Document:

<PAGE>

                                                                   Exhibit 10.11

April 18, 1991

By DHL Express

Dr. Reinaldo Gomez
124 Woodbridge Circle
San Mateo, CA 94403

Dear Rey:

This letter, together with the attached Proprietary Information and Inventions
Agreement and the Stock Option Agreement (together referred to as "Letters")
sets forth the terms of your employment with Terrapin Technologies, Inc.
("Company").

1.   Employment. You will be employed as President of the Company beginning May
     1, 1991, or earlier if your schedule permits. At the next Board Meeting you
     will be nominated for the Board of Directors to serve until the next Annual
     Meeting of Shareholders, at which point the existing Board will stand for
     re-election.

2.   Base Salary. Your initial base salary will be $185,000 per year, payable
     semi- monthly. When we have completed objective "D", referred to in
     paragraph 3 below, your base salary will be increased by the Board to bring
     you to the level that is consistent with the base salary paid by your
     present employer, i.e. a range of $210,000 to $215,000 per annum.

3.   Bonus. You will be eligible for consideration for an annual bonus of up to
     $40,000 in stock grants, to be determined by the Board of Directors, based
     on your performance during the year. The principal, although not exclusive,
     factors and weighting which will be considered are as follows:

                              Objective                              Percent of
                                                                        Bonus

A.   Development of the GST assay described in the Business Plan         50%
     within the first year of your employment.

B.   Management of the laboratory within the total head counts and       20%
     amounts as agreed in the operating budget, to be finalized after
     your arrival.

C.   Expansion of the Science Advisory Board.  This expansion will       15%
     include the addition of world-leaders in the field of cancer
     research, and this objective will be met by the addition of
     at least one excellent oncologist to the Science Advisory
     Board within the first year of your employment.

                                       1.
<PAGE>

D.   Assisting the Board of Directors in raising capital. This 15%
     objective will be achieved if the Company is able to raise at
     least $4 million from all sources within one year from the
     date of your employment.

     These are the first year objectives, the bonus amount, and the proposed
percentages to apply to the bonus.  Prior to the beginning of the second and
subsequent years, we will agree individual goals, objectives, the percentages,
and the bonus objective amount for that year.

     The bonus will be paid in Common Stock of the Company.  The value to be
utilized for the stock will be the current market price at the time the bonus is
due, and the bonus will be paid within 30 days after the end of the first
anniversary of your employment.  Achievement of an individual objective will
provide a basis for consideration of a bonus, even though less than all
objectives are met.

4.   Stock Option. I will recommend to the Board at the next meeting that you be
granted a Stock Option to purchase 250,000 shares of Common Stock of the Company
at $1.50 per share. Each of the Board Members has informally indicated their
willingness to approve this Option. That Option Agreement is attached to this
Agreement and it sets forth the terms of the Stock Option Grant, the vesting
schedule, and other particulars. Please separately execute both copies of that
document, and return one to me.

5.   Fringe Benefits.  You will be entitled to all of the usual employee fringe
benefits available at Terrapin including group insurance.  The Company has a
policy of paying the employee's cost of the insurance, with the employee paying
one-half of the dependent coverage.  A copy of the group insurance pamphlet is
enclosed.

6.   Proprietary Information and Inventions Agreement. You agree to abide by the
terms and conditions of the Proprietary Information and Inventions Agreement
which is attached to this letter and made a part hereof. Please separately
execute that document.

7.   Termination. You may terminate this agreement at any time upon 60 days
prior notice to the Company. In that case all compensation and other benefits
shall terminate as of the date of termination. The Company may terminate this
agreement at any time upon 60 days prior notice for cause or for performance
which is determined by the Company's Board of Directors to be unsatisfactory. If
this agreement is terminated by the Company for cause or unsatisfactory
performance, then (a) your base salary and group insurance as in effect at that
time will be continued until the sooner of the expiration of four months from
the date of termination or the date you accept other employment and (b) in the
case of termination within the first 12 months of your employment with the
Company, a portion of the stock option described in paragraph 4 above will
automatically vest as of the date of termination, such portion to equal 50,000
shares if there has been a change of control of the Board during that 12 month
period or 30,000 shares otherwise.

8.   General. This Letter shall be governed by California law. If any provision
of this Letter or the application thereof to any situation or circumstance shall
be invalid or unenforceable, the remainder of the provisions of this Letter or
the application of such provisions to situations or

                                       2.
<PAGE>

circumstances other than those as to which it is invalid or unenforceable shall
not be affected, and each provision of this Letter shall be valid and
enforceable to the fullest extent permitted by applicable law. The parties agree
to negotiate in good faith to substitute for any such invalid or unenforceable
provision a valid and enforceable provision which most nearly effects the
parties' original intent in entering into this Letter.

     Rey, we are all very enthusiastic about your joining Terrapin.  I believe
that it's one of the most important decisions we have made, and I look forward
to working together.

     If you agree to the arrangement set forth in this Letter, please sign in
the space provided below, and return one copy to me.

Very truly yours,

Terrapin Technologies, Inc.

By:  /s/ Jerrold L. Glick
   ----------------------------
    Jerrold L. Glick, Chairman

Accepted and agreed to:

/s/ Reinaldo Gomez
--------------------------------
Reinaldo Gomez, Ph.D.

                                       3.
<PAGE>

             ADDENDUM TO EMPLOYMENT AGREEMENT OF REINALDO F. GOMEZ

     The employment agreement between Terrapin Technologies, Inc. ("the
Company") and Reinaldo F. Gomez, Ph.D. is hereby amended as follows:

     "In the event that the employment of Dr. Gomez is terminated by the Company
     without cause, Dr. Gomez shall continue to receive, as severance, continued
     payment of his base salary and health care benefits for nine (9) months, or
     until such time as Dr. Gomez obtains other employment, whichever occurs
     first."

Terrapin Technologies, Inc.

/s/ Clifford Orent
-------------------------------

Dated:  March 4, 1997

Accepted and Agreed:

/s/ Reinaldo Gomez
-------------------------------
Reinaldo F. Gomez, Ph.D.

Dated:  March 4, 1997

                                       4.
<PAGE>

                    SECOND ADDENDUM TO EMPLOYMENT AGREEMENT

     The employment agreement between Telik, Inc. (the "Company") and Reinaldo
Gomez, Ph.D, effective September 1, 1999 (the "Effective Date") is hereby
amended as follows:

Paragraph 1 - Employment - You will have the title of Vice President, Corporate
Alliances, with the duties and responsibilities customarily afforded such a
position, and as more specifically set forth on Exhibit A.

Paragraph 2 - Base Salary - Your base salary, as of the Effective Date, shall be
$12,500 per month, less payroll deductions and withholdings, payable in semi-
monthly in arrears.

Paragraph 7 - Termination - shall be amended to read in its entirety as follows:

     "Term; Termination."  This Agreement will automatically terminate on August
31, 2000 unless earlier terminated pursuant to the terms of this Agreement, but
in no instance with less than three months' notice.  This Agreement may be
extended by mutual agreement of the parties.  As an employee of the Company you
may terminate your employment at any time for any reason whatsoever, with or
without cause.  This at-will employment relationship cannot be changed except in
writing signed by the Chief Executive Office of the Company.

     Paragraph 8 - General - shall be retitled Paragraph 9 and a new paragraph
8, entitled "Severance Benefits" shall be added to read as follows:

If your employment is terminated by the Company without cause, you will receive,
as severance, continued payment of your base salary and health care benefits
until August 31, 2000 or date which allows no less than three months from date
of notice, or until such time as you obtain other employment, whichever occurs
first.  In the event of such termination, you will not be entitled to any
additional compensation or benefits beyond what is provided in this paragraph.
If you resign or your employment is terminated for cause, all compensation and
benefits will cease immediately, and you will receive no severance benefits.
For purposes of this Agreement, "cause" shall mean misconduct, including:  (i)
conviction of any felony or any crime involving moral turpitude or dishonesty;
(ii) participation in a fraud or act of dishonesty against the Company; (iii)
willful breach of the Company's policies; (iv) intentional damage to the
Company's property; (v) material breach of this Agreement or your Proprietary
Information and Inventions Agreement; or (vi) conduct by you which in the good
faith and reasonable determination of the Company's Board of Directors
demonstrates gross unfitness to serve.  Physical or mental disability shall not
constitute "cause".  Except as expressly provided herein, you will not be
entitled to any other compensation, severance, pay-in-lieu of notice or any
other such compensation.  This severance provision does not affect the "at-will"
nature of your employment.

TELIK, INC.           /s/ Michael M. Wick
                      -----------------------------------   ------------------
                      Michael M. Wick, President and CEO    Date

Accepted and agreed:  /s/ Reinaldo Gomez
                      -----------------------------------   ------------------
                      Reinaldo Gomez, Ph.D.                 Date

                                      1.
<PAGE>

                                   Exhibit A

                                Job Description

 .    Manage all established external partnerships and collaborations with U.S.
     and Japanese pharmaceutical companies.
 .    Guide the Director of Corporate Alliances in the management of product
     development activities.
 .    Participate in the negotiation of new business arrangements.
 .    Advise the Chairman and CEO on strategic business and scientific matters.
 .    Manage interactions with the Scientific Advisory Board and assist the
     Director of Corporate Alliances with the Clinical Advisory Board.

                                      2.<PAGE>

                                                                   EXHIBIT 10.12

August 1, 1999

Dr. Michael Wick
135 Hardwick Road
Woodside, CA 94062

Re:  Employment Agreement

Dear Michael:

     On July 30, 1999, the Board of Directors of Telik, Inc. (the "Company")
appointed you to the additional position of Chief Executive Officer of the
Company.  The purpose of this agreement (the "Agreement") is to set forth the
terms of your employment as the President and Chief Executive Officer of the
Company on the terms set forth below:

     1.  Duties.  As the President and Chief Executive Officer, you will perform
the duties customarily associated with this position and such duties as may be
assigned to you by the Board of Directors. You will report to the Board of
Directors.

     2.  Compensation and Benefits. As compensation for your services and for
your covenants and promises in this Agreement, the Company agrees to provide you
with the following:

          (a)  Base Salary. A base salary of twenty-two thousand, five hundred
dollars ($22,500) per month, less payroll deductions and withholdings, payable
semi-monthly in arrears.

          (b) Stock Options. In recognition of your role, the Company's Board of
Directors, has granted you an additional option to purchase one hundred fifty
thousand (150,000) shares of Telik Common Stock at an exercise price equal to
one dollar and sixty cents ($1.60) per share. These options shall vest as
follows: twenty-five percent (25%) on July 30, 2000, and then monthly pro-rata
over the next thirty-six (36) month period beginning on July 30, 2000.

          (c)  Benefits. The Company will provide you with health, dental and
life insurance consistent with Company practice for exempt employees. Details
about these benefits are provided in the employee handbook and summary plan
descriptions available for your review. Of course, the Company reserves the
right to modify your compensation and benefits from time to time, as it deems
necessary.

     2.  Company Policies and Proprietary Information Agreement.  As an employee
of the Company, you will be expected to abide by all of the Company's policies
and procedures, and hereby acknowledge that you have received and read the
Company's employee

                                       1
<PAGE>

handbook. As a condition of your employment, you also agree to sign and comply
with the Company's Proprietary Information and Inventions Agreement (attached
hereto as Exhibit A).

     3.  Other Agreements. By accepting this offer, you represent and warrant
that your performance of your duties for the Company will not violate any
agreements, obligations or understandings that you may have with any third party
or prior employer. You agree not to make any unauthorized disclosure or use, on
behalf of the Company, of any confidential information belonging to any of your
former employers. You also represent that you are not in unauthorized possession
of any materials containing a third party's confidential and proprietary
information. Of course, during your employment with the Company, you may make
use of information generally known and used by persons with training and
experience comparable to your own, and information which is common knowledge in
the industry or is otherwise legally available in the public domain.

     4.  Duty of Loyalty. While employed by the Company, you will not engage in
any business activity in competition with the Company nor make preparations to
do so, and you will not engage in any new outside employment or consulting
without written authorization from the Board of Directors.

     5.  Termination.  As an employee of the Company you may terminate your
employment at any time and for any reason whatsoever simply by notifying the
Company.  Similarly, the Company may terminate your employment at any time and
for any reason whatsoever, with or without cause.  This at-will employment
relationship cannot be changed except in writing signed by a duly authorized
officer of the Company.

     6.  Severance Benefits. If your employment is terminated by the Company
without cause, you will receive, as severance, continued payment of your base
salary and health care benefits for twelve (12) months. The monthly vesting of
stock options will also continue for the same twelve (12) months. In the event
of such termination, you will not be entitled to any additional compensation or
benefits beyond what is provided in this paragraph. If you resign or your
employment is terminated for cause, all compensation and benefits will cease
immediately, and you will receive no severance benefits. For purposes of this
Agreement, "cause" shall mean misconduct, including: (i) conviction of any
felony or any crime involving moral turpitude or dishonesty; (ii) participation
in a fraud or act of dishonesty against the Company; (iii) willful breach of the
Company's policies; (iv) intentional damage to the Company's property; (v)
material breach of this Agreement or your Proprietary Information and Inventions
Agreement; or (vi) conduct by you which in the good faith and reasonable
determination of the Company's Board of Directors demonstrates gross unfitness
to serve. Physical or mental disability shall not constitute "cause". Except as
expressly provided herein, you will not be entitled to any other compensation,
severance, pay-in-lieu of notice or any other such compensation. This severance
provision does not affect the "at-will" nature of your employment.

     7.  Return of Materials. At the termination of your relationship with the
Company, you will promptly return to the Company, and will not take with you or
use, all items of any nature that belong to the Company, and all materials (in
any form, format, or medium) containing information relating to the Company's
business.

                                       2
<PAGE>

     8.  Termination of Prior Agreement.  If you accept this offer and sign this
letter below, you agree that in consideration of the compensation and benefits
to be provided pursuant to this letter all prior agreements between you and the
Company shall be terminated and be superceded by this Agreement.  You further
acknowledge and agree that all stock and other compensation owed to you as of
the date first set forth above (the "Transition Date") have been satisfied in
full

     9.  Nonsolicitation. For one (1) year following the termination of your
employment, you will not, either directly or through others, through the use of
confidential company information, solicit or attempt to solicit: any employee,
consultant or independent contractor of the Company to terminate his or her
relationship with the Company in order to become an employee, consultant or
independent contractor to or for any other person or business entity; or the
business of any customer, vendor or distributor of the Company which, within one
(1) year immediately prior to the termination, thereto, was a customer, vendor
or distributor of the Company, if to do so would involve the use of the
Company's proprietary information.

     10. Entire Agreement. This Agreement, including Exhibit A, constitutes the
complete, final and exclusive embodiment of the entire agreement between you and
the Company with respect to the terms and conditions of your employment. If you
enter into this Agreement you are doing so voluntarily, and without reliance
upon any promise, warranty or representation, written or oral, other than those
expressly contained herein. This Agreement supersedes any other such promises,
warranties, representations or agreements. This Agreement may not be amended or
modified except by a written instrument signed by you and a duly authorized
officer of the Company.

     11. Enforceability. If any provision of this Agreement is determined to be
invalid or unenforceable, in whole or in part, this determination will not
affect any other provision of this Agreement, and the Agreement, including the
invalid or unenforceable provisions, should be enforced insofar as possible to
achieve the intent of the parties.

     12. Binding Nature. This Agreement will be binding upon and inure to the
benefit of the personal representatives and successors of the respective parties
hereto.

     13. Governing Law. This Agreement will be governed by and construed in
accordance with the laws of the State of California.

     14. Dispute Resolution/Attorneys' Fees. Unless otherwise prohibited by law
or specified below, all disputes, claims, and causes of action (including but
not limited to any claims of statutory discrimination of any type), in law or
equity, arising from or relating to this Agreement or its enforcement,
performance, breach, or interpretation shall be resolved solely and exclusively
by final, binding and confidential arbitration through Judicial Arbitration &
Mediation Services/Endispute, Inc. ("JAMS") under the then existing JAMS
arbitration rules. This arbitration shall be held in the San Francisco Bay Area.
Nothing in this section is intended to prevent either party from obtaining
injunctive relief in court to prevent irreparable harm pending the conclusion of
any such arbitration.

                                       3
<PAGE>

     We look forward to continuing a productive and enjoyable work relationship.

                              Very truly yours,

                              Telik, Inc.

                              Jean Deleage
                              Board Member

Accepted and Agreed:

/s/ Michael Wick
----------------------------------
Dr. Michael Wick

----------------------------------
Date

                                       4
<PAGE>

                                   Exhibit A

               PROPRIETARY INFORMATION AND INVENTIONS AGREEMENT

                                       5
<PAGE>

                    First Addendum to Employment Agreement

In accordance with the resolutions passed by the Telik Board of Directors on
December 17, 1999, your employment agreement dated August 1, 1999 is hereby
amended as follows effective January 1, 2000:

1.   Paragraph 1. - Duties - The title "President and Chief Executive Officer"
     is changed to "Chairman, President and Chief Executive Officer."
2.   Paragraph 2, Section a(1). - Base Salary - is changed to a base salary of
     $25,000 per month, less payroll deductions and withholdings, payable in
     semi-monthly in arrears.

Telik, Inc.

By:_____________________________

Title:__________________________

Accepted and Agreed:

________________________________
Michael Wick

Dated:__________________________
<PAGE>

December 10, 1997

Michael M. Wick, M.D., Ph.D.
108 Portola Road, Suite 130
Portola Valley, CA 94028-7899

Dear Mike:

You have made an extremely positive impression on the team at Terrapin
Technologies, Inc. (Terrapin) during the course of our discussions.  It is with
great personal pleasure that I am writing to formally offer you the position of
Executive Vice President, Research and Development and Chief Operating Office,
reporting to me.  Additionally, at the December 9 meeting of Terrapin's Board of
Directors (Board), you have been elected as a Board member effective on you
acceptance of this offer.  Your starting salary will be the equivalent of
$250,000 per annum and you will receive a one-time signing bonus of $20,000.
Your start date will be December 15, 1997.

We are also pleased to offer you an option to purchase 250,000 shares of
Terrapin stock subject to the formal approval by the Board, at a price to be
established at the next Board  meeting following your date of hire.  The vesting
of the Option will provide that no shares will be vested during the first twelve
months of your employment, at which time 25% will vest and the balance will be
vested on a monthly basis over the following three years.  The total option term
will be ten years from the date of your grant.  The other provisions of the Plan
will be contained in the Stock Option Agreement to be entered into after the
Board approves the Option.

Terrapin offers company sponsored health, dental, vision, long-term disability,
and life/accidental death & dismemberment insurance.  The current cost to you
for this insurance is $5 per month for you and $100 per month for
spouse/dependent coverage.  You will be eligible for these benefits on the first
day of the month following your date of hire.  You will be covered for short-
term disability and worker's compensation insurance effective your first day of
employment.  You will also be eligible to participate in our 401(k) retirement
program beginning the first day of the month following your hire date.  Terrapin
also offers 12 paid holidays per year.  Vacation for corporate officers is
accrued at the rate of 15 days per year.

This offer is conditioned upon the execution of the enclosed Confidentiality
Agreement.  If you accept this offer, the terms described in this letter shall
be the terms of your employment.  The terms described in this letter do not
imply an employment contract for a specified period of time.  Employment at
Terrapin is at will.  Either you or Terrapin may terminate your employment
<PAGE>

at any time.  This letter shall be governed by the laws of California without
giving effect to conflicts of law principles.  This letter and the
Confidentiality Agreement constitute the entire understanding of Terrapin and
you with respect to your employment and supersede all prior oral or written
representations, understanding, and agreements.  This letter cannot be amended
or modified, nor can any term hereof for the benefit of Terrapin be waived,
except in a writing duly executed by an authorized officer of Terrapin.

Additionally, the Board has agreed that your performance will initially be
evaluated in six months, at which time the Board will review a possible change
in title to President and Chief Operating Officer.  Please be aware, however,
that any such change in title will be made at the total discretion of the Board,
and may be influenced by factors other than your individual performance.

Please sign and return one copy of this letter and the Confidentiality Agreement
to indicate your acceptance of our offer.  Mike, my colleagues and I are excited
to have you as the newest member of the Terrapin team.  We are confident that
your background and skills will enable you to make significant contributions to
the success of the company and I personally very much look forward to a close
working relationship with you.

If you have any questions, please feel free to call me at (650) 244-9303, ext.
317.

Sincerely,

Clifford Orent
Chairman, President and Chief Executive Officer

ACKNOWLEDGMENT

I have read, understand, and accept the foregoing terms and conditions of
employment.  I further understand that while my salary, benefits, job title, and
job duties may change from time to time without a written modification of this
Agreement, such changes will not affect the validity of this Agreement or my
right or the Company's right to terminate my employment.

/s/ Michael M. Wick
-------------------------------               ------------------
Signature                                     Date

-------------------------------
Printed Name

Source: [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00007-of-00352.parquet"}, [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00007-of-00352.parquet"}]]