunctive relief against any breach or threatened breach by the Employee of any
of the provisions of this Section 5, without having to post bond. So that the
Company may enjoy the full benefit of the covenants contained above, the
Employee agrees that the Restricted Period shall be tolled, and shall not run,
during the period of any breach by the Employee of such covenants.

f.If any of the covenants contained in this Section 5, or any part thereof, is
hereafter construed to be invalid or unenforceable, the same shall not affect
the remainder of the covenant or covenants, which shall be given full effect
without regard to the invalid portions.

g.If any of the covenants contained in this Section 5, or any part thereof, is
held to be unenforceable because of the duration or scope of such provision or
the area covered thereby, the parties agree that the court making such
determination shall have the power to reduce the duration and/or area of such
provision, and that the parties intend for the court to modify the duration
and/or area of such provision to the maximum extent permitted by law. The
parties agree that in its reduced form, such provision shall then be
enforceable.

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h.In the event that the courts of any one or more of such states shall hold any
such covenant wholly unenforceable by reason of the breadth of such scope or
otherwise, it is the intention of the parties hereto that such determination not
bar or in any way affect the Company’s right to the relief provided above in the
courts of any other states within the geographical scope of such other
covenants, as to breaches of such covenants in such other respective
jurisdictions, the above covenants as they relate to each state being, for this
purpose, severable into diverse and independent covenants.
6.    Termination by the Company.
The Company may terminate the employment of the Employee as follows during the
Term of this Agreement if any one or more of the following shall occur:
a.Death. If the Employee shall die during the Term, the Employee’s employment
hereunder shall automatically terminate.

b.Disability. If the Employee shall become physically or mentally disabled so
that the Employee is unable substantially to perform his services hereunder for
(1) a period of 120 consecutive days, or (2) for shorter periods aggregating to
180 days during any twelve-month period, the Company may terminate the
Employee’s employment hereunder upon not less than thirty (30) days’ prior
written notice given by the Company to the Employee.

c.For Cause. If the Employee acts, or fails to act, in a manner that provides
Cause for termination, the Company may at any time terminate the Employee’s
employment hereunder upon written notice given by the Company to the Employee.
For purposes of this Agreement, the term “Cause” means (1) the Employee’s
indictment for, or conviction of, a felony or other crime involving moral
turpitude, or any crime or serious offense involving money or other property
which constitutes a felony in the jurisdiction involved, (2) the Employee’s
willful and continual neglect or failure to discharge duties (including
fiduciary duties), responsibilities and obligations with respect to the Company
hereunder; provided such neglect or failure, if susceptible of cure, remains
uncured for a period of thirty (30) days after written notice describing the
same is given to the Employee; provided further that isolated and insubstantial
neglect or failures shall not constitute Cause hereunder, (3) the Employee’s
material breach of this Agreement or any other material agreement with the
Company; provided such breach, if susceptible of cure, remains uncured for a
period of thirty (30) days after written notice describing the same is given to
the Employee, (4) the Employee’s violation of Section 5 hereof or the Employee’s
breach of any confidentiality provisions contained in the Proprietary
Information and Inventions Agreement, or (5) any act of fraud or embezzlement by
the Employee involving the Company or any of its Affiliates.

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d.Without Cause. The Company may at any time terminate the Employee’s employment
hereunder without Cause upon written notice given by the Company to the
Employee.
7.    Termination by the Employee.
a.Other than for Constructive Termination. The Employee may terminate his
employment hereunder at any time, for any reason and for no reason, upon not
less than sixty (60) days’ prior written notice to the Company.

b.Constructive Termination. The Employee may terminate his employment hereunder
upon written notice to the Company if any one or more of the following shall
occur, each of which is deemed a Constructive Termination:
i.a material breach of the terms of this Agreement by the Company and such
breach continues uncured for thirty (30) days after the Employee first gives
written notice of such breach to the Company;
ii.a material breach by the Company of any other material agreement with the
Employee and such breach continues uncured for thirty (30) days after the
Employee first gives written notice of such breach to the Company
Notwithstanding the foregoing, the Employee shall not be deemed to have a
“Constructive Termination” unless the Employee gives the Company written notice
of such a condition within ninety (90) days after such condition first comes
into existence, the Company fails to remedy such condition within thirty (30)
days after receiving the Employee’s written notice and the Employee terminates
this Agreement not later than thirty (30) days after the Company so fails to
remedy such condition.
8.    Termination by Employee for Good Reason Following a Change in Control.
In addition to Section 7(b)(i) through (iii) above, during the period commencing
on the Change in Control (as defined in Section 14) and ending on the eighteen
(18) month anniversary of such Change in Control, the Employee may terminate
this Agreement upon expiration of ninety (90) days’ prior written notice if
“Good Reason” exists for the Employee’s termination. For this purpose,
termination by the Employee for “Good Reason” shall mean a termination by the
Employee of his employment hereunder following the initial occurrence, without
his prior written consent, of any of the following events, unless the Company or
its successor fully cures all grounds for such termination within thirty (30)
days after receipt of the Employee’s written notice (it being understood that a
termination of employment hereunder shall only be for Good Reason if the
Employee terminates his employment not later than thirty (30) days after the
Company so fails to cure such grounds):
a.any material adverse change in the Employee's authority, duties, titles or
offices (including reporting responsibility), from those existing immediately
prior to the Change in Control;

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b.a diminution of the Employee’s Base Salary or annual bonus opportunity as
provided for in Section 3; or

c.the failure of the Company to obtain the assumption in writing of its
obligation to perform this Agreement by any successor to the Company in the
event of a Change in Control, under circumstances where such assumption is
required. .
9.    Severance and Benefit Continuation.
a.Termination for Cause or Voluntary Termination. In the event of a termination
of the Employee’s employment by the Company for Cause pursuant to Section 6(c)
hereof or by the Employee pursuant to Section 7(a) hereof, no severance or other
termination pay or benefits shall be due to the Employee and the only obligation
of the Company shall be to pay the Employee any accrued but unpaid Base Salary
as of the date of termination and any accrued but unpaid vacation as of the date
of termination (the “Accrued Obligations”), which amounts shall be paid to the
Employee within thirty (30) days of the date of termination. In the event of a
termination of the Employee’s employment pursuant to Section 7(a), the Company
may elect to waive the period of notice required by Section 7(a), or any portion
thereof, and, if the Company so elects, the Company will pay the Employee his
Base Salary for the period so waived. Upon a termination covered by this Section
9(a), the Employee shall have the same opportunity to continue group health
benefits at the Employee’s expense in accordance with the Consolidated Omnibus
Budget Reconciliation Act of 1985 (“COBRA”) as is available generally to other
employees terminating employment with the Company. Any outstanding equity awards
previously granted to the Employee under the Equity Plan shall be treated in
accordance with the terms of the Equity Plan and any individual award agreements
under which such equity awards were granted. A termination of the Employee’s
employment that occurs by reason of the Employee’s notice to the Company of
non-renewal of the Term under Section 2 hereof will be treated as a termination
by the Employee under Section 7(a) unless otherwise agreed to in writing by the
Company and the Employee.

b.Termination for Death or Disability. In the event of termination of the
Employee’s employment pursuant to Section 6(a) or Section 6(b) by reason of the
death or disability of the Employee, the Company shall pay the Employee (or his
estate in the event of a termination due to death), any accrued but unpaid Base
Salary as of the date of termination and a pro-rata annual bonus for the year in
which such termination of employment occurs, calculated by multiplying the
Employee’s target annual bonus by a fraction, the numerator of which is the
number of days the Employee was employed during such year and the denominator of
which is 365 and shall provide the Health Continuation Benefits (as defined in
Section 9(c)(ii)). In the event of a termination of the Employee’s employment
due to death, the Company shall also pay to the Employee’s estate an amount
equal to three (3) months of Base Salary. The Base Salary (if applicable) and
the pro-rata bonus shall be paid within thirty (30) days of the date of
termination. All Time-Vesting Equity Awards previously granted to the Employee
shall become immediately

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vested and shall remain exercisable for such periods as provided under the terms
of the Equity Plan and any individual award agreements under which such awards
were granted. All other equity awards previously granted to the Employee will
vest as determined in good faith by the Board of Directors based on the
percentage of goals and objectives achieved by the Employee and the Company.

c.Involuntary Termination Other Than for Cause, Voluntary Termination Following
Constructive Termination, or Non-Renewal by the Company. If (1) the Company
terminates the Employee’s employment pursuant to Section 6(d) hereof, (2) the
Employee terminates his employment pursuant to Section 7(b) hereof or (3) at the
end of the Term of this Agreement the Employee shall cease to be employed by the
Company by reason of the Company’s decision not to renew the Term under Section
2 hereof (“Non-Renewal”), and in each case the termination of employment does
not occur within eighteen (18) months following the consummation of a Change in
Control of the Company, then, in addition to the Accrued Obligations:
i.the Company shall pay the Employee 1.5 times the sum of (A) the Employee’s
Base Salary at the time of his termination of employment plus (B) the amount
equal to the Employee’s bonus target under the Bonus Plan as determined by the
Company for the year in which the termination of employment occurs. Subject to
Section 9(g), such amounts will be paid to the Employee sixty (60) days after
such Separation from Service in a cash lump sum; and
ii.if the Employee timely elects to continue his participation and that of his
eligible dependents in the Company’s group medical, dental and vision plans
under COBRA, the Company shall pay the Employee a lump-sum amount that, after
all applicable taxes and withholdings are deducted, is the economic equivalent
of the monthly health premiums paid by the Company on behalf of the Employee and
his eligible dependents immediately prior to the date of his Separation from
Service for a period of eighteen (18) months (the “Health Continuation
Benefits”); provided that all such payments shall comply with the reimbursement
rules of Treasury Regulations Sections 1.409A-1(b)(9)(v) or 1.409A-3(i)(1)(iv);
iii.all Time-Vesting Equity Awards granted to the Employee on or about the
Effective Date shall fully and immediately vest as of the Separation Date, and
all other Time-Vesting Equity Awards that have both been previously granted to
the Employee and are at least 50% vested as of the Separation Date shall fully
and immediately vest as of the Separation Date; any such Time-Vesting awards
that consist of stock options shall become exercisable immediately prior to such
termination of employment and shall remain exercisable for such periods as
provided under the terms of the Equity Plan and any individual award agreements
under which such equity awards were granted; and
iv.equity awards, other than the Time-Vested Equity Awards, that have been
granted to and earned by the Employee and are at least 50% vested as of the
Separation

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Date, shall fully and immediately vest as of the Separation Date and become
exercisable immediately prior to such termination of employment, and shall
remain exercisable for such periods as provided under the terms of the Equity
Plan and any individual award agreements under which such equity awards were
granted.
d.Involuntary Termination Other Than for Cause, Voluntary Termination Following
Constructive Termination or for Good Reason, or Non-Renewal by the Company, Upon
a Change in Control. In the event that (1) the Company terminates this Agreement
pursuant to Section 6(d) hereof, (2) the Employee terminates this Agreement
Following Constructive Termination under Section 7(b) hereof or for Good Reason
under Section 8 hereof, or (3) there is a Non-Renewal by the Company, and in
each case the termination of employment or Non-Renewal occurs within eighteen
(18) months following the consummation of a Change in Control of the Company,
then, in addition to the Accrued Obligations:

i.the Company shall pay the Employee two (2) times the sum of (A) the Employee’s
Base Salary at the time of his termination of employment plus (B) the amount
equal to the Employee’s bonus target under the Bonus Plan as determined by the
Company for the year in which the termination of employment occurs. The Company
shall also pay the Employee a pro-rata annual bonus for the year in which such
termination of employment occurs, calculated by multiplying the Employee’s
target annual bonus by a fraction, the numerator of which is the number of days
the Employee was employed during such year and the denominator of which is 365.
Subject to Section 9(g), such amounts will be paid to the Employee sixty (60)
days after such Separation from Service in a cash lump sum; and the Company
shall provide the Employee with the Health Continuation Benefits; provided that
all such payments shall comply with the reimbursement rules of Treasury
Regulations Sections 1.409A-1(b)(9)(v) or 1.409A-3(i)(1)(iv);

ii.all equity awards for which the vesting schedule is based solely on the
passage of time and continuation of employment (“Time-Vesting Equity Awards”)
previously granted to the Employee under the Equity Plan shall fully and
immediately vest and become exercisable immediately prior to such termination of
employment and shall remain exercisable for such periods as provided under the
terms of the Equity Plan and any individual award agreements under which such
equity awards were granted; and

iii.all equity awards, other than the Time-Vesting Equity Awards, previously
earned by and granted to the Employee shall fully and immediately vest and
become exercisable immediately prior to such termination of employment and shall
remain exercisable for such periods as provided under the terms of the Equity
Plan and any individual award agreements under which such equity awards were
granted. All other non-time vesting awards previously granted to the Employee,
but not earned as of the date of termination of employment, will vest, if at
all, as determined in good faith by the

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Board of Directors based upon the achievement of performance conditions by the
Employee and the Company.

e.The payments provided in Sections 9(c) and 9(d) are intended as enhanced
severance for a termination by the Company or by the Employee in the
circumstances provided and are subject to the Employee’s continued compliance
with the provisions of Section 5 hereof. As a condition to receiving such
payments, the Employee shall first execute and deliver a general release of all
claims against the Company, its Affiliates, agents and employees (other than any
claims or rights pursuant to this Agreement or pursuant to equity or employee
benefit plans), in a form and substance reasonably satisfactory to the Company
(the “Release”). Any such payments and benefits shall be paid in a lump sum
sixty (60) days after the Employee’s Separation from Service, subject to Section
9(g) below. The Employee must execute and return the Release on or before the
date specified by the Company in the prescribed form (the “Release Deadline”).
The Release Deadline will in no event be later than fifty (50) days after the
Employee’s Separation from Service. If the Employee fails to return the Release
on or before the Release Deadline, or if the Release is revoked by the Employee,
then the Employee will not be entitled to the payments described in Sections
9(c) and 9(d).

f.Termination of Employment and Separation from Service. All references in the
Agreement to termination of employment, a termination, retirement, cessation of
employment, separation from service, and correlative terms, that result in the
payment or vesting of any amounts or benefits that constitute “nonqualified
deferred compensation” within the meaning of Section 409A shall be construed to
require a Separation from Service, and the date of such termination in any such
case shall be construed to mean the date of the Separation from Service (the
“Separation Date”).

g.Payment to a “Specified Employee”. To the extent any payment hereunder that is
payable by reason of termination of the Employee’s employment constitutes
“nonqualified deferred compensation” subject to Section 409A and would otherwise
have been required to be paid during the six (6)-month period following such
termination of employment, it shall instead (unless at the relevant time the
Employee is no longer a Specified Employee) be delayed and paid, without
interest, in a lump sum on the date that is six (6) months and one (1) day after
the Employee’s termination (or, if earlier, the date of the Employee’s death).

h.In the event that the Employee’s employment with the Company terminates for
any reason, except as otherwise expressly provided by the Company, the
Employee’s employment with, or other service to, all Affiliates of the Company
by which he is then employed or otherwise engaged in service shall automatically
and immediately terminate.

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10.Cooperation.
Following his termination of employment, the Employee agrees to cooperate with,
and assist, the Company to ensure a smooth transition in management and, if
requested by the Company, will make himself available to consult during regular
business hours at mutually agreed upon times for up to a three month period
thereafter. At any time following his termination of employment for any reason,
the Employee will provide such information as the Company may reasonably request
with respect to any Company-related transaction or other matter in which the
Employee was involved in any way while employed by the Company. The Employee
further agrees to assist and cooperate with the Company in connection with the
defense, prosecution, government investigation, or internal investigation of any
claim or matter that may be made against, concerning, or by, the Company or its
Affiliates. Such assistance and cooperation shall include timely, comprehensive,
and truthful disclosure of all relevant facts known to the Company, including
through in-person interview(s) with the Company’s internal Legal Department or
outside counsel for the Company. The Employee shall be entitled to reimbursement
for all properly documented expenses incurred in connection with rendering
services under this Section, including, but not limited to, reimbursement for
all reasonable travel, lodging, and meal expenses.
11.Indemnification.
The Company shall indemnify the Employee to the fullest extent permitted by
applicable law and its then-current articles of incorporation and by-laws. The
Employee agrees to promptly notify the Company of any actual or threatened claim
arising out of or as a result of his employment with the Company, or cooperation
pursuant to Section 10 above. The Company shall provide, at its expense,
Directors and Officers insurance for the Employee in amounts reasonably
satisfactory to the Employee, to the extent such insurance is available at
reasonable rates, which determination shall be made by the Board of Directors.
The Employee shall also be party to an Indemnification Agreement with the
Company in substantially the form attached as Exhibit A hereto.
12.Excise Tax.
If any payment or benefit that Employee would receive following a Change in
Control of the Company or otherwise (“Payment”) would (i) constitute a
“parachute payment” within the meaning of Section 280G of the Code, and (ii) but
for this sentence, be subject to the excise tax imposed by Section 4999 of the
Code (the “Excise Tax”), then such Payment shall be reduced to the Reduced
Amount. The “Reduced Amount” shall be either (a) the largest portion of the
Payment that would result in no portion of the Payment being subject to the
Excise Tax or (b) the largest portion, up to and including the total amount, of
the Payment, whichever of the amounts determined under (a) and (b), after taking
into account all applicable federal, state and local employment taxes, income
taxes, and the Excise Tax (all computed at the highest applicable marginal
rate), results in the Employee’s receipt, on an after-tax basis, of the greater
amount of the Payment notwithstanding that all or some portion of the Payment
may be subject to the Excise Tax. If a reduction in payments or benefits
constituting “parachute payments” is

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necessary so that the Payment equals the Reduced Amount, reduction shall occur
in the following order: reduction of cash payments; cancellation of accelerated
vesting of outstanding awards under the Equity Plan; and reduction of employee
benefits. In the event that acceleration of vesting of outstanding awards under
the Equity Plan is to be reduced, such acceleration of vesting shall be
undertaken in the reverse order of the date of grant of the Employee’s
outstanding equity awards.
The accounting firm engaged by the Company for general audit purposes as of the
day prior to the effective date of the Change in Control of the Company shall
perform the foregoing calculations. If the accounting firm so engaged by the
Company is serving as accountant or auditor for the individual, entity or group
effecting the Change in Control, then the Company shall appoint another,
nationally recognized accounting firm to make the determinations required
hereunder. The Company shall bear all expenses with respect to the
determinations by such accounting firm required to be made hereunder.
The accounting firm engaged to make the determinations hereunder shall provide
its calculations, together with detailed supporting documentation, to the
Employee and the Company within a commercially reasonable period of time after
the date on which the Employee’s right to a Payment is triggered (if requested
at that time by the Employee or the Company). Any good faith determinations of
the accounting firm made hereunder shall be final, binding and conclusive upon
the Employee and the Company.
13.No Mitigation.
The Employee shall not be required to mitigate the amount of any payment
provided for hereunder by seeking other employment or otherwise, nor shall the
amount of any payment provided for hereunder be reduced by any compensation
earned by the Employee as the result of employment by another employer after the
date of termination of employment by the Company (other than as described above
in Section 9(c)(ii) and Section 9(d)(ii)).
14.    Definitions.
As used herein, the following terms have the following meaning:
(a)“Affiliate” means and includes any person, corporation or other entity
controlling, controlled by or under common control with the corporation in
question.
(b)“Change in Control” means the occurrence of any of the following events:

i.Any Person, other than the Company, its affiliates (as defined in Rule 12b-2
under the Exchange Act) or any Company employee benefit plan (including any
trustee of such plan acting as trustee), is or becomes the Beneficial Owner,
directly or indirectly, of securities of the Company representing more than 40%
of the combined voting power of the then outstanding securities entitled to vote
generally in the election of Directors (“Voting Securities”) of the Company, or

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ii.Individuals who constitute the Board of Directors of the Company (the
“Incumbent Directors”) as of the beginning of any twenty-four month period (not
including any period prior to the date of this Agreement), cease for any reason
to constitute at least a majority of the Directors. Notwithstanding the
foregoing, any individual becoming a Director subsequent to the beginning of
such period, whose election or nomination for election by the Company’s
stockholders was approved by a vote of at least two-thirds of the Directors then
comprising the Incumbent Directors, shall be considered an Incumbent Director;
or

iii.Consummation by the Company of a recapitalization, reorganization, merger,
consolidation or other similar transaction (a “Business Combination”), with
respect to which all or substantially all of the individuals and entities who
were the Beneficial Owners of the Voting Securities immediately prior to such
Business Combination (the “Incumbent Shareholders”) do not, following
consummation of all transactions intended to constitute part of such Business
Combination, beneficially own, directly or indirectly, 50% or more of the Voting
Securities of the corporation, business trust or other entity resulting from or
being the surviving entity in such Business Combination (the “Surviving
Entity”), in substantially the same proportion as their ownership of such Voting
Securities immediately prior to such Business Combination; or

iv.Consummation of a complete liquidation or dissolution of the Company, or the
sale or other disposition of all or substantially all of the assets of the
Company, other than to a corporation, business trust or other entity with
respect to which, following consummation of all transactions intended to
constitute part of such sale or disposition, more than 50% of the combined
Voting Securities is then owned beneficially, directly or indirectly, by the
Incumbent Shareholders in substantially the same proportion as their ownership
of the Voting Securities immediately prior to such sale or disposition.

For purposes of this definition 14(b), the following terms shall have the
meanings set forth below:
(A)“Beneficial Owner” shall have the meaning set forth in Rule 13d-3 under the
Exchange Act;
(B)“Exchange Act” shall mean the Securities Exchange Act of 1934, as amended;
and
(C)“Person” shall have the meaning as used in Sections 13(d) and 14(d) of the
Exchange Act.
(c)“Code” means the Internal Revenue Code of 1986, as amended.
(d)“Restricted Period” shall mean eighteen (18) months.

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(e)“Separation from Service” shall mean a “separation from service” (as that
term is defined at Section 1.409A-1(h) of the Treasury Regulations under Section
409A) from the Company and from all other corporations and trades or businesses,
if any, that would be treated as a single “service recipient” with the Company
under Section 1.409A-1(h)(3) of such Treasury Regulations. The Board of
Directors or the Compensation Committee of the Board of Directors may, but need
not, elect in writing, subject to the applicable limitations under Section 409A,
any of the special elective rules prescribed in Section 1.409A-1(h) of the
Treasury Regulations for purposes of determining whether a “separation from
service” has occurred. Any such written election shall be deemed part of the
Agreement.
(f)“Specified Employee” shall mean an individual determined by the Board of
Directors, Compensation Committee of the Board of Directors or their delegate to
be a specified employee as defined in subsection (a)(2)(B)(i) of Section 409A.
The Committee may, but need not, elect in writing, subject to the applicable
limitations under Section 409A, any of the special elective rules prescribed in
Section 1.409A-1(i) of the Treasury Regulations for purposes of determining
“specified employee” status. Any such written election shall be deemed part of
the Agreement.
15.Representations by Employee.

The Employee represents and warrants that he has full right, power and authority
to execute the terms of this Agreement; this Agreement has been duly executed by
the Employee and such execution and the performance of this Agreement by the
Employee does not result in any conflict, breach or violation of or default
under any other agreement or any judgment, order or decree to which the Employee
is a party or by which he is bound. The Employee acknowledges and agrees that
any material breach of the representations set forth in this Section will
constitute Cause under Section 6.

16.Arbitration.

Any controversy or claim arising out of or relating to this Agreement or the
breach thereof, or arising out of Employee’s employment and the termination of
such employment, shall be settled by arbitration in Connecticut, in accordance
with the employment dispute rules then existing of the American Arbitration
Association, and judgment upon the award rendered may be entered in any court
having jurisdiction thereof. Such claims shall include, without limitation,
claims for breach of contract or breach of the covenant of good faith and fair
dealing, any claims of discrimination or other claims under Title VII of the
Civil Rights Act of 1964, as amended, the Age Discrimination in Employment Act
of 1967, as amended by the Older Workers Benefits Protection Act, the Americans
with Disabilities Act, the Family and Medical Leave Act, the Fair Labor
Standards Act, ERISA, and/or any applicable or equivalent state or local laws,
claims for wrongful termination, including employment termination in violation
of public policy, and claims for personal injury including, without limitation,
defamation, fraud and infliction of emotional distress. The parties shall be
free to pursue any remedy before the arbitrator that they

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shall be otherwise permitted to pursue in a court of competent jurisdiction. As
a material part of this agreement to arbitrate claims, the Employee and company
expressly waive all rights to a jury trial in court on all statutory or other
claims. The award of the arbitrator shall be final and binding. The costs of the
American Arbitration Association and the arbitrator will be borne equally by the
Company and the Employee. Nothing contained herein, however, shall limit the
right of the Company or any of its Affiliates to seek equitable or other relief
from any court of competent jurisdiction for violation of any provision of
Sections 4 and 5 above.

17.Recoupment.

The Employee hereby acknowledges and agrees that the annual bonus described in
Section 3(b) and all other payments of incentive-based compensation payable to
the Employee by the Company or its Affiliates (whether under this Agreement or
otherwise) shall be subject to any applicable clawback or recoupment policy of
the Company, as such policy may be amended and in effect from time to time, and
shall be subject to recoupment as otherwise required by applicable law or
applicable stock exchange listing standards, including, without limitation,
Section 10D of the Securities Exchange Act of 1934, as amended.
18.Notices.
All notices, requests, consents and other communications required or permitted
to be given hereunder shall be in writing and shall be deemed to have been duly
given if sent by private overnight mail service (delivery confirmed by such
service), registered or certified mail (return receipt requested and received),
telecopy (confirmed receipt by return fax from the receiving party) or delivered
personally, as follows (or to such other address as either party shall designate
by notice in writing to the other in accordance herewith):
If to the Company:
Alexion Pharmaceuticals, Inc.
100 College Street
New Haven, Connecticut 06510
Telephone: (203) 272-2596
Fax: (203) 271-8198
Attn: General Counsel

If to the Employee: to the Employee’s Address on file with the Company.
19.    General.
a.This Agreement shall be governed by and construed and enforced in accordance
with the laws of the State of Connecticut applicable to agreements made and to
be performed entirely in Connecticut by Connecticut residents.

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b.This Agreement sets forth the entire agreement and understanding of the
parties relating to the subject matter hereof, and supersedes all prior
agreements, arrangements and understandings, written or oral, relating to the
subject matter hereof, except for the Proprietary Information and Inventions
Agreement and the Indemnification Agreement and except that the provisions of
the Offer Letter remain in force to the extent that they grant additional
benefits in favor of the Employee. No representation, promise or inducement has
been made by either party that is not embodied in this Agreement, and neither
party shall be bound by or liable for any alleged representation, promise or
inducement not so set forth.

c.This Agreement may be amended, modified, superseded, canceled, renewed or
extended, and the terms or covenants hereof may be waived, only by a written
instrument executed by the parties hereto, or in the case of a waiver, by the
party waiving compliance. The failure of a party at any time or times to require
performance of any provision hereof shall in no manner affect the right at a
later time to enforce the same. No waiver by a party of the breach of any term
or covenant contained in this Agreement, whether by conduct or otherwise, or any
one or more or continuing waivers of any such breach, shall constitute a waiver
of the breach of any other term or covenant contained in this Agreement.

d.This Agreement shall be binding upon the legal representatives, heirs,
distributees, successors and assigns of the parties hereto. The Company may not
assign its rights and obligation under this Agreement without the prior written
consent of the Employee, except to a successor of substantially all the
Company’s business which expressly assumes the Company’s obligations hereunder
in writing. In the event of a sale of all or substantially all of the assets of
the Company, the Company shall use its best efforts to cause the purchaser to
expressly assume this Agreement. The Employee may not assign, transfer, alienate
or encumber any rights or obligations under this Agreement, except by will or
operation of law, provided that the Employee may designate beneficiaries to
receive any payments permitted under the terms of the Company’s benefit plans.

e.If any portion or provision of this Agreement shall to any extent be declared
illegal or unenforceable by a court of competent jurisdiction, then the
remainder of this Agreement, or the application of such portion or provision in
circumstances other than those as to which it is so declared illegal or
unenforceable, shall not be affected thereby, and each portion and provision of
this Agreement shall be valid and enforceable to the fullest extent permitted by
law.

f.Provisions of this Agreement shall survive any termination of employment if so
provided herein or if necessary or desirable fully to accomplish the purposes of
other surviving provisions, including without limitation, the obligations of the
Employee under Section 5 hereof. Upon termination of the Employee’s employment
hereunder by either the Employee or the Company as permitted hereby, all rights,
duties and obligations of the Employee and the Company to each other pursuant to
this Agreement shall cease, except for the provisions

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hereof that contemplate performance after termination, including without
limitation the obligations of the Employee under Section 5 hereof.

g.This Agreement is intended to comply with the applicable requirements of
Section 409A and shall be construed accordingly. Each payment made under this
Agreement shall be treated as a separate payment and the right to a series of
installment payments under this Agreement is to be treated as a right to a
series of separate payments. In no event shall the Company have any liability
relating to the failure or alleged failure of any payment or benefit under this
Agreement to comply with, or be exempt from, the requirements of Section 409A.
IN WITNESS WHEREOF, the parties have executed this Agreement as of the date
first above written.
ALEXION PHARMACEUTICALS, INC.

By:_/s/ Ludwig Hantson__________
Name: Ludwig Hantson
Title: Chief Executive Officer
EMPLOYEE

_/s/ Paul J. Clancy_________________
Paul J. Clancy

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