**Exhibit 10.22**

**EXTENSION AND AMENDMENT AGREEMENT**

**AGREEMENT**dated as of February15, 2007 (the “Agreement”) between Callisto Pharmaceuticals, Inc., a  Delaware corporation (the “Company”) and GaryS. Jacob (the “Executive”).

TheCompany’s Board of Directors has determined, in light of the importance of theExecutive’s services to the stability and interests of the Company and itsstockholders, to extend the term and amend certain provisions of the EmploymentAgreement between the Company and the Executive dated as of June 13, 2003, asamended October 19, 2005 (the “Employment Agreement”).

NOW,THEREFORE, in consideration of the premises and the mutual covenants containedin this Agreement, it is agreed between the Company and the Executive asfollows:

1.             EXTENSION AND AMENDMENT OF EMPLOYMENT AGREEMENT.

(a)           Extension.  The “Employment Term” defined in Section 1.2of the Employment Agreement as amended by the Extension and SeveranceCompensation Agreement dated as of June 9, 2005 between the Company and the Executive (the “Extension Agreement”) ishereby extended to December 31, 2009, unless earlier terminated in accordancewith Section 4 of the Employment Agreement and the Extension Agreement.

(b)           Compensation.  The Company agrees to maintain Executive’s “BaseSalary” (as defined in the Employment Agreement) at $300,000 per year, payablemonthly in approximate equal installments in advance.  In addition, the Executive shall be grantedan aggregate of 225,000 ten-year incentive stock options pursuant to the Company’sStock Option Plan (the “Plan”) at an exercise price  per share equal to the fair market value ofthe Company’s Common Stock on the date of execution of this Agreement, as suchvalue is defined in the Plan.  Subject tothe provisions of the Plan, the Extension Agreement and Section 4 of theEmployment Agreement, one third of such options shall vest on December 31,2007, 2008 and 2009.  Once vested, theoptions may be exercised until their expiration, notwithstanding any provisionof the Plan which requires exercise following termination of services in ashorter period.  The Company will includethe shares of equity securities of the Company which may be issued upon theexercise of the options in any registration statement under the Securities Actof 1933 which includes securities issuable to any other executive officer ofthe Company.  The Executive shall beeligible to earn a cash bonus of up to $60,000 for each twelve-month periodduring the Term based on meeting performance objectives and bonus criteria tobe mutually identified by Executive and the Company’s Board of Directors andany additonal bonuses and option grants as may be determined by theCompensation Committee of the Company’s Board in its sole discretion.

(c)           Effect on Employment Agreement.  Except as modified by this Agreement, all ofthe terms of the Employment Agreement shall continue in full force and effect.In the event of a discrepancy between the Employment Agreement and thisAgreement, the terms of this Agreement shall be controlling.

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2.             NOTICE.

Forpurposes of this Agreement, notices and all other communications provided forin this Agreement shall be in writing and shall be deemed to have been dulygiven when delivered or mailed by United States registered mail, return receiptrequested, postage prepaid, as follows:

if to the Company:

Callisto Pharmaceuticals,Inc.

420 Lexington Avenue,Suite 1609

New York, New York 10070

or such otheraddress as either party may have furnished to the other in writing inaccordance herewith, except that notices of change of address shall beeffective only upon receipt.

3.             MISCELLANEOUS.

Noprovisions of this Agreement may be modified, waived or discharged unless suchwaiver, modification or discharge is agreed to in a writing signed by the Executiveand the Company. No waiver by either party hereto at any time of any breach bythe other party hereto of, or compliance with, any condition or provision ofthis Agreement to be performed by such other party shall be deemed a waiver ofsimilar or dissimilar provisions or conditions at the same or at any prior tosubsequent time. No agreements or representations, oral or otherwise, expressor implied, with respect to the subject matter hereof have been made by****either party which are not set forth expressly in thisAgreement. This Agreement shall be governed by and construed in accordance withthe laws of Delaware.

4.               VALIDITY.

The invalidity or enforceability of any provi­sions ofthis Agreement shall not affect the validity or enforce­ability of any other provision of this Agreement, which shallremain in full force and effect.

5.             COUNTERPARTS.

ThisAgreement may be executed in one or more counterparts, each of which shall bedeemed to be an original but all of which together will constitute one and sameinstrument*.*

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6.             LEGAL FEES AND EXPENSES.

TheCompany or one of its subsidiaries shall pay all legal fees and expenses whichthe Executive may incur as a result of the Company’s contesting the**validity, enforceability or the Executive’s interpretation of,or determinations under, this Agreement.
|        | CALLISTO PHARMACEUTICALS, INC., |
|--------|---------------------------------|
|   |                            |
|   |                            |
|   |                            |
|   | By:                             | /s/ Gabriele  M. Cerrone |   |
|   |                            | Name: Gabriele M. Cerrone |
|   |                            | Title:   Chairman |
|   |                            |
|   |                            |
|   |                            |
|   | /s/ Gary S.  Jacob              |   |
|   | Gary S. Jacob                   |
|   |                            |
|   |                            |
|        |                                 |  |  |  |  |

 

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