ENTRUSTMENT AGREEMENT

EXHIBIT 10.1

ENTRUSTMENT AGREEMENT

THIS ENTRUSTMENT AGREEMENT (“Agreement”) is made and effective as of this 31^st day of January, 2007, by and among Bioenvision Japan Co Ltd., a corporation organized under the laws of Japan with a place of business at Regus ARK Hills Centre ARK Mori Bldg.W12F, 1-12-32 Akasaka Minato-ku Tokyo 107-6012 Japan (the “Company”), Bioenvision, Inc., a Delaware corporation with principle executive offices located at 345 Park Avenue, 41^st Floor, New York, New York 10154 (the “Parent Company”) and Yoshimaru Yamamoto (“Executive”).

WHEREAS, the Company is a wholly-owned subsidiary of the Parent Company; and

WHEREAS the Company and the Parent Company desire that the Executive serve in the capacity of director of the Company, and the Executive is willing to serve as a director of the Company, on terms set forth herein;

NOW, THEREFORE, in consideration of the mutual agreements set forth herein, the parties agree as follows:

1. Entrustment. As from the Effective Date, the Company entrusts the Executive to serve as a director of the Company and the Executive accepts such entrustment to work for the Company in such capacity. The Executive acknowledges and agrees that the nature of his relationship with the Company is one of entrustment (inin) and not one of employment and no “lifetime employment” is created, implied or expected hereunder.

2. Term of Agreement. The term of this Agreement shall commence on February 19, 2007 (“Effective Date”) and shall end on the first anniversary of the Effective Date (“Expiration Date”) or such earlier date on which this Agreement terminates in accordance with Section 5 of this Agreement. On the Expiration Date and each anniversary thereof, the Expiration Date shall be extended by one year unless (a) the Agreement has been earlier terminated under Section 5 or (b) either party gives written notice not less than 60 days prior to the then Expiration Date that the Agreement will not be extended. Notwithstanding any extension of the Expiration Date, this Agreement may terminate at any time in accordance with Section 5, below. As the sole shareholder of the Company, the Parent Company agrees to appoint Executive as the director of the Company at the relevant shareholder’s meeting of the Company, so that the Executive may maintain the status of the director of the Company during the term of this Agreement, including the extended term as stipulated in this Section 2.

3. Nature of Duties. Executive shall initially be the Company’s director and General Manager (“GM”). As such, Executive shall devote his full business time and effort to the performance of his duties for the Company, which he shall perform faithfully and to the best of his ability. Executive shall have all of the customary powers and duties associated with his position. Executive shall be subject to the Company’s policies, work rules, procedures, and approval practices, as generally in effect from time to time for all employees of the Company, to the

extent necessary and appropriate. Executive will report directly to the board of directors of the Company as well as to the non-resident Representative Director of the Company (who also serves as the Parent Company’s Executive Vice President and General Counsel). Notwithstanding the foregoing, nothing contained herein shall preclude the Executive from (a) serving on the boards of directors of other companies or organizations with the approval of the Company’s Board (not to be unreasonably withheld) or serving on the boards of directors of not-for-profit companies or organizations without the approval of the Board, (b) investing in and managing passive investments, or (c) pursuing his personal, financial and legal affairs provided that such activity does not materially interfere with the performance of the Executive's obligations hereunder.

4. Compensation and Related Matters.

(a)           Base Remuneration. The Company shall pay Executive minimum base remuneration at an annual rate of 20,000,000 Yen. Executive’s annual base remuneration shall be divided into 12 installments and one portion thereof (“Base Installment”) shall be paid on the first business day of each month during the term of Executive’s serving as the director of the Company. Executive shall receive a one-time signing bonus upon execution of this Agreement in the amount of 500,000 Yen.

(b)           Discretionary Bonuses. Executive shall be eligible to receive annual bonus compensation in such amounts, if any, to be determined in the sole discretion of the Parent Company’s Board of Directors (the “Board”) or as otherwise set forth under the terms of any future written agreements that Executive and the Company may enter into. Notwithstanding the above, a minimum one-time bonus of $75,000 (USD) shall be promptly paid to Executive if and to the extent the Company receives approval of its lead drug in Japan for the treatment of childhood or adult acute leukemia (or both). This one-time bonus shall be irrespective of any and all other bonus payments which may be approved at any time or from time to time by the Parent Company Board and is intended to be the initial bonus paid to Executive for services rendered under this Agreement. Executive must be providing services hereunder to the Company on the date annual bonuses are distributed in order to receive an annual bonus.

(c)           Stock Options. The Parent Company agrees to grant and issue to Executive stock options (pursuant to the terms of an Option Award Agreement, by and between the Parent Company and the Executive, dated the Effective Date (the “Option Award Agreement”) with terms substantially commensurate with the terms of options previously issued to the Parent Company’s management, to purchase 50,000 shares of common stock of the Parent Company at its fair market value on the Effective Date (the average of the high and low bid price of shares of the Parent Company's common stock). 10,001 of these options shall vest immediately on the Effective Date, and 13,333 of these options shall vest on each of the first, second and third anniversaries of the Effective Date, or earlier pursuant to the terms of the Option Award Agreement.

(d)           Standard Benefits. During his entrustment relationship with the Company, Executive shall be entitled to participate in all employee benefit plans and programs to the extent available to Executive, in accordance with the terms of those plans and programs. Initially, Executive shall receive from the Company and the Company shall provide Executive

with the coverage of Welfare Pension, Unemployment Insurance, Health Insurance and Workers’ Accident Compensation Insurance.

(e)           Vacation. Executive shall be entitled to 20 days paid vacation per year, which shall be pro-rated for partial years. Unused vacation days will carry over only to the following year.

(f)            Expenses. Executive shall be entitled to receive prompt reimbursement for all reasonable and customary travel and business expenses he incurs in connection with his services with the Company, but he must incur and account for those expenses in accordance with the policies and procedures established by the Company.

(g)           Place of Performance. In connection with his providing services as the director of the Company, unless otherwise agreed by the Executive, the Executive shall be based at the principal executive offices of the Company in Tokyo, Japan, except for travel reasonably required for Company business (the "Place of Performance").

5. Termination.

(a)          Rights and Duties. If this Agreement is terminated, he shall be entitled to the amounts or benefits shown on the applicable row of the following table, subject to the balance of this Section 5, beyond which the Company and Executive shall have no further obligations to each other, except Executive’s confidentiality and other obligations under Section 7, the parties’ mutual obligations of dispute resolution under Section 8, or as set forth in any written agreement the parties subsequently enter into.