Exhibit 10.73

                          IMCLONE SYSTEMS INCORPORATED

                              EMPLOYMENT AGREEMENT

                                      with

                              DR. CARL GOLDFISCHER


AGREEMENT entered into as of May 17, 1996 between CARL GOLDFISCHER residing at
161 West 61st Street, New York, U.S.A. ("Employee"), and IMCLONE SYSTEMS
INCORPORATED ("ImClone" or the "Company"), a company organized under the laws of
the State of Delaware.

                                   WITNESSETH:

WHEREAS, ImClone is in the business of biopharmaceutical research and
development (the "Business"); and

WHEREAS, ImClone desires to employ Employee as its Chief Financial Officer and
Vice-President of Finance and Strategic Planning at ImClone.

NOW THEREFORE, in consideration of the premises and mutual agreements
hereinafter contained, the parties hereto agree as follows:

1.   Employment. With effect from the Effective Date (as defined in Section
3.1), ImClone employs Employee and Employee accepts employment with ImClone upon
the terms and conditions set forth herein.

2.   Duties.

2.1  ImClone hereby engages Employee to serve as Vice-President of Finance and
Strategic Planning and Chief Financial Officer of ImClone responsible for the
day to day financial reporting and control and strategic planning of ImClone
according to the general direction of the Company's Chief Executive Officer.

2.2  Employee shall devote his full business time and attention to the Business
of the Company and shall perform his duties diligently and promptly for the
benefit of ImClone. During his engagement hereunder, Employee shall not
undertake or accept any other paid or unpaid employment or occupation or engage
in or be associated with, directly or indirectly any other businesses, duties or
pursuits except for the de minimis non-commercial or non-business activities,
without prior written consent of the CEO of the Company.


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2.3  Employee shall report regularly to the CEO and Board of Directors of the
Company or as otherwise requested by the Board, in accordance with Company
policy.

3.   Term.

3.1  Employee's employment under this Agreement shall commence on May 20, 1996
(the "Effective Date") and shall end on the earliest of: (i) the death or
disability (as defined herein) of Employee; (ii) termination of employment by
the Company with cause (as defined herein); (iii) termination of empoyment by
the Company without cause (as defined herein); (iv) the termination of
Employee's employment by Employee after providing ninety (90) days advance
notice or such lesser written notice as Employer shall at the time accept; or
(v) two (2) years from the Effective Date of this Agreement ("Initial Term").
Employee, or his heirs, executors, personal representatives or assigns, shall
not be entitled to any compensation after expiration of period of notice of
termination of employment, including with respect to bonus, other than as
specifically set forth in Section 8.1 herein. In the event the Employee's
employment under this Agreement continues until the expiration of the Initial
Term, the term may be extended by written agreement of the parties ("Extended
Term").

3.2  For the purpose of this Agreement, "disability" shall mean any physical or
mental illness or injury as a result of which (1) Employee remains absent from
work for a period of two successive months, or an aggregate of two months in any
twelve month period or, (2) the Employee is deemed unable to perform the
essential functions of his employment, with or without accomodation, as
documented by a physician in writing.

3.3  For the purpose of this Agreement, "cause" shall exist if Employee (i)
breaches the terms of this Agreement; (ii) engages in willful misconduct or acts
in bad faith with respect to ImClone in connection with and related to the
employment hereunder; (iii) is subjected to criminal indictment or the filing of
information for a felony or is held liable by a court of competent jurisdiction
for fraud against ImClone; or (iv) fails to comply with the instructions of the
Company's Board of Directors or CEO given in good faith; provided that, with
respect to clauses (i) and (iv), if Employee has cured any such condition (that
is reasonably susceptible to cure) within 10 business days of the advance notice
(as defined herein) then "cause" shall be deemed not to exist. For purposes of
this paragraph 3.3, "advance notice" shall constitute a written notice delivered
to Employee that sets forth with particularity the facts and circumstances
relied on by ImClone as the basis for cause.

3.4  During the period following notice of termination by any party for any
reason, the Employee shall, if and to the degree requested by ImClone, cooperate
with ImClone and use his

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best efforts to assist the integration into the ImClone organization of the
person or persons who will assume the Employee's responsibilities.

4.   Compensation.

4.1  During the Employee's employment under this Agreement and subject to the
performance of the services required to be performed hereunder by Employee,
ImClone shall pay to Employee for all services rendered by Employee under this
Agreement an annual gross salary paid in accordance with ImClone's normal and
reasonable payroll practices of $175,000 exclusive of amounts payable by the
Company for the benefits set forth in paragraph 4.2 (the "Gross Salary").

4.2  The Employee shall be eligible to participate in ImClone's contributory
comprehensive health plan, including major medical, hospitalization, life,
disability and dental insurance currently offered by the Company through the
Guardian Life Insurance Company. Employee will also be eligible to participate
in the ImClone 401K Employee Savings Plan, to the degree allowable under the
Company's plan document and appropriate regulations.

4.3  At the end of his first year of employment, Employee will receive a bonus
in the amount of $75,000, and at the end of the second year of employment, and
any renewable term thereafter, Employee shall be entitled to receive a bonus, as
determined by the Board of Directors, based upon Company practices.

5.   Expenses. Employee may incur reasonable expenses in connection with the
performance of his duties, including expense for entertainment, travel and
similar items. ImClone will reimburse Employee for all business expenses after
Employee presents an itemized account of expenditures, together with receipts,
vouchers and other supporting material, subject to ImClone's approval. Per diem
allowances and petty cash advances shall be in accordance with ImClone's
standard policy as agreed to by the CEO and/or the Board of Directors of the
Company from time to time.

6.   Vacation. Employee shall be entitled to 20 working days of paid vacation
during each year that this Agreement is in effect, to be taken at times subject
to the reasonable approval of ImClone. Vacation time may not be accumulated and
Employee shall forfeit any unused vacation remaining at the end of each year.

7.   Participation in Stock Option Plans. Employee shall receive options to
purchase 225,000 shares of the Company at an exercise price equal to the average
closing trading price of ImClone stock for the sixty days through April 24,
1996. Of these options, 50,000 shall be immediately exercisable, and the
remainder shall vest equally over a three year period from the Effective Date,
such that one-third shall vest on each of the first, second, and third
anniversaries of the Effective Date. In accordance with the terms of ImClone's
stock option plans, vested options which have not been exercised upon
termination of employment shall not be exercisable and shall revert to the
Company.

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8.   Termination of Employment by Company without Cause

8.1  In the event this Agreement is terminated by the Company without cause
under Section 3.1 (iii) hereof during the Initial Term or any Extended Term, as
defined in Section 3.1 above, in addition to any right to notice described
herein, the Employee shall have the right to receive amounts equal to the Gross
Salary and to receive reimbursement for the purchase of benefits equal to those
set forth in Section 4.2 for the following periods, which shall be the sole
remedy available to the Employee as a result of such termination. Employee's
employment shall be deemed terminated upon the expiration of the notice period
given with respect to such termination.

(i)   in the event termination is effective during 1996 - 2 months;
(ii)  in the event termination is effective during 1997 - 10 months; and
(iii) in the event termination is effective after January 1, 1998 - 12 months.

8.2  Employee's rights pursuant to this section 8 shall apply only in the event
this Agreement is terminated by the Company without cause under Section 3.1
(iii). For purposes of this section, termination by the Company without cause
shall be deemed to include termination of this Agreement by the Employee due to:
(1) the disposing of all or substantially all of the Company's property,
business or assets; or (2) the consolidation with or merger of the Company into
another corporation, resulting in a shift in voting control of more than 75% of
the Company's shares.

9.   Secrecy and Nondisclosure. The Employee shall treat as secret and
confidential all of the processes, methods, formulas, procedures, techniques,
software, designs, data, drawings and other information which are not of public
knowledge or record pertaining to ImClone's Business (existing, potential and
future), including without limitation, all business information relating to
customers and suppliers and products of which the Employee becomes aware during
and as a result of his employment or association with ImClone, and Employee
shall not disclose, use, publish, or in any other manner reveal, directly or
indirectly, at any time during or after the term of this Agreement, any such
processes, methods, formulas, procedures, techniques, software, designs, data,
drawings and other information pertaining to ImClone's existing or future
Business or products. The Employee may disclose or use such information, if at
all, only with the prior express written consent of ImClone. The Employee also
agrees to enter into ImClone's Discovery and Non-Disclosure Agreement, a copy of
which is attached hereto.

10.  Non-Competition.

10.1 Employee agrees that during the term of this Agreement and any extensions
hereof and for a period of one (1) year after he ceases to be employed by
ImClone he will not, directly or indirectly, for his own account or as an
employee, officer, director, partner, joint venturer, shareholder, investor,
consultant or otherwise (except as an investor in a corporation whose stock is
publicly traded and in which Employee holds less than 5% of the outstanding
shares) interest himself in or engage in any business or enterprise, anywhere in
the world, that directly or indirectly competes with the Business of ImClone,
that exists now or in the future during the 

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term of this Agreement or is proposed by ImClone prior to the time of
termination or is based on similar technology to that of ImClone.

10.2 Employee agrees that during a period of one year from termination of this
Agreement or any extension hereof he shall not employ directly or indirectly any
individual then employed by the Company.

10.3 Employee acknowledges that the restricted period of time and geographical
area specified under paragraph 10.1 hereof are reasonable, in view of the nature
of the business in which ImClone is engaged and Employee's knowledge of
ImClone's Business and products.

10.4 Notwithstanding anything contained in paragraph 10.3 to the contrary, if
the period of time or the geographical area specified under paragraph 10.1
hereof should be determined to be unreasonable in any judicial proceeding, then
the period of time and area of the restriction shall be reduced so that this
Agreement may be enforced in such area and during such period of time as shall
be determined to be reasonable by such judicial proceeding.

11.  Development  Rights.  The Employee agrees and declares that all proprietary
information including but not limited to trade secrets and know-how, patents and
other rights in connection  therewith  developed by or with the  contribution of
Employee's  efforts  during his employment by ImClone shall be the sole property
of ImClone and the Employee shall execute all documents  necessary to assign any
patents to ImClone and otherwise transfer such proprietary rights to ImClone.

12.  Employee Representations. The Employee represents and warrants to ImClone
that the execution and delivery of this Agreement and the fulfillment of the
terms hereof (i) will not constitute a default under or breach of any agreement
or other instrument to which he is a party or by which he is bound, including
without limitation, any confidentiality or noncompetition agreement, (ii) do not
require the consent of any person or entity, and (iii) shall not utilize during
the term of this employment any proprietary information of any third party,
including prior employers of the Employee.

13.  Benefit. Except as otherwise herein expressly provided, this Agreement
shall inure to the benefit of and be binding upon ImClone, its successors and
assigns, including, without limitation, any subsidiary or affiliated entity and
shall inure to the benefit of, and may not be amended, modified or supplemented
in any respect, except by a subsequent writing executed by both parties hereto.

14.  Entire Agreement. This Agreement constitutes the entire understanding and
agreement between the parties hereto, supersedes any and all prior discussions,
agreements and correspondence with regard to the subject matter thereof, and may
not be amended, modified or supplemented in any respect, except by a subsequent
writing executed by both parties hereto.

15.  Notices. All notices, requests and other communications to any party
hereunder shall be given or made in writing and telecopies, mailed (by
registered or certified mail) or delivered by 

<PAGE>

hand to the respective party at the address set forth in the caption of this
Agreement or to such other address (or telecopies number) as such party may
hereafter specify for the purpose of notice to the other party hereto. Each such
notice, request or other communication shall be effective (i) if given by
telecopier, when such telecopy is transmitted to the telecopier number specified
herein and the appropriate answerback is received or (ii) if given in writing by
any other means, when delivered at the address specified herein.

16.  Applicable Law. This Agreement shall be governed by, and construed and
enforced in accordance with, the laws of the State of New York without giving
effect to principles of conflicts of law and the courts of New York, shall have
exclusive jurisdiction over the parties hereto and subject matter hereof.

IN WITNESS WHEREOF, the parties have executed this Agreement as of the date
first appearing above.

IMCLONE SYSTEMS INCORPORATED                  EMPLOYEE


By:  /s/Samuel D. Waksal                      /s/Carl Goldfischer
     ---------------------                    ---------------------
President and Chief Executive Officer/title   Dr. Carl Goldfischer

<PAGE>

                          ImClone Systems Incorporated

                     Discovery and Non-Disclosure Agreement

     For value received, and for other good and valuable consideration including
my employment or other association with ImClone Systems Incorporated (the
"Company") and the compensation to be paid to me, I hereby covenant and agree
with the Company (which term shall include any parent, subsidiary or successor
to the Company) as follows:

     1. Disclosure of Discoveries

     I hereby agree that I shall promptly communicate in writing to the Company,
or to such individual as the Company may, from time to time, designate, a full
and complete disclosure of any and all research and other information,
inventions, discoveries and improvements ("Discoveries") made, developed and/or
conceived and/or reduced to practice by me alone or jointly with others, whether
or not patentable or copyrightable, (i) while in the employ of, or other
association with, the Company, whether during or outside of the usual hours of
work, and (ii) during a one (1) year period following the termination of my
employment or other association with the Company, and which are reasonably
related to the business of the Company during the term of my employment or other
association with the Company. All such Discoveries shall be and remain the sole
and exclusive property of the Company.

<PAGE>

     2. Assignment of Discoveries

     I hereby agree to, and hereby do, assign and transfer to the Company, or to
its nominee or designee, without any separate remuneration or compensation to me
other than the compensation received or assigned to me from time to time in the
course of my aforesaid employment or other association with the Company, all my
right, title and interest throughout the world in and to such Discoveries,
together with the right to file, and/or own wholly and without restriction,
applications for United States and foreign patents on all Discoveries, and to
do, execute and deliver any and all acts and instruments that may be necessary
and proper to vest in the Company all such Discoveries, patents, copyrights and
trademarks; and that I will render to the Company, or to its nominee or
designee, all such assistance as it may require in the prosecution of all such
patent, copyright and trademark applications, and applications for the reissue
of such patents, copyrights and trademarks. I agree that I shall also execute,
upon request, documents which secure to the Company the interests here conveyed.

     I further agree that I shall assist, upon request, in locating writings and
other physical evidence of the making of my Discoveries, and provide unrecorded
information relating to such Discoveries, and give testimony in any proceeding
in which any of my Discoveries, or any application or patent, copyright or
trademark directed thereto, may be involved.


<PAGE>

     3. Copyright; Publishing

     I hereby agree that I shall promptly disclose to the company any and all
publishable an/or copyrightable material which I produce, compose or write,
individually or in collaboration with others, which arises out of work delegated
to me by the Company, and further agree that such materials shall be considered
works made for hire.

     At the expense of the Company, and to the extent that such material may not
be considered works made for hire, I shall assign to the Company all my interest
in such copyrightable material, and will sign all papers and do all other acts
necessary to assist the Company in obtaining copyrights on such material in any
and all countries.

     4. Trade Secrets; Confidential Information

     I hereby agree that I will not, during my employment by, or other
association with, the Company, or afterwards, disclose to others or use for my
own benefit any trade secrets (as hereinafter defined) or other confidential
information acquired by me from the Company, its customers, suppliers,
consultants, affiliates, or third parties contracting with the Company, except
to the extent that the disclosure of such trade secrets and other confidential
information is necessary to perform my duties and fulfill my responsibilities as
an employee or other associate of the company. A trade secret is information,
not generally known to the trade, which gives the Company an advantage over its
competitors. Trade secrets can include, by way of example, research being
planned and developed, research methods and processes, sources of supply,
materials used in research, 

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marketing plans, and information concerning the filing or pendency of patent
applications.

     Such obligation of confidentiality shall be waived as to information which
(i) is in the public domain, (ii) comes into the public domain through no fault
of my own, (iii) was known to me prior to its disclosure under this Agreement,
or (iv) is disclosed to me by a third party having lawful right to make such
disclosure.

     5. Company Information

     I hereby agree that I will not, without first obtaining the written
approval of the Company, or of such individual as the Company may, from time to
time, designate, divulge or disclose to anyone outside of the Company, whether
by private communication or by public address, publication or otherwise, any
information not already lawfully available to the public concerning the
Company's business and/or products, including, but not limited to, all
information about (a) the Company's production, profitability, business and
legal plans, finances, internal affairs, competitive position, customers and
vendors; (b) its formulae, processes, methods, reports, machines, or inventions;
and (c) any such information relating to the business of any corporation, firm
or person for whom the Company is conducting, or shall conduct, research
services, or is providing, or shall provide, other services, whether supplied by
the Company or such corporation, firm or person, or whether made, developed
and/or conceived by me or by others in the employ or other association with the
Company.

<PAGE>

     6. Non-Compete

     I hereby agree that I will not, during my period of employment or other
association with the Company, compete with the company or design, manufacture or
sell items which relate to products or business planned or under development by
the Company; and I further agree that I will not, during the period of my
employment or other association with the Company, directly or indirectly enter
the employment of, or render any business or technical services (except as
requested by the Company) to, any individual, partnership, association or
corporation who or which is a competitor of the Company, or who or which is
developing, making or selling products which relate to any research or
development project of the Company.

     7. Company Property; Termination Certificate

     Upon the termination of my employment or other association with the
Company, I hereby agree to turn over to the Company all models, prototypes,
notes, memoranda, notebooks, drawings, specifications, records, customer lists,
proposals, business plans, and other documents in my possession or under my
control, relating to any work done for, or otherwise belonging to, the Company,
it being acknowledged and agreed to by me that all such items are the sole
property of the Company, and I hereby agree to sign the following "Termination
Certificate" upon such termination of my employment or other association with
the Company:

     "This is to certify that I do not have in my possession or custody, nor
have I failed to return, any models, prototypes, notes, memoranda, notebooks,
drawings, 

<PAGE>

specifications, records, customer lists, proposals business plans, or copies of
any of these, and other documents and/or materials, tools, equipment programs,
databases or other property belonging to the Company.

     8. Governing Law

     The substantive laws of the State of New York which apply to contracts
executed and to be performed in New York shall govern this Agreement.

     9. General Provisions

     (a) The scope and effect of the covenants in this Agreement shall be as
broad in time, geography and in all other respects as is permitted by applicable
law, and should a court or other body of competent jurisdiction determine that
any term or provision of this Agreement is excessive in scope, invalid or
otherwise unenforceable, such term or provision shall be adjusted rather than
voided, if possible, and all other terms and provisions of this Agreement shall
be deemed valid and enforceable to the fullest extent possible.

     (b) I further agree that this Agreement shall be binding upon me
irrespective of the duration of my employment or other association with the
Company, the reasons for the cessation of my employment or other association
with the Company, or the amount of my compensation and/or salary.

     (c) This instrument is the whole agreement, and no modification or
variation shall be deemed valid unless in writing signed by the Company.


<PAGE>

     (d) This Agreement shall be binding upon my heirs, executors, successors,
administrators, and legal representative, and shall inure to the benefit of the
successors and assigns or the Company.

     (e) I represent and warrant to the Company that I am not under any
obligations to any person, firm or corporation, and have no other interest which
is inconsistent or in conflict with this Agreement, or which would prevent,
limit or impair in any way the performance by me of the covenants hereunder or
my duties in my said employment or other association with the Company.

     IN WITNESS WHEREOF, I have hereunto set my hand this 12 day of March, 1997,
at New York, New York.

WITNESS:                                    Carl Goldfischer
                                            --------------------------
                                            Print Name


/s/Judith Hansen                            /s/Carl Goldfischer
----------------------                      --------------------------
                                            Signature