COUGAR
      BIOTECHNOLOGY, INC.

     

    RESTRICTED
      STOCK AGREEMENT

    
 

     

    This
      Restricted Stock Agreement (this
      “Agreement”)
      made
      effective as of December 29, 2006, is by and between Cougar Biotechnology,
      Inc.,
      a Delaware corporation (the “Company”),
      and
      Arie Belldegrun (“Director”).

     

    INTRODUCTION

     

    A. The
      Company has adopted the 2003 Stock Option Plan (the “Plan”)
      to
      increase stockholder value and to advance the interests of the Company by
      furnishing a variety of economic incentives, including restricted stock,
      designed to attract, retain and motivate employees.

     

    B. The
      Board
      of Directors of the Company (the “Committee”)
      believes that entering into this Agreement with Director is consistent with
      the
      stated purposes for which the Plan was adopted.

     

    C. Pursuant
      to a Stock Option Agreement dated August 24, 2004 with Dr. Arie Belldegrun,
      a
      director and Chairman of the Corporation’s Scientific Advisory Board, the
      Corporation issued to Dr. Belldegrun an option to purchase 38,411 shares of
      the
      Corporation’s common stock at an exercise price of $0.39 per share (as adjusted
      to give effect to the Company’s April 3, 2006 merger and related transactions
      with SRKP 4, Inc.) (the “Option”);

     

    D. At
      the
      time of the grant of the Option, the fair market value of the common stock,
      as
      determined by the Board, was $2.60 per share;

     

    E. Section
      409A of the Internal Revenue Code, which was enacted in late 2004, provides
      that
      options granted with an exercise price less than the fair market value of the
      common stock on the date of grant are deemed “non-qualified deferred
      compensation” and are subject to income tax as the option vests, plus a 20%
      excise tax;

     

    F. Pursuant
      to IRS transition regulations relating to 409A, taxpayers are allowed to amend
      such option awards until the end of 2006 to increase the exercise price to
      the
      fair market value of the common stock on the date of grant, and further allowed
      to receive restricted stock as compensation for the increase exercise price
      applicable to such holder’s option;

     

    G. Pursuant
      to the transition regulations, the Board believes it is in the best interest
      of
      the Corporation to amend the Option to increase the exercise price from $0.39
      per share to $2.60 per share, the fair market value of the common stock on
      the
      date of grant, and to issue to Dr. Belldegrun 18,864 shares of restricted stock
      as additional compensation for the increase in exercise price applicable to
      the
      Option, such number of shares of restricted stock determined by calculating
      the
      aggregate increased exercise price of the Option ($84,888.31) and dividing
      such
      amount by the fair market value of the common stock as of the date hereof
      ($4.50).

     

    AGREEMENT

     

    Now,
      Therefore,
      it is
      agreed as follows:

     

    1. Grant
      of Stock.
      Subject
      to the terms and provisions of this Agreement and the Plan, the Company hereby
      grants to Director Eighteen Thousand Eight Hundred Sixty-Four (18,864) shares
      of
      Company’s common stock (the “Shares”).
      Upon
      the execution of this Agreement, the Shares shall be registered on the books
      of
      the Company, and the Company shall cause the transfer agent and registrar of
      its
      common stock to issue a certificate in Director’s name evidencing the Shares
      (the “Stock
      Certificate”).
      Director shall immediately thereafter deposit with the Company, together with
      a
      stock power endorsed in blank by Director, the Stock Certificate to be held
      by
      the Company until such time as the restrictions set forth herein and under
      the
      Plan have lapsed pursuant to paragraph 4 of this Agreement. The Stock
      Certificate shall bear a legend in substantially the following
      form:

     

    
      
        
        

      

      
         

        
          

        

      

      
        
        

      

    

    The
      transferability of this certificate and the shares of Common Stock represented
      by it are subject to the terms and conditions of a Restricted Stock Agreement
      dated December 29, 2006 entered into between the registered owner and the
      Company. A copy of the agreement is on file in the office of the secretary
      of
      the Company.

     

    2. Rights
      of Director.
      Upon
      the execution of this Agreement and issuance of the Shares, Director shall
      become a stockholder with respect to the Shares and shall have all of the rights
      of a stockholder with respect to the Shares, including the right to vote the
      Shares and to receive all dividends and other distributions paid with respect
      to
      the Shares; provided,
      however,
      that
      the Shares shall be subject to the restrictions set forth in paragraph 3 of
      this
      Agreement.

     

    3. Restrictions.
      Director agrees that, in addition to the restrictions set forth in the Plan,
      at
      all times prior to the vesting of the Shares as contemplated by paragraph 4
      hereof:

     

    (a) Director
      shall not sell, transfer, pledge, hypothecate or otherwise encumber the Shares;
      and

     

    (b) If
      Director’s service to the Company as a director is terminated for any reason
      whatsoever, or Director violates the terms of any confidentiality agreement,
      non-solicitation covenant or covenant not to compete, however delineated, then,
      subject to paragraph 4 hereof, Director shall, for no consideration, forfeit
      and
      transfer to the Company all of the Shares that remain subject to the
      restrictions set forth in this paragraph 3.

     

    4. Lapse
      of Restrictions.
      The
      restrictions set forth in paragraph 3 shall lapse on January 2, 2007. Upon
      request of Director at any time after the date that the restrictions set forth
      in paragraph 3 of this Agreement have lapsed and the Shares have become vested,
      free and clear of all restrictions, except as provided in the Plan, the Company
      shall remove any restrictive notations placed on the books of the Company and
      the Stock Certificate in connection with such restrictions.

     

    5. Copy
      of 2003 Stock Option Plan.
      By the
      execution of this Agreement, Director acknowledges receipt of a copy of the
      Plan, the terms of which are hereby incorporated herein by reference and made
      a
      part hereof by reference as if set forth in full.

     

    6. Administration.
      This
      Agreement shall at all times be subject to the terms of the Plan. The Board
      of
      Directors of the Company (the “Board”)
      or, if
      delegated to a committee of the Board of Directors of the Company under the
      Plan, the committee (the “Committee”)
      shall
      have the sole and complete discretion with respect to all matters reserved
      to it
      by the Plan and decisions of the Board or the Committee with respect thereto
      and
      to this Agreement shall be final and binding upon Director. In the event of
      any
      conflict between the terms of this Agreement and the Plan, the provisions of
      the
      Plan shall govern and control.

     

    7. Continuation
      of Employment.
      This
      Agreement shall not confer upon Director, and shall not be construed to confer
      upon Director, any right to continue to serve as a director of the Company
      or to
      employment with the Company for any period of time, and shall not limit the
      rights of the Company in its sole discretion (absent any other agreements to
      the
      contrary).

     

    
      
        
        

      

      
        2

        
          

        

      

      
        
        

      

    

    8. Withholding
      of Tax.
      To the
      extent that the receipt of the Shares or the lapse of any restrictions thereon
      results in income to Director for federal or state income-tax purposes, Director
      shall deliver to the Company at the time of such receipt or lapse, as the case
      may be, such amount of money or shares of unrestricted stock as the Company
      may
      require to meet its withholding obligation under applicable tax laws or
      regulations, and, if Director fails to do so, the Company is authorized to
      withhold from any cash or stock remuneration then or thereafter payable to
      Director any tax required to be withheld by reason of such resulting
      compensation income. The Director may have Shares withheld to satisfy the
      withholding tax obligation pursuant to an election under the Plan.

     

    9. Section
      83(b) Election.
      Director understands that he (and not the Company) shall be responsible for
      his
      own federal, state, local or foreign tax liability and any of his other tax
      consequences that may arise as a result of the transactions contemplated by
      this
      Agreement. Director shall rely solely on the determinations of his tax advisors
      or his own determinations, and not on any statements or representations by
      the
      Company or any of its agents, with regard to all such tax matters. Director
      understands that Section 83 of the Code taxes as ordinary income the difference
      between the amount paid for the Shares and the fair market value of the Shares
      as of the date any restrictions on the Shares lapse. In this context,
“restriction” includes without limitation the vesting restrictions set forth in
      paragraph 4 hereof. “Restriction” with respect to officers, directors and 10%
      stockholders also means the period during which such officer, director and
      10%
      stockholders could be subject to suit under Section 16(b) of the Securities
      Exchange Act of 1934 in connection with a sale. Director understands that
      Director may elect to be taxed at the time the Shares are received rather than
      when and as the restrictions on the Shares lapse or expire by filing an election
      under Section 83(b) of the Code with the Internal Revenue Service within 30
      days
      from the date of the acquisition. In the event Director files an election under
      Section 83(b) of the Code, such election shall contain all information required
      under the applicable treasury regulation(s) and Director shall deliver a copy
      of
      such election to the Company contemporaneously with filing such election with
      the Internal Revenue Service.

     

    DIRECTOR
      ACKNOWLEDGES THAT IT IS DIRECTOR’S SOLE RESPONSIBILITY AND NOT THE COMPANY’S TO
      FILE TIMELY THE ELECTION UNDER SECTION 83(B) OF THE CODE, EVEN IF DIRECTOR
      REQUESTS THAT THE COMPANY OR ITS REPRESENTATIVES MAKE THIS FILING ON DIRECTOR’S
      BEHALF.

     

    10. Governing
      Law.
      This
      Agreement, in its interpretation and effect, shall be governed by the laws
      of
      the State of Delaware applicable to contracts executed and to be performed
      therein.

     

    11. Amendments.
      This
      Agreement may be amended only by a written agreement executed by the Company
      and
      Director.

     

    12. Entire
      Agreement.
      This
      Agreement embodies the entire agreement made between the parties hereto with
      respect to matters covered herein and shall not be modified except in accordance
      with paragraph 11 of this Agreement.

     

    13. Counterparts.
      This
      Agreement may be executed in any number of counterparts, each of which shall
      be
      deemed an original, but all of which shall constitute but one and the same
      agreement. Signatures hereto may be delivered by facsimile or other means of
      electronic transmission, and signatures so delivered shall be valid and binding
      to the same extent as original signatures.

     

    Signature
      Page Follows

     

    


     


    
      
        
        

      

      
        3

        
          

        

      

       

    



    In
      Witness Whereof,
      the
      parties have executed this Restricted Stock Agreement to be effective as of
      the
      date first set forth above.

     

    
      	 	 	 
	 	COUGAR
              BIOTECHNOLOGY, INC.
	 
 	 
 	 
 
	 	By:  	 
	 	 	
              
                

              

              Alan H. Auerbach

              President and Chief Executive Officer

            
	 	 	 
	 	 	 
	 	 	DIRECTOR:
	 	 	 
	 	 	 
	 	
              
                

              

              
                Arie
                  Belldegrun

              

            
	 	 


    

     

    


    
Signature
      Page—Restricted Stock
      Agreement

     

    
      
        
        

      

      
        4