**Exhibit
      10.23**


**EXECUTIVE
      EMPLOYMENT AGREEMENT**




This
      EXECUTIVE EMPLOYMENT AGREEMENT (the “Agreement”) dated October 10, 2005 by and
      between Callisto Pharmaceuticals, Inc., a Delaware corporation (the “Company”),
      and Dan D’Agostino, an individual (the “Executive”).





The
      Company desires to employ the Executive, and the Executive wishes to accept
      such
      employment with the Company, upon the terms and conditions set forth in this
      Agreement.





NOW
      THEREFORE, in consideration of the foregoing facts and mutual agreements set
      forth below, the parties, intending to be legally bound, agree as
      follows:





1.  Employment .
      The
      Company hereby agrees to employ Executive, and Executive hereby accepts such
      employment and agrees to perform Executive’s duties and responsibilities in
      accordance with the terms and conditions hereinafter set forth.





1.1  Duties
      and Responsibilities .
      Executive shall serve as Chief Business Officer. During the Employment Term,
      Executive shall perform all duties and accept all responsibilities incident
      to
      such positions and other appropriate duties as may be assigned to Executive
      by
      the Company’s Chief Executive Officer from time to time. The Company shall
      retain full direction and control of the manner, means and methods by which
      Executive performs the services for which she is employed hereunder and of
      the
      place or places at which such services shall be rendered.





1.2  Employment
      Term .
      The
      term of Executive’s employment under this Agreement shall commence as of
      October10, 2005 (the “Effective Date”) and shall continue for 12 months, unless
      earlier terminated in accordance with Section 4 hereof. The term of Executive’s
      employment shall be automatically renewed for successive one (1) year periods
      until the Executive or the Company delivers to the other party a written notice
      of their intent not to renew the “Employment Term,” such written notice to be
      delivered at least sixty (60) days prior to the expiration of the then-effective
      “Employment Term” as that term is defined below. The period commencing as of the
      Effective Date and ending 12 months thereafter or such later date to which
      the
      term of Executive’s employment under the Agreement shall have been extended by
      mutual written Agreement is referred to herein as the “Employment
      Term.”





1.3  Extent
      of Service .
      During
      the Employment Term, Executive agrees to use Executive’s best efforts to carry
      out the duties and responsibilities under Section 1.1 hereof and to devote
      substantially all Executive’s business time, attention and energy thereto.
      Executive further agrees not to work either on a part-time or independent
      contracting basis for any other business or enterprise during the Employment
      Term without the prior written consent of the Company’s Board of Directors (the
“Board”), which consent shall not be unreasonably withheld.





1.4  Base
      Salary .
      The
      Company shall pay Executive a base salary (the “Base Salary”) at the annual rate
      of $175,000 (U.S.), payable at such times as the Company customarily pays its
      other senior level executives (but in any event no less often than monthly).
      The
      Base Salary shall be subject to all state, federal, and local payroll tax
      withholding and any other withholdings required by law.









1.5  Incentive
      Compensation .
      Executive shall be eligible to earn a cash bonus of up to 15% of base salary
      for
      each twelve-month period during the Employment Term based on meeting performance
      objectives and bonus criteria to be mutually identified by Executive and the
      Chief Executive Officer. Executive’s bonus, if any, shall be subject to all
      applicable tax and payroll withholdings. Executive is also eligible to receive
      a
      $25,000 cash bonus for the successful in-licensing or acquisition of INX-0125
      (sphingosomal vinorelbine) by the Company or a comparable or greater expansion
      of the Callisto drug pipeline arising from negotiations with Inex
      Pharmaceuticals, Inc. or any other person or entity.




1.6  Options .
      The
      Company’s Compensation Committee (the “Committee”) will make an initial grant of
      options to the Executive as follows:





(a)  an
      incentive ten year option to purchase up to 300,000 additional Company Common
      Shares at an exercise price equal to the fair market value of the Company’s
      common stock on the date of grant, which shall vest in 100,000 amounts on each
      of October 10, 2006, 2007 and 2008, assuming the Executive is employed by the
      Company on such vesting dates; and





(b)  an
      incentive ten year option to purchase 100,000 additional Company Common Shares
      at an exercise price equal to the fair market value of the Company’s common
      stock on the date of grant which vest upon the successful in-licensing or
      acquisition of INX-0125 (sphingosomal vinorelbine) by the Company or a
      comparable or greater expansion of the Callisto drug pipeline arising from
      negotiations with Inex Pharmaceuticals, Inc. or any other person or
      entity.





(c)  The
      option agreement will contain a provision that in the event there shall have
      been a Change in Control of the Company while the Executive is an employee
      of
      the Company and the Executive’s employment by the Company thereafter shall have
      been terminated by the Company (the “Termination Date”) or by the Executive for
      Good Reason, within two years of the date upon which the Change in Control
      shall
      have occurred, unless such termination is as a result of (i) the Executive’s
      death; (ii) the Executive’s Disability; (iii) the Executive’s Retirement
      (termination in accordance with the Company’s Retirement Plan applicable
      to **** its
      employees or in accordance with any other retirement arrangements which have
      been entered into with the Executive) or (iv) the Executive’s termination for
      Cause, all unvested stock options shall immediately and irrevocably vest and
      the
      exercise period of such options shall be automatically extended to the later
      of
      the longest period permitted by the Company’s stock option plans or ten years
      following the Termination Date. For purposes of the option agreement, a “Change
      in Control” shall be deemed to have occurred if (i) there shall be consummated
      (A) any consolidation or merger of the Company in which the Company is not
      the
      continuing or surviving corporation or pursuant to which shares of the Company’s
      Common Stock would be converted into cash, securities or other property, other
      than a merger of the Company in which the holders of the Company’s Common Stock
      immediately prior to the merger have substantially the same proportionate
      ownership of common stock of the surviving









corporation
      immediately after the merger, or (B) any sale, lease, exchange or other transfer
      (in one transaction or a series of related transactions) of all or substantially
      all the assets of the Company; or (ii) the stockholders of the Company shall
      approve any plan or proposal for the liquidation or dissolution of the Company,
      (ii) any person (as such term is used in Sections 13(d) and 14(d)(2) of the
      Securities Exchange Act of 1934 (the “Exchange Act”)), other than the Company or
      any employee benefit plan sponsored by the Company, shall become the beneficial
      owner (within the meaning of Rule 13d-3 under the Exchange Act) of securities
      of
      the Company representing 20% or more of the combined voting power of the
      Company’s then outstanding securities ordinarily (and apart from rights accruing
      in special circumstances) having the right to vote in the election of directors,
      as a result of a tender or exchange offer, open market purchases, privately
      negotiated purchases or otherwise, or (iv) at any time during a period of two
      consecutive years, individuals who at the beginning of such period constituted
      the Board of Directors of the Company shall cease for any reason to constitute
      at least a majority thereof, unless the election or the nomination for election
      by the Company’s stockholders of each new director during such two-year period
      was approved by a vote of at least two-thirds of the directors then still in
      office who were directors at the beginning of such two-year period. “Good
      Reason” shall mean any of the following events unless it occurs with the
      Executive’s express prior written consent:





(i)
            any
                assignment to the Executive by the Company of any duties inconsistent
                with, or any diminution of, the Executive’s position, duties, titles,
                offices, responsibilities and status with the Company immediately
                prior to
                a Change in Control of the Company, or any removal of the Executive
                from
                or any failure to reelect the Executive to any of such positions
                or
                offices, except in connection with the termination of the Executive’s
                employment for Disability, Retirement or Cause or as a result of
                the
                Executive’s death;





(ii)
            any
                reduction by the Company in the Executive’s base salary as in effect on
                the date hereof or as the same may be increased from time to time
                during
                the term of the Agreement or the Company’s failure to increase (within 15
                months of the Executive’s last increase in base salary) the Executive’s
                base salary after a Change in Control of the Company in an amount
                which is
                at least equal, on a percentage basis, to the average percentage
                increase
                in base salary for all officers of the Company effected during the
                preceding 12 months;


(iii)
              any
                  failure by the Company to continue in effect any benefit or incentive
                  plan
                  or arrangement(including,
                  without limitation, the Company’s Retirement Plan, Stock Option Plan for
                  Key Employees, Employee Stock Purchase Plan, 401(k) Savings Plan,
                  group
                  life insurance plan, medical, dental accident and disability insurance
                  plans, annual bonus and contingent bonus arrangement, and any plan
                  or
                  arrangement to receive and exercisestock
                  appreciation rights, or to acquire stock or other securities of
                  the
                  Company) in which the Executive is participating at the time of
                  a Change
                  in Control of the Company (or to substitute and continue other
                  plans
                  providing the Executive with substantially similar benefits) hereinafter
                  referred to as “Benefit Plans”), the taking of any action by the Company
                  which would adversely affect the Executive’s participation in or
                  materially reduce the Executive’s benefits under any such Benefit Plan or
                  deprive the Executive of any material employee benefit enjoyed
                  by the
                  Executive at the time of a Change in Control of the Company, or
                  any
                  failure by the Company to provide the Executive with the number
                  of paid
                  vacation days to which the Executive is entitled in accordance
                  with the
                  vacation policies in effect at the time of a Change of Control
                  of the
                  Company;


(iv)
            a
                relocation of the Company’s principal executive offices from or the
                Executive’s relocation to any place other than the location at which the
                Executive performed the Executive’s duties immediately prior to a Change
                in Control of the Company;





(v)
            a
                substantial increase in business travel obligations of the Executive
                over
                such obligations as they existed at the time of a Change in Control
                of the
                Company;





(vi)
            any
                material breach by the Company of any provision of the stock option
                agreement;





(vii)
            any
                failure by the Company to obtain the assumption of the stock option
                agreement by any successor or assign of the Company;
                or





(viii)
            any
                purported termination of the Executive’s employment after a Change in
                Control which is not effected pursuant to a Company Notice of Termination
                and, for purposes of the stock option agreement, no such purported
                termination shall be effective. For purposes of the stock option
                agreement, a “Company Notice of Termination” shall mean a written notice
                which shall indicate the specific termination provision in this Agreement
                relied upon and which sets forth in reasonable detail the facts and
                circumstances claimed to provide a basis for termination of the
                Executive’s employment under the provision so
                indicated.




(c)  the
      Committee in exercising its unrestricted discretion may grant such additional
      options to the Executive each year of the Employment Term as it deems
      appropriate.




1.7  Other
      Benefits .
      During
      the Employment Term, Executive shall be entitled to participate in all employee
      benefit plans and programs made available to the Company’s senior level
      executives as a group or to its employees generally, as such plans or programs
      may be in effect from time to time (the “Benefit Coverages”), including, without
      limitation, medical, dental, hospitalization, short-term and long-term
      disability and life insurance plans, accidental death and dismemberment
      protection and travel accident insurance. Executive shall be provided office
      space and staff assistance appropriate for Executive’s position and adequate for
      the performance of her duties.




1.8  Reimbursement
      of Expenses; Vacation; Sick Days and Personal Days .
      Executive shall be provided with reimbursement of expenses related to
      Executive’s employment by the Company on a basis no less favorable than that
      which may be authorized from time to time by the Board, in its sole discretion,
      for senior level executives as a group. Executive shall be entitled to vacation
      and holidays in accordance with the Company’s normal personnel policies for
      senior level executives, but not less than three (3) weeks of vacation per
      calendar year, provided Executive shall not utilize more than ten (10)
      consecutive business days without the express consent of the Chief Executive
      Officer. Unused vacation time will be forfeited as of December 31 of each
      calendar year of the Employment Term. Executive shall be entitled to no more
      than an aggregate of ten (10 ) sick days and personal days per calendar
      year.





1.8  No
      Other Compensation .
      Except
      as expressly provided in Sections 1.4 through 1.9, Executive shall not be
      entitled to any other compensation or benefits.





2.  Confidential
      Information .
      Executive recognizes and acknowledges that by reason of Executive’s employment
      by and service to the Company before, during and, if applicable, after the
      Employment Term, Executive will have access to certain confidential and
      proprietary information relating to the Company’s business, which may include,
      but is not limited to, trade secrets, trade “know-how,” product development
      techniques and plans, formulas, customer lists and addresses, financing
      services, funding programs, cost and pricing information, marketing and sales
      techniques, strategy and programs, computer programs and software and financial
      information (collectively referred to as “Confidential Information”). Executive
      acknowledges that such Confidential Information is a valuable and unique asset
      of the Company and Executive covenants that he will not, unless expressly
      authorized in writing by the Company, at any time during the course of
      Executive’s employment use any Confidential Information or divulge or disclose
      any Confidential Information to any person, firm or corporation except in
      connection with the performance of Executive’s duties for the Company and in a
      manner consistent with the Company’s policies regarding Confidential
      Information. Executive also covenants that at any time after the termination
      of
      such employment, directly or indirectly, he will not use any Confidential
      Information or divulge or disclose any Confidential Information to any person,
      firm or corporation, unless such information is in the public domain through
      no
      fault of Executive or except when required to do so by a court of law, by any
      governmental agency having supervisory authority over the business of the
      Company or by any administrative or legislative body (including a committee
      thereof) with apparent jurisdiction to order Executive to divulge, disclose
      or
      make accessible such information. All written Confidential Information
      (including, without limitation, in any computer or other electronic format)
      which comes into Executive’s possession during the course of Executive’s
      employment shall remain the property of the Company. Except as required in
      the
      performance of Executive’s duties for the Company, or unless expressly
      authorized in writing by the Company, Executive shall not remove any written
      Confidential Information from the Company’s premises, except in connection with
      the performance of Executive’s duties for the Company and in a manner consistent
      with the Company’s policies regarding Confidential Information. Upon termination
      of Executive’s employment, the Executive agrees to return immediately to the
      Company all written Confidential Information (including, without limitation,
      in
      any computer or other electronic format) in Executive’s possession. As a
      condition of Executive’s continued employment with the Company and in order to
      protect the Company’s interest in such proprietary information, the Company
      shall require Executive’s execution of a Confidentiality Agreement and
      Inventions Agreement in the form attached hereto as Exhibit “A”, and
      incorporated herein by this reference.









3.  Non-Competition;
      Non-Solicitation .





3.1  Non-Compete .
      The
      Executive hereby covenants and agrees that during the term of this Agreement
      and
      for a period of one year following the end of the Employment Term, the Executive
      will not, without the prior written consent of the Company, directly or
      indirectly, on his own behalf or in the service or on behalf of others, whether
      or not for compensation, engage in any business activity, or have any interest
      in any person, firm, corporation or business, through a subsidiary or parent
      entity or other entity (whether as a shareholder, agent, joint venturer,
      security holder, trustee, partner, consultant, creditor lending credit or money
      for the purpose of establishing or operating any such business, partner or
      otherwise) with any Competing Business in the Covered Area. For the purpose
      of
      this Section 3.1, (i) “Competing Business” means any biotechnology or
      pharmaceutical company, any contract manufacturer, any research laboratory
      or
      other company or entity (whether or not organized for profit) that has, or
      is
      seeking to develop, one or more products or therapies that is related to
      azaspiranes, anthracyclines and guanylyl cyclase receptor agonists and (ii)
      “Covered Area” means all geographical areas of the United States, Ireland,
      Germany and other foreign jurisdictions where Company then has offices and/or
      sells its products directly or indirectly through distributors and/or other
      sales agents. Notwithstanding the foregoing, the Executive may own shares of
      companies whose securities are publicly trades, so long as such securities
      do
      not constitute more than one percent (1%) of the outstanding securities of
      any
      such company.





3.2  Non-Solicitation .
      The
      Executive further agrees that as long as the Agreement remains in effect and
      for
      a period of one (1) year from its termination, the Executive will not divert
      any
      business of the Company and/or its affiliates or any customers or suppliers
      of
      the Company and/or the Company’s and/or its affiliates’ business to any other
      person, entity or competitor, or induce or attempt to induce, directly or
      indirectly, any person to leave his or her employment with the
      Company.





3.3  Remedies .
      The
      Executive acknowledges and agrees that his obligations provided herein are
      necessary and reasonable in order to protect the Company and its affiliates
      and
      their respective business and the Executive expressly agrees that monetary
      damages would be inadequate to compensate the Company and/or its affiliates
      for
      any breach by the Executive of his covenants and agreements set forth herein.
      Accordingly, the Executive agrees and acknowledges that any such violation
      or
      threatened violation of this Section 3 will cause irreparable injury to the
      Company and that, in addition to any other remedies that may be available,
      in
      law, in equity or otherwise, the Company and its affiliates shall be entitled
      to
      obtain injunctive relief against he threatened breach of this Section 3 or
      the
      continuation of any such breach by the Executive without the necessity of
      proving actual damages.





4.  Termination .





4.1  By
      Company .
      The
      Company, by action of the Chief Executive Officer or acting by duly adopted
      resolutions of the Board of Directors, may, in its discretion and at its option,
      terminate the Executive’s employment with or without Cause, and without
      prejudice to any other right or remedy to which the Company or Executive may
      be
      entitled at law or in equity









or
      under
      this Agreement. In the event the Company desires to terminate the Executive’s
      employment without Cause, the Company shall give the Executive not less than
      sixty (60) days advance written notice. Termination of Executive’s employment
      hereunder shall be deemed to be “for Cause” in the event that Executive violates
      any provisions of this Agreement, is guilty of any criminal act other than
      minor
      traffic violations, is guilty of willful misconduct or gross neglect, or gross
      dereliction of his duties hereunder or refuses to perform his duties hereunder
      after notice of such refusal to perform such duties or directions was given
      to
      Executive by the Chief Executive Officer or Board of Directors.





4.2  By
      Executive’s Death or Disability .
      This
      Agreement shall also be terminated upon the Executive’s death and/or a finding
      of permanent physical or mental disability, such disability expected to result
      in death or to be of a continuous duration of no less than twelve (12) months,
      and the Executive is unable to perform his usual and essential duties for the
      Company.





4.3  Compensation
      on Termination .
      In the
      event the Company terminates Executive’s employment, all payments under this
      Agreement shall cease, except for Base Salary to the extent already accrued.
      In
      the event of termination by reason of Executive’s death and/or permanent
      disability, Executive or his executors, legal representatives or administrators,
      as applicable, shall be entitled to an amount equal to Executive’s Base Salary
      accrued through the date of termination, plus a pro rata share of any annual
      bonus to which Executive would otherwise be entitled for the year which death
      or
      permanent disability occurs. Upon termination of Executive, if Executive
      executes a written release, substantially in the form attached hereto as Exhibit
      “B” (the “Release”), of any and all claims against the Company and all related
      parties with respect to all matters arising out of Executive’s employment by the
      Company (other than Executive’s entitlement under any employee benefit plan or
      program sponsored by the Company in which Executive participated), unless the
      Employment Term expires or termination is for Cause, the Executive shall
      receive, in full settlement of any claims Executive may have related to his
      employment by the Company, Base Salary for 90 calendar days from the date of
      termination, provided Executive is in full compliance with the provisions of
      Sections 2 and 3 of this Agreement.





4.4  Voluntary
      Termination .
      Executive may voluntarily terminate the Employment Term upon sixty (60) days’
prior written notice for any reason; provided, however, that no further payments
      shall be due under this Agreement in that event except that Executive shall
      be
      entitled to any benefits due under any compensation or benefit plan provided
      by
      the Company for executives or otherwise outside of this Agreement.





5.  General
      Provisions .





5.1  Modification:
      No Waiver .
      No
      modification, amendment or discharge of this Agreement shall be valid unless
      the
      same is in writing and signed by all parties hereto. Failure of any party at
      any
      time to enforce any provisions of this Agreement or any rights or to exercise
      any elections hall in no way be considered to be a waiver of such provisions,
      rights or elections and shall in no way affect the validity of this Agreement.
      The exercise by any party of any of its rights or any of this elections under
      this Agreement shall not preclude or prejudice such party from exercising the
      same or any other right it may have under this Agreement irrespective of any
      previous action taken.









5.2  Notices .
      All
      notices and other communications required or permitted hereunder or necessary
      or
      convenient in connection herewith shall be in writing and shall be deemed to
      have been given when hand delivered or mailed by registered or certified mail
      as
      follows (provided that notice of change of address shall be deemed given only
      when received):




If to the Company, to:
            
            Callisto Pharmaceuticals, Inc.420 Lexington Avenue, Suite 1609New
                York, NY 10170If to Executive, to:
            
            Dan D’Agostino61 East 86thSt., #33New York, NY 10018212-427-1640




Or
      to
      such other names or addresses as the Company or Executive, as the case may
      be,
      shall designate by notice to each other person entitled to receive notices
      in
      the manner specified in this Section.





5.3  Governing
      Law .
      This
      Agreement shall be governed by and construed in accordance with the laws of
      the
      State of Delaware.





5.4  Further
      Assurances .
      Each
      party to this Agreement shall execute all instruments and documents and take
      all
      actions as may be reasonably required to effectuate this Agreement.





5.5  Severability .
      Should
      any one or more of the provisions of this Agreement or of any agreement entered
      into pursuant to this Agreement be determined to be illegal or unenforceable,
      then such illegal or unenforceable provision shall be modified by the proper
      court or arbitrator to the extent necessary and possible to make such provision
      enforceable, and such modified provision and all other provisions of this
      Agreement and of each other agreement entered into pursuant to this Agreement
      shall be given effect separately from the provisions or portion thereof
      determined to be illegal or unenforceable and shall not be affected
      thereby.





5.6  Successors
      and Assigns .
      Executive may not assign this Agreement without the prior written consent of
      the
      Company. The Company may assign its rights without the written consent of the
      executive, so long as the Company or its assignee complies with the other
      material terms of this Agreement. The rights and obligations of the Company
      under this Agreement shall inure to the benefit of and be binding upon the
      successors and permitted assigns of the Company, and the Executive’s rights
      under this Agreement shall inure to the benefit of and be binding upon his
      heirs
      and executors. The Company’s subsidiaries and controlled affiliates shall be
      express third party beneficiaries of this Agreement.









5.7  Entire
      Agreement .
      This
      Agreement supersedes all prior agreements and understandings between the
      parties, oral or written. No modification, termination or attempted waiver
      shall
      be valid unless in writing, signed by the party against whom such modification,
      termination or waiver is sought to be enforced.





5.8  Counterparts;
      Facsimile .
      This
      Agreement may be executed in one or more counterparts, each of which shall
      for
      all purposes be deemed to be an original, and all of which taken together shall
      constitute one and the same instrument. This Agreement may be executed by
      facsimile with original signatures to follow.









IN
      WITNESS WHEREOF, the undersigned, intending to be legally bound, have executed
      this Agreement as of the date first written above.


CALLISTO
                PHARMACEUTICALS, INC.By:
            /s/
              Gary
              S. JacobGary
                S. Jacob, Ph.D.
              Chief
                Executive Officer/s/ Dan D’AgostinoDan D’Agostino