Document:

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                                                                    Exhibit 10.3

                                     KASHKIN
                              EMPLOYMENT AGREEMENT

         EMPLOYMENT AGREEMENT (as it may be amended from time to time,
"Agreement") made and entered into as of September 21, 2000 (the "Effective
Date"), by and between GENAISSANCE PHARMACEUTICALS, INC. (the "Corporation"), a
Delaware corporation with its principal office at 5 Science Park, New Haven,
Connecticut, 06511, and KENNETH B. KASHKIN, M.D. ("Executive"), an individual
who resides at 8 Hemlock Terrace, Sparta, New Jersey 07871.

         WHEREAS, the Corporation desires to employ Executive, and Executive
desires to accept employment with the Corporation, subject to the terms and
conditions hereinafter set forth.

         NOW, THEREFORE, in consideration of the mutual covenants and agreements
contained herein, and other good and valuable consideration, the receipt and
sufficiency of which is hereby acknowledged, the parties agree as follows:

         1.       EMPLOYMENT. Executive shall be employed as an officer in the
capacity of Executive Vice President ("EVP"), Chief Medical Officer ("CMO") of
the Corporation during the term of this Agreement, and Executive hereby accepts
such employment, on the terms and conditions hereinafter set forth. Executive
represents that his employment by the Corporation pursuant to this Agreement
does not violate any agreement, covenant or obligation to which he is a party or
by which he is bound.

         2.       DUTIES. During the term of this Agreement, Executive shall
devote his full business time and best efforts to the advancement of the
interests and business of the Corporation, and he shall perform all duties,
consistent with his position as EVP/CMO in order to advance the Corporation's
business efforts, assigned or delegated to him by the Chief Executive Officer of
the Corporation or his delegate (the "CEO"), and normally associated with the
position of EVP/CMO, including, without limitation:

                  a.       Responsibility and direction for all (i) clinical
research conducted by the Corporation and medical affiliates, which shall
include each of Clinical Discovery and Clinical Development, as hereinafter
defined and (ii) Medical Affairs, as hereinafter defined, including planning and
implementing of all the Corporation's Mednostics-TM- programs as well as
directing all of the Corporation's HAP2000 member clinical programs and review
of and participation in all matters related to Clinical Discovery, Clinical
Development and Medical Affairs for all the Corporation's medical affiliates.

                  b.       The creation and oversight of a project management
system whereby the Corporation organizes, manages and tracks all of its
interdisciplinary or interfunctional clinical projects.

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                  c.       Managing all of the Corporation's matters related to
the interface between the Corporation and the United States Food and Drug
Administration.

                  d.       Review of, and participation in, the Corporation's
business development efforts.

                  e.       Serving on the Corporation's executive (or successor
management) committee consisting of the Corporation's senior executives.

         3.       TERM. The Executive's work will be based in the Corporation's
headquarters in New Haven, Connecticut. The term of Executive's employment under
this Agreement shall begin on the Effective Date and shall expire at the close
of business on September 21, 2004, unless earlier terminated as provided in this
Agreement (the "Initial Term"). Upon expiration of the Initial Term, and each
subsequent term or extension thereof, this Agreement shall automatically be
extended for an additional term of one (1) year, unless Executive or the
Corporation shall have notified the other of his or its election to terminate
this Agreement not later than sixty (60) days prior to the end of such
subsequent term or extension thereof (the "Initial Term", together with any
extensions, until termination in accordance herewith, shall be referred to
herein as the "Employment Term"). If the Executive continues in the full-time
employ of the Corporation after the end of the Employment Term (it being
expressly understood and agreed that the Corporation does not now, nor hereafter
shall have, any obligation to continue the Executive in its employ, whether or
not on a full-time basis, after the Employment Term ends), then the Executive's
continued employment by the Corporation shall, notwithstanding anything to the
contrary expressed or implied herein, be terminable by the Corporation at will.

         4.       COMPENSATION. As compensation for the services to be rendered
by Executive to the Corporation pursuant to this Agreement, the Corporation
shall pay Executive and provide Executive with the following compensation and
benefits which Executive agrees to accept in full satisfaction for his services:

                  a.       BASE SALARY. The Corporation shall pay Executive a
base salary, payable in equal installments at such payment intervals as are the
usual custom of the Corporation, but not less often than monthly, at an annual
rate of $250,000, less such deductions or amounts to be withheld as shall be
required by applicable law (the "Base Salary"). The Base Salary shall be
reviewed annually by the CEO and shall be increased, if at all, (effective as of
each successive anniversary of the Effective Date) by such amount, if any, as
the CEO, in his sole discretion, shall determine.

                  b.       BONUSES. Beginning in the year 2001, during the first
quarter of each of the Corporation's fiscal years during the Employment Term,
the Corporation shall pay Executive a bonus (an "Incentive Bonus") equal to up
to 50% of his Base Salary, which amount shall be determined by the CEO in his
sole discretion based upon Executive's achievements in meeting his performance
goals and those of the Corporation for its most recently ended fiscal year. For
the fiscal year ending December 31, 2000, such goals shall be established as of
the Effective Date and any Incentive Bonus payable thereafter for said fiscal
year 2000 shall be prorated from September

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13, 2000 through December 31, 2000. Thereafter, such goals shall be established
in the first quarter of each fiscal year after the commencement of the
Employment Term.

                  c.       BENEFITS.

                           (i) Executive shall be entitled to participate, to
                  the extent he is eligible, in all group insurance programs,
                  health, medical, dental, and disability plans, and other
                  employee benefit programs and plans (including, without
                  limitation, the Corporation's 401(k) plan) which the
                  Corporation may hereafter in its sole and absolute discretion
                  make available generally to its senior management (including
                  any incentive compensation or equity ownership plan, PROVIDED,
                  the terms of his participation therein shall be at the
                  discretion of the Corporation's compensation committee of the
                  board of directors), but the Corporation shall not be required
                  to establish or maintain any such program or plan.

                           (ii) Executive shall be entitled to three (3) weeks
                  paid vacation during each calendar year. Such vacation shall
                  accrue ratably throughout each year and may be taken at such
                  time or times as is reasonably consistent with the
                  Corporation's vacation policies and the performance by
                  Executive of his duties and responsibilities hereunder. During
                  the balance of the calendar year 2000, Executive shall be
                  entitled to one week paid vacation.

                           (iii) Executive shall be entitled to participate in
                  the Corporation's Stock Option Plan and any successor plan
                  (the "Plan") with respect to his future performance as a
                  senior executive of the Corporation.

                           (iv) The Corporation shall, during the Employment
                  Term, pay the premiums for a $1,000,000 policy of term life
                  insurance insuring the life of Executive (subject to his
                  meeting the insurability requirements of the insurer). The
                  Corporation shall pay the premiums for such insurance policy
                  up to the cost charged by the insurer to insure a healthy male
                  non-smoker of Executive's then current age. Executive shall be
                  the owner of such policy and entitled to all of the rights of
                  ownership including designation of the beneficiary thereof.

                           (v) The Corporation shall provide Executive with a
                  policy of long-term disability insurance with reasonable
                  coverages, which shall include the payment of benefits equal
                  to at least 60% of Executive's Base Salary during the
                  disability coverage period, and the Corporation shall pay the
                  premiums for such disability insurance policy up to the cost
                  charged by the insurer to insure a healthy male non-smoker of
                  Executive's then current age.

                           (vi) Subject to reasonable guidelines adopted by the
                  board of directors, throughout the Employment Term, the
                  Corporation shall pay the costs of dues for Executive's
                  membership in at least one professional organization whose
                  activities are related to the business of the Corporation.

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                           (vii) The Corporation, at its expense, shall pay or
                  reimburse Executive for all reasonable moving expenses
                  attributable to the relocation of the Executive from Sparta,
                  New Jersey to Connecticut or surrounding locale including, but
                  not limited to the costs of movers, brokers fees, legal fees
                  associated with a sale or purchase of a residence, bank
                  charges, origination fees, title insurance fees and charges,
                  recording costs and similar expenses of such move. At or about
                  the commencement of the Employment Term, the Corporation, at
                  its expense, shall provide Executive with a furnished
                  apartment or executive suite in the New Haven area until the
                  Executive and his family relocate.

         5.       BUSINESS EXPENSES. The Corporation shall pay or reimburse
Executive for the reasonable and necessary business expenses of Executive
incurred in the performance of his duties hereunder, subject to reasonable
documentation thereof and the reasonable rules and regulations of the
Corporation relating thereto.

         6.       COVENANTS AGAINST COMPETITION.

                  a.       In view of the unique value to the Corporation of the
services of Executive, and as a material inducement to the Corporation to enter
into this Agreement and to pay to Executive the compensation and benefits set
forth in this Agreement, Executive covenants and agrees that during Executive's
employment and for a period of twelve (12) months after he ceases to be employed
by the Corporation if his employment ends prior to the expiration of the
Employment Term, he will not, except as otherwise authorized by this Agreement,
compete (as defined hereafter) in the field of pharmacogenomics with the
Corporation or any affiliate (as defined hereafter) of the Corporation, solicit
the Corporation's customers (as defined hereafter) or the customers of any of
its affiliates in the field of pharmacogenomics, or directly or indirectly
solicit for employment any of the Corporation's employees.

                  b.       None of the provisions of this Section 6 shall
prohibit Executive from investing in securities listed on a national securities
exchange or actively traded over-the-counter so long as such investments are not
greater than five percent (5%) of the outstanding securities of any issuer of
the same class or issue.

         7.       REASONABLENESS OF RESTRICTIONS.

                  a.       Executive has carefully read and considered the
provisions of Section 6, and, having done so, agrees that:

                           (i) The restrictions set forth in Section 6,
                  including but not limited to the time period, scope and
                  geographical area of restriction, are fair and reasonable and
                  are reasonably required for the protection of the good will
                  and other legitimate business interests of the Corporation and
                  its affiliates, officers, directors, shareholders, and other
                  employees;

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                           (ii) Executive has received, or is entitled to
                  receive pursuant to the provisions of this Agreement, adequate
                  consideration for such obligations; and

                           (iii) Such obligations do not prevent Executive from
                  earning a livelihood.

                  b.       If, notwithstanding the foregoing, any of the
provisions of Section 6 shall be held to be invalid or unenforceable, the
remaining provisions thereof shall nevertheless continue to be valid and
enforceable as though the invalid and unenforceable parts had not been included
therein. If any provision of Section 6 relating to the time period and/or the
areas of restriction and/or related aspects shall be declared by a court of
competent jurisdiction to exceed the maximum restrictiveness such court deems
reasonable and enforceable, the time period and/or areas of restriction and/or
related aspects deemed reasonable and enforceable by the court shall become and
thereafter be the maximum restriction in such regard, and the restriction shall
remain enforceable to the fullest extent deemed reasonable by such court.

         8.       REMEDIES FOR BREACH OF EXECUTIVE'S COVENANT OF
NON-COMPETITION. Executive recognizes and agrees that the Corporation would
suffer irreparable harm due to any breach of Section 6 and that the
Corporation's remedy at law for any such breach would be inadequate, and he
agrees that, for breach of such provisions, the Corporation shall, in addition
to such other remedies as may be available to it at law or in equity or as
provided in this Agreement, be entitled to injunctive relief and to enforce its
rights by an action for specific performance.

         9.       TERMINATION.

                  a.       In the event that Executive dies during the
Employment Term, this Agreement shall terminate upon his death, upon which event
Executive's legal representatives shall be entitled to receive, and the
Corporation shall pay or cause to be paid to Executive's legal representatives,
any Base Salary and other compensation or benefits accrued but as yet unpaid on
the date of Executive's death.

                  b.       If during the Employment Term, Executive is prevented
from performing the duties or fulfilling responsibilities of his employment
under this Agreement by reason of any incapacity or disability for a continuous
period of six (6) months, as determined by an independent qualified physician
selected by the Corporation and reasonably acceptable to Executive (or his
representative), then the Corporation may, upon thirty (30) days prior written
notice to Executive, terminate Executive's employment hereunder, provided
Executive shall continue to be eligible to receive any benefits to which he may
be entitled under the terms of any disability plan or insurance policy
maintained by the Corporation for its employees generally or for Executive
specifically. In the event of such incapacity or disability, the Corporation
shall continue to pay full compensation to Executive in accordance with the
terms of this Agreement until the date of such termination, less any amounts
received by the Executive under any disability plan maintained by the
Corporation.

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                  c.       The Corporation may, upon written notice to
Executive, terminate Executive's employment hereunder For Cause. For purposes of
this Agreement, the term "For Cause" shall mean:

                           (i) A willful and material breach by Executive of his
                  duties hereunder;

                           (ii) Executive's conviction of any felony, or of a
                  lesser crime having as its predicate element fraud, dishonesty
                  or misappropriation of property of the Corporation;

                           (iii) Executive's failure, after having received
                  notice and reasonable opportunity to cure, to adequately
                  fulfill his duties set forth hereunder for whatever reason,
                  including without limitation, Executive's engaging in bad
                  faith or gross negligence in the performance of his duties
                  under this Agreement as determined in good faith by the board
                  of directors;

                           (iv) Executive's engaging in chronic alcoholism, drug
                  addiction or substance abuse which has interfered with the
                  performance of his duties under this Agreement; and/or

                           (v) Executive's perpetration of any act or omission
                  which submits the Corporation to criminal liability.

         In the event of termination For Cause of Executive's employment,
Executive's right to receive compensation and other benefits hereunder (other
than any Base Salary accrued but as yet unpaid on the effective date of such
termination) shall terminate on the effective date of such termination, and
Executive shall not be entitled to any severance payments or benefits pursuant
to Section 10.

         d.       The Corporation may, at any time, for reason other than For
Cause, terminate Executive's employment upon at least thirty (30) days written
notice to Executive. In the event of such termination for reason other than For
Cause, the Corporation shall be obligated to pay Executive the severance
payments specified in Section 10.

         e.       Executive may, at his option, upon sixty (60) days prior
written notice to the Corporation, terminate his employment hereunder. In the
event of a voluntary termination of his employment by the Executive pursuant to
this Section 9(e), Executive's rights to receive compensation and other benefits
(other than any Base Salary, vacation pay, and stock options, accrued but as yet
unpaid on the effective date of such termination) shall terminate on the
effective date of such termination, and Executive shall be entitled to payment
of each of the above on his termination date but shall not be entitled to any
severance payments pursuant to Section 10.

         f.       Executive may, at his option, upon at least fifteen (15) days
written notice to the Corporation, terminate his employment hereunder, if the
Corporation, without Executive's express written consent, (i) demotes him from
Executive Vice President, Chief Medical Officer, (ii)

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assigns him duties materially inconsistent with the position and/or duties
described in Sections 1 or 2, (iii) diminishes his responsibilities described in
Sections 1 or 2, (iv) relocates him to an office other than the Corporation's
headquarters, unless he consents thereto in writing, or (v) breaches any
material obligations to Executive under this Agreement. Upon any termination by
Executive under this Section 9(f) the Corporation shall be obligated to pay
Executive the severance payments specified in Section 10.

         g.       In the event of termination or expiration of Executive's
employment other than for death, Executive shall resign from all positions held
in the Corporation, including without limitation any position as a director,
officer, agent, trustee or consultant of the Corporation or any affiliate of the
Corporation.

         10.      SEVERANCE PAYMENTS.

                  a.       If the Corporation terminates Executive's employment
         pursuant to Section 9(d) or if Executive terminates his employment
         pursuant to Section 9(f), the parties recognize and agree that actual
         damages due Executive would be difficult if not impossible to ascertain
         and agree that, in lieu of any other rights to which Executive may be
         entitled (but not in lieu of any rights or remedies that Executive may
         have in respect of tortious conduct on the part of the Corporation or
         in respect of any violation by the Corporation of any employment
         practice, employment discrimination, age discrimination or civil rights
         law or regulation applicable to the Executive), the Corporation shall,
         as severance pay or as liquidated damages, or both, (i) pay to
         Executive, Executive's Base Salary, as in effect at the time of such
         termination or expiration for a period of one year following the date
         of such termination or expiration, such payments to be made in the same
         manner in which such salary payments were made to Executive immediately
         prior to the date of such termination or expiration; (ii) cause
         Executive to immediately vest in all stock options which he has been
         granted; and (iii) cause all loans from the Corporation to the
         Executive to be immediately deemed to be forgiven. Under no
         circumstances shall severance payments be reduced in the event
         Executive obtains other employment.

                  b.       In the event substantially all of the assets of the
         Corporation or all of its capital stock is acquired by an unrelated
         entity (the "Acquisition"), then all stock options granted to Executive
         by the Corporation shall vest immediately upon the consummation of the
         Acquisition.

         11.      WAIVER. A party's failure to insist on compliance or
enforcement of any provision of this Agreement shall not affect the validity or
enforceability or constitute a waiver of future enforcement of that provision or
of any other provision of this Agreement by that party or any other party.

         12.      GOVERNING LAW. This Agreement shall in all respects be subject
to, and governed by, the laws of the State of Connecticut.

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         13.      SEVERABILITY. The invalidity or unenforceability of any
provision in the Agreement shall not in any way affect the validity or
enforceability of any other provision and this Agreement shall be construed in
all respects as if such invalid or unenforceable provision had never been in the
Agreement.

         14.      NOTICE. Any and all notices required or permitted herein shall
be in writing and shall be deemed to have been duly given (a) when delivered if
delivered personally, (b) on the fifth day following the date of deposit in the
United States mail if sent first class, postage prepaid, by registered or
certified mail, or (c) one day after delivery to a nationally recognized
overnight courier service. The parties' respective addresses for such notices
shall be those set forth following their respective signatures below, or such
other address or addresses as either party may hereafter designate in writing to
the other.

         15.      ASSIGNMENT. This Agreement, together with any amendments
hereto, shall be binding upon and shall inure to the benefit of the parties
hereto and their respective successors, assigns, heirs, executors, and legal and
personal representatives, except that the rights and benefits of Executive under
this Agreement may not be assigned or delegated without the prior written
consent of the Corporation. Without limiting the generality of the foregoing,
this Agreement shall be binding upon and inure to the benefit of any corporation
with which or into which the Corporation or its successors may be merged or
which may succeed to its assets or business.

         16.      AMENDMENTS. This Agreement may be amended at any time by
mutual consent of the parties hereto, with any such amendment to be invalid
unless in writing and signed by the Corporation and Executive.

         17.      ENTIRE AGREEMENT. This Agreement and the agreements concerning
stock option grants and confidentiality and non-disclosure executed in
connection herewith contain the entire agreement and understanding by and
between Executive and the Corporation with respect to the employment of
Executive and supersede all existing agreements between the Corporation and
Executive with respect to such employment. No representations, promises,
agreements, or understandings, written or oral, relating to the employment of
Executive by the Corporation not contained herein shall be of any force or
effect.

         18.      REFERENCES TO GENDER AND NUMBER TERMS. In construing this
Agreement, feminine or number pronouns shall be substituted for those masculine
in form and vice versa, and plural terms shall be substituted for singular and
singular for plural in any place in which the context so requires.

         19.      COUNTERPARTS; HEADINGS; SECTIONS. This Agreement may be
executed in multiple counterparts, each of which shall be considered to have the
force and effect of any original but all of which taken together shall
constitute but one and the same instrument. The various headings in this
Agreement are inserted for convenience only and are not part of the Agreement.
All references to "Sections" and "paragraphs" in this Agreement refer to the
various corresponding sections and paragraphs of this Agreement.

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         20.      SURVIVAL. The covenants and agreements contained in Sections 6
through 10 shall survive any termination or expiration of this Agreement and the
termination of Executive's employment hereunder.

         21.      ARBITRATION. Executive and the Corporation will submit any
disputes arising under this Agreement to an arbitration panel, consisting of one
or more natural persons (as set forth below) each of whom has experience
arbitrating employment disputes involving executives, conducting a binding
arbitration in New Haven, Connecticut, administered by the AAA (as defined
hereafter) and in accordance with the Commercial Arbitration Rules of the
American Arbitration Association ("AAA") in effect on the date of such
arbitration (the "Rules"), and judgment upon the award rendered by the
arbitrator or arbitrators may be entered in any court having jurisdiction
thereof; PROVIDED, HOWEVER, that nothing herein shall impair the Corporation's
right to seek equitable relief from a court of competent jurisdiction for breach
or threatened breach of Section 7 or Section 8. The award of the arbitrators
shall be final and shall be the sole and exclusive remedy between the parties
regarding any claims, counterclaims, issue or accounting presented to the
arbitration panel. The parties hereto further agree that the arbitration panel
shall consist of one (1) person mutually acceptable to the Corporation and
Executive, PROVIDED, THAT, if the parties cannot agree on an arbitrator within
fifteen (15) days of filing a notice of arbitration, the arbitration panel shall
consist of three (3) persons, one selected by the Corporation, one selected by
Executive (or his representative) and one selected by the arbitrators so
selected by the parties hereto, or if the parties hereto cannot agree, selected
by the manager of the principal office of the American Arbitration Association
in Hartford County in the State of Connecticut. All fees and expenses of the
arbitration charged by the AAA, including a transcript if either party requests,
shall be borne equally by the parties. If Executive prevails as to any material
issue presented in the arbitration, the entire cost of such proceedings
(including, without limitation, Executive's reasonable attorney's fees but
excluding the fees and expenses charged by the AAA) shall be borne by the
Corporation. If Executive does not prevail as to any material issue, each party
will pay for the fees and expenses of its own attorneys, experts, witnesses, and
preparation and presentation of proofs and post-hearing briefs (unless the party
prevails on a claim for which attorney's fees are recoverable under the Rules).
Any action to enforce or vacate the arbitrator's award shall be governed by the
federal Arbitration Act, if applicable, and otherwise by applicable state law.
If either the Corporation or Executive pursues any claim, dispute or controversy
against the other in a proceeding other than the arbitration provided for
herein, the responding party shall be entitled to dismissal or injunctive relief
regarding such action and recovery of all costs, losses and attorney's fees
related to such action.

         22.      DEFINITIONS. Definitions for the purposes of this Agreement:

                  a.       The term "compete" means engaging in the same or any
similar business as the Corporation or any of its affiliates in any manner
whatsoever, including without limitation as a proprietor, partner, investor,
shareholder, member, director, officer, employee, consultant, independent
contractor or otherwise, within any geographic area in which the Corporation's
products are offered or distributed.

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                  b.       The term "medical affiliate", when used in reference
to any Person (as hereinafter defined), means any other Person that directly or
indirectly through one or more intermediaries is controlled by the first such
Person or for which Person the Corporation is to be under contractual control of
such Person's Clinical Discovery, Clinical Development or Medical Affairs.

                  c.       The term "affiliate", when used in reference to any
Person (as hereinafter defined), means any other Person that directly or
indirectly through one or more intermediaries controls, is controlled by or is
under common control with, the first such Person.

                  d.       The term "customers" means all Persons to whom the
Corporation or any of its affiliates has provided any product or service,
whether or not for compensation, within a period of two (2) years prior to the
time Executive ceases to be employed by the Corporation.

                  e.       The term "Person" means any natural person,
corporation, limited liability company, partnership of any type, proprietorship,
other business organization, trust, union, association or governmental body.

                  f.       The term "Clinical Discovery" means the act or acts
of research involving the production and analysis of data on human subjects,
patients, or volunteers, and attempting to discover the relationships of genetic
variations to diseases and drug responses.

                  g.       The term "Clinical Development" means the process of
confirming Clinical Discoveries and incorporating therewith genetic guided
medical research in Phases I - IV of traditional drug development.

                  h.       The term "Medical Affairs" means clinical programs
for drugs either in development or which are being currently marketed, including
pharmaco and medical economics.

         IN WITNESS WHEREOF, the Corporation and Executive have duly executed
this Agreement as of the day and year first above written.

                                            CORPORATION:
                                            GENAISSANCE PHARMACEUTICALS, INC.

                                            By:/s/ Gualberto Ruano
                                               ---------------------------------
                                            Name: Gualberto Ruano
                                            Its:  President

                                            Address for Notice Purposes:
                                            5 Science Park
                                            Suite 2103
                                            New Haven, CT 06511

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                                            EXECUTIVE:

                                            /s/ Kenneth B. Kashkin
                                            ------------------------------------
                                            KENNETH B. KASHKIN, M.D.

                                            Address for Notice Purposes:
                                            8 Hemlock Terrace
                                            Sparta, New Jersey

                                            and

                                            Edward P. McKenzie, Esq.
                                            Graham, Curtin & Sheridan, P.A.
                                            P.O. Box 1991
                                            4 Headquarters Plaza
                                            Morristown, NJ 07932

                                      -11-<PAGE>

                                                                    Exhibit 10.4

$240,000                      New Haven, Connecticut              August 1, 2000

         For value received, KENNETH B. KASHKIN, M.D. ("MAKER"), of Sparta, New
Jersey, hereby promises to pay to GENAISSANCE PHARMACEUTICALS, INC., a Delaware
corporation (the "Company"), or order, five (5) years from date, the principal
sum of TWO HUNDRED FORTY THOUSAND DOLLARS ($240,000), with interest from the
date hereof on said principal sum, or the unpaid balance thereof from time to
time outstanding, payable in equal annual installments of principal and
interest, on each anniversary of the date of this Note, at the applicable
federal rate per annum effective on the date hereof, together with all costs,
including reasonable attorneys' fees, incurred in the collection of this Note,
or in any proceedings to otherwise enforce or protect this Note; provided that,
if not sooner paid, the entire unpaid principal amount of this Note, with all
accrued and unpaid interest thereon, shall be due and payable on the fifth
anniversary of the date of this Note.

         (1) Both the principal of and interest on this Note shall be payable in
lawful money of the United States of America, at the principal office of the
Company, 5 Science Park, New Haven, Connecticut 06511, or at such other place as
the holder hereof, from time to time or at any time, shall designate in writing.

         (2) This Note may be prepaid at any time, in whole or in part, without
premium or penalty but with accrued interest on the amount being so prepaid.

         (3) This Note is secured by a Stock Pledge Agreement, of even date (the
"Pledge Agreement"), between the Maker and the Company, pursuant to which the
Maker has pledged to the Company certain shares of stock of the Company.

         (4) The entire unpaid principal amount of this Note and all accrued and
unpaid interest thereon shall become due and payable on demand of the holder
hereof if any one or more of the following "events of default" shall occur:

                  (a) default in the payment of any installment of the interest
on this Note when and as the same becomes due and payable and the continuance
thereof for a period of ten (10) days;

                  (b) default in the due observance or performance of any of the
covenants or agreements on the part of the Maker hereof contained in Maker's
employment agreement with the Company, and/or under the Pledge Agreement and the
continuance thereof for thirty (30) days after written notice shall have been
given to the maker hereof by the holder hereof; or

                  (c) The Maker (i) shall be adjudicated a bankrupt or
insolvent, or (ii) is unable, or admits in writing, his inability to pay his
debts as they mature or calls a meeting of his creditors, or (iii) files a
voluntary petition in bankruptcy or a petition or an answer seeking a
composition or an arrangement with creditors or to take advantage of any
insolvency law, or an

<PAGE>

answer admitting the material allegations of a petition filed against him in any
bankruptcy or insolvency proceedings.

         (5) No course of dealing between the Maker and the holder of this Note
shall operate as a waiver of any right of such holder, and no delay on the part
of the holder hereof in exercising any right hereunder shall operate as such a
waiver.

         (6) All of the promises, agreements and stipulations by the Maker
hereof in this Note contained shall bind his heirs, executors, administrators
and assigns, whether or not so expressed.

         (7) This Note shall be construed in accordance with and governed by the
laws of the State of Connecticut, without regard to its conflict of laws rules.

         (8) Maker hereby irrevocably submits, for himself and his property, to
the nonexclusive jurisdiction of any Connecticut State or United States Federal
court sitting in the State of Connecticut, and any appellate court from any
thereof, in any action or proceeding arising out of or relating to this Note, or
for recognition or enforcement of any judgment, and Maker hereby irrevocably and
unconditionally agrees that all claims in respect to such action or proceeding
may be heard and determined in such Connecticut State or Federal court.

         IN WITNESS WHEREOF, KENNETH B. KASHKIN, M.D. has signed and dated this
Note on the day and year first above written.

                                            /s/ Kenneth B. Kashkin
                                            ------------------------------------
                                            Kenneth B. Kashkin

                                      -2-

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