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                                                                    EXHIBIT 1.31

May 4, 1999



Marlene Booth, M.Sc., R.A.C.
11 Judges Hill Drive
Norwell, MA
02061


Dear Marlene:

On behalf of the Company, I am pleased to offer you the position of Vice
President, Regulatory Affairs and Project Management at AltaRex Corp. reporting
to Christopher Nicodemus M.D., Senior Vice President, Clinical Research and
Development. I know you share with me and our employees the enthusiasm for the
opportunity AltaRex represents.

As Vice President of Regulatory Affairs and Project Management, you will be
responsible for directing and controlling all regulatory activities. This
includes developing and implementing strategies for optimizing external
regulatory review, maintaining proactive dialogue with relevant regulatory
authorities, providing expert analysis and evaluation of regulations, and
evaluating impact and analyzing trends of government regulatory activities. Your
project management responsibilities will involve directing other Company
departments in completing their projects in order to reach Company timelines.
You will be responsible for communicating with and updating other Senior
Management as to the status of each of these projects. Joe McPherson, Exec.
Director of Technical Operations and Quality Assurance, will assist you in
maintaining QA standards based on internal and external specifications and
enforcing corrective action necessary to assure conformity with quality
specifications. You will assure that finished products conform to government and
company standards and satisfy GMP regulations.

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

Base Salary:             $140,000 per annum, based on four (4) days per week,
                         with flexibility of time commitment as required to meet
                         the demands of the job. You will be paid in 24 equal
                         payments, with a commencement date of June 1, 1999.
                         Future time obligations to AltaRex are subject to
                         mutual negotiations and agreement to increase or
                         decrease commitment according to the requirements of
                         the position.

Performance Bonus:       You will be eligible for bonus participation in 1999
                         and subsequent years if and as established by the Board
                         of Directors.

Sign-on Stock Options:   You will be offered options to purchase 100,000 common
                         shares of the Company vesting 33 1/3% per year in
                         arrears annually over 3 years commencing on the date of
                         commencement of your employment with the Company. The
                         exercise price will be set by the Board of Directors in
                         accordance with the terms of the Company's stock option
                         plan, subject to the availability of appropriate
                         exemptions from Canadian and U.S. securities laws.
                         These options (to the extent they have vested) must be

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                         exercised within the earlier of 90 days after any
                         termination of your employment and the expiry date of
                         the options established at the time of grant.

Corporate Benefits:      You are eligible for our employee benefits immediately.
                         AltaRex Corp. will pay 100% of the premiums on your
                         behalf for health and dental coverage provided by
                         Guardian. A Life Insurance benefit of 1 times annual
                         salary and Long Term Disability coverage are provided
                         through the Company with Mutual of Omaha. An additional
                         Life Insurance benefit of $25,000 is provided through
                         Guardian. A 401K plan is available that matches the
                         employee's contribution up to a maximum of 3% of the
                         employee's salary as a Company contribution.

Leave:                   We will provide an annual paid vacation of four (4)
                         weeks accruing at 1.66 days per month. A planned
                         vacation dated August 6, 1999 to August 24, 1999 has
                         been approved by Dr. Nicodemus.

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

Severance Compensation:  You understand that your employment with the Company is
                         at 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 reasons
                         other than just cause, the Company shall in exchange
                         for a release of claims which you may have against it,
                         provide salary continuation of six months. 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.

We would like to move forward as soon as possible with this position.

Sincerely,

/s/ Richard E. Bagley

Richard E. Bagley
President & CEO

Acknowledged this    5th    day of    May    , 1999
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     /s/ Marlene R. Booth
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Marlene Booth

Accepted this    5th    day of    May    , 1999
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