Exhibit
      10.55

    SUNESIS
      PHARMACEUTICALS, INC.

     

    2008
      Bonus Program

     

     

    I.         
Overview

     

    The 2008 Bonus Program
      (the “Program”) of Sunesis Pharmaceuticals, Inc. (the
“Company”) is designed to motivate,
      retain and reward
      its employees through a combination of corporate and individual
      performance-based incentive compensation components. Employees of the Company
      employed at the Company during 2008 who are designated by the Compensation
      Committee of the Company’s Board of Directors (the
“Committee”) and who remain employed by the Company as
      of the Payment Date (as defined below) (each a
“Participant”) shall be eligible to participate in the
      Program unless otherwise determined by the Committee. The Program is
      administered by the Committee in its sole discretion.  

     

    The Program is designed
      to
      award a cash bonus payment (each a “Cash Bonus”) for
      performance in 2008 to  Participants based on the level of achievement by
      the Company of certain corporate objectives (the “Corporate
      Objectives”) and, in the case of each Participant, based on such
      Participant’s level of achievement of certain individual performance objectives,
      which may take into consideration certain department, group and/or team
      objectives applicable to such Participant (the “Individual
      Objectives”). 

     

    II.       
Program Objectives

     

    The Program is intended
      to
      encourage and incentivize the following:

     

    	the annual achievement of Corporate Objectives; and
        
	the annual achievement of Individual Objectives, 


     

    as well as to recognize
      individual contributions and effort. 

     

    III.      
Determination
      of 2008 Objectives

     

    The Corporate Objectives
      shall be approved by the Committee, with input from management, and generally
      relate to the achievement of certain research, clinical development, business
      development, financial, business and similar milestones.  Each Corporate
      Objective is also assigned a relative weighting from the Committee, reflecting
      its importance to the achievement of the Company’s key results for 2008.

     

    The Individual Objectives
      shall be set as follows:

     

    	For the Chief Executive Officer and the Executive Chairman, the Individual
        Objectives shall be set by the Committee, subject to approval by the Company’s
        Board of Directors;
        
	For the Participants that are executive officers (as that term is defined
        under Section 16 of the Securities Exchange Act of 1934, as amended, and
        Rule
        16a-1 thereunder), other than the Chief Executive Officer and the Executive
        Chairman (collectively, the “Executive
        Participants”), the Individual Objectives shall be set by
        the Committee based upon recommendations made by the Chief Executive Officer;
        and
        
	For non-Executive Participants (collectively, the
        “Non-Executive Participants”), the Individual
        Objectives shall be set by each such Participant’s immediate supervisor, with
        input from team leaders, group and department heads and the Human Resources
        department, as appropriate. 


     

    
      
        
        

      

      
        
        

        
          

        

      

      
        
        

      

    

     

    IV.      
2008 Bonus Targets

     

    For 2008, each Participant
      is eligible for up to a specified percentage of his or her annual base salary,
      based upon the position such Participant holds with the Company (the
“Bonus Target”).  Under the Program, the Bonus
      Targets range from 25% to 40% of
      a
      Participant’s annual base salary for Vice President level employees and
      above and a range from 6% to 20% of a Participant’s annual base salary for other
      Participants.  

     

    V.        
Determination
      of 2008 Cash Bonus Payments

     

    Cash bonuses under the
      Program are anticipated to be paid out in the first quarter of 2009. 
Actual determination of cash bonuses to be paid out under the Program for 2008
      shall be made as follows:

     

    Determination of Level
      of Achievement of Corporate Objectives

     

    In the first quarter of
      2009, the Committee shall determine, after receiving and considering
      recommendations from management, the degree to which the Corporate Objectives
      have been met, expressed as a percentage of Corporate Objectives achieved,
      taking into consideration the weighting assigned to each Corporate
      Objective.  At this time, the Committee determines the final aggregate
      bonus pool under the Program for all Participants (the “Bonus
      Pool”),  depending on the extent to which the Corporate
      Objectives were met or exceeded.  

     

    Adjustment of Bonus
      Targets based on Level of Achievement of Corporate Objectives

     

    Bonus Target levels for
      Participants are also adjusted based on level of achievement of Corporate
      Objectives as determined by the Committee.  For example, if the Committee
      determines that only 80% of the 2008 Corporate Objectives are achieved, each
      Participant’s Bonus Target is decreased by 20% (in other words, a Participant
      with a 10% Bonus Target will have that Bonus Target reduced to 8%, or 80% of
      10%.)  Such adjusted Bonus Targets are referred to as the
“Adjusted Bonus Targets.”

     

    Determination of Bonus
      Payments for Individual Participants

     

    Individual bonus payouts
      to individual Participants are based on their (i) level of contribution to
      the
      achievement of the Corporate Objectives; and (ii) level of achievement of such
      Participant’s Individual Objectives.  The determination of the level of
      such contribution and achievement shall be made as follows:

     

    	For the Chief Executive Officer and the Executive Chairman, the Committee
        shall determine if and to what extent their Individual Objectives have been
        achieved, as well as their contribution to the achievement of Corporate
        Objectives, subject to approval by the Company’s Board of Directors;
        
	For Executive Participants, the Committee shall determine if and to what
        extent their Individual Objectives have been achieved, as well as their
        contribution to the achievement of Corporate Objectives, based upon
        recommendations made by the Chief Executive Officer; and 


    	For Non-Executive Participants, the Company’s Executive Committee shall
        determine if and to what extent their Individual Objectives have been
        achieved, as well as their contribution to the achievement of Corporate
        Objectives, with input from team leaders, group and department heads and
        supervisors, as appropriate. 


     

    
      
        
        

      

      
        
        

        
          

        

      

      
        
        

      

    

    After assessing each such
      Participant’s achievements as described above, each Participant’s actual cash
      bonus payout (“Cash Bonus”), as a percentage of such
      Participant’s Adjusted Target Bonus, will be determined based on the assessment
      of each such Participant’s 2008 achievements as follows:

     

    	The Committee shall determine the Cash Bonus for each of the Chief
        Executive Officer and the Executive Chairman, subject to approval by the
        Company’s Board of Directors;
        
	The Committee shall determine the Cash Bonus for each Vice President level
        employee and above, other than the Company’s Chief Executive Officer and
        Executive Chairman, based upon recommendations made by the Chief Executive
        Officer; and 


    	The Company’s Executive Committee shall determine the Cash Bonus for each
        Non-Executive Participant, with input from team leaders, group and department
        heads and supervisors, as appropriate. 


     

    The Committee has final
      authority with respect to the determination of the Cash Bonus, if any, for
      each
      Executive Participant and Non-Executive Participant.

     

    VI.      
Timing of Cash
      Payments Under the Program

     

    Payment of Cash Bonuses under the Program shall
      occur on February 27, 2009 or upon such other date as determined by the
      Committee in its sole discretion (the “Payment
      Date”).  

     

    VII.     
Miscellaneous
      Provisions

     

    Participation in the
      Program shall not alter in any way the at will nature of the Company’s
      employment of a Participant, and such employment may be terminated at any time
      for any reason, with or without cause and with or without prior notice. 
Nothing in this Program shall be construed to be a guarantee that any
      Participant will receive all or part of a Cash Bonus or to imply a contract
      between the Company and any Participant. 

     

    This Program supersedes
      and replaces all prior cash incentive and bonus plans of the
      Company.  The Board of Directors or the Committee may amend or
      terminate this Program at any time, with or without notice. The Committee may
      likewise terminate an individual’s participation in the Program at any time,
      with or without notice.  Further, the Board of Directors or the Committee
      may modify the Corporate Objectives, the Individual Objectives, the Bonus
      Targets and/or the Cash Bonus amounts at any time.  The Committee may
      adjust the cash payouts hereunder based on achievement of publicly announced
      targets, clinical milestones, strategic goals, cross-functional teamwork and
      collaboration, and unforeseen changes in the economy and/or geopolitical
      climate.

     

    The Program shall be
      interpreted in accordance with California law without reference to conflicts
      of
      law principles.