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                                                                    Exhibit 1.20


December 16, 1998



Dr. Christopher Nicodemus
197 Eighth Street, #706
Charlestown, MA 02129

Dear Dr. Nicodemus:

On behalf of the Company, I am pleased to offer you the position of Senior Vice
President, Medical and Regulatory Affairs at AltaRex Corp. I know you share with
me, Tony Noujaim, the Board and our employees the enthusiasm for the opportunity
AltaRex represents.

As Senior Vice President Medical and Regulatory Affairs, you will report to me
and be responsible for clinical trial design and execution, regulatory filings
and compliance, and final medical approval. Initially reporting to you will be
Connie Sykes, Exec. Director of Regulatory Affairs; Jane Mitchell reports to
Connie as Manager of Medical Support; Jim Pankovich, Senior Medical Marketing
Associate; Donna Robinson, Senior Medical Marketing Consultant; and Heather
Schramm, Admin. Assistant.

The terms of your offer are as follows (all amounts are in U.S. dollars):

Base Salary:        $205,000 per annum paid in 24 equal payments, subject to an
                    increase on an annual basis, and commencing January 18,
                    1999.

Sign-on Bonus:      $10,000 paid on joining the Company.

Performance Bonus:  Eligible for bonus participation in 1999 IF and AS
                    established by the Board of Directors.

Stock:              You will be offered options to purchase 175,000 shares of
                    common stock of the Company vesting 33 1/3% per year in
                    arrears annually over 3 years commencing on the date of
                    approval by the Toronto Exchange. The exercise price will be
                    set by the Board of Directors at fair market value, subject
                    to the availability of appropriate exemptions from Canadian
                    and U.S. regulations. These options must be exercised within
                    90 days after any termination of your employment unless
                    termination is for cause (in which case the options will
                    terminate immediately). Vesting of these options will be
                    accelerated in full if the Company is sold.

Corporate Benefits: You are eligible for our employee benefits immediately.
                    AltaRex Corp. will pay the Guardian premiums on your behalf
                    for health and dental coverage. A Life Insurance benefit of
                    1 times annual salary and Long Term Disability coverage are
                    provided through the Company with Mutual of Omaha. A Life
                    Insurance benefit of $25,000 is provided through Guardian. A
                    401K plan is available that


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                    matches up to a maximum of 3% of the employee's salary as a
                    Company contribution.

Leave:              We will provide an annual vacation of four (4) weeks paid
                    vacation accruing at 1.66 days per month.

Professional Fees:  Your annual professional dues and subscriptions will be paid
                    for by the Company as requested.

Academic            The Company has approved your continued academic appointment
Appointment:        for not more than 1/2 day twice a month (or as we might
                    otherwise mutually agree).

Agreements:         As a condition of employment, you will be required to sign
                    customary invention, non-disclosure and non-compete
                    agreements.

Severance           You understand that your employment with the Company is at
Compensation:       will which means you or the Company may end the employee
                    relationship with or without notice. In the event that your
                    employment is terminated for reason other than just cause,
                    the Company shall in exchange for a release of claims which
                    the employee may have against it, provide the salary
                    continuation for one year. Just cause for termination shall
                    be deemed to exist upon a) a good faith finding by the
                    Company of your failure to perform your assigned duties for
                    the Company, dishonesty, gross negligence or misconduct, or
                    b) conviction or the entry of a pleading of guilty or nolo
                    contendere, to any crime involving moral turpitude or any
                    felony.

Both parties agree that upon your receipt of this letter, neither party will
disclose the terms of this letter, directly or indirectly to any outside parties
until signed acknowledgement of the letter by Tuesday, December 22, 1998 at 5:00
pm E.S.T. Facsimile your signed acceptance to AltaRex Corp., Attn: Trudy
Chirnko, facsimile number 781-466-8740. This offer is contingent on an
appropriate completion of references for a position of this nature. Finally, the
Company will make every effort to maintain confidentiality of your signing this
offer letter until you've had the chance to properly notify your current
employer in early January.

Sincerely,

 /s/ Richard E. Bagley
-------------------------
Richard E. Bagley
President & CEO


Accepted this 18th day of December, 1998


 /s/ Christopher Nicodemus
---------------------------------
Dr. Christopher Nicodemus


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June 1, 1999



Dr. Christopher Nicodemus
197-8 Street #706
Charlestown, MA
02129

Dear Chris:

RE: AMENDMENT TO THE TERMS OF YOUR EMPLOYMENT AS SET OUT IN THE LETTER DATED
NOVEMBER 15, 1998 (THE "LETTER AGREEMENT") FROM THE COMPANY TO YOU.

This letter serves as an amendment to the terms of your employment as set out in
the Letter Agreement. You and the Company agree that the second sentence of the
paragraph in the Letter Agreement related to severance compensation be and
hereby is deleted in its entirety and that the following sentence shall be
inserted in lieu thereof:

If your employment is terminated by the Company without just cause prior to
December 31, 2001, you will be entitled to receive severance payments at a
monthly rate equal to 1/12 of the annual base salary to which you were entitled
on the effective date of termination until the later of (a) December 31, 2001
and (b) the first anniversary of the effective date of termination. For purposes
of applying the foregoing, just cause for termination shall be deemed to exist
upon a) a good faith finding by the Company of your failure to perform your
assigned duties for the Company, dishonesty, gross negligence or misconduct, or
b) conviction, or the entry of a pleading of guilty or nolo contendere, to any
crime involving moral turpitude or any felony. Notwithstanding the foregoing, in
the event that you breach the Invention, Non-disclosure and Non-compete
Agreement dated as of February 5, 1999 between you and the Company at any time
during the period during which the Company is making severance payments to you
under this Agreement, the Company's obligation to make, and your entitlement to
receive, such severance payments under this Agreement shall terminate
immediately upon such breach.

All other terms of your employment as set out in the Letter Agreement remain in
full force and effect.


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Please confirm that you are in agreement with the foregoing by signing below. If
you have any questions, please contact me.


Sincerely,

/s/ Richard E. Bagley
Richard E. Bagley
President & CEO


The parties hereto have executed this agreement of the 3rd day of June,
1999.

                                             AltaRex Corp.

/s/ Christopher Nicodemus                    /s/ Richard E. Bagley
-------------------------                    --------------------------------
Christopher Nicodemus                        Richard E. Bagley
                                             President & CEO


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Dr. Christopher Nicodemus
197-8 Street #706
Charlestown, MA
02129

Dear Chris:

RE: AMENDMENT TO THE TERMS OF YOUR EMPLOYMENT AS SET OUT IN THE LETTER DATED
NOVEMBER 15, 1998 (THE "LETTER AGREEMENT") AND THE AMENDMENT DATED JUNE 1, 1999

This letter serves as an amendment to the terms of your employment as set out in
the Letter Agreement as amended. Provisions for severance compensation as stated
in the June 1, 1999 amendment are further amended by deleting the first sentence
of such amended provision and inserting the following sentence:

     If your employment is terminated by the Company without just cause, you
     will be entitled to receive severance payments at a monthly rate equal to
     1/12 of the annual base salary to which you were entitled on the effective
     date of termination until the first anniversary of the effective date of
     termination.

All other terms of your employment as set out in the Letter Agreement and
Amendments remain in full force and effect.

Please confirm that you are in agreement with the foregoing by signing below. If
you have any questions, please contact me.

Sincerely,


/s/ Richard E. Bagley
Richard E. Bagley
President & CEO


The parties hereto have executed this agreement on the 22nd day of December,
1999.

                                                 AltaRex Corp.

/s/ Christopher F. Nicodemus                     /s/ Richard E. Bagley
---------------------------------                ------------------------------
Christopher F. Nicodemus                         Richard E. Bagley