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                                                                    CONFIDENTIAL

                                                                    EXHIBIT 10.1

                                    AGREEMENT

     AGREEMENT made and entered into in New York, New York, by and between
Antigenics, Inc. (the "Company"), a Delaware corporation with a principal place
of business at 630 Fifth Ave. Suite 2100 New York, NY, and Garo Armen (the
"Executive"), effective as of the 1st day of December 2005 (the "Effective
Date") (the "Agreement").

     WHEREAS, the operations of the Company and its Affiliates are a complex
matter requiring direction and leadership in a variety of arenas;

     WHEREAS, the Executive is possessed of certain experience and expertise
that qualify him to provide the direction and leadership required by the
Company; and

     WHEREAS, subject to the terms and conditions hereinafter set forth, the
Company therefore wishes to continue to employ the Executive as its Chief
Executive Officer and the Executive wishes to continue such employment;

     NOW, THEREFORE, in consideration of the foregoing premises and the mutual
promises, terms, provisions and conditions set forth in this Agreement, the
parties hereby agree:

     1. Employment. Subject to the terms and conditions set forth in this
Agreement, the Company hereby offers and the Executive hereby accepts continued
employment.

     2. Term. Subject to earlier termination as hereafter provided, this
Agreement shall have an original term of one year commencing on the Effective
Date hereof and shall be automatically extended thereafter for successive terms
of one year each, unless either party provides notice to the other at least
ninety (90) days prior to the expiration of the original or any extension term
this Agreement is not to be extended. 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 hereof".

     3. Capacity and Performance.

          (a) During the Term hereof, the Executive shall serve the Company as
its Chief Executive Officer and shall report to the Board of Directors. In
addition, and without further compensation, the Executive shall serve as a
director and/or officer of one or more of the Company's Affiliates if so elected
or appointed from time to time.

          (b) During the term hereof, the Executive shall be employed by the
Company on a full-time basis and shall perform such duties and responsibilities
on behalf of the Company and its Affiliates as may be designated from time to
time consistent with his position as Chief Executive Officer.

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          (c) During the Term hereof, the Executive shall devote his best
efforts, business judgment, skill and knowledge to the advancement of the
business and interests of the Company and its Affiliates and to the discharge of
his duties and responsibilities hereunder. The Executive shall not engage in any
other business activity or serve in any industry, trade, professional,
governmental or academic position during the Term of this Agreement, except as
may be approved by the Board of Directors of the Company (the "Board") or its
designee.

     4. Compensation and Benefits. As compensation for all services performed by
the Executive under and during the term hereof and subject to performance of the
Executive's duties and of the obligations of the Executive to the Company and
its Affiliates, pursuant to this Agreement or otherwise:

          (a) Base Salary. During the term hereof, the Company shall pay the
Executive a minimum base salary at the rate of Four Hundred and Twenty Thousand
Dollars ($420,000 United States dollars) per annum, payable in accordance with
the payroll practices of the Company for its executives and subject to increase
by the Board, in its sole discretion. Such base salary, as from time to time
increased, is hereafter referred to as the "Base Salary". The Board shall review
the Base Salary no less than annually.

          (b) Incentive and Bonus Compensation. During the term hereof, the
Executive shall be entitled to participate in the Company's Executive Incentive
Plan, in accordance with the terms thereof, as such terms may be modified or
amended by the Company from time to time; provided, however, that nothing
contained herein shall obligate the Company to continue such incentive
compensation program. The Executive's target incentive bonus under the Executive
Incentive Plan is 50% of his Base Salary. Such target may be modified by the
Company from time to time, in its sole discretion. Any compensation paid to the
Executive under the Executive Incentive Plan shall be in addition to the Base
Salary.

          (c) Stock Options. The Executive has been granted options to purchase
shares of common stock of the Company. At the discretion of the Compensation
Committee of the Board, the Executive may be granted additional options to
purchase shares of stock of the Company in the future. Any existing or future
grants shall be governed by the terms of the applicable Company stock option
plan, as amended from time to time, and any stock option certificate, stock
option agreement, and other restrictions generally applicable to Company stock
options.

          (d) Vacations. During the term hereof, the Executive shall be entitled
to four weeks of vacation per annum, to be taken at such times and intervals as
shall be determined by the Executive, subject to the reasonable business needs
of the Company.

          (e) Other Benefits. During the term hereof and subject to any
contribution therefor generally required of executives of the Company, the
Executive shall be entitled to participate in any and all employee benefit plans
from time to time in effect for executives of the Company generally, except to
the extent such plans are in a category of benefit otherwise provided to the
Executive. Such participation shall be subject to (i) the terms of the
applicable plan documents, (ii) generally applicable Company policies and (iii)
the discretion of the Board


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or any administrative or other committee provided for in or contemplated by such
plan. The Company may alter, modify, add to or delete its employee benefit plans
at any time as it, in its sole judgment, determines to be appropriate, without
recourse by the Executive.

          (f) Business Expenses. The Company shall pay or reimburse the
Executive for all reasonable, customary and necessary business expenses incurred
or paid by the Executive in the performance of his duties and responsibilities
hereunder, subject to any maximum annual limit and other restrictions on such
expenses as set forth in the Company's Travel Policy as may be amended from time
to time, and to such reasonable substantiation and documentation as may be
specified by the Company from time to time.

     5. Termination of Employment and Severance Benefits. Notwithstanding the
provisions of Section 2 hereof, but subject to Section 6 hereof, the Executive's
employment hereunder shall terminate prior to the expiration of the term under
the following circumstances:

          (a) Death. In the event of the Executive's death during the term
hereof, the Executive's employment hereunder shall immediately and automatically
terminate. In the event of the Executive's death during the term hereof, the
Company shall pay to the Executive's designated beneficiary or, if no
beneficiary has been designated by the Executive, to his estate, any earned and
unpaid Base Salary and accrued but unused vacation through the date of his
death.

          (b) Disability.

               (i) The Company may terminate the Executive's employment
     hereunder, upon notice to the Executive, in the event that the Executive
     becomes disabled during his employment hereunder through any illness,
     injury, accident or condition of either a physical or psychological nature
     and, as a result, is unable to perform substantially all of his duties and
     responsibilities hereunder, with or without a reasonable accommodation, for
     ninety (90) days during any period of three hundred and sixty-five (365)
     consecutive calendar days.

               (ii) The Board may designate another employee to act in the
     Executive's place during any period of the Executive's disability.
     Notwithstanding any such designation, the Executive shall continue to
     receive the Base Salary in accordance with Section 4.a and benefits in
     accordance with Section 4.e, to the extent permitted by the then-current
     terms of the applicable benefit plans, until the Executive becomes eligible
     for disability income benefits under the Company's disability income plan
     or until the termination of his employment, whichever shall first occur.

               (iii) While receiving disability income payments under the
     Company's disability income plan, the Executive shall not be entitled to
     receive any Base Salary under Section 4.a hereof, but shall continue to
     participate in Company benefit plans in accordance with Section 4.e and the
     terms of such plans, until the termination of his employment.


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               (iv) If any question shall arise as to whether during any period
     the Executive is disabled through any illness, injury, accident or
     condition of either a physical or psychological nature so as to be unable
     to perform substantially all of his duties and responsibilities hereunder,
     the Executive may, and at the request of the Company shall, submit to a
     medical examination by a physician selected by the Company to whom the
     Executive or his duly appointed guardian, if any, has no reasonable
     objection to determine whether the Executive is so disabled and such
     determination shall for the purposes of this Agreement be conclusive of the
     issue. If such question shall arise and the Executive shall fail to submit
     to such medical examination, the Company's determination of the issue shall
     be binding on the Executive.

               (v) In the event the Company terminates the Executive's
     employment hereunder due to disability, the Company shall pay to the
     Executive any accrued and unpaid Base Salary and accrued but unused
     vacation through the date of termination.

          (c) By the Company for Cause. The Company may terminate the
Executive's employment hereunder for Cause at any time upon fourteen (14) day
notice to the Executive setting forth in reasonable detail the nature of such
Cause. The following, as determined by the Company in its reasonable judgment,
shall constitute Cause for termination:

               (i) The Executive's failure to perform (other than by reason of
     disability), or negligence in the performance of, his duties and
     responsibilities to the Company or any of its Affiliates; or

               (ii) Material breach by the Executive of any provision of this
     Agreement; or

               (iii) Other conduct by the Executive that is materially harmful
     to the business, interests or reputation of the Company or any of its
     Affiliates.

     Upon the giving of notice of termination of the Executive's employment
hereunder for Cause, the Company shall have no further obligation or liability
to the Executive, other than for Base Salary earned and unpaid and accrued
vacation earned but not taken at the date of termination.

          (d) By the Company Other than for Cause. The Company may terminate the
Executive's employment hereunder other than for Cause at any time upon notice to
the Executive. In the event of such termination, the Company shall either (i)
pay the Executive the benefits payable under an executive severance plan, if
such a plan is in place on the date of termination and if the Executive is
eligible for such benefits under such a plan or, if the present value to the
Executive is greater, (ii) continue to pay the Executive his Base Salary, at the
rate in effect on the date of termination, until the conclusion of a period of
eighteen (18) months following the date of termination. In addition, the Company
shall pay to the Executive in one lump sum an amount equal to 150% of the higher
of (x) the Executive's target incentive bonus under the Executive Incentive Plan
for the year in which the Executive's employment is terminated or (y) the actual
incentive bonus paid to the Executive, if any, under the Executive


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Incentive Plan for the last full fiscal year preceding the year in which the
Executive's employment is terminated; and shall also, until the conclusion of a
period of eighteen (18) months following the date of termination, pay the full
premium cost of the Executive's participation in the Company's group medical and
dental insurance plans, provided that the Executive is entitled to continue such
participation under applicable law and plan terms. The Company will also provide
the Executive with an outplacement assistance benefit in the form of a lump-sum
payment of $15,000 plus an additional lump-sum payment in an amount sufficient,
after giving effect to all federal, state and other taxes with respect to such
additional payment, to make Executive whole for all taxes (including withholding
taxes) on such outplacement assistance benefit. Furthermore, at the sole
discretion of the Compensation Committee of the Board, any unvested options to
purchase Company stock may be accelerated.

          (e) By the Executive for Good Reason. The Executive may terminate his
employment hereunder for Good Reason, upon notice to the Company setting forth
in reasonable detail the nature of such Good Reason. The following shall
constitute Good Reason for termination by the Executive:

               (i) Failure of the Company to continue the Executive in the
     position of Chief Executive Officer; or

               (ii) Material and substantial diminution in the nature or scope
     of the Executive's responsibilities, duties or authority; however, the
     Company's failure to continue the Executive's appointment or election as a
     director or officer of any of its Affiliates and any diminution of the
     business of the Company or any of its Affiliates, including without
     limitation the sale or transfer of any or all of the assets of the Company
     or any of its Affiliates, shall not constitute "Good Reason"; or

               (iii) Material reduction in Base Salary or benefits due in
     accordance with the terms of this Agreement.

In the event of termination in accordance with this Section 5.e, the Company
shall either (i) pay the Executive the benefits payable under an executive
severance plan, if such a plan is in place on the date of termination and if the
Executive is eligible for such benefits under such a plan or, if the present
value to the Executive is greater, (ii) continue to pay the Executive his Base
Salary, at the rate in effect on the date of termination, until the conclusion
of a period of eighteen (18) months following the date of termination. In
addition, the Company shall pay to the Executive in one lump sum an amount equal
to 150% of the higher of (x) the Executive's target incentive bonus under the
Executive Incentive Plan for the year in which the Executive's employment is
terminated or (y) the actual incentive bonus paid to the Executive, if any,
under the Executive Incentive Plan for the last full fiscal year preceding the
year in which the Executive's employment is terminated; and shall also, until
the conclusion of a period of eighteen (18) months following the date of
termination, pay the full premium cost of the Executive's participation in the
Company's group medical and dental insurance plans, provided that the Executive
is entitled to continue such participation under applicable law and plan terms.
The Company will also provide the Executive with an outplacement assistance
benefit in the form of


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a lump-sum payment of $15,000 plus an additional lump-sum payment in an amount
sufficient, after giving effect to all federal, state and other taxes with
respect to such additional payment, to make Executive whole for all taxes
(including withholding taxes) on such outplacement assistance benefit. In
addition, at the sole discretion of the Compensation Committee of the Board, any
unvested options to purchase Company stock may be accelerated.

          (f) By the Executive Other than for Good Reason. The Executive may
terminate his employment hereunder at any time upon sixty (60) days' notice to
the Company, unless such termination would violate any obligation of the
Executive to the Company under a separate severance agreement. In the event of
termination of the Executive pursuant to this Section 5.f, the Board may elect
to waive the period of notice, or any portion thereof, and, if the Board so
elects, the Company will pay the Executive his Base Salary for the notice period
(or for any remaining portion of the period).

          (g) Upon a Change of Control.

               (i) If a Change of Control occurs on the date of such Change in
     Control, fifty-percent (50%) of any outstanding unvested stock options
     granted to the Executive as of that date shall become vested and
     exercisable, provided that the Executive is employed by the Company on the
     date of such Change in Control.

               (ii) If a Change of Control occurs and within twenty-four (24)
     months following such Change of Control, the Company terminates the
     Executive's employment other than for Cause, or the Executive terminates
     his employment for Good Reason, then, in lieu of any payments to or on
     behalf of the Executive under Section 5.d or 5.e hereof, the Company shall
     pay to the Executive in one lump sum an amount equal to (A) twenty-four
     (24) months Base Salary at the rate in effect on the date of termination,
     plus (B) two times the higher of (x) the Executive's target incentive bonus
     under the Executive Incentive Plan for the year in which the Executive's
     employment is terminated or (y) the actual incentive bonus paid to the
     Executive, if any, under the Executive Incentive Plan for the last full
     fiscal year preceding the year in which the Executive's employment is
     terminated; and shall also, until the conclusion of a period of twenty-four
     (24) months following the date of termination, pay the full premium cost of
     the Executive's participation in the Company's group medical and dental
     insurance plans, provided that the Executive is entitled to continue such
     participation under applicable law and plan terms. In addition, any
     outstanding unvested options granted to the Executive as of the date of the
     Change in Control shall become vested and shall be exercisable for ninety
     (90) days following termination of the Executive's employment. The Company
     will also provide the Executive with an outplacement assistance benefit in
     the form of a lump-sum payment of $15,000 plus an additional lump-sum
     payment in an amount sufficient, after giving effect to all federal, state
     and other taxes with respect to such additional payment, to make Executive
     whole for all taxes (including withholding taxes) on such outplacement
     assistance benefit. For the purpose of this Section 5.g alone, in addition
     to the definition provided in Section 5.e, Good Reason shall also mean the
     relocation of the


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     Executive's principal office, without his prior consent, to a location more
     than thirty (30) miles from its location on the day prior to the Change in
     Control.

               (iii) All payments required to be made by the Company hereunder
     to Executive or his dependents, beneficiaries, or estate will be subject to
     the withholding of such amounts relating to tax and/or other payroll
     deductions as may be required by law.

          In the event that it is determined that any payment or benefit
provided by the Company to or for the benefit of Executive, either under this
Agreement or otherwise, will be subject to the excise tax imposed by Section
4999 of the Internal Revenue Code or any successor provision(s) ("Section
4999"), the Company will, prior to the date on which any amount of the excise
tax must be paid or withheld, make an additional lump-sum payment (the "Gross-up
Payment") to Executive in an amount sufficient, after giving effect to all
federal, state and other taxes and charges (including interest and penalties, if
any) with respect to the gross-up payment, to make Executive whole for all taxes
(including withholding taxes) and any associated interest and penalties, imposed
under or as a result of Section 4999.

          Determinations under this Section 5.g.iii will be made by an
accounting firm engaged by the Company (the "Firm"). The determinations of the
Firm will be binding upon the Company and Executive except as the determinations
are established in resolution (including by settlement) of a controversy with
the Internal Revenue Service to have been incorrect. All fees and expenses of
the Firm will be paid by the Company.

          If the Internal Revenue Service asserts a claim that, if successful,
would require the Company to make a Gross-up Payment or an additional Gross-up
Payment, the Company and Executive will cooperate fully in resolving the
controversy with the Internal Revenue Service. The Company will make or advance
such Gross-up Payments as are necessary to prevent Executive from having to bear
the cost of payments made to the Internal Revenue Service in the course of, or
as a result of, the controversy. The Firm will determine the amount of such
Gross-up Payments or advances and will determine after final resolution of the
controversy whether any advances must be returned by Executive to the Company.
The Company will bear all expenses of the controversy and will gross Executive
up for any additional taxes that may be imposed upon Executive as a result of
its payment of such expenses.

               (iv) For the purpose of this Section 5.g, a "Change in Control"
     shall mean: (A) the acquisition by any Organization of beneficial ownership
     (within the meaning of Rule 13d-3 promulgated under the Exchange Act) of
     50% or more of the common stock of the Company; provided, however, that for
     purposes of the subsection (A), an acquisition shall not constitute a
     Change in Control if it is: (x) by a Benefit Plan sponsored or maintained
     by the Company or an entity controlled by the Company or (y) by an entity
     pursuant to a transaction that complies with clauses (x), (y) and (z) of
     subsection (C) of this Section 5(g)(iv); or (B) individuals who, as of June
     1, 2005, constitute the Board (the "Incumbent Board") cease for any reason
     to constitute at least a majority of the Board;


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     provided, however, that any individual becoming a director subsequent to
     June 1, 2005 whose election, or nomination for election by the Company's
     stockholders, was approved by a vote of at least a majority of the
     directors then comprising the Incumbent Board (or a majority of the members
     of a nominating committee who are members of the Incumbent Board) shall be
     treated as a member of the Incumbent Board unless he or she assumed office
     as a result of an actual or threatened election contest with respect to the
     election or removal of directors or other actual or threatened solicitation
     of proxies or consents by or on behalf of an Organization other than the
     Board; or (C) consummation of a merger or consolidation involving the
     Company, or a sale or other disposition of all or substantially all of the
     assets of the Company, (a "transaction") in each case unless, immediately
     following such transaction, (x) the beneficial owners of the common stock
     of the Company outstanding immediately prior to such transaction
     beneficially own, directly or indirectly, more than 50% of the combined
     voting power of the outstanding voting securities of the entity resulting
     from such transaction (including, without limitation, an entity which as a
     result of such transaction owns the Company or all or substantially all of
     the Company's assets either directly or through one or more subsidiaries),
     (y) no Organization (excluding any entity resulting from such transaction
     or any Benefit Plan of the Company or such entity resulting from such
     transaction) beneficially owns, directly or indirectly, 50% or more of the
     combined voting power of the then outstanding voting securities of such
     entity and (z) at least a majority of the members of the board of directors
     or similar board of the entity resulting from such transaction were members
     of the Incumbent Board at the time of the execution of the initial
     agreement, or of the action of the Board, providing for such transaction;
     or (D) approval by the stockholders of the Company of a complete
     liquidation or dissolution of the Company. For purposes of the foregoing:
     "Benefit Plan" means any employee benefit plan, including any related
     trust; "Board" means the Board of Directors of the Company; "Exchange Act"
     means the Securities Exchange Act of 1934, as amended; and "Organization"
     means any individual, entity or group (within the meaning of Section
     13(d)(3) or Section 14(d)(2) of the Exchange Act).

          (h) Effect of Failure to Renew by Company. In the event the Company
chooses not to renew the term hereof, such failure to renew shall be treated as
a termination by the Company other than for "Cause" unless the Company gives
notice that the failure to renew is for "Cause" as defined in Section 5.c.

     6. Effect of Termination. The provisions of this Section 6 shall apply to
termination due to the expiration of the term, termination pursuant to Section 5
or otherwise.

          (a) Payment(s) by the Company and contributions to the cost of the
Executive's continued participation in the Company's group health and dental
plans that may be due the Executive in each case under the applicable
termination provision of Section 5 shall constitute the entire obligation of the
Company to the Executive. In order to receive any payments, benefits
continuation, accelerated vesting of stock options or any other benefits under
Section 5.d or 5.e or 5.g or 5.h, the Executive must first execute a General
Release of Claims in a form acceptable to the Company.


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          (b) Except for medical and dental insurance coverage continued
pursuant to Section 5.d or 5.e or 5.g or 5.h hereof, benefits shall terminate
pursuant to the terms of the applicable benefit plans based on the date of
termination of the Executive's employment without regard to any continuation of
Base Salary or other payment to the Executive following such date of
termination.

          (c) Provisions of this Agreement shall survive any termination if so
provided herein or if necessary or desirable fully to accomplish the purposes of
such provision, including without limitation the obligations of the Executive
under Sections 7, 8, 9 and 13 hereof. The obligation of the Company to make
payments to or on behalf of the Executive under Section 5.d or 5.e or 5.g or 5.h
hereof is expressly conditioned upon the Executive's continued full performance
of obligations under Sections 7, 8 and 9 hereof. The Executive recognizes that,
except as expressly provided in Section 5.d or 5.e or 5.g or 5.h, no
compensation is earned after termination of employment.

          (d) Any lump-sum payments to be made to the Executive hereunder shall
be made as soon as administratively practicable and in any event no later than 2
1/2 months after the end of the year in which the Executive becomes entitled to
such payment.

          (e) To the extent any payment hereunder shall be required to be
delayed until six months following separation from service to comply with the
"specified employee" rules of Section 409A of the Internal Revenue Code, it
shall be delayed (but not more than is required) to comply with such rules, and
shall promptly after such delay be paid with interest at a reasonable market
rate as determined by the Company.

     7. Confidential Information.

          (a) The Executive acknowledges that the Company and its Affiliates
continually develop Confidential Information, that the Executive may develop
Confidential Information for the Company or its Affiliates and that the
Executive may learn of Confidential Information during the course of employment.
The Executive will comply with the policies and procedures of the Company and
its Affiliates for protecting Confidential Information and shall never disclose
to any Person or to any governmental agency or political subdivision of any
government (except as required by applicable law or for the proper performance
of his duties and responsibilities to the Company and its Affiliates), or use
for his own benefit or gain, any Confidential Information obtained by the
Executive incident to his employment or other association with the Company or
any of its Affiliates. The Executive understands that the restriction shall
continue to apply after his employment terminates, regardless of the reason for
such termination.

          (b) All documents, records, tapes and other media of every kind and
description relating to the business, present or otherwise, of the Company or
its Affiliates and any copies, in whole or in part, thereof (the "Documents"),
whether or not prepared by the Executive, shall be the sole and exclusive
property of the Company and its Affiliates. The Executive shall safeguard all
Documents and shall surrender to the Company at the time his employment
terminates, or at such earlier time or times as the Board or its designee may
specify,


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all Documents then in the Executive's possession or control.

          (c) The Executive acknowledges and agrees that all Confidential
Information and proprietary materials that are provided by the Company to the
Executive under this Agreement are and shall remain the exclusive property of
the Company or the third party entrusting such Confidential Information or
proprietary materials to the Company.

     8. Restricted Activities. The Executive agrees that some restrictions on
his activities during and after his employment are necessary to protect the
goodwill, Confidential Information and other legitimate interests of the Company
and its Affiliates:

          (a) While the Executive is employed by the Company and for the greater
of (i) eighteen (18) months after his employment terminates or (ii) the period
during which the Executive is receiving payments under Section 5.d or 5.e or 5.g
or 5.h (the "Non-Competition Period"), the Executive 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. Specifically, but without limiting the foregoing, the Executive
agrees not to engage in any manner in any activity that is directly or
indirectly competitive or potentially competitive with the business of the
Company or any of its Affiliates as conducted or under consideration at any time
during the Executive's employment. Restricted activity includes without
limitation accepting employment or a consulting position with any Person who is,
or at any time within twelve (12) months prior to the termination of the
Executive's employment has been, a customer of the Company or any of its
Affiliates. For the purposes of this Section 8, the business of the Company and
its Affiliates shall include all Products and the Executive's undertaking shall
encompass all items, products and services that may be used in substitution for
Products. The foregoing shall not prohibit the Executive's passive ownership of
two percent (2%) or less of the equity securities of any publicly traded
company.

          (b) The Executive agrees that, during his employment with the Company
or any Affiliate of the Company, he will not undertake any outside activity,
whether or not competitive with the business of the Company or its Affiliates,
that could reasonably give rise to a conflict of interest or otherwise interfere
with his duties and obligations to the Company or any of its Affiliates.

          (c) The Executive further agrees that while he is employed by the
Company or any Affiliate of the Company and thereafter during the remainder of
the Non-Competition Period, the Executive will not hire or attempt to hire any
employee of the Company or any of its Affiliates, assist in such hiring by any
Person, encourage any such employee to terminate his or her relationship with
the Company or any of its Affiliates or solicit or encourage any customer or
vendor of the Company or any of its Affiliates to terminate its relationship
with them, or, in the case of a customer, to conduct with any Person any
business or activity which such customer conducts or could conduct with the
Company or any of its Affiliates.

     9. Assignment of Rights to Intellectual Property. The Executive shall
promptly and fully disclose, if he has not done so already, all Intellectual
Property to the Company. The


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Executive shall maintain adequate records (whether written, electronic, or
otherwise) to document the Intellectual Property, including without limitation
the conception and reduction to practice of all inventions, and shall make such
records available to the Company upon request. The Company shall have sole
ownership of all Intellectual Property and all such records with respect
thereto. The Executive hereby assigns, conveys, and grants to the Company (or as
otherwise directed by the Company), and agrees to assign, convey and grant to
the Company (or as otherwise directed by the Company), all of his right, title,
and interest in and to the Intellectual Property and any and all patents, patent
applications, and copyrights relating to the Intellectual Property. The
Executive agrees to execute any and all applications for domestic and foreign
patents, copyrights or other proprietary rights and to do such other acts
(including without limitation the execution and delivery of instruments of
further assurance or confirmation) requested by the Company to assign the
Intellectual Property to the Company and to permit the Company to enforce any
patents, copyrights or other proprietary rights to the Intellectual Property.
The Executive will not charge the Company for time spent in complying with these
obligations. All copyrightable works that the Executive creates shall be
considered "work made for hire".

The Executive recognizes that the protection of the Intellectual Property of the
Company against unauthorized disclosure and use is of critical importance to the
Company, and therefore, the Executive agrees to use his best efforts and
exercise utmost diligence to protect and safeguard the Intellectual Property of
the Company and its Affiliates, if any, and, except as may be expressly required
by the Company in connection with the Executive's performance of his obligations
to the Company under this Agreement, the Executive shall not, either during the
term of this Agreement or thereafter, directly or indirectly, use for his own
benefit or for the benefit of another, or disclose to another, any of such
Intellectual Property.

     10. Notification Requirement. Until the conclusion of the Non-Competition
Period the Executive shall give notice to the Company of each new business
activity he plans to undertake, at least twenty-one (21) days prior to beginning
any such activity. Such notice shall state the name and address of the Person
for whom such activity is undertaken and the nature of the Executive's business
relationship(s) and position(s) with such Person. The Executive shall provide
the Company with such other pertinent information concerning such business
activity as the Company may reasonably request in order to determine the
Executive's continued compliance with his obligations under Sections 7, 8 and 9
hereof.

     11. Enforcement of Covenants. The Executive acknowledges that he has
carefully read and considered all the terms and conditions of this Agreement,
including the restraints imposed upon him pursuant to Sections 7 and 8 hereof.
The Executive agrees that said restraints are necessary for the reasonable and
proper protection of the Company and its Affiliates and that each and every one
of the restraints is reasonable in respect to subject matter, length of time and
geographic area. The Executive further acknowledges that, were he to breach any
of the covenants contained in Sections 7 or 8 hereof, the damage to the Company
would be irreparable. The Executive 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
Executive of any of said covenants, without having to post bond. The


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<PAGE>

parties further agree that, in the event that any provision of Section 7 or 8
hereof shall be determined by any court of competent jurisdiction to be
unenforceable by reason of its being extended over too great a time, too large a
geographic area or too great a range of activities, such provision shall be
deemed to be modified to permit its enforcement to the maximum extent permitted
by law.

     12. Conflicting Agreements. The Executive hereby represents and warrants
that the execution of this Agreement and the performance of his obligations
hereunder will not breach or be in conflict with any other agreement to which
the Executive is a party or is bound and that the Executive is not now subject
to any covenants against competition or similar covenants that would affect the
performance of his obligations hereunder. The Executive will not disclose to or
use on behalf of the Company any proprietary information of a third party
without such party's consent.

     13. Indemnification. The Company shall indemnify the Executive to the
extent provided in its then current Articles or By-Laws. The Executive 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.

     14. Definitions. Words or phrases which are initially capitalized or are
within quotation marks shall have the meanings provided in this Section 14 and
as provided elsewhere herein. For purposes of this Agreement, the following
definitions apply:

          (a) "Affiliates" means all persons and entities directly or indirectly
controlling, controlled by or under common control with the Company, where
control may be by either management authority or equity interest.

          (b) "Confidential Information" means any and all information of the
Company and its Affiliates that is not generally known by others. Confidential
Information includes without limitation such information relating to (i) the
development, research, testing, manufacturing, marketing and financial
activities of the Company and its Affiliates, (ii) the Products, (iii) the
costs, sources of supply, financial performance and strategic plans of the
Company and its Affiliates, (iv) the identity and special needs of the customers
of the Company and its Affiliates and (v) the people and organizations with whom
the Company and its Affiliates have business relationships and those
relationships. Confidential Information also includes comparable information
that the Company or any of its Affiliates have received belonging to others or
which was received by the Company or any of its Affiliates with any
understanding that it would not be disclosed.

          (c) "Intellectual Property" means inventions, discoveries,
developments, methods, processes, compositions, works, concepts and ideas
(whether or not patentable or copyrightable or constituting trade secrets)
conceived, made, created, developed or reduced to practice by the Executive
(whether alone or with others, whether or not during normal business hours or on
or off Company premises) during the Executive's employment and during the period
of eighteen (18) months immediately following termination of his employment that
relate to either the Products or any prospective activity of the Company or any
of its Affiliates.


                                      -12-

<PAGE>

          (d) "Person" means an individual, a corporation, an association, a
partnership, an estate, a trust and any other entity or organization, other than
the Company or any of its Affiliates.

          (e) "Products" mean all products planned, researched, developed, under
development, tested, manufactured, sold, licensed, leased or otherwise
distributed or put into use by the Company or any of its Affiliates, together
with all services provided or planned by the Company or any of its Affiliates,
during the Executive's employment.

     15. Withholding. All payments made by the Company under this Agreement
shall be reduced by any tax or other amounts required to be withheld by the
Company under applicable law.

     16. Assignment. Neither the Company nor the Executive may make any
assignment of this Agreement or any interest herein, by operation of law or
otherwise, without the prior written consent of the other; provided, however,
that the Company may assign its rights and obligations under this Agreement
without the consent of the Executive in the event that the Company shall
hereafter affect a reorganization, consolidate with, or merge into, any other
Person or transfer all or substantially all of its properties or assets to any
other Person. This Agreement shall inure to the benefit of and be binding upon
the Company and the Executive, their respective successors, executors,
administrators, heirs and permitted assigns.

     17. Severability. 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.

     18. Waiver. No waiver of any provision hereof shall be effective unless
made in writing and signed by the waiving party. The failure of either party to
require the performance of any term or obligation of this Agreement, or the
waiver by either party of any breach of this Agreement, shall not prevent any
subsequent enforcement of such term or obligation or be deemed a waiver of any
subsequent breach.

     19. Notices. Any and all notices, requests, demands and other
communications provided for by this Agreement shall be in writing and shall be
effective when delivered in person or deposited in the United States mail,
postage prepaid, registered or certified, and addressed to the Executive at his
last known personal address on the books of the Company or, in the case of the
Company, at its principal place of business, attention of Associate General
Counsel, or to such other address as either party may specify by notice to the
other actually received.

     20. Entire Agreement. This Agreement constitutes the entire agreement
between the parties and supersedes all prior communications, agreements and
understandings, written or oral, with respect to the terms and conditions of the
Executive's employment, excluding any


                                      -13-

<PAGE>

obligations with respect to the securities of the Company or the grant
of any stock options and the Employee Nondisclosure Agreement dated December 1,
2005 by and between the Executive and the Company (the "Nondisclosure
Agreement").

     21. Amendment. This Agreement may be amended or modified only by a written
instrument signed by the Executive and by an expressly authorized representative
of the Company.

     22. Headings. The headings and captions in this Agreement are for
convenience only and in no way define or describe the scope or content of any
provision of this Agreement.

     23. Counterparts. This Agreement may be executed in two or more
counterparts, each of which shall be an original and all of which together shall
constitute one and the same instrument.

     24. Governing Law. This is a contract and shall be construed and enforced
under and be governed in all respects by the laws of the Commonwealth of
Massachusetts, without regard to the conflict of laws principles thereof.

IN WITNESS WHEREOF, this Agreement has been executed as a sealed instrument by
the Company, by its duly authorized representative, and by the Executive, as of
the date first above written.

THE EXECUTIVE:                   ANTIGENICS INC.


/s/ Garo H. Armen                By: /s/ Wadih Jordan
------------------------------       -----------------------------------------
                                 Title: Chairman of the Compensation Committee
                                        --------------------------------------


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