Document:

Exhibit
        4.2

       

    

    NEITHER
      THESE SECURITIES NOR THE SECURITIES ISSUABLE UPON EXERCISE OF THESE SECURITIES
      HAVE BEEN REGISTERED WITH THE SECURITIES AND EXCHANGE COMMISSION OR THE
      SECURITIES COMMISSION OF ANY STATE IN RELIANCE UPON AN EXEMPTION FROM
      REGISTRATION UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES ACT”)
      AND APPLICABLE STATE SECURITIES LAWS AND, ACCORDINGLY, MAY NOT BE OFFERED OR
      SOLD EXCEPT PURSUANT TO (I) AN EFFECTIVE REGISTRATION STATEMENT UNDER THE
      SECURITIES ACT OR (II) AN AVAILABLE EXEMPTION FROM, OR IN A TRANSACTION NOT
      SUBJECT TO, THE REGISTRATION REQUIREMENTS OF THE SECURITIES ACT AND IN
      ACCORDANCE WITH APPLICABLE STATE SECURITIES LAWS OR BLUE SKY LAWS. THESE
      SECURITIES AND THE SECURITIES ISSUABLE UPON EXERCISE OF THESE SECURITIES MAY
      BE
      PLEDGED IN CONNECTION WITH A BONA FIDE MARGIN ACCOUNT OR OTHER LOAN SECURED
      BY
      SUCH SECURITIES.

     

    ZIOPHARM
      ONCOLOGY, INC.

     

    WARRANT
      TO PURCHASE COMMON STOCK

     

    
      	
              Warrant
                No. 2007 - [___] 

            	
                

            	
              Original
                Issue Date: February [__], 2007

            

    

     

    ZIOPHARM
      Oncology, Inc., a Delaware corporation (the “Company”),
      hereby certifies that, for value received,
      [            ] or
      its permitted registered assigns (the “Holder”),
      is
      entitled to purchase from the Company up to a total of
      [           ] shares of
      common stock, $0.001 par value (the “Common
      Stock”),
      of
      the Company (each such share, a “Warrant
      Share”
and
      all
      such shares, the “Warrant
      Shares”)
      at an
      exercise price per share equal to $5.75 (as adjusted from time to time as
      provided in Section 9 herein, the “Exercise
      Price”),
      at
      any time and from time to time from on or after the date hereof (the “Trigger
      Date”) and through and including 5:30 P.M., New York City time, on February
      [     ], 2012 (the “Expiration
      Date”),
      and
      subject to the following terms and conditions: 

    

    This
      Warrant (this “Warrant”)
      is
      being issued in connection with a private placement of common stock and warrants
      to purchase common stock pursuant to Securities Purchase Agreements dated
      February 16, 2007, by and among the Company and the Purchasers identified
      therein (the “Purchase
      Agreements”).
      This
      Warrant (this “Warrant”)
      is one
      of a series of similar warrants issued pursuant to that certain Placement
      Agents’ engagement letter dated February 15, 2007, by and among the Company and
      the Placement Agents identified therein (the “Engagement
      Letter”).
      All
      such warrants are referred to herein, collectively, as the “Warrants.”

    

     1.
       Definitions.
      In
      addition to the terms defined elsewhere in this Warrant, capitalized terms
      that
      are not otherwise defined herein have the meanings given to such terms in the
      Purchase Agreement. 

      

    2.  Registration
      of Warrants.
      The
      Company shall register this Warrant, upon records to be maintained by the
      Company for that purpose (the “Warrant
      Register”),
      in
      the name of the record Holder (which shall include the initial Holder or, as
      the
      case may be, any registered assignee to which this Warrant is permissibly
      assigned hereunder) from time to time. The Company may deem and treat the
      registered Holder of this Warrant as the absolute owner hereof for the purpose
      of any exercise hereof or any distribution to the Holder, and for all other
      purposes, absent actual notice to the contrary. 

     

    
      
        
        

      

      
        
        

        
          

        

      

      
        
        

      

    

     

    3.
       Registration
      of Transfers.
      Subject
      to the restrictions on transfer set forth in Section 4.1 of the Purchase
      Agreement and compliance with all applicable securities laws, the Company shall
      register the transfer of all or any portion of this Warrant in the Warrant
      Register, upon (i) surrender of this Warrant, with the Form of Assignment
      attached as Schedule
      2
      hereto
      duly completed and signed, to the Company’s transfer agent or to the Company at
      its address specified herein and (ii) if the Registration Statement is not
      effective, (x) delivery, at the request of the Company, of an opinion of counsel
      reasonably satisfactory to the Company to the effect that the transfer of such
      portion of this Warrant may be made pursuant to an available exemption from
      the
      registration requirements of the Securities Act and all applicable state
      securities or blue sky laws and (y) delivery by the transferee of a written
      statement to the Company certifying that the transferee is an “accredited
      investor” as defined in Rule 501(a) under the Securities Act and making the
      representations and certifications set forth in Section 3.2(b), (c) and (d)
      of
      the Purchase Agreement, to the Company at its address specified in the Purchase
      Agreement. Upon any such registration or transfer, a new warrant to purchase
      Common Stock in substantially the form of this Warrant (any such new warrant,
      a
“New
      Warrant”)
      evidencing the portion of this Warrant so transferred shall be issued to the
      transferee, and a New Warrant evidencing the remaining portion of this Warrant
      not so transferred, if any, shall be issued to the transferring Holder. The
      acceptance of the New Warrant by the transferee thereof shall be deemed the
      acceptance by such transferee of all of the rights and obligations of a Holder
      of a Warrant. 

     

    4.
       Exercise
      and Duration of Warrants.
      

     

    (a)
       All
      or
      any part of this Warrant shall be exercisable by the registered Holder at any
      time and from time to time on or after the Trigger Date and through and
      including 5:30 P.M. New York City time on the Expiration Date. Subject to
      Section 11 hereof, at 5:30 P.M., New York City time, on the Expiration Date,
      the
      portion of this Warrant not exercised prior thereto shall be and become void
      and
      of no value and this Warrant shall be terminated and no longer outstanding;
      

    

    (b) The
      Holder may exercise this Warrant by delivering to the Company (i) an exercise
      notice, in the form attached as Schedule 1 hereto (the “Exercise
      Notice”),
      appropriately completed and duly signed, (ii) payment of the Exercise Price
      for
      the number of Warrant Shares as to which this Warrant is being exercised (which
      may take the form of a “cashless exercise” if so indicated in the Exercise
      Notice and if a “cashless exercise” may occur at such time pursuant to Section
      10 below), and the date such items are delivered to the Company (as determined
      in accordance with the notice provisions hereof) is an “Exercise
      Date.”
The
      delivery by (or on behalf of) the Holder of the Exercise Notice and the
      applicable Exercise Price as provided above shall constitute the Holder’s
      certification to the Company that its representations contained in Section
      3.2(b), (c) and (d) of the Purchase Agreement are true and correct as of the
      Exercise Date as if remade in their entirety (or, in the case of any transferee
      Holder that is not a party to the Purchase Agreement, such transferee Holder’s
      certification to the Company that such representations are true and correct
      as
      to such assignee Holder as of the Exercise Date). The Holder shall not be
      required to deliver the original Warrant in order to effect an exercise
      hereunder. Execution and delivery of the Exercise Notice shall have the same
      effect as cancellation of the original Warrant and issuance of a New Warrant
      evidencing the right to purchase the remaining number of Warrant
      Shares.

     

    
      
        
        

      

      
        
        

        
          

        

      

      
        
        

      

    

    

    5.
       Delivery
      of Warrant Shares.
       Upon
      exercise of this Warrant, the Company shall promptly (but in no event later
      than
      three Trading Days after the Exercise Date) issue or cause to be issued and
      cause to be delivered to or upon the written order of the Holder and in such
      name or names as the Holder may designate (provided that, if the Registration
      Statement is not effective and the Holder directs the Company to deliver a
      certificate for the Warrant Shares in a name other than that of the Holder
      or an
      Affiliate of the Holder, it shall deliver to the Company on the Exercise Date
      an
      opinion of counsel reasonably satisfactory to the Company to the effect that
      the
      issuance of such Warrant Shares in such other name may be made pursuant to
      an
      available exemption from the registration requirements of the Securities Act
      and
      all applicable state securities or blue sky laws), a certificate for the Warrant
      Shares issuable upon such exercise, free of restrictive legends, unless a
      registration statement covering the resale of the Warrant Shares and naming
      the
      Holder as a selling stockholder thereunder is not then effective or the Warrant
      Shares are not freely transferable without volume restrictions pursuant to
      Rule
      144(k) under the Securities Act. The Holder, or any Person permissibly so
      designated by the Holder to receive Warrant Shares, shall be deemed to have
      become the holder of record of such Warrant Shares as of the Exercise Date.
      If
      the Warrant Shares are to be issued free of all restrictive legends, the Company
      shall, upon the written request of the Holder, use its best efforts to deliver,
      or cause to be delivered, Warrant Shares hereunder electronically through The
      Depository Trust Company or another established clearing corporation performing
      similar functions, if available; provided, that, the Company may, but will
      not
      be required to, change its transfer agent if its current transfer agent cannot
      deliver Warrant Shares electronically through such a clearing
      corporation.

      

    6.
       Charges,
      Taxes and Expenses.
      Issuance and delivery of certificates for shares of Common Stock upon exercise
      of this Warrant shall be made without charge to the Holder for any issue or
      transfer tax, transfer agent fee or other incidental tax or expense in respect
      of the issuance of such certificates, all of which taxes and expenses shall
      be
      paid by the Company; provided,
      however,
      that
      the Company shall not be required to pay any tax which may be payable in respect
      of any transfer involved in the registration of any certificates for Warrant
      Shares or Warrants in a name other than that of the Holder or an Affiliate
      thereof. The Holder shall be responsible for all other tax liability that may
      arise as a result of holding or transferring this Warrant or receiving Warrant
      Shares upon exercise hereof. 

     

    7.
       Replacement
      of Warrant.
      If this
      Warrant is mutilated, lost, stolen or destroyed, the Company shall issue or
      cause to be issued in exchange and substitution for and upon cancellation
      hereof, or in lieu of and substitution for this Warrant, a New Warrant, but
      only
      upon receipt of evidence reasonably satisfactory to the Company of such loss,
      theft or destruction (in such case) and, in each case, a customary and
      reasonable indemnity (which shall not include a surety bond), if requested.
      Applicants for a New Warrant under such circumstances shall also comply with
      such other reasonable regulations and procedures and pay such other reasonable
      third-party costs as the Company may prescribe. If a New Warrant is requested
      as
      a result of a mutilation of this Warrant, then the Holder shall deliver such
      mutilated Warrant to the Company as a condition precedent to the Company’s
      obligation to issue the New Warrant. 

     

    8.
       Reservation
      of Warrant Shares.
      The
      Company covenants that it will at all times reserve and keep available out
      of
      the aggregate of its authorized but unissued and otherwise unreserved Common
      Stock, solely for the purpose of enabling it to issue Warrant Shares upon
      exercise of this Warrant as herein provided, the number of Warrant Shares which
      are then issuable and deliverable upon the exercise of this entire Warrant,
      free
      from preemptive rights or any other contingent purchase rights of persons other
      than the Holder (taking into account the adjustments and restrictions of
Section
      9).
      The
      Company covenants that all Warrant Shares so issuable and deliverable shall,
      upon issuance and the payment of the applicable Exercise Price in accordance
      with the terms hereof, be duly and validly authorized, issued and fully paid
      and
      nonassessable. The Company will take all such action as may be necessary to
      assure that such shares of Common Stock may be issued as provided herein without
      violation of any applicable law or regulation, or of any requirements of any
      securities exchange or automated quotation system upon which the Common Shares
      may be listed.

     

    
      
        
        

      

      
        
        

        
          

        

      

      
        
        

      

    

     

    9.
       Certain
      Adjustments.
      The
      Exercise Price and number of Warrant Shares issuable upon exercise of this
      Warrant are subject to adjustment from time to time as set forth in this
Section
      9.
      

     

    (a)  Stock
      Dividends and Splits.
      If the
      Company, at any time while this Warrant is outstanding, (i) pays a stock
      dividend on its Common Stock or otherwise makes a distribution on any class
      of
      capital stock that is payable in shares of Common Stock, (ii) subdivides its
      outstanding shares of Common Stock into a larger number of shares, or (iii)
      combines its outstanding shares of Common Stock into a smaller number of shares,
      then in each such case the Exercise Price shall be multiplied by a fraction,
      the
      numerator of which shall be the number of shares of Common Stock outstanding
      immediately before such event and the denominator of which shall be the number
      of shares of Common Stock outstanding immediately after such event. Any
      adjustment made pursuant to clause (i) of this paragraph shall become effective
      immediately after the record date for the determination of stockholders entitled
      to receive such dividend or distribution, and any adjustment pursuant to clause
      (ii) or (iii) of this paragraph shall become effective immediately after the
      effective date of such subdivision or combination. 

     

    (b) Fundamental
      Transactions.
      If, at
      any time while this Warrant is outstanding (i) the Company effects any merger
      or
      consolidation of the Company with or into another Person, in which the Company
      is not the survivor, (ii) the Company effects any sale of all or substantially
      all of its assets or a majority of its Common Stock is acquired by a third
      party, in each case, in one or a series of related transactions, (iii) any
      tender offer or exchange offer (whether by the Company or another Person) is
      completed pursuant to which all or substantially all of the holders of Common
      Stock are permitted to tender or exchange their shares for other securities,
      cash or property, or (iv) the Company effects any reclassification of the Common
      Stock or any compulsory share exchange pursuant to which the Common Stock is
      effectively converted into or exchanged for other securities, cash or property
      (other than as a result of a subdivision or combination of shares of Common
      Stock covered by Section 9(a) above) (in any such case, a “Fundamental
      Transaction”),
      then
      the Holder shall have the right thereafter to receive, upon exercise of this
      Warrant, the same amount and kind of securities, cash or property as it would
      have been entitled to receive upon the occurrence of such Fundamental
      Transaction if it had been, immediately prior to such Fundamental Transaction,
      the holder of the number of Warrant Shares then issuable upon exercise in full
      of this Warrant without regard to any limitations on exercise contained herein
      (the “Alternate
      Consideration”).
      The
      Company shall not effect any such Fundamental Transaction unless prior to or
      simultaneously with the consummation thereof, any successor to the Company,
      surviving entity or the corporation purchasing or otherwise acquiring such
      assets or other appropriate corporation or entity shall assume the obligation
      to
      deliver to the Holder, such Alternate Consideration as, in accordance with
      the
      foregoing provisions, the Holder may be entitled to purchase and/or receive
      (as
      the case may be), and the other obligations under this Warrant. The provisions
      of this paragraph (c) shall similarly apply to subsequent transactions analogous
      to a Fundamental Transaction.

    

    (c)
       Number
      of Warrant Shares.
      Simultaneously with any adjustment to the Exercise Price pursuant to paragraph
      (a) of this Section, the number of Warrant Shares that may be purchased upon
      exercise of this Warrant shall be increased or decreased proportionately, so
      that after such adjustment the aggregate Exercise Price payable hereunder for
      the increased or decreased number of Warrant Shares shall be the same as the
      aggregate Exercise Price in effect immediately prior to such adjustment.

     

    
      
        
        

      

      
        
        

        
          

        

      

      
        
        

      

    

                                    

    (d)
       Calculations.
      All
      calculations under this Section
      9
      shall be
      made to the nearest cent or the nearest 1/100th
      of a
      share, as applicable. The number of shares of Common Stock outstanding at any
      given time shall not include shares owned or held by or for the account of
      the
      Company, and the sale or issuance of any such shares shall be considered an
      issue or sale of Common Stock. 

     

    (e)
       Notice
      of Adjustments.
      Upon
      the occurrence of each adjustment pursuant to this Section
      9,
      the
      Company at its expense will, at the written request of the Holder, promptly
      compute such adjustment, in good faith, in accordance with the terms of this
      Warrant and prepare a certificate setting forth such adjustment, including
      a
      statement of the adjusted Exercise Price and adjusted number or type of Warrant
      Shares or other securities issuable upon exercise of this Warrant (as
      applicable), describing the transactions giving rise to such adjustments and
      showing in detail the facts upon which such adjustment is based. Upon written
      request, the Company will promptly deliver a copy of each such certificate
      to
      the Holder and to the Company’s transfer agent. 

     

    (f)
       Notice
      of Corporate Events.
      If,
      while this Warrant is outstanding, the Company (i) declares a dividend or any
      other distribution of cash, securities or other property in respect of its
      Common Stock, including, without limitation, any granting of rights or warrants
      to subscribe for or purchase any capital stock of the Company, (ii) authorizes
      or approves, enters into any agreement contemplating or solicits stockholder
      approval for any Fundamental Transaction or (iii) authorizes the voluntary
      dissolution, liquidation or winding up of the affairs of the Company, then,
      except if such notice and the contents thereof shall be deemed to constitute
      material non-public information, the Company shall deliver to the Holder a
      notice describing the material terms and conditions of such transaction at
      least
      ten (10) Trading Days prior to the applicable record or effective date on which
      a Person would need to hold Common Stock in order to participate in or vote
      with
      respect to such transaction, and the Company will take all steps reasonably
      necessary in order to insure that the Holder is given the practical opportunity
      to exercise this Warrant prior to such time so as to participate in or vote
      with
      respect to such transaction; provided,
      however,
      that
      the failure to deliver such notice or any defect therein shall not affect the
      validity of the corporate action required to be described in such notice.

     

    10.
       Payment
      of Exercise Price.
      The
      Holder shall pay the Exercise Price in immediately available funds, or the
      Holder may, in its sole discretion, satisfy its obligation to pay the Exercise
      Price through a “cashless exercise”, in which event the Company shall issue to
      the Holder the number of Warrant Shares determined as follows: 

     

    X
      = Y
      [(A-B)/A] 

     

    where:
      

     

    X
      = the
      number of Warrant Shares to be issued to the Holder. 

     

    Y
      = the
      total number of Warrant Shares with respect to which this Warrant is being
      exercised. 

     

    A
      = the
      average of the Closing Sale Prices of the shares of Common Stock (as reported
      by
      Bloomberg Financial Markets) for the five Trading Days ending on the date
      immediately preceding the Exercise Date. 

     

    B
      = the
      Exercise Price then in effect for the applicable Warrant Shares at the time
      of
      such exercise. 

     

    
      
        
        

      

      
        
        

        
          

        

      

      
        
        

      

    

     

    For
      purposes of this Warrant, “Closing
      Sale Price”
means,
      for any security as of any date, the last trade price for such security on
      the
      principal securities exchange or trading market for such security, as reported
      by Bloomberg Financial Markets, or, if such exchange or trading market begins
      to
      operate on an extended hours basis and does not designate the last trade price,
      then the last trade price of such security prior to 4:00:00 p.m., New York
      Time,
      as reported by Bloomberg Financial Markets, or if the foregoing do not apply,
      the last trade price of such security in the over-the-counter market on the
      electronic bulletin board for such security as reported by Bloomberg Financial
      Markets, or, if no last trade price is reported for such security by Bloomberg
      Financial Markets, the average of the bid prices, or the ask prices,
      respectively, of any market makers for such security as reported in the "pink
      sheets" by Pink Sheets LLC. If the Closing Sale Price cannot be calculated
      for a
      security on a particular date on any of the foregoing bases, the Closing Sale
      Price of such security on such date shall be the fair market value as mutually
      determined by the Company and the Holder. If the Company and the Holder are
      unable to agree upon the fair market value of such security, then the Company
      shall, within two business days submit via facsimile (a) the disputed
      determination of the Warrant Exercise Price to an independent, reputable
      investment bank selected by the Company and approved by the Holder or (b) the
      disputed arithmetic calculation of the Warrant Shares to the Company's
      independent, outside accountant. The Company shall cause at its expense the
      investment bank or the accountant, as the case may be, to perform the
      determinations or calculations and notify the Company and the Holder of the
      results no later than ten business days from the time it receives the disputed
      determinations or calculations. Such investment bank's or accountant's
      determination or calculation, as the case may be, shall be binding upon all
      parties absent demonstrable error. All such determinations to be appropriately
      adjusted for any stock dividend, stock split, stock combination or other similar
      transaction during the applicable calculation period.

    

    For
      purposes of Rule 144 promulgated under the Securities Act, it is intended,
      understood and acknowledged that the Warrant Shares issued in a cashless
      exercise transaction shall be deemed to have been acquired by the Holder, and
      the holding period for the Warrant Shares shall be deemed to have commenced,
      on
      the date this Warrant was originally issued pursuant to the Purchase Agreement
      (provided that the Commission continues to take the position that such treatment
      is proper at the time of such exercise). 

     

    11.
       Intentionally
      Omitted.
      

    

    12.
       No
      Fractional Shares.
      No
      fractional Warrant Shares will be issued in connection with any exercise of
      this
      Warrant. In lieu of any fractional shares which would otherwise be issuable,
      subject to Section 11, the number of Warrant Shares to be issued shall be
      rounded up to the next whole number. 

     

    13.
       Notices.
      Any and
      all notices or other communications or deliveries hereunder (including, without
      limitation, any Exercise Notice) shall be in writing and shall be deemed given
      and effective on the earliest of (i) the date of transmission, if such notice
      or
      communication is delivered via facsimile at the facsimile number specified
      in
      the Purchase Agreement prior to 5:30 p.m. (New York City time) on a Trading
      Day,
      (ii) the next Trading Day after the date of transmission, if such notice or
      communication is delivered via facsimile at the facsimile number specified
      in
      the Purchase Agreement on a day that is not a Trading Day or later than 5:30
      p.m. (New York City time) on any Trading Day, (iii) the Trading Day following
      the date of mailing, if sent by nationally recognized overnight courier service
      specifying next business day delivery, or (iv) upon actual receipt by the party
      to whom such notice is required to be given, if by hand delivery. The address
      and facsimile number of a party for such notices or communications shall be
      as
      set forth in the Purchase Agreement unless changed by such party by two Trading
      Days’ prior notice to the other party in accordance with this Section 13.

     

    
      
        
        

      

      
        
        

        
          

        

      

      
        
        

      

    

     

    14.
       Warrant
      Agent.
      The
      Company shall serve as warrant agent under this Warrant. Upon thirty (30) days’
notice to the Holder, the Company may appoint a new warrant agent. Any
      corporation into which the Company or any new warrant agent may be merged or
      any
      corporation resulting from any consolidation to which the Company or any new
      warrant agent shall be a party or any corporation to which the Company or any
      new warrant agent transfers substantially all of its corporate trust or
      shareholders services business shall be a successor warrant agent under this
      Warrant without any further act. Any such successor warrant agent shall promptly
      cause notice of its succession as warrant agent to be mailed (by first class
      mail, postage prepaid) to the Holder at the Holder’s last address as shown on
      the Warrant Register. 

     

    15.
       Miscellaneous.
      

     

    (a)  The
      Holder, solely in such Person's capacity as a holder of this Warrant, shall
      not
      be entitled to vote or receive dividends or be deemed the holder of share
      capital of the Company for any purpose, nor shall anything contained in this
      Warrant be construed to confer upon the Holder, solely in such Person's capacity
      as the Holder of this Warrant, any of the rights of a stockholder of the Company
      or any right to vote, give or withhold consent to any corporate action (whether
      any reorganization, issue of stock, reclassification of stock, consolidation,
      merger, amalgamation, conveyance or otherwise), receive notice of meetings,
      receive dividends or subscription rights, or otherwise, prior to the issuance
      to
      the Holder of the Warrant Shares which such Person is then entitled to receive
      upon the due exercise of this Warrant. In addition, nothing contained in this
      Warrant shall be construed as imposing any liabilities on the Holder to purchase
      any securities (upon exercise of this Warrant or otherwise) or as a stockholder
      of the Company, whether such liabilities are asserted by the Company or by
      creditors of the Company. Notwithstanding this Section 15(a), the Company shall
      provide the Holder with copies of the same notices and other information given
      to the shareholders of the Company, contemporaneously with the giving thereof
      to
      the shareholders.

     

    (b)  Subject
      to the restrictions on transfer set forth on the first page hereof and in
      Section 4.1 of the Purchase Agreement, and compliance with applicable securities
      laws, this Warrant may be assigned by the Holder. This Warrant may not be
      assigned by the Company except to a successor in the event of a Fundamental
      Transaction. This Warrant shall be binding on and inure to the benefit of the
      parties hereto and their respective successors and assigns. Subject to the
      preceding sentence, nothing in this Warrant shall be construed to give to any
      Person other than the Company and the Holder any legal or equitable right,
      remedy or cause of action under this Warrant. This Warrant may be amended only
      in writing signed by the Company and the Holder, or their successors and
      assigns. 

     

    (c)  GOVERNING
      LAW; VENUE; WAIVER OF JURY TRIAL. ALL QUESTIONS CONCERNING THE CONSTRUCTION,
      VALIDITY, ENFORCEMENT AND INTERPRETATION OF THIS WARRANT SHALL BE GOVERNED
      BY
      AND CONSTRUED AND ENFORCED IN ACCORDANCE WITH THE LAWS OF THE STATE OF NEW
      YORK
      WITHOUT REGARD TO THE PRINCIPLES OF CONFLICTS OF LAW THEREOF. EACH PARTY HEREBY
      IRREVOCABLY SUBMITS TO THE EXCLUSIVE JURISDICTION OF THE STATE AND FEDERAL
      COURTS SITTING IN THE CITY OF NEW YORK, BOROUGH OF MANHATTAN, FOR THE
      ADJUDICATION OF ANY DISPUTE HEREUNDER OR IN CONNECTION HEREWITH OR WITH ANY
      TRANSACTION CONTEMPLATED HEREBY OR DISCUSSED HEREIN (INCLUDING WITH RESPECT
      TO
      THE ENFORCEMENT OF ANY OF THE TRANSACTION DOCUMENTS), AND HEREBY IRREVOCABLY
      WAIVES, AND AGREES NOT TO ASSERT IN ANY SUIT, ACTION OR PROCEEDING, ANY CLAIM
      THAT IT IS NOT PERSONALLY SUBJECT TO THE JURISDICTION OF ANY SUCH COURT, THAT
      SUCH SUIT, ACTION OR PROCEEDING IS IMPROPER. EACH PARTY HEREBY IRREVOCABLY
      WAIVES PERSONAL SERVICE OF PROCESS AND CONSENTS TO PROCESS BEING SERVED IN
      ANY
      SUCH SUIT, ACTION OR PROCEEDING BY MAILING A COPY THEREOF VIA REGISTERED OR
      CERTIFIED MAIL OR OVERNIGHT DELIVERY (WITH EVIDENCE OF DELIVERY) TO SUCH PARTY
      AT THE ADDRESS IN EFFECT FOR NOTICES TO IT UNDER THIS AGREEMENT AND AGREES
      THAT
      SUCH SERVICE SHALL CONSTITUTE GOOD AND SUFFICIENT SERVICE OF PROCESS AND NOTICE
      THEREOF. NOTHING CONTAINED HEREIN SHALL BE DEEMED TO LIMIT IN ANY WAY ANY RIGHT
      TO SERVE PROCESS IN ANY MANNER PERMITTED BY LAW. THE COMPANY HEREBY WAIVES
      ALL
      RIGHTS TO A TRIAL BY JURY. 

     

    
      
        
        

      

      
        
        

        
          

        

      

      
        
        

      

    

     

    (d)
       The
      headings herein are for convenience only, do not constitute a part of this
      Warrant and shall not be deemed to limit or affect any of the provisions hereof.
      

     

    (e)
       In
      case
      any one or more of the provisions of this Warrant shall be invalid or
      unenforceable in any respect, the validity and enforceability of the remaining
      terms and provisions of this Warrant shall not in any way be affected or
      impaired thereby, and the parties will attempt in good faith to agree upon
      a
      valid and enforceable provision which shall be a commercially reasonable
      substitute therefor, and upon so agreeing, shall incorporate such substitute
      provision in this Warrant. 

     

    (f)
       Except
      as
      otherwise set forth herein, prior to exercise of this Warrant, the Holder hereof
      shall not, by reason of by being a Holder, be entitled to any rights of a
      stockholder with respect to the Warrant Shares. 

     

    [REMAINDER
      OF PAGE INTENTIONALLY LEFT BLANK, 

    SIGNATURE
      PAGE FOLLOWS] 

    
      
        
        

      

      
        
        

        
          

        

      

       

    

    IN
      WITNESS WHEREOF, the Company has caused this Warrant to be duly executed by
      its
      authorized officer as of the date first indicated above. 

     

    
      	 	 	 
	 	
              ZIOPHARM
                ONCOLOGY, INC

            
	 
 	 
 	 
 
	
            	By:  	
            
	 	
              
                

              
Name:
	 	
              Title:

            

    

     

    
      
        
        

      

      
        
        

        
          

        

      

       

    

    SCHEDULE
      1

    FORM
      OF
      EXERCISE NOTICE 

    

    (To
      be
      executed by the Holder to exercise the right to purchase shares of Common Stock
      under the foregoing Warrant)

     

    Ladies
      and Gentlemen:

    

    (1) The
      undersigned is the Holder of Warrant No. __________ (the “Warrant”) issued by
      ZIOPHARM Oncology, Inc. a Delaware corporation (the “Company”). Capitalized
      terms used herein and not otherwise defined herein have the respective meanings
      set forth in the Warrant. 

    

    (2) The
      undersigned hereby exercises its right to purchase __________ Warrant Shares
      pursuant to the Warrant.

      

    (3) The
      Holder intends that payment of the Exercise Price shall be made as (check
      one):

    

    
      	
              o

            	 	Cash Exercise 
	 	 	 
	
              o

            	 	“Cashless Exercise” under Section
              10

    

     

    (4) If
      the
      Holder has elected a Cash Exercise, the Holder shall pay the sum of $_______
      in
      immediately available funds to the Company in accordance with the terms of
      the
      Warrant.

    

    (5) Pursuant
      to this Exercise Notice, the Company shall deliver to the Holder _____________
      Warrant Shares in accordance with the terms of the Warrant.

     

    (6) By
      its
      delivery of this Exercise Notice, the undersigned represents and warrants to
      the
      Company that in giving effect to the exercise evidenced hereby the Holder will
      not beneficially own in excess of the number of shares of Common Stock (as
      determined in accordance with Section 13(d) of the Securities Exchange Act
      of
      1934) permitted to be owned under Section 11 of the Warrant to which this notice
      relates. 

    

    
      	
              Dated:_______________,
                _____ 

            	 	 	 
	 	 	 	 
	
              Name
                of Holder: ___________________________

            	 	 	 
	 	 	 	 
	By:	 	 	
            
	
              
                

              
Name: 	 	 	
            
	
              
                

              

              
                
                  Title:
                    

                

              

            	 	 	
            
	
              
                
 

            	 	 	 

    

    (Signature
      must conform in all respects to name of Holder as specified on the face of
      the
      Warrant)

    
      
        
        

      

      
        
        

        
          

        

      

       

    

    SCHEDULE
      2

    

    ZIOPHARM
      ONCOLOGY, INC.

    

    FORM
      OF
      ASSIGNMENT 

     

    [To
      be
      completed and signed only upon transfer of Warrant]

     

    FOR
      VALUE
      RECEIVED, the undersigned hereby sells, assigns and transfers unto                             
      (the
“Transferee” the right represented by the within Warrant to purchase
                
      shares
      of Common Stock of ZIOPHARM Oncology, Inc. (the “Company”) to which the within
      Warrant relates and appoints                             
      attorney
      to transfer said right on the books of the Company with full power of
      substitution in the premises. In connection therewith, the undersigned
      represents, warrants, covenants and agrees to and with the Company
      that:

    

    
      	 	
              (a)

            	
              the
                offer and sale of the Warrant contemplated hereby is being made in
                compliance with Section 4(1) of the United States Securities Act
                of 1933,
                as amended (the “Securities Act”) or another valid exemption from the
                registration requirements of Section 5 of the Securities Act and
                in
                compliance with all applicable securities laws of the states of the
                United
                States;

            

    

     

    
      	 	
              (b)

            	
              the
                undersigned has not offered to sell the Warrant by any form of general
                solicitation or general advertising, including, but not limited to,
                any
                advertisement, article, notice or other communication published in
                any
                newspaper, magazine or similar media or broadcast over television
                or
                radio, and any seminar or meeting whose attendees have been invited
                by any
                general solicitation or general
                advertising;

            

    

     

    
      	 	
              (c)

            	
              the
                undersigned has read the Transferee’s investment letter included herewith,
                and to its actual knowledge, the statements made therein are true
                and
                correct; and

            

    

     

    
      	 	
              (d)

            	
              the
                undersigned understands that the Company may condition the transfer
                of the
                Warrant contemplated hereby upon the delivery to the Company by the
                undersigned or the Transferee, as the case may be, of a written opinion
                of
                counsel (which opinion shall be in form, substance and scope customary
                for
                opinions of counsel in comparable transactions) to the effect that
                such
                transfer may be made without registration under the Securities Act
                and
                under applicable securities laws of the states of the United
                States.

            

    

     

     

    
      	
              Dated:
                            ,
                    

            	 	 
	
            	
               

            	
              
                

              

              (Signature
                must conform in all respects to name of holder as specified on the
                face of
                the Warrant)

            
	
               

            	
               

            	
            
	
               

            	
               

            	
              
                

                Address
                  of Transferee

              

            
	
               

            	
               

            	
            
	
               

            	
               

            	
              
                
 

            
	
               

            	
               

            	
              
                
 

            

    

     

    
      	
              
                

                In
                  the presence of:EXHIBIT
      10.1

     

    SECURITIES
      PURCHASE AGREEMENT

     

    This
      Securities Purchase Agreement (this “Agreement”)
      is
      dated as of February 16, 2007, by and among ZIOPHARM Oncology, Inc, a Delaware
      corporation (the “Company”),
      and
      each purchaser identified on the signature pages hereto (each, including its
      successors and assigns, a “Purchaser”
and
      collectively, the “Purchasers”).

     

    RECITALS

     

    A. The
      Company and each Purchaser is executing and delivering this agreement in
      reliance upon the exemption from securities registration afforded by Section
      4(2) of the Securities Act of 1933, as amended (the “Securities
      Act”),
      and
      Rule 506 of Regulation D (“Regulation
      D”)
      as
      promulgated by the United States Securities and Exchange Commission under the
      Securities Act.

    

    B. The
      Company desires to raise gross proceeds of up to $35,000,000 pursuant to the
      issuance and sale of (i) shares
      of the
      Common Stock, par value $0.001 per share (the “Common
      Stock”),
      of
      the Company (which shares of Common Stock and shall be collectively referred
      to
      herein as the “Shares”),
      and
      (ii) and warrants, in substantially the form attached hereto as Exhibit
      A
      (the
“Warrants”).

    

    C. Each
      Purchaser, severally and not jointly, wishes to purchase, and the Company wishes
      to sell, upon the terms and conditions stated in this Agreement, (i) that
      aggregate number of Shares set forth below such Purchaser’s name on the
      signature page of this Agreement, and (ii) Warrants to acquire up to that number
      of additional shares of Common Stock equal to 20.0% of the number of Shares
      purchased by such Purchaser (rounded up to the nearest whole share) (the shares
      of Common Stock issuable upon exercise of or otherwise pursuant to the Warrants,
      collectively, the “Warrant
      Shares”).

    

    D. The
      Shares, the Warrants and the Warrant Shares issued pursuant to this Agreement
      are collectively referred to herein as the “Securities”.

    

    E. The
      Company has engaged Oppenheimer & Co. Inc., Griffin Securities, Inc. and
      Paramount BioCapital, Inc. as its placement agents (the “Placement
      Agents”)
      for
      the offering of the Securities on a “best efforts” basis.

    

    F. Contemporaneously
      with the execution and delivery of this Agreement, the parties hereto are
      executing and delivering a Registration Rights Agreement, in the form attached
      hereto as Exhibit
      B
      (the
“Registration
      Rights Agreement”),
      pursuant to which, among other things, the Company will agree to provide certain
      registration rights with respect to the Shares and the Warrant Shares under
      the
      Securities Act and applicable state securities laws.

    

    NOW,
      THEREFORE, IN CONSIDERATION of the mutual covenants contained in this Agreement,
      and for other good and valuable consideration, the receipt and adequacy of
      which
      are hereby acknowledged, the Company and the Purchasers hereby agree as
      follows:

    

    
      
        
          
          

        

        
          
          

          
            

          

        

         

      

    

     

    ARTICLE
      I.

    DEFINITIONS

     

    1.1 Definitions.
      In
      addition to the terms defined elsewhere in this Agreement, for all purposes
      of
      this Agreement, the following terms shall have the meanings indicated in this
      Section 1.1:

     

    “Action”
means
      any action, suit, inquiry, notice of violation, proceeding (including any
      partial proceeding such as a deposition) or investigation pending or, to the
      Company’s Knowledge, threatened in writing against or affecting the Company or
      any of their respective properties before or by any court, arbitrator,
      governmental or administrative agency, regulatory authority (federal, state,
      county, local or foreign), stock market, stock exchange or trading
      facility.

     

    “Affiliate”
means,
      with respect to any Person, any other Person that, directly or indirectly
      through one or more intermediaries, Controls, is controlled by or is under
      common control with such Person, as such terms are used in and construed under
      Rule 144. With respect to a Purchaser, any investment fund or managed account
      that is managed on a discretionary basis by the same investment manager as
      such
      Purchaser will be deemed to be an Affiliate of such Purchaser.

     

    “Agents’
      Representative”
means
      Paramount BioCapital, Inc., as representative of the Placement
      Agents.

     

    “Business
      Day”
means
      a
      day, other than a Saturday or Sunday, on which banks in New York City are open
      for the general transaction of business.

     

    “Closing”
means
      the closing of the purchase and sale of the Shares and the Warrants pursuant
      to
      this Agreement.

     

    “Closing
      Date”
means
      the Trading Day when all of the Transaction Documents have been executed and
      delivered by the applicable parties thereto, and all of the conditions set
      forth
      in Sections 2.1, 2.2, 5.1 and 5.2 hereof are satisfied, or such other date
      as
      the parties may agree.

     

    “Commission”
means
      the United States Securities and Exchange Commission.

     

    “Common
      Stock”
has
      the
      meaning set forth in the Recitals, and also includes any securities into which
      the Common Stock may hereafter be reclassified or changed. 

     

    “Common
      Stock Equivalents”
means
      any securities of the Company which would entitle the holder thereof to acquire
      at any time Common Stock, including, without limitation, any debt, preferred
      stock, rights, options, warrants or other instrument that is at any time
      convertible into or exchangeable for, or otherwise entitles the holder thereof
      to receive, Common Stock or other securities that entitle the holder to receive,
      directly or indirectly, Common Stock.

     

    “Company
      Counsel”
means
      Maslon Edelman Borman & Brand, LLP.

    

       “Company
      Deliverables”
has
      the
      meaning set forth in Section 2.2(a).

    

       “Company’s
      Knowledge”
means
      with respect to any statement made to the knowledge of a party, that the
      statement is based upon the actual knowledge of the officers of such party
      having responsibility for the matter or matters that are the subject of the
      statement.

    

    “Control”
      (including the terms “controlling”, “controlled by” or “under common control
      with”) means the possession, direct or indirect, of the power to direct or cause
      the direction of the management and policies of a Person, whether through the
      ownership of voting securities, by contract or otherwise.

    

    
      
        
          
          

        

        
          2

          
            

          

        

         

      

    

     

    “Disclosure
      Materials”
has
      the
      meaning set forth in Section 3.1(h).

     

    “Effective
      Date”
means
      the date on which the initial Registration Statement required by Section 2(a)
      of
      the Registration Rights Agreement is first declared effective by the
      Commission.

     

    “Effectiveness
      Deadline”
means
      the date on which the initial Registration Statement is required to be declared
      effective by the Commission under the terms of the Registration Rights
      Agreement.

     

    “Environmental
      Laws”
has
      the
      meaning set forth in Section 3.1(l).

     

    “Exchange
      Act”
means
      the Securities Exchange Act of 1934, as amended, or any successor statute,
      and
      the rules and regulations promulgated thereunder.

     

    “GAAP”
means
      U.S. generally accepted accounting principles, as applied by the
      Company.

     

    “Intellectual
      Property”
has
      the
      meaning set forth in Section 3.1(r).

     

    “Irrevocable
      Transfer Agent Instructions”
means,
      with respect to the Company, the Irrevocable Transfer Agent Instructions, in
      the
      form of Exhibit
      E,
      executed by the Company and delivered to and acknowledged in writing by the
      Transfer Agent.

     

    “Lien”
means
      any lien, charge, claim, encumbrance, security interest, right of first refusal,
      preemptive right or other restrictions of any kind.

     

    “Losses”
has
      the
      meaning set forth in Section 4.9(a).

     

    “Material
      Adverse Effect”
means
      any of (i) a material and adverse effect on the legality, validity or
      enforceability of any Transaction Document, (ii) a material and adverse effect
      on the results of operations, assets, prospects, business or financial condition
      of the Company, or (iii) any material adverse impairment to the Company's
      ability to perform in any material respect on a timely basis its obligations
      under any Transaction Document.

     

    “Material
      Contract”
means
      any contract of the Company that was filed as an exhibit to the SEC Reports
      pursuant to Item 601(b)(4) or Item 601(b)(10) of Regulation S-K.

    

    “Material
      Permits”
has
      the
      meaning set forth in Section 3.1(p).

     

    “New
      York Courts”
means
      the state and federal courts sitting in the City of New York, Borough of
      Manhattan.

     

    “Outside
      Date”
means
      five Trading Days following the date of this Agreement.

     

    “Person”
means
      an individual, corporation, partnership, limited liability company, trust,
      business trust, association, joint stock company, joint venture, sole
      proprietorship, unincorporated organization, governmental authority or any
      other
      form of entity not specifically listed herein.

     

    “Principal
      Trading Market”
means
      the Trading Market on which the Common Stock is primarily listed on and quoted
      for trading, which, as of the date of this Agreement and the Closing Date,
      shall
      be the NASDAQ Capital Market.

    

    
      
        
          
          

        

        
          3

          
            

          

        

         

      

    

     

    “Proceeding”
means
      an action, claim, suit, investigation or proceeding (including, without
      limitation, an investigation or partial proceeding, such as a deposition),
      whether commenced or threatened.

     

    “Purchase
      Price”
means
      the sum of (i) the closing bid price of the Company’s Common Stock, as listed on
      the Principal Trading Market, on the date of this Agreement, plus (ii)
      $0.025.

     

    “Purchaser
      Deliverables”
has
      the
      meaning set forth in Section 2.2(b).

     

    “Registration
      Rights Agreement”
has
      the
      meaning set forth in the Recitals.

     

    “Registration
      Statement”
means
      a
      registration statement meeting the requirements set forth in the Registration
      Rights Agreement and covering the resale by the Purchasers of the Registrable
      Securities (as defined in the Registration Rights Agreement).

     

    “Required
      Approvals”
has
      the
      meaning set forth in Section 3.1(e).

     

    “Rule
      144”
means
      Rule 144 promulgated by the Commission pursuant to the Securities Act, as such
      Rule may be amended from time to time, or any similar rule or regulation
      hereafter adopted by the Commission having substantially the same effect as
      such
      Rule.

     

    “SEC
      Reports”
has
      the meaning set forth in Section 3.1(h).

     

    “Secretary’s
      Certificate”
has
      the
      meaning set forth in Section 2.2(a)(vii).

     

    “Securities
      Act”
means
      the Securities Act of 1933, as amended.

     

    “Short
      Sales”
      include, without limitation, all “short sales” as defined in Rule 200
      promulgated under Regulation SHO under the Exchange Act, whether or not against
      the box, and all types of direct and indirect stock pledges, forward sale
      contracts, options, puts, calls, short sales, swaps, “put equivalent positions”
(as defined in Rule 16a-1(h) under the Exchange Act) and similar arrangements
      (including on a total return basis), and sales and other transactions through
      non-US broker dealers or foreign regulated brokers.

     

    “Subscription
      Amount”
means
      with respect to each Purchaser, the aggregate amount to be paid for the Shares
      and the related Warrants purchased hereunder as indicated on such Purchaser’s
      signature page to this Agreement next to the heading “Purchase Price
      (Subscription Amount)”.

     

    “Trading
      Affiliate”
has
      the
      meaning set forth in Section 3.2(g).

     

    “Trading
      Day”
means
      (i) a day on which the Common Stock is listed or quoted and traded on its
      primary Trading Market (other than the OTC Bulletin Board), or (ii) if the
      Common Stock is not listed on a Trading Market (other than the OTC Bulletin
      Board), a day on which the Common Stock is traded in the over-the-counter
      market, as reported by the OTC Bulletin Board, or (iii) if the Common Stock
      is
      not quoted on any Trading Market, a day on which the Common Stock is quoted
      in
      the over-the-counter market as reported by the National Quotation Bureau
      Incorporated (or any similar organization or agency succeeding to its functions
      of reporting prices); provided,
      that in
      the event that the Common Stock is not listed or quoted as set forth in (i),
      (ii) and (iii) hereof, then Trading Day shall mean a Business Day.

     

    “Trading
      Market”
means
      whichever of the New York Stock Exchange, the American Stock Exchange, the
      NASDAQ Global Select Market, the NASDAQ Global Market, the NASDAQ Capital Market
      or the OTC Bulletin Board on which the Common Stock is listed or quoted for
      trading on the date in question.

    

    
      
        
          
          

        

        
          4

          
            

          

        

         

      

    

     

    “Transaction
      Documents”
means
      this Agreement, the schedules and exhibits attached hereto, the Warrants, the
      Registration Rights Agreement, the Irrevocable Transfer Agent Instructions
      and
      any other documents or agreements executed in connection with the transactions
      contemplated hereunder.

     

    “Transfer
      Agent”
means
      American Stock Transfer and Trust Company or any successor transfer agent for
      the Company.

     

    “Warrants”
has
      the
      meaning set forth in the Preamble to this Agreement. The Placement Agents and/or
      their designees are also receiving placement agent warrants as compensation
      for
      services rendered in connection with the transactions set forth herein, which
      warrants shall also constitute “Warrants” for all purposes
      hereunder.

     

    ARTICLE
      II.

    PURCHASE
      AND SALE

     

    2.1 Closing.
      (a)
      Subject to the terms and conditions set forth in this Agreement, at the Closing,
      the Company shall issue and sell to each Purchaser, and each Purchaser shall,
      severally and not jointly, purchase from the Company, such number of Shares
      of
      Common Stock equal to the quotient resulting from dividing (i) the aggregate
      purchase price for such Purchaser, as indicated below such Purchaser’s name on
      the signature page of this Agreement (the “Subscription
      Amount”)
      by
      (ii) the Purchase Price, rounded to the nearest whole Share. In addition, each
      Purchaser shall receive a Warrant to purchase a number of Warrant Shares equal
      to 20% of the number of Shares purchased by such Purchaser, as indicated below
      such Purchaser’s name on the signature page of this Agreement. The Warrants
      shall have an exercise price equal to 110% of the Purchase Price and shall
      be
      exercisable at any time prior to the fifth anniversary of the date of
      issuance.

     

    (b) Each
      Purchaser must complete and return a duly executed, unaltered copy of this
      Agreement (including without limitation the completed Accredited Investor
      Questionnaire and the Stock Certificate Questionnaire included as Exhibits
      C-1
      and C-2 hereto, respectively) to the Agents’ Representative. The Company and the
      Agents’ Representative retain complete discretion to accept or reject any
      subscription unless and until the Company executes a counterpart to this
      Agreement that includes such Purchaser’s signature. Within five Business Days
      after the execution and delivery of this Agreement by Purchaser and the Company,
      each Purchaser shall deposit the amount of readily available funds equal to
      such
      Purchaser’s Subscription Amount in a segregated escrow account (the
“Escrow
      Account”)
      with
      an escrow agent designated by the Agents’ Representative (the “Escrow
      Agent”)
      by
      wire transfer of immediately available funds pursuant to the instructions
      provided below:

     

    (c) The
      Closing shall be held at a date and time designated by the Company and the
      Placement Agents prior to 11:59 p.m. Eastern Standard Time on the Outside Date.
      The Closing shall occur at the offices of the Agents’ Representative, located at
      787 Seventh Avenue, New York, New York 10019, or at such other locations or
      remotely by facsimile transmission or other electronic means as the parties
      may
      mutually agree. Upon satisfaction or waiver of all conditions to the Closing,
      the Agents’ Representative and the Company shall instruct the Escrow Agent to
      release the proceeds held in the Escrow Account to the Company, less fees and
      expenses due to the Placement Agents. Interest, if any, that has accrued with
      respect to the Subscription Amount while in escrow shall also be distributed
      to
      the Company at the Closing and the Purchaser will have no right to such
      interest, even if there is no Closing. 

    

    
      
        
          
          

        

        
          5

          
            

          

        

         

      

    

     

    (d) The
      Company shall deliver, or cause to be delivered, a certificate or certificates,
      registered in such name or names as the Purchasers may designate, representing
      the Shares and Warrants purchased by the Purchaser hereunder as soon as
      practical after the Closing, and in any event within five Business Days, to
      the
      Purchaser’s mailing address indicated on the Stock Certificate Questionnaire
      included as Exhibit C-2 hereto. 

     

    2.2 Closing
      Deliveries.
        (a) On
      or
      prior to the Closing, the Company shall issue, deliver or cause to be delivered
      to each Purchaser the following (the “Company
      Deliverables”):

     

    (i) this
      Agreement, duly executed by the Company;

     

    (ii) one
      or
      more stock certificates, free and clear of all restrictive and other legends
      (except as provided in Section 4.1(b) hereof), evidencing the Shares subscribed
      for by Purchaser hereunder, registered in the name of such Purchaser as set
      forth on the Stock Certificate Questionnaire included as Exhibit C-2
      hereto;

     

    (iii) a
      Warrant, executed by the Company and registered in the name of such Purchaser
      as
      set forth on the Stock Certificate Questionnaire included as Exhibit C-2 hereto,
      pursuant to which such Purchaser shall have the right to acquire such number
      of
      Warrant Shares equal to 20.0% of the number of Shares issuable to such Purchaser
      pursuant to Section 2.2(a)(ii), rounded up to the nearest whole share, on the
      terms set forth therein;

     

    (iv) a
      legal
      opinion of Company Counsel, in the form attached hereto as Exhibit
      D,
      executed by such counsel and addressed to the Purchasers and the Placement
      Agents; 

     

    (v) the
      Registration Rights Agreement, duly executed by the Company; 

     

    (vi) duly
      executed Irrevocable Transfer Agent Instructions acknowledged in writing by
      the
      Transfer Agent;

     

    (vii) a
      certificate of the Secretary of the Company (the “Secretary’s
      Certificate”),
      dated
      as of the Closing Date, (a) certifying the resolutions adopted by the Board
      of
      Directors of the Company approving the transactions contemplated by this
      Agreement and the other Transaction Documents and the issuance of the
      Securities, (b) certifying the current versions of the certificate of
      incorporation, as amended and by-laws of the Company and (c) certifying as
      to
      the signatures and authority of persons signing the Transaction Documents and
      related documents on behalf of the Company;

     

    (viii) the
      Compliance Certificate referred to in Section 5.1(h);

     

    (ix) a
      certificate evidencing the formation and good standing of the Company in the
      State of Delaware issued by the Secretary of State (or comparable office),
      as of
      a date within 10 days of the Closing Date; and

    

    
      
        
          
          

        

        
          6

          
            

          

        

         

      

    

     

    (x) a
      certified copy of the Certificate of Incorporation as certified by the Secretary
      of State of the State of Delaware within ten (10) days of the Closing
      Date.

     

    (b) On
      or
      prior to the Closing, each Purchaser shall deliver or cause to be delivered
      to
      the Company the following (the “Purchaser
      Deliverables”):

     

    (i) this
      Agreement, duly executed by such Purchaser;

     

    (ii) its
      Subscription Amount, in United States dollars and in immediately available
      funds, in the amount set forth as the “Purchase Price” indicated below such
      Purchaser’s name on the applicable signature page hereto by wire transfer to an
      account designated in writing by the Company for such purpose, as set forth
      on
Exhibit
      F
      attached
      hereto; 

     

    (iii) the
      Registration Rights Agreement, duly executed by such Purchaser; 

     

    (iv) a
      fully
      completed and duly executed Selling Stockholder Questionnaire in the form
      attached as Annex
      B
      to the
      Registration Rights Agreement; and

     

    (v) a
      fully
      completed and duly executed Accredited Investor Questionnaire and Stock
      Certificate Questionnaire in the forms attached hereto as Exhibits
      C-1
      and
C-2,
      respectively.

     

    ARTICLE
      III.

    REPRESENTATIONS
      AND WARRANTIES

     

    3.1 Representations
      and Warranties of the Company.
      The
      Company hereby represents and warrants to the Purchasers and to the Placement
      Agents that, except as set forth in the Schedules delivered
      herewith:

     

    (a) Subsidiaries.
      With
      the exception of ZIOPHARM Oncology Limited, a private limited company
      incorporated in England and Wales, the Company has no direct or indirect
      subsidiaries. 

     

    (b) Organization
      and Qualification.
      The
      Company is an entity duly incorporated or otherwise organized, validly existing
      and in good standing under the laws of the jurisdiction of its incorporation
      or
      organization (as applicable), with the requisite power and authority to own
      or
      lease and use its properties and assets and to carry on its business as
      currently conducted. The Company is not in violation of any of the provisions
      of
      its certificate of incorporation, bylaws or other organizational or charter
      documents. The Company is duly qualified to conduct business and is in good
      standing as a foreign corporation or other entity in each jurisdiction in which
      the nature of the business conducted or property owned by it makes such
      qualification necessary, except where the failure to be so qualified or in
      good
      standing, as the case may be, could not have or reasonably be expected to have,
      individually or in the aggregate, resulted in a Material Adverse Effect, and
      no
      Proceeding has been instituted in any such jurisdiction revoking, limiting
      or
      curtailing or seeking to revoke, limit or curtail such power and authority
      or
      qualification. 

     

    (c) Authorization;
      Enforcement; Validity.
      The
      Company has the requisite corporate power and authority to enter into and to
      consummate the transactions contemplated by each of the Transaction Documents
      to
      which it is a party and otherwise to carry out its obligations hereunder and
      thereunder. The execution and delivery of each of the Transaction Documents
      to
      which it is a party by the Company and the consummation by it of the
      transactions contemplated hereby and thereby (including, but not limited to,
      the
      sale and delivery of the Shares and the Warrants and the subsequent issuance
      of
      the Warrant Shares upon exercise of the Warrants) have been duly authorized
      by
      all necessary corporate action on the part of the Company, and no further
      corporate action is required by the Company, its Board of Directors or its
      shareholders in connection therewith other than in connection with the Required
      Approvals. Each of the Transaction Documents to which it is a party has been
      (or
      upon delivery will have been) duly executed by the Company and is, or when
      delivered in accordance with the terms hereof, will constitute the valid and
      binding obligation of the Company enforceable against the Company in accordance
      with its terms, except as such enforceability may be limited by applicable
      bankruptcy, insolvency, reorganization, moratorium, liquidation or similar
      laws
      relating to, or affecting generally the enforcement of, creditors’ rights and
      remedies or by other equitable principles of general application. Except as
      set
      forth on Schedule
      3.1(c)
      hereto,
      there are no shareholder agreements, voting agreements, or other similar
      arrangements with respect to the Company’s capital stock to which the Company is
      a party or, to the Company’s Knowledge, between or among any of the Company’s
      shareholders.

    

    
      
        
          
          

        

        
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    (d) No
      Conflicts.
      The
      execution, delivery and performance by the Company of the Transaction Documents
      to which it is a party and the consummation by the Company of the transactions
      contemplated hereby or thereby (including, without limitation, the issuance
      of
      the Shares and the reservation for issuance and issuance of the Warrant Shares)
      do not and will not (i) conflict with or violate any provision of the Company’s
      certificate of incorporation, bylaws or other organizational or charter
      documents, (ii) conflict with, or constitute a default (or an event that with
      notice or lapse of time or both would become a default) under, result in the
      creation of any Lien upon any of the properties or assets of the Company or
      give
      to others any rights of termination, amendment, acceleration or cancellation
      (with or without notice, lapse of time or both) of, any agreement, credit
      facility, debt or other instrument (evidencing a Company debt or otherwise)
      or
      other understanding to which the Company is a party or by which any property
      or
      asset of the Company is bound or affected, or (iii) subject to the Required
      Approvals, conflict with or result in a violation of any law, rule, regulation,
      order, judgment, injunction, decree or other restriction of any court or
      governmental authority to which the Company is subject (including federal and
      state securities laws and regulations and the rules and regulations, assuming
      the correctness of the representations and warranties made by the Purchasers
      herein, of any self-regulatory organization to which the Company or its
      securities are subject, including all applicable Trading Markets), or by which
      any property or asset of the Company is bound or affected, except in the case
      of
      clauses (ii) and (iii), such as would not, individually or in the aggregate,
      have or reasonably be expected to result in a Material Adverse
      Effect.

     

    (e) Filings,
      Consents and Approvals.
      The
      Company is not required to obtain any consent, waiver, authorization or order
      of, give any notice to, or make any filing or registration with, any court
      or
      other federal, state, local or other governmental authority or other Person
      in
      connection with the execution, delivery and performance by the Company of the
      Transaction Documents (including the issuance of the Securities), other than
      (i)
      the filing with the Commission of one or more Registration Statements in
      accordance with the requirements of the Registration Rights Agreement, (ii)
      filings required by applicable state securities laws, (iii) the filing of a
      Notice of Sale of Securities on Form D with the Commission under Regulation
      D of
      the Securities Act, (iv) the filing of any requisite notices and/or
      application(s) to the Principal Trading Market for the issuance and sale of
      the
      Common Stock and the Warrants and the listing of the Common Stock for trading
      or
      quotation, as the case may be, thereon in the time and manner required thereby
      (except as disclosed on Schedule 3.1(e)), (v) the filings required in accordance
      with Section 4.8 of this Agreement and (vi) those that have been made or
      obtained prior to the date of this Agreement (collectively, the “Required
      Approvals”).

     

    (f) Issuance
      of the Securities.
      The
      Shares have been duly authorized and, when issued and paid for in accordance
      with the terms of the Transaction Documents, will be duly and validly issued,
      fully paid and nonassessable, free and clear of all Liens, other than
      restrictions on transfer provided for in the Transaction Documents or imposed
      by
      applicable securities laws, and shall not be subject to preemptive or similar
      rights of shareholders. The Warrants have been duly authorized and, when issued
      and paid for in accordance with the terms of the Transaction Documents, will
      be
      duly and validly issued, free and clear of all Liens, other than restrictions
      on
      transfer provided for in the Transaction Documents or imposed by applicable
      securities laws, and shall not be subject to preemptive or similar rights of
      shareholders. The Warrant Shares issuable upon exercise of the Warrants have
      been duly authorized and, when issued and paid for in accordance with the terms
      of the Transaction Documents and the Warrants, will be duly and validly issued,
      fully paid and nonassessable, free and clear of all Liens, other than
      restrictions on transfer provided for in the Transaction Documents or imposed
      by
      applicable securities laws, and shall not be subject to preemptive or similar
      rights of shareholders. Assuming the accuracy of the representations and
      warranties of the Purchasers in this Agreement, the Shares and the Warrant
      Shares will be issued in compliance with all applicable federal and state
      securities laws. The Company shall, so long as any of the Warrants are
      outstanding, take all action necessary to reserve and keep available out of
      its
      authorized and unissued capital stock, solely for the purpose of effecting
      the
      exercise of the Warrants, 100% of the number of shares of Common Stock issuable
      upon exercise of the Warrants..

    

    
      
        
          
          

        

        
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    (g) Capitalization.
      The
      number of shares and type of all authorized, issued and outstanding capital
      stock, options and other securities of the Company (whether or not presently
      convertible into or exercisable or exchangeable for shares of capital stock
      of
      the Company) has been set forth in the SEC Reports and has changed since the
      date of such SEC Reports only to reflect stock option and warrant exercises
      that
      do not, individually or in the aggregate, have a material affect on the issued
      and outstanding capital stock, options and other securities. All of the
      outstanding shares of capital stock of the Company are duly authorized, validly
      issued, fully paid and non-assessable, have been issued in compliance in all
      material respects with all applicable federal and state securities laws, and
      none of such outstanding shares was issued in violation of any preemptive rights
      or similar rights to subscribe for or purchase any capital stock of the Company.
      Except as specified in the SEC Reports: (i) no shares of the Company's capital
      stock are subject to preemptive rights or any other similar rights or any liens
      or encumbrances suffered or permitted by the Company; (ii) there are no
      outstanding options, warrants, scrip, rights to subscribe to, calls or
      commitments of any character whatsoever relating to, or securities or rights
      convertible into, or exercisable or exchangeable for, any shares of capital
      stock of the Company, or contracts, commitments, understandings or arrangements
      by which the Company is or may become bound to issue additional shares of
      capital stock of the Company or options, warrants, scrip, rights to subscribe
      to, calls or commitments of any character whatsoever relating to, or securities
      or rights convertible into, or exercisable or exchangeable for, any shares
      of
      capital stock of the Company; (iii) there are no outstanding debt securities,
      notes, credit agreements, credit facilities or other agreements, documents
      or
      instruments evidencing indebtedness of the Company or by which the Company
      is or
      may become bound; (iv) there are no financing statements securing obligations
      in
      any material amounts, either singly or in the aggregate, filed in connection
      with the Company; (v) there are no agreements or arrangements under which the
      Company is obligated to register the sale of any of their securities under
      the
      Securities Act (except the Registration Rights Agreement); (vi) there are no
      outstanding securities or instruments of the Company or which contain any
      redemption or similar provisions, and there are no contracts, commitments,
      understandings or arrangements by which the Company is or may become bound
      to
      redeem a security of the Company; (vii) there are no securities or instruments
      containing anti-dilution or similar provisions that will be triggered by the
      issuance of the Securities; (viii) the Company does not have any stock
      appreciation rights or “phantom stock” plans or agreements or any similar plan
      or agreement; and (ix) the Company has no liabilities or obligations required
      to
      be disclosed in the SEC Reports (as defined herein) but not so disclosed in
      the
      SEC Reports, other than those incurred in the ordinary course of the Company's
      businesses and which, individually or in the aggregate, do not or would not
      have
      a Material Adverse Effect. 

     

    (h) SEC
      Reports.
      The
      Company has filed all reports, schedules, forms, statements and other documents
      required to be filed by it under the Exchange Act, including pursuant to Section
      13(a) or 15(d) thereof, for the two years preceding the date hereof (or such
      shorter period as the Company was required by law or regulation to file such
      material) (the foregoing materials, including the exhibits thereto and documents
      incorporated by reference therein, being collectively referred to herein as
      the
“SEC
      Reports”
and
      together with this Agreement and the Schedules to this Agreement (if any),
      the
“Disclosure
      Materials”),
      on a
      timely basis or has received a valid extension of such time of filing and has
      filed any such SEC Reports prior to the expiration of any such extension. As
      of
      the date hereof, the Company is not aware of any event occurring on or prior
      to
      the Closing Date (other than the transactions contemplated by the Transaction
      Documents) that requires the filing of a Form 8-K after the Closing. As of
      their
      respective dates, or to the extent corrected by a subsequent restatement, the
      SEC Reports complied in all material respects with the requirements of the
      Securities Act and the Exchange Act and the rules and regulations of the
      Commission promulgated thereunder, and none of the SEC Reports, when filed,
      contained any untrue statement of a material fact or omitted to state a material
      fact required to be stated therein or necessary in order to make the statements
      therein, in light of the circumstances under which they were made, not
      misleading.

     

    
      
        
          
          

        

        
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    (i) Financial
      Statements. The
      financial statements of the Company included in the SEC Reports comply in all
      material respects with applicable accounting requirements and the rules and
      regulations of the Commission with respect thereto as in effect at the time
      of
      filing (or to the extent corrected by a subsequent restatement). Such financial
      statements have been prepared in accordance with GAAP applied on a consistent
      basis during the periods involved, except as may be otherwise specified in
      such
      financial statements or the notes thereto and except that unaudited financial
      statements may not contain all footnotes required by GAAP, and fairly present
      in
      all material respects the financial position of the Company of and for the
      dates
      thereof and the results of operations and cash flows for the periods then ended,
      subject, in the case of unaudited statements, to normal, year-end audit
      adjustments. All material agreements to which the Company is a party or to
      which
      the property or assets of the Company are subject are included as part of or
      specifically identified in the SEC Reports.

     

    (j) Tax
      Matters The
      Company (i) has accurately and timely prepared and filed all foreign, federal
      and state income and all other tax returns, reports and declarations required
      by
      any jurisdiction to which it is subject, (ii) has paid all taxes and other
      governmental assessments and charges that are material in amount, shown or
      determined to be due on such returns, reports and declarations, except those
      being contested in good faith, with respect to which adequate reserves have
      been
      set aside on the books of the Company and (iii) has set aside on its books
      provisions reasonably adequate for the payment of all taxes for periods
      subsequent to the periods to which such returns, reports or declarations apply,
      except, in the case of clauses (i) and (ii) above, where the failure to so
      pay
      or file any such tax, assessment, charge or return would not result in a
      Material Adverse Effect. There are no unpaid taxes in any material amount
      claimed to be due by the Company by the taxing authority of any jurisdiction.
      

     

    (k) Material
      Changes.
      Since
      the date of the latest audited financial statements included within the SEC
      Reports, (i) there have been no events, occurrences or developments that have
      had or that could reasonably be expected to result, either individually or
      in
      the aggregate, in a Material Adverse Effect, (ii) the Company has not incurred
      any liabilities (contingent or otherwise) other than (A) trade payables, accrued
      expenses and other liabilities incurred in the ordinary course of business
      consistent with past practice and (B) liabilities not required to be reflected
      in the Company's financial statements pursuant to GAAP or required to be
      disclosed in filings made with the Commission, (iii) the Company has not altered
      its method of accounting or the manner in which it keeps its accounting books
      and records, (iv) the Company has not declared or made any dividend or
      distribution of cash or other property to its shareholders or purchased,
      redeemed or made any agreements to purchase or redeem any shares of its capital
      stock (other than in connection with repurchases of unvested stock issued to
      employees of the Company) and (v) the Company has not issued any equity
      securities to any officer, director or Affiliate, except Common Stock issued
      in
      the ordinary course as dividends on outstanding preferred stock or pursuant
      to
      existing Company stock option or stock purchase plans or executive and director
      corporate arrangements disclosed in the SEC Reports and (vi) there has not
      been
      any material change or amendment to, or any waiver of any material right under,
      any contract under which the Company or any of their assets is bound or subject.
      Except for the issuance of the Securities contemplated by this Agreement or
      as
      set forth in Schedule
      3.1(k)
      hereto,
      no event, liability or development has occurred or exists with respect to the
      Company or its business, properties, operations or financial condition that
      would be required to be disclosed by the Company under applicable securities
      laws at the time this representation is made that has not been publicly
      disclosed at least one Trading Day prior to the date that this representation
      is
      made.

     

    
      
        
          
          

        

        
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    (l) Environmental
      Matters.
      To the
      Company’s Knowledge, the Company (i) is not in violation of any statute, rule,
      regulation, decision or order of any governmental agency or body or any court,
      domestic or foreign, relating to the use, disposal or release of hazardous
      or
      toxic substances or relating to the protection or restoration of the environment
      or human exposure to hazardous or toxic substances (collectively, “Environmental
      Laws”),
      (ii)
      does not own or operate any real property contaminated with any substance that
      is in violation of any Environmental Laws, (iii) is not liable for any off-site
      disposal or contamination pursuant to any Environmental Laws, and (iv) is not
      subject to any claim relating to any Environmental Laws; which violation,
      contamination, liability or claim has had or could reasonably be expected to
      have a Material Adverse Effect, individually or in the aggregate; and there
      is
      no pending or, to the Company’s Knowledge, threatened investigation that might
      lead to such a claim.

     

    (m) Litigation.
      There
      is no Action which (i) adversely affects or challenges the legality, validity
      or
      enforceability of any of the Transaction Documents or the Securities or (ii)
      except as specifically disclosed in the SEC Reports, would, if there were an
      unfavorable decision, individually or in the aggregate, have or reasonably
      be
      expected to result in a Material Adverse Effect. The Company, nor, to the
      Company’s Knowledge, any current director or officer thereof (in his or her
      capacity thereof), is or has been during the five-year period prior to the
      Closing Date the subject of any Action involving a claim of violation of or
      liability under federal or state securities laws or a claim of breach of
      fiduciary duty. There has not been and, to the Company’s Knowledge, there is not
      pending or contemplated, any investigation by the Commission involving the
      Company or, to the Company’s Knowledge, any current or former director or
      officer of the Company (in his or her capacity as such). The Commission has
      not
      issued any stop order or other order suspending the effectiveness of any
      registration statement filed by the Company under the Exchange Act or the
      Securities Act.

     

    (n) Employment
      Matters.
      No
      material labor dispute exists or, to the knowledge of the Company, is imminent
      with respect to any of the employees of the Company which could reasonably
      be
      expected to result in a Material Adverse Effect. None of the Company’s employees
      is a member of a union that relates to such employee’s relationship with the
      Company, and the Company is not a party to a collective bargaining agreement,
      and the Company believes that their relationships with their employees are
      good.
      No executive officer, to the knowledge of the Company, is, or is now expected
      to
      be, in violation of any material term of any employment contract,
      confidentiality, disclosure or proprietary information agreement or
      non-competition agreement, or any other contract or agreement or any restrictive
      covenant, and the continued employment of each such executive officer does
      not
      subject the Company to any liability with respect to any of the foregoing
      matters. The Company is in compliance with all U.S. federal, state, local and
      foreign laws and regulations relating to employment and employment practices,
      terms and conditions of employment and wages and hours, except where the failure
      to be in compliance could not, individually or in the aggregate, reasonably
      be
      expected to have a Material Adverse Effect. 

     

    (o) Compliance.
      The
      Company is not (i) in default under or in violation of (and no event has
      occurred that has not been waived that, with notice or lapse of time or both,
      would result in a default by the Company), nor has the Company received notice
      of a claim that it is in default under or that it is in violation of, any
      indenture, loan or credit agreement or any other agreement or instrument to
      which it is a party or by which it or any of its properties is bound (whether
      or
      not such default or violation has been waived), (ii) in violation of any order
      of any court, arbitrator or governmental body having jurisdiction over the
      Company or its properties or assets, or (iii) in violation of, or in receipt
      of
      notice that it is in violation of, any statute, rule or regulation of any
      governmental authority applicable to the Company, except in each case as could
      not, individually or in the aggregate, have or reasonably be expected to result
      in a Material Adverse Effect. 

    

    
      
        
          
          

        

        
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    (p) Regulatory
      Permits.
      The
      Company possesses all certificates, authorizations and permits issued by the
      appropriate federal, state, local or foreign regulatory authorities necessary
      to
      conduct its business as described in the SEC Reports, except where the failure
      to possess such permits, individually or in the aggregate, has not and could
      not
      reasonably be expected to result in a Material Adverse Effect (“Material
      Permits”),
      and
      the Company has not received any notice of proceedings relating to the
      revocation or modification of any such Material Permits.

     

    (q) Title
      to Assets.
      Except
      for property that is specifically the subject of, and covered by, other
      representations and warranties as to ownership or title contained herein, the
      Company has good and marketable title in fee simple to all real property owned
      by it that is material to its business and good and marketable title in all
      personal property owned by it that is material to its business, in each case
      free and clear of all Liens, except for Liens as do not materially affect the
      value of such property and do not materially interfere with the use made and
      proposed to be made of such property by the Company and Liens for the payment
      of
      federal, state or other taxes, the payment of which is neither delinquent nor
      subject to penalties. Any real property and facilities held under lease by
      the
      Company are held by it under valid, subsisting and enforceable leases of which
      the Company is in material compliance.

     

    (r) Patents
      and Trademarks.
      The
      Company owns, possesses, licenses or has other rights to use all foreign and
      domestic patents, patent applications, trade and service marks, trade and
      service mark registrations, trade names, copyrights, licenses, inventions,
      trade
      secrets, technology, Internet domain names, know-how and other intellectual
      property (collectively, the “Intellectual
      Property”)
      necessary for the conduct of its business as now conducted or as proposed to
      be
      conducted. Except as set forth in the SEC Reports and except where such
      violations or infringements would not reasonably be expected to result, either
      individually or in the aggregate, in a Material Adverse Effect, (a) there
      are no rights of third parties to any such Intellectual Property; (b) to the
      Company’s Knowledge, there is no infringement by third parties of any such
      Intellectual Property; (c) there is no pending or, to the Company’s Knowledge,
      threatened action, suit, proceeding or claim by others challenging the Company’s
      rights in or to any such Intellectual Property, and the Company is unaware
      of
      any facts which would form a reasonable basis for any such claim; (d) there
      is
      no pending or, to the Company’s Knowledge, threatened action, suit, proceeding
      or claim by others challenging the validity or scope of any such Intellectual
      Property; and (e) there is no pending or, to the Company’s Knowledge, threatened
      action, suit, proceeding or claim by others that the Company infringes or
      otherwise violates any patent, trademark, copyright, trade secret or other
      proprietary rights of others, and the Company is unaware of any other fact
      which
      would form a reasonable basis for any such claim.

     

    (s) Insurance.
      The
      Company is insured by insurers of recognized financial responsibility against
      such losses and risks and in such amounts as are prudent and customary in the
      businesses and location in which the Company is engaged. The Company does not
      have any knowledge that it will be unable to renew its existing insurance
      coverage for the Company as and when such coverage expires or to obtain similar
      coverage from similar insurers as may be necessary to continue its business
      without a significant increase in cost.

     

    (t) Transactions
      With Affiliates and Employees.
      Except
      as set forth in the SEC Reports or reported on a Form 4, 3 or 5 filed with
      the
      Commission, in either case at least ten days prior to the date hereof, none
      of
      the officers, directors or employees of the Company is presently a party to
      any
      transaction with the Company (other than for ordinary course services as
      employees, officers or directors), including any contract, agreement or other
      arrangement providing for the furnishing of services to or by, providing for
      rental of real or personal property to or from, or otherwise requiring payments
      to or from any such officer, director or employee or, to the knowledge of the
      Company, any corporation, partnership, trust or other entity in which any such
      officer, director, or employee has a substantial interest or is an officer,
      director, trustee or partner.

    

    
      
        
          
          

        

        
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    (u) Internal
      Accounting Controls.
      The
      Company maintains a system of internal accounting controls sufficient to provide
      reasonable assurance that (i) transactions are executed in accordance with
      management's general or specific authorizations, (ii) transactions are recorded
      as necessary to permit preparation of financial statements in conformity with
      GAAP and to maintain asset accountability, (iii) access to assets is permitted
      only in accordance with management's general or specific authorization, and
      (iv)
      the recorded accountability for assets is compared with the existing assets
      at
      reasonable intervals and appropriate action is taken with respect to any
      differences. 

     

    (v) Sarbanes-Oxley;
      Disclosure Controls.
      The
      Company is in compliance in all material respects with all of the provisions
      of
      the Sarbanes-Oxley Act of 2002 which are applicable to it as of the Closing
      Date. The Company maintains disclosure controls and procedures (as such term
      is
      defined in Rule 13a-15(e) under the Exchange Act) that are effective in ensuring
      that information required to be disclosed by the Company in the reports that
      it
      files or submits under the Exchange Act is recorded, processed, summarized
      and
      reported, within the time periods specified in the rules and forms of the
      Commission, including, without limitation, controls and procedures designed
      in
      to ensure that information required to be disclosed by the Company in the
      reports that it files or submits under the Exchange Act is accumulated and
      communicated to the Company's management, including its principal executive
      officer or officers and its principal financial officer or officers, as
      appropriate, to allow timely decisions regarding required disclosure.

     

    (w) Certain
      Fees.
      No
      person
      or entity will have, as a result of the transactions contemplated by this
      Agreement, any valid right, interest or claim against or upon the Company or
      a
      Purchaser for any commission, fee or other compensation pursuant to any
      agreement, arrangement or understanding entered into by or on behalf of the
      Company, other than the Placement Agents with respect to the offer and sale
      of
      the Securities. Such Placement Agent fees and expenses are set forth on
Schedule
      3.1(w)
      hereto
      and are being paid by the Company. The Company shall pay, and hold each
      Purchaser harmless against, any liability, loss or expense (including, without
      limitation, attorneys’ fees and out-of-pocket expenses) arising in connection
      with any such right, interest or claim.

     

    (x) Private
      Placement.
       Assuming
      the accuracy of the Purchasers’ representations and warranties set forth in
      Section 3.2 of this Agreement, no registration under the Securities Act is
      required for the offer and sale of the Securities by the Company to the
      Purchasers under the Transaction Documents. Other than each of the Purchasers,
      no Person has any right to cause the Company to effect the registration under
      the Securities Act of any securities of the Company other than those securities
      which are currently registered on an effective registration statement on file
      with the Commission. 

     

    (y) No
      Directed Selling Efforts or General Solicitation.
      Neither
      the Company, nor any of its Affiliates, nor any Person acting on its or their
      behalf has conducted any “general solicitation” or “general advertising” (as
      those terms are used in Regulation D) in connection with the offer or sale
      of
      any of the Securities.

     

    (z) No
      Integrated Offering.
      Assuming the accuracy of the Purchasers’ representations and warranties set
      forth in Section 3.2, neither the Company, its Affiliates, nor any Person acting
      on its or their behalf has, directly or indirectly, at any time within the
      past
      six months, made any offers or sales of any Company security or solicited any
      offers to buy any security under circumstances that would (i) eliminate the
      availability of the exemption from registration under Regulation D under the
      Securities Act in connection with the offer and sale by the Company of the
      Securities as contemplated hereby or (ii) cause the offering of the Securities
      pursuant to the Transaction Documents to be integrated with prior offerings
      by
      the Company for purposes of any applicable law, regulation or shareholder
      approval provisions, including, without limitation, under the rules and
      regulations of any Trading Market on which any of the securities of the Company
      are listed or designated.

     

    
      
        
          
          

        

        
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    (aa) Listing
      and Maintenance Requirements.
      The
      Company’s Common Stock is registered pursuant to Section 12(b) of the Exchange
      Act, and the Company has taken no action designed to terminate the registration
      of the Common Stock under the Exchange Act nor has the Company received any
      notification that the Commission is contemplating terminating such registration.
      Except as specified in the SEC Reports, the Company has not, in the two years
      preceding the date hereof, received written notice from any Trading Market
      on
      which the Common Stock is or has been listed or quoted to the effect that the
      Company is not in compliance with the listing or maintenance requirements of
      such Trading Market. The Company is, and has no reason to believe that it will
      not in the foreseeable future continue to be, in compliance in all material
      respects with the listing and maintenance requirements for continued trading
      of
      the Common Stock on the Principal Trading Market. 

     

    (bb) Investment
      Company The
      Company is not required to be registered as, and is not an Affiliate of, and
      immediately following the Closing will not be required to register as, an
“investment company” within the meaning of the Investment Company Act of 1940,
      as amended.

     

    (cc) Questionable
      Payments. The
      Company, nor, to the Company’s Knowledge, any directors, officers, employees,
      agents or other Persons acting on behalf of the Company has, in the course
      of
      its actions for, or on behalf of, the Company: (a) directly or indirectly,
      used
      any corporate funds for unlawful contributions, gifts, entertainment or other
      unlawful expenses relating to foreign or domestic political activity; (b) made
      any direct or indirect unlawful payments to any foreign or domestic governmental
      officials or employees or to any foreign or domestic political parties or
      campaigns from corporate funds; (c) violated in any material respect any
      provision of the Foreign Corrupt Practices Act of 1977, as amended, or (d)
      made
      any other unlawful bribe, rebate, payoff, influence payment, kickback or other
      unlawful payment to any foreign or domestic government official or
      employee.

     

    (dd) Application
      of Takeover Protections; Rights Agreements.
      The
      Company and its board of directors have taken all necessary action, if any,
      in
      order to render inapplicable any control share acquisition, business
      combination, poison pill (including any distribution under a rights agreement)
      or other similar anti-takeover provision under the Company's charter documents
      or the laws of its state of incorporation that is or could reasonably be
      expected to become applicable to any of the Purchasers as a result of the
      Purchasers and the Company fulfilling their obligations or exercising their
      rights under the Transaction Documents, including, without limitation, the
      Company's issuance of the Securities and the Purchasers' ownership of the
      Securities. The Company has not adopted a stockholder rights plan or similar
      arrangement relating to accumulations of beneficial ownership of Common Stock
      or
      a change in control of the Company.

     

    (ee) Disclosure.
      The
      Company confirms that neither it nor any of its officers or directors nor any
      other Person acting on its or their behalf has provided, and it has not
      authorized the Placement Agents to provide, any Purchaser with any information
      that it believes constitutes or could reasonably be expected to constitute
      material, non-public information except insofar as the existence, provisions
      and
      terms of the Transaction Documents and the proposed transactions hereunder
      may
      constitute such information, all of which will be disclosed by the Company
      in
      the Press Release as contemplated by Section 4.8 hereof. The Company understands
      and confirms that the Purchasers will rely on the foregoing representations
      in
      effecting transactions in securities of the Company. All disclosure provided
      to
      the Purchasers regarding the Company, its business and the transactions
      contemplated hereby furnished by the Company or authorized by the Company and
      furnished by the Placement Agents on behalf of the Company (including the
      Company’s representations and warranties set forth in this Agreement) are true
      and correct in all material respects and do not contain any untrue statement
      of
      a material fact or omit to state any material fact necessary in order to make
      the statements made therein, in light of the circumstances under which they
      were
      made, not misleading. No event or circumstance has occurred or information
      exists with respect to the Company or or its business, properties, operations
      or
      financial conditions, which, under applicable law, rule or regulation, requires
      public disclosure or announcement by the Company but which has not been so
      publicly announced or disclosed, except for the announcement of this Agreement
      and related transactions.

     

    
      
        
          
          

        

        
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    (ff) Off
      Balance Sheet Arrangements.
      There
      is no transaction, arrangement, or other relationship between the Company and
      an
      unconsolidated or other off balance sheet entity that is required to be
      disclosed by the Company in its Exchange Act filings and is not so disclosed
      or
      that otherwise would be reasonably likely to have a Material Adverse
      Effect.

     

    (gg) Consultation
      with Auditors.
      The
      Company has consulted its independent auditors concerning the accounting
      treatment of the transactions contemplated by the Transaction Documents and
      in
      connection therewith has furnished such auditors complete copies of the
      Transaction Documents. The Company intends to account for the gross proceeds
      raised from the financing which is the subject of this Agreement as equity
      in
      its financial statements.

     

    (hh) No
      Additional Agreements. The
      Company does not have any agreement or understanding with any Purchaser with
      respect to the transactions contemplated by the Transaction Documents other
      than
      as specified in the Transaction Documents.

     

    (ii) Use
      of
      Form S-3. The
      Company meets the registration and transaction requirements for use of Form
      S-3
      for the registration of the Shares and the Warrant Shares for resale by the
      Purchasers.

     

    3.2 Representations
      and Warranties of the Purchasers.
      Each
      Purchaser hereby, for itself and for no other Purchaser, represents and warrants
      as of the date hereof and as of the Closing Date to the Company and the
      Placement Agents as follows:

     

    (a) Organization;
      Authority.
      Such
      Purchaser is an entity duly organized, validly existing and in good standing
      under the laws of the jurisdiction of its organization with the requisite
      corporate or partnership power and authority to enter into and to consummate
      the
      transactions contemplated by the applicable Transaction Documents and otherwise
      to carry out its obligations hereunder and thereunder. The execution, delivery
      and performance by such Purchaser of the transactions contemplated by this
      Agreement have been duly authorized by all necessary corporate or, if such
      Purchaser is not a corporation, such partnership, limited liability company
      or
      other applicable like action, on the part of such Purchaser. Each of this
      Agreement, the Warrant and the Registration Rights Agreement has been duly
      executed by such Purchaser, and when delivered by such Purchaser in accordance
      with terms hereof, will constitute the valid and legally binding obligation
      of
      such Purchaser, enforceable against it in accordance with its terms, except
      as
      such enforceability may be limited by applicable bankruptcy, insolvency,
      reorganization, moratorium, liquidation or similar laws relating to, or
      affecting generally the enforcement of, creditors’ rights and remedies or by
      other equitable principles of general application.

     

    (b) Investment
      Intent.
      Such
      Purchaser understands that the Securities are “restricted securities” and have
      not been registered under the Securities Act or any applicable state securities
      law and is acquiring the Securities and, upon exercise of the Warrants, will
      acquire the Warrant Shares issuable upon exercise thereof as principal for
      its
      own account and not with a view to, or for distributing or reselling such
      Securities or any part thereof in violation of the Securities Act or any
      applicable state securities laws, provided,
      however,
      that by
      making the representations herein, such Purchaser does not agree to hold any
      of
      the Securities for any minimum period of time and reserves the right, subject
      to
      the provisions of this Agreement and the Registration Rights Agreement, at
      all
      times to sell or otherwise dispose of all or any part of such Securities or
      Warrant Shares pursuant to an effective registration statement under the
      Securities Act or under an exemption from such registration and in compliance
      with applicable federal and state securities laws. Such Purchaser is acquiring
      the Securities hereunder in the ordinary course of its business. Such Purchaser
      does not presently have any agreement, plan or understanding, directly or
      indirectly, with any Person to distribute or effect any distribution of any
      of
      the Securities (or any securities which are derivatives thereof) to or through
      any person or entity. Such Purchaser is not a registered broker-dealer under
      Section 15 of the Exchange Act or an entity engaged in a business that would
      require it to be so registered as a broker-dealer.

     

    
      
        
          
          

        

        
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    (c) Purchaser
      Status.
      At the
      time such Purchaser was offered the Securities, it was, and at the date hereof
      it is, and on each date on which it exercises the Warrants it will be, an
“accredited investor” as defined in Rule 501(a) under the Securities Act.

     

    (d) General
      Solicitation. Such
      Purchaser is not purchasing the Securities as a result of any advertisement,
      article, notice or other communication regarding the Securities published in
      any
      newspaper, magazine or similar media or broadcast over television or radio
      or
      presented at any seminar or any other general advertisement.

     

    (e) Experience
      of Such Purchaser.
      Such
      Purchaser, either alone or together with its representatives, has such
      knowledge, sophistication and experience in business and financial matters
      so as
      to be capable of evaluating the merits and risks of the prospective investment
      in the Securities, and has so evaluated the merits and risks of such investment.
      Such Purchaser is able to bear the economic risk of an investment in the
      Securities and, at the present time, is able to afford a complete loss of such
      investment.

     

    (f) Access
      to Information.
      Such
      Purchaser acknowledges that it has had the opportunity to review the Disclosure
      Materials and has been afforded (i) the opportunity to ask such questions as
      it
      has deemed necessary of, and to receive answers from, representatives of the
      Company concerning the terms and conditions of the offering of the Securities
      and the merits and risks of investing in the Securities; (ii) access to
      information about the Company and its financial condition, results of
      operations, business, properties, management and prospects sufficient to enable
      it to evaluate its investment; and (iii) the opportunity to obtain such
      additional information that the Company possesses or can acquire without
      unreasonable effort or expense that is necessary to make an informed investment
      decision with respect to the investment. Neither such inquiries nor any other
      investigation conducted by or on behalf of such Purchaser or its representatives
      or counsel shall modify, amend or affect such Purchaser's right to rely on
      the
      truth, accuracy and completeness of the Disclosure Materials and the Company's
      representations and warranties contained in the Transaction
      Documents.

     

    (g)  Certain
      Trading Activities.
      Other
      than with respect to the transactions contemplated herein, since the earlier
      to
      occur of (1) the time that such Purchaser was first contacted by the Company,
      the Placement Agents or any other Person regarding the transactions contemplated
      hereby and (2) the tenth (10th)
      day
      prior to the date of this Agreement, neither the Purchaser nor any Affiliate
      of
      such Purchaser which (x) had knowledge of the transactions contemplated hereby,
      (y) has or shares discretion relating to such Purchaser’s investments or trading
      or information concerning such Purchaser’s investments, including in respect of
      the Securities, and (z) is subject to such Purchaser’s review or input
      concerning such Affiliate’s investments or trading (collectively, “Trading
      Affiliates”)
      has
      directly or indirectly, nor has any Person acting on behalf of or pursuant
      to
      any understanding with such Purchaser or Trading Affiliate, effected or agreed
      to effect any transactions in the securities of the Company (including, without
      limitation, any Short Sales involving the Company’s securities). Notwithstanding
      the foregoing, in the case of a Purchaser and/or Trading Affiliate that is,
      individually or collectively, a multi-managed investment vehicle whereby
      separate portfolio managers manage separate portions of such Purchaser's or
      Trading Affiliate’s assets and the portfolio managers have no direct knowledge
      of the investment decisions made by the portfolio managers managing other
      portions of such Purchaser's or Trading Affiliate’s assets, the representation
      set forth above shall apply only with respect to the portion of assets managed
      by the portfolio manager that have knowledge about the financing transaction
      contemplated by this Agreement. Other than to other Persons party to this
      Agreement, such Purchaser has maintained the confidentiality of all disclosures
      made to it in connection with this transaction (including the existence and
      terms of this transaction). Notwithstanding the foregoing, no Purchaser makes
      any representation, warranty or covenant hereby that it will not engage in
      Short
      Sales in the securities of the Company after the time that the transactions
      contemplated by this Agreement are first publicly announced as described in
      Section 4.8.

     

    
      
        
          
          

        

        
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    (h) Brokers
      and Finders.
      No
      Person will have, as a result of the transactions contemplated by this
      Agreement, any valid right, interest or claim against or upon the Company or
      any
      Purchaser for any commission, fee or other compensation pursuant to any
      agreement, arrangement or understanding entered into by or on behalf of the
      Purchaser.

     

    (i) Limited
      Ownership.
      The
      purchase by such Purchaser of the Securities issuable to it at the Closing
      will
      not result in such Purchaser (individually or together with other Person with
      whom such Purchaser has identified, or will have identified, itself as part
      of a
“group” in a public filing made with the Commission involving the Company’s
      securities) acquiring, or obtaining the right to acquire, in excess of 19.99%
      of
      the outstanding shares of Common Stock or the voting power of the Company on
      a
      post transaction basis that assumes that the Closing shall have occurred. Such
      Purchaser does not presently intend to, alone or together with others, make
      a
      public filing with the Commission to disclose that it has (or that it together
      with such other Persons have) acquired, or obtained the right to acquire, as
      a
      result of the Closing (when added to any other securities of the Company that
      it
      or they then own or have the right to acquire), in excess of 19.99% of the
      outstanding shares of Common Stock or the voting power of the Company on a
      post
      transaction basis that assumes that the Closing shall have occurred.

     

    (j) Independent
      Investment Decision.
      Such
      Purchaser has independently evaluated the merits of its decision to purchase
      Securities pursuant to the Transaction Documents, and such Purchaser confirms
      that it has not relied on the advice of any other Purchaser’s business and/or
      legal counsel in making such decision. Such Purchaser understands that nothing
      in this Agreement or any other materials presented by or on behalf of the
      Company to the Purchaser in connection with the purchase of the Securities
      constitutes legal, tax or investment advice. Such Purchaser has consulted such
      legal, tax and investment advisors as it, in its sole discretion, has deemed
      necessary or appropriate in connection with its purchase of the Securities.
      Such
      Purchaser understands that the Placement Agents have acted solely as the agent
      of the Company in this placement of the Securities and such Purchaser has not
      relied on the business or legal advice of the Placement Agents or any of their
      agents, counsel or Affiliates in making its investment decision hereunder,
      and
      confirms that none of such Persons has made any representations or warranties
      to
      such Purchaser in connection with the transactions contemplated by the
      Transaction Documents.

     

    (k) Reliance
      on Exemptions.
      Such
      Purchaser understands that the Securities being offered and sold to it in
      reliance on specific exemptions from the registration requirements of United
      States federal and state securities laws and that the Company is relying in
      part
      upon the truth and accuracy of, and such Purchaser’s compliance with, the
      representations, warranties, agreements, acknowledgements and understandings
      of
      such Purchaser set forth herein in order to determine the availability of such
      exemptions and the eligibility of such Purchaser to acquire the
      Securities.

     

    (l) No
      Governmental Review.
      Such
      Purchaser understands that no United States federal or state agency or any
      other
      government or governmental agency has passed on or made any recommendation
      or
      endorsement of the Securities or the fairness or suitability of the investment
      in the Securities nor have such authorities passed upon or endorsed the merits
      of the offering of the Securities.

     

    
      
        
          
          

        

        
          17

          
            

          

        

         

      

    

     

    The
      Company acknowledges and agrees that no Purchaser has made or makes any
      representations or warranties with respect to the transactions contemplated
      hereby other than those specifically set forth in this Section 3.2.

     

    ARTICLE
      IV.

    OTHER
      AGREEMENTS OF THE PARTIES

     

    4.1 (a) Compliance
      with Laws.
      Notwithstanding any other provision of this Article IV, each Purchaser covenants
      that the securities may be disposed of only pursuant to an effective
      registration statement under, and in compliance with the requirements of, the
      Securities Act, or pursuant to an available exemption from, or in a transaction
      not subject to, the registration requirements of the Securities Act, and in
      compliance with any applicable state and federal securities laws. In connection
      with any transfer of the Securities other than (i) pursuant to an effective
      registration statement, (ii) to the Company, (iii) to an Affiliate of a
      Purchaser, (iv) pursuant to Rule 144 (provided
      that the
      Purchaser provides the Company with reasonable assurances (in the form of seller
      and broker representation letters) that the securities may be sold pursuant
      to
      such rule) or Rule 144A, (v) pursuant to Rule 144(k) following the applicable
      holding period or (vi) in connection with a bona fide pledge as contemplated
      in
      Section 4.1(b), except as otherwise provided herein, the Company may require
      the
      transferor thereof to provide to the Company an opinion of counsel selected
      by
      the transferor and reasonably acceptable to the Company, the form and substance
      of which opinion shall be reasonably satisfactory to the Company, to the effect
      that such transfer does not require registration of such transferred Securities
      under the Securities Act. As a condition of transfer, any such transferee shall
      agree in writing to be bound by the terms of this Agreement and shall have
      the
      rights of a Purchaser under this Agreement and the Registration Rights
      Agreement. 

     

    (b) Legends.
      Certificates evidencing the Securities shall bear any legend as required by
      the
“blue sky” laws of any state and a restrictive legend in substantially the
      following form, until such time as they are not required under Section
      4.1(c):

     

    [NEITHER
      THESE SECURITIES NOR THE SECURITIES ISSUABLE UPON EXERCISE OF THESE SECURITIES
      HAVE BEEN REGISTERED] [THESE SECURITIES HAVE NOT BEEN REGISTERED] WITH THE
      SECURITIES AND EXCHANGE COMMISSION OR THE SECURITIES COMMISSION OF ANY STATE
      IN
      RELIANCE UPON AN EXEMPTION FROM REGISTRATION UNDER THE SECURITIES ACT OF 1933,
      AS AMENDED (THE “SECURITIES ACT”), AND, ACCORDINGLY, MAY NOT BE OFFERED OR SOLD
      EXCEPT PURSUANT TO AN EFFECTIVE REGISTRATION STATEMENT UNDER THE SECURITIES
      ACT
      OR PURSUANT TO AN AVAILABLE EXEMPTION FROM, OR IN A TRANSACTION NOT SUBJECT
      TO,
      THE REGISTRATION REQUIREMENTS OF THE SECURITIES ACT AND IN ACCORDANCE WITH
      APPLICABLE STATE SECURITIES LAWS OR BLUE SKY LAWS AS EVIDENCED BY A LEGAL
      OPINION OF COUNSEL REASONABLY SATISFACTORY TO THE COMPANY. 

     

    The
      Company acknowledges and agrees that a Purchaser may from time to time pledge,
      and/or grant a security interest in, some or all of the legended Securities
      in
      connection with applicable securities laws, pursuant to a bona fide margin
      agreement in compliance with a bona fide margin loan. Such a pledge would not
      be
      subject to approval or consent of the Company and no legal opinion of legal
      counsel to the pledgee, secured party or pledgor shall be required in connection
      with the pledge, but such legal opinion shall be required in connection with
      a
      subsequent transfer or foreclosure following default by the Purchaser's
      transferee of the pledge. No notice shall be required of such pledge, but
      Purchaser’s transferee shall promptly notify the Company of any such subsequent
      transfer or foreclosure. Each Purchaser acknowledges that the Company shall
      not
      be responsible for any pledges relating to, or the grant of any security
      interest in, any of the Securities or for any agreement, understanding or
      arrangement between any Purchaser and its pledgee or secured party. At the
      appropriate Purchaser’s expense, the Company will execute and deliver such
      reasonable documentation as a pledgee or secured party of Shares may reasonably
      request in connection with a pledge or transfer of the Shares, including the
      preparation and filing of any required prospectus supplement under Rule
      423(b)(3) of the Securities Act or other applicable provision of the Securities
      Act to appropriately amend the list of Selling Stockholders thereunder. Each
      Purchaser acknowledges and agrees that, except as otherwise provided in Section
      4.1(c), any Shares subject to a pledge or security interest as contemplated
      by
      this Section 4.1(b) shall continue to bear the legend set forth in this Section
      4.1(b) and be subject to the restrictions on transfer set forth in Section
      4.1(a).

    

    
      
        
          
          

        

        
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    (c) Removal
      of Legends.
      The
      legend set forth in Section 4.1(b) above shall be removed and the Company shall
      issue a certificate without such legend to the holder of the Securities upon
      which it is stamped or issue to such holder by electronic delivery at the
      applicable balance account at The Depository Trust Company (“DTC”),
      if
      (i) such Securities are registered for resale under the Securities Act, (ii)
      such Securities are sold or transferred pursuant to Rule 144 (assuming the
      transferor is not an Affiliate of the Company) or Rule 144A, or (iii) such
      Securities are eligible for sale under Rule 144(k). The Company shall cause
      its
      counsel to issue the legal opinion referred to in the Irrevocable Transfer
      Agent
      Instructions to the Company’s transfer agent on the Effective Date. Any fees
      (with respect to the Transfer Agent, counsel to the Company or otherwise)
      associated with the issuance of such opinion or the removal of such legend
      shall
      be borne by the Company. If any portion of the Warrant is exercised at a time
      when there is an effective registration statement to cover the resale of the
      Warrant Shares, or if such Warrant Shares may be sold under Rule 144(k), then
      such Warrant Shares shall be issued free of all legends. Following the Effective
      Date, or at such earlier time as a legend is no longer required for certain
      Securities, the Company will no later than three (3) Trading Days following
      the
      delivery by a Purchaser to the Company or the Transfer Agent (with notice to
      the
      Company) of (i) a legended certificate representing such Shares or Warrant
      Shares (endorsed or with stock powers attached, signatures guaranteed, and
      otherwise in form necessary to affect the reissuance and/or transfer) or (ii)
      an
      Exercise Notice in the manner stated in the Warrants to effect the exercise
      of
      such Warrant in accordance with its terms and an opinion of counsel to the
      extent required by Section 4.1(a), deliver or cause to be delivered to such
      Purchaser a certificate representing such Securities that is free from all
      restrictive and other legends. The Company may not make any notation on its
      records or give instructions to the Transfer Agent that enlarge the restrictions
      on transfer set forth in this Section.

    

    (d) Irrevocable
      Transfer Agent Instructions. 
      The
      Company shall issue irrevocable instructions to its transfer agent, and any
      subsequent transfer agent, to issue certificates or credit shares to the
      applicable balance accounts at DTC, registered in the name of each Purchaser
      or
      its respective nominee(s), for the Shares and the Warrant Shares in such amounts
      as specified from time to time by each Purchaser to the Company in the form
      of
Exhibit
      E
      attached
      hereto (the “Irrevocable
      Transfer Agent Instructions”).
      The
      Company warrants that no instruction other than the Irrevocable Transfer Agent
      Instructions referred to in this Section 4(d) will be given by the Company
      to
      its transfer agent in connection with this Agreement, and that the Securities
      shall otherwise be freely transferable on the books and records of the Company
      as and to the extent provided in this Agreement and the other Transaction
      Documents. 

    

    (e) Acknowledgement.
      Each
      Purchaser hereunder acknowledges its primary responsibilities under the
      Securities Act and accordingly will not sell the Shares, the Warrant Shares
      or
      any interest therein without complying with the requirements of the Securities
      Act. While the above-referenced registration statement remains effective, each
      Purchaser hereunder may sell the shares in accordance with the plan of
      distribution contained in the registration statement and if it does so it will
      comply therewith and with the related prospectus delivery requirements unless
      an
      exemption therefrom is available. Each Purchaser, severally and not jointly
      with
      the other Purchasers, agrees that if it is notified by the Company at any time
      after the date any legend is removed pursuant to Section
      4.1(c)
      hereof
      that the registration statement registering the resale of the Shares or the
      Warrant Shares is not effective or that the prospectus included in such
      registration statement no longer complies with the requirements of Section
      10 of
      the Securities Act, the Purchaser will refrain from selling such Shares and
      Warrant Shares until such time as the Purchaser is notified by the Company
      that
      such registration statement is effective or such prospectus is compliant with
      Section 10 of the Exchange Act, unless such Purchaser is able to, and does,
      sell
      such Shares or Warrant Shares pursuant to an available exemption from the
      registration requirements of Section 5 of the Securities Act. Each Purchaser,
      severally and not jointly with the other Purchasers, agrees to indemnify the
      Company for any damages or losses resulting to the Company from the Purchaser’s
      breach of its covenants set forth in the preceding sentence.

    

    
      
        
          
          

        

        
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    4.2 Reservation
      of Common Stock.
      The
      Company shall take all action necessary to at all times have authorized, and
      reserved for the purpose of issuance from and after the Closing Date, no less
      than 100% of the number of shares of Common Stock issuable upon exercise of
      the
      Warrants issued at the Closing (without taking into account any limitations
      on
      exercise of the Warrants set forth in the Warrants).

     

    4.3 Furnishing
      of Information.
      In
      order to enable the Purchasers to sell the Securities under Rule 144 of the
      Securities Act, for a period of two years from the Closing, the Company shall
      use its commercially reasonable efforts to timely file (or obtain extensions
      in
      respect thereof and file within the applicable grace period) all reports
      required to be filed by the Company after the date hereof pursuant to the
      Exchange Act. During such two year period, if the Company is not required to
      file reports pursuant to such laws, it will prepare and furnish to the
      Purchasers and make publicly available in accordance with Rule 144(c) such
      information as is required for the Purchasers to sell the Shares and Warrant
      Shares under Rule 144. The Company further covenants that it will take such
      further action as any holder of Securities may reasonably request, all to the
      extent required from time to time to enable such Person to sell the Shares
      and
      Warrant Shares without registration under the Securities Act within the
      limitation of the exemptions provided by Rule 144. 

     

    4.4  Reporting
      Status.
      During
      the two year period from and after the Closing, the Company shall not terminate
      its status as an issuer required to file reports under the Exchange Act even
      if
      the Exchange Act or the rules and regulations thereunder would otherwise permit
      such termination.

     

    4.5  Form
      D
      and Blue Sky.
      The
      Company agrees to file a Form D with respect to the Securities as required
      under
      Regulation D and to provide a copy thereof to each Purchaser promptly after
      such
      filing. The Company, on or before the Closing Date, shall take such action
      as
      the Company shall reasonably determine is necessary in order to obtain an
      exemption for or to qualify the Securities for sale to the Purchasers at the
      Closing pursuant to this Agreement under applicable securities or “Blue Sky”
laws of the states of the United States (or to obtain an exemption from such
      qualification), and shall provide evidence of any such action so taken to the
      Purchasers on or prior to the Closing Date. The Company shall make all filings
      and reports relating to the offer and sale of the Securities required under
      applicable securities or “Blue Sky” laws of the states of the United States
      following the Closing Date. 

     

    4.6  No
      Integration.
      The
      Company shall not, and shall use its best efforts to ensure that no Affiliate
      of
      the Company shall, sell, offer for sale or solicit offers to buy or otherwise
      negotiate in respect of any security (as defined in Section 2 of the Securities
      Act) that will be integrated with the offer or sale of the Securities in a
      manner that would require the registration under the Securities Act of the
      sale
      of the Securities to the Purchasers, or that will be integrated with the offer
      or sale of the Securities for purposes of the rules and regulations of any
      Trading Market such that it would require shareholder approval prior to the
      closing of such other transaction unless shareholder approval is obtained before
      the closing of such subsequent transaction.

     

    
      
        
          
          

        

        
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    4.7 Intentionally
      Omitted.
      

     

    4.8 Securities
      Laws Disclosure; Publicity.
      By 9:00
      a.m. (New York City time) on the Trading Day immediately following the execution
      of this Agreement, the Company shall issue a press release (the “Press
      Release”)
      reasonably acceptable to the Placement Agents disclosing all material terms
      of
      the transactions contemplated hereby. On or before 9:00 a.m. (New York City
      time) on the Trading Day following the Closing Date, the Company will file
      a
      Current Report on Form 8-K with the Commission describing the terms of the
      Transaction Documents (and including as exhibits to such Current Report on
      Form
      8-K the material Transaction Documents (including, without limitation, this
      Agreement including the schedule and exhibit thereto, the form of Warrant and
      the Registration Rights Agreement)). Notwithstanding the foregoing, the Company
      shall not publicly disclose the name of any Purchaser or an Affiliate of any
      Purchaser, or include the name of any Purchaser or an Affiliate of any Purchaser
      in any press release or filing with the Commission (other than the Registration
      Statement) or any regulatory agency or Trading Market, without the prior written
      consent of such Purchaser, except to the extent such disclosure is required
      by
      law, request of the Staff of the Commission or Trading Market regulations.
      From
      and after the issuance of the Press Release, no Purchaser shall be in possession
      of any material, non-public information received from the Company or any of
      its
      officers, directors, employees or agents, that is not disclosed in the Press
      Release. The Company shall not, and shall cause each of its officers, directors,
      employees and agents, not to, provide any Purchaser with any material,
      non-public information regarding the Company from and after the filing of the
      Press Release without the express written consent of such Purchaser. If a
      Purchaser has received from the Company, or any of its officers, directors,
      employees or agents, any such material, non-public information regarding the
      Company, it shall provide the Company with written notice thereof. The Company
      shall within five (5) Trading Days of receipt of such notice, make public
      disclosure of such material, non-public information. Each Purchaser, severally
      and not jointly with the other Purchasers, covenants that until such time as
      the
      transactions contemplated by this Agreement are publicly disclosed by the
      Company as described in Section 4.8, such Purchaser will maintain the
      confidentiality of all disclosures made to it in connection with this
      transaction (including the existence and terms of this transaction).

     

    4.9  Intentionally
      Omitted.

     

    4.10 Listing
      of Securities.
      Promptly following the date hereof, the Company shall take all necessary action
      to cause the Shares, the Warrant Shares and the shares of Common Stock issuable
      upon exercise of the Placement Agents’ Warrants to be listed upon the Principal
      Trading Market, if any, upon which shares of Common Stock are then listed
      (subject to official notice of issuance) and shall maintain, so long as any
      other shares of Common Stock shall be so listed, such listing. Further, if
      the
      Company applies to have its Common Stock or other securities listed on any
      other
      Trading Market, it shall include in such application the Shares and the Warrant
      Shares (including the shares of Common Stock issuable upon exercise of the
      warrants issued to the Placement Agents) and will take such other action as
      is
      necessary to cause the Shares, and the Warrant Shares (including the shares
      of
      Common Stock issuable upon exercise of the warrants issued to the Placement
      Agents) to be listed on such other Trading Market as promptly as practicable.
      

     

    4.11 Use
      of
      Proceeds.
      The
      Company intends to use the net proceeds from the sale of the Securities
      hereunder for working capital and general corporate purposes. 

     

    4.12  Short
      Sales and Confidentiality After The Date Hereof.
      Such
      Purchaser shall not, and shall cause its Trading Affiliates not to, engage,
      directly or indirectly, in any transactions in the securities of the Company
      (including, without limitation, any Short Sales) during the period from the
      date
      hereof until such time as (i) the transactions contemplated by this Agreement
      are first publicly announced as described in Section 4.8 or (ii) this Agreement
      is terminated in full pursuant to Section 6.18. Notwithstanding the foregoing,
      in the case of a Purchaser that is a multi-managed investment vehicle whereby
      separate portfolio managers manage separate portions of such Purchaser's assets
      and the portfolio managers have no direct knowledge of the investment decisions
      made by the portfolio managers managing other portions of such Purchaser's
      assets, the representation set forth above shall apply only with respect to
      the
      portion of assets managed by the portfolio manager that have knowledge about
      the
      financing transaction contemplated by this Agreement. Each
      Purchaser understands
      and acknowledges, severally and not jointly with any other Purchaser, that
      the
      Commission currently takes the position that covering a short position
      established prior to effectiveness of a resale registration statement with
      shares included in such registration statement would be a violation of Section
      5
      of the Securities Act, as set forth in Item 65, Section 5 under Section A,
      of
      the Manual of Publicly Available Telephone Interpretations, dated July 1997,
      compiled by the Office of Chief Counsel, Division of Corporation Finance.

     

    
      
        
          
          

        

        
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    ARTICLE
      V.

    CONDITIONS
      PRECEDENT TO CLOSING

    

    5.1 Conditions
      Precedent to the Obligations of the Purchasers to Purchase
      Securities.
      The
      obligation of each Purchaser to acquire Securities at the Closing is subject
      to
      the fulfillment to such Purchaser’s satisfaction, on or prior to the Closing
      Date, of each of the following conditions, any of which may be waived by such
      Purchaser (as to itself only):

     

    (a) Representations
      and Warranties.
      The
      representations and warranties of the Company contained herein shall be true
      and
      correct in all material respects as of the date when made and as of the Closing
      Date, as though made on and as of such date except for representations and
      warranties that speak as of a specific date; 

     

    (b) Performance.
      The
      Company shall have performed, satisfied and complied in all material respects
      with all covenants, agreements and conditions required by the Transaction
      Documents to be performed, satisfied or complied with by it at or prior to
      the
      Closing;

     

    (c) No
      Injunction.
      No
      statute, rule, regulation, executive order, decree, ruling or injunction shall
      have been enacted, entered, promulgated or endorsed by any court or governmental
      authority of competent jurisdiction that prohibits the consummation of any
      of
      the transactions contemplated by the Transaction Documents;

     

    (d) Consents.
      The
      Company shall have obtained in a timely fashion any and all consents, permits,
      approvals, registrations and waivers necessary or appropriate for consummation
      of the purchase and sale of the Securities, all of which shall be and remain
      so
      long as necessary in full force and effect;

     

    (e) Adverse
      Changes.
      Since
      the date of execution of this Agreement, no event or series of events shall
      have
      occurred that has resulted or reasonably could result in a Material Adverse
      Effect; 

     

    (f) No
      Suspensions of Trading in Common Stock; Listing.
      The
      Common Stock (i) shall be designated for quotation or listed on the Principal
      Market and (ii) shall not have been suspended, as of the Closing Date, by the
      Commission or the Principal Market from trading on the Principal Market nor
      shall suspension by the Commission or the Principal Market have been threatened,
      as of the Closing Date, either (A) in writing by the Commission or the Principal
      Market or (B) by falling below the minimum listing maintenance requirements
      of
      the Principal Market; 

     

    (g) Company
      Deliverables.
      The
      Company shall have delivered the Company Deliverables in accordance with Section
      2.2(a); 

    

    
      
        
          
          

        

        
          22

          
            

          

        

         

      

    

     

    (h) Compliance
      Certificate.
      The
      Company shall have delivered to each Purchaser a certificate, dated as of the
      Closing Date and signed by its Chief Executive Officer or its Chief Financial
      Officer, dated as of the Closing Date, certifying to the fulfillment of the
      conditions specified in Sections 5.1(a), (b), (c), (d) and (f); and

     

    (i) Termination. This
      Agreement shall not have been terminated as to such Purchaser in accordance
      with
      Section 6.18 herein.

     

    5.2 Conditions
      Precedent to the Obligations of the Company to sell Securities.
      The
      Company's obligation to sell and issue the Securities at the Closing is subject
      to the fulfillment to the satisfaction of the Company on or prior to the Closing
      Date of the following conditions, any of which may be waived by the
      Company:

     

    (a) Representations
      and Warranties.
      The
      representations and warranties made by the Purchasers in Section
      3.2
      hereof
      shall be true and correct in all material respects as of the date when made,
      and
      as of the Closing Date as though made on and as of such date (except for
      representations and warranties that speak as of a specific date);

     

    (b) Performance.
      The
      Purchasers shall have performed, satisfied and complied in all material respects
      with all covenants, agreements and conditions required by the Transaction
      Documents to be performed, satisfied or complied with by the Purchasers at
      or
      prior to the Closing Date;

     

    (c) No
      Injunction.
      No
      statute, rule, regulation, executive order, decree, ruling or injunction shall
      have been enacted, entered, promulgated or endorsed by any court or governmental
      authority of competent jurisdiction that prohibits the consummation of any
      of
      the transactions contemplated by the Transaction Documents; 

     

    (d) Consents.
      The
      Company shall have obtained in a timely fashion any and all consents, permits,
      approvals, registrations and waivers necessary or appropriate for consummation
      of the purchase and sale of the Securities, all of which shall be and remain
      so
      long as necessary in full force and effect;

     

    (e) Purchasers
      Deliverables.
      Each
      Purchaser shall have delivered its Purchaser Deliverables in accordance with
      Section 2.2(b); and

     

    (f) Termination. This
      Agreement shall not have been terminated as to such Purchaser in accordance
      with
      Section 6.18 herein.

    

    ARTICLE
      VI.

    MISCELLANEOUS

     

    6.1 Fees
      and Expenses.
      The
      Company shall provide the Placement Agents with an aggregate non-accountable
      expense allowance of $50,000, which is intended to reimburse the Placement
      Agents for fees and expenses incurred by them in connection with the
      transactions contemplated by this Agreement. The Company and the Purchasers
      shall each pay the fees and expenses of their respective advisers, counsel,
      accountants and other experts, if any, and all other expenses incurred by such
      party in connection with the negotiation, preparation, execution, delivery
      and
      performance of this Agreement. The Company shall pay all Transfer Agents’ fees,
      stamp taxes and other taxes and duties levied in connection with the sale and
      issuance of the Securities to the Purchasers. Each party acknowledges that
      Lowenstein Sandler PC has rendered legal advice to certain of the Placement
      Agents and not to such party in connection with the transactions contemplated
      hereby, and that such party has relied for such matters on the advice of its
      own
      respective counsel.

     

    
      
        
          
          

        

        
          23

          
            

          

        

         

      

    

     

    6.2 Entire
      Agreement.
      The
      Transaction Documents, together with the Exhibits and Schedules thereto, contain
      the entire understanding of the parties with respect to the subject matter
      hereof and supersede all prior agreements, understandings, discussions and
      representations, oral or written, with respect to such matters, which the
      parties acknowledge have been merged into such documents, exhibits and
      schedules. At or after the Closing, and without further consideration, the
      Company and the Purchasers will execute and deliver to the other such further
      documents as may be reasonably requested in order to give practical effect
      to
      the intention of the parties under the Transaction Documents.

     

    6.3 Notices.
      Any and
      all notices or other communications or deliveries required or permitted to
      be
      provided hereunder shall be in writing and shall be deemed given and effective
      on the earliest of (a) the date of transmission, if such notice or communication
      is delivered via facsimile (provided the sender receives a machine-generated
      confirmation of successful transmission) at the facsimile number specified
      in
      this Section prior to 5:00 p.m. (New York City time) on a Trading Day, (b)
      the
      next Trading Day after the date of transmission, if such notice or communication
      is delivered via facsimile at the facsimile number specified in this Section
      on
      a day that is not a Trading Day or later than 5:00 p.m. (New York City time)
      on
      any Trading Day, (c) the Trading Day following the date of mailing, if sent
      by
      U.S. nationally recognized overnight courier service with next day delivery
      specified, or (d) upon actual receipt by the party to whom such notice is
      required to be given. The address for such notices and communications shall
      be
      as follows:

     

    If
      to the
      Company:             
ZIOPHARM
      Oncology, Inc.

    1180
      Avenue of the Americas

    19th
      Floor

    New
      York,
      New York 10036

    Telephone
      No.: (646) 214-0707

    Facsimile
      No.: (646) 214-0711

    Attention:
      Jonathan Lewis. M.D., Ph.D.

    

    With
      a
      copy to:      Maslon
      Edelman Borman & Brand, LLP

    3300
      Wells Fargo Center

    90
      South
      Seventh Street

    Minneapolis,
      MN 55402

    Telephone
      No.: (612) 672- 8200

    Facsimile
      No.: (612) 672-8397

    Attention:
      Alan Gilbert

    

    If
      to a
      Purchaser:             
 To
      the
      address set forth under such Purchaser’s name on the signature page
      hereof;

    

    or
      such
      other address as may be designated in writing hereafter, in the same manner,
      by
      such Person.

    

    6.4 Amendments;
      Waivers; No Additional Consideration.
      No
      provision of this Agreement may be waived or amended except in a written
      instrument signed, in the case of an amendment, by the Company and each of
      the
      Purchasers or, in the case of a waiver, by the party against whom enforcement
      of
      any such waiver is sought. No waiver of any default with respect to any
      provision, condition or requirement of this Agreement shall be deemed to be
      a
      continuing waiver in the future or a waiver of any subsequent default or a
      waiver of any other provision, condition or requirement hereof, nor shall any
      delay or omission of either party to exercise any right hereunder in any manner
      impair the exercise of any such right. No consideration shall be offered or
      paid
      to any Purchaser to amend or consent to a waiver or modification of any
      provision of any Transaction Document unless the same consideration is also
      offered to all Purchasers who then hold Securities.

    

    
      
        
          
          

        

        
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    6.5 Construction.
      The
      headings herein are for convenience only, do not constitute a part of this
      Agreement and shall not be deemed to limit or affect any of the provisions
      hereof. The language used in this Agreement will be deemed to be the language
      chosen by the parties to express their mutual intent, and no rules of strict
      construction will be applied against any party. This Agreement shall be
      construed as if drafted jointly by the parties, and no presumption or burden
      of
      proof shall arise favoring or disfavoring any party by virtue of the authorship
      of any provisions of this Agreement or any of the Transaction
      Documents.

     

    6.6 Successors
      and Assigns.
      The
      provisions of this Agreement shall inure to the benefit of and be binding upon
      the parties and their successors and permitted assigns. This Agreement, or
      any
      rights or obligations hereunder, may not be assigned by the Company without
      the
      prior written consent of the Purchasers. Any Purchaser may assign its rights
      hereunder in whole or in part to any Person to whom such Purchaser assigns
      or
      transfers any Securities in compliance with this Agreement and applicable law,
      provided
      such
      transferee shall agree in writing to be bound, with respect to the transferred
      Securities, by the terms and conditions of this Agreement that apply to the
      “Purchasers”.

     

    6.7  No
      Third-Party Beneficiaries.
      This
      Agreement is intended for the benefit of the parties hereto and their respective
      successors and permitted assigns and is not for the benefit of, nor may any
      provision hereof be enforced by, any other Person, except the Placement Agents
      are intended third party beneficiaries of Article III hereof and each Placement
      Agent may enforce the provisions of such Sections directly against the parties
      with obligations thereunder.

     

    6.8 Governing
      Law.
      All
      questions concerning the construction, validity, enforcement and interpretation
      of this Agreement shall be governed by and construed and enforced in accordance
      with the internal laws of the State of New York, without regard to the
      principles of conflicts of law thereof. Each party agrees that all Proceedings
      concerning the interpretations, enforcement and defense of the transactions
      contemplated by this Agreement and any other Transaction Documents (whether
      brought against a party hereto or its respective Affiliates, employees or
      agents) shall be commenced exclusively in the New York Courts. Each party hereto
      hereby irrevocably submits to the exclusive jurisdiction of the New York Courts
      for the adjudication of any dispute hereunder or in connection herewith or
      with
      any transaction contemplated hereby or discussed herein (including with respect
      to the enforcement of any of the Transaction Documents), and hereby irrevocably
      waives, and agrees not to assert in any Proceeding, any claim that it is not
      personally subject to the jurisdiction of any such New York Court, or that
      such
      Proceeding has been commenced in an improper or inconvenient forum. Each party
      hereto hereby irrevocably waives personal service of process and consents to
      process being served in any such Proceeding by mailing a copy thereof via
      registered or certified mail or overnight delivery (with evidence of delivery)
      to such party at the address in effect for notices to it under this Agreement
      and agrees that such service shall constitute good and sufficient service of
      process and notice thereof. Nothing contained herein shall be deemed to limit
      in
      any way any right to serve process in any manner permitted by law. EACH
      PARTY HERETO HEREBY IRREVOCABLY WAIVES, TO THE FULLEST EXTENT PERMITTED BY
      APPLICABLE LAW, ANY AND ALL RIGHT TO TRIAL BY JURY IN ANY LEGAL PROCEEDING
      ARISING OUT OF OR RELATING TO THIS AGREEMENT OR THE TRANSACTIONS CONTEMPLATED
      HEREBY.
      If
      either party shall commence a Proceeding to endorse any provisions of a
      Transaction Document, then the prevailing party in such Proceeding shall be
      reimbursed by the other party for its reasonable attorney’s fees and other costs
      and expenses uncured with the investigation preparation and prosecution of
      such
      Proceeding.

     

    6.9
      Survival.
      Subject
      to applicable statute of limitations, the representations, warranties,
      agreements and covenants contained herein shall survive the Closing and the
      delivery of the Securities.

     

    
      
        
          
          

        

        
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    6.10 Execution.
      This
      Agreement may be executed in two or more counterparts, all of which when taken
      together shall be considered one and the same agreement and shall become
      effective when counterparts have been signed by each party and delivered to
      the
      other party, it being understood that both parties need not sign the same
      counterpart. In the event that any signature is delivered by facsimile
      transmission, or by e-mail delivery of a “.pdf” format data file, such signature
      shall create a valid and binding obligation of the party executing (or on whose
      behalf such signature is executed) with the same force and effect as if such
      facsimile signature page were an original thereof.

     

    6.11 Severability.
      If any
      provision of this Agreement is held to be invalid or unenforceable in any
      respect, the validity and enforceability of the remaining terms and provisions
      of this Agreement shall not in any way be affected or impaired thereby and
      the
      parties will attempt to agree upon a valid and enforceable provision that is
      a
      reasonable substitute therefor, and upon so agreeing, shall incorporate such
      substitute provision in this Agreement.

     

    6.12 Rescission
      and Withdrawal Right.
      Notwithstanding anything to the contrary contained in (and without limiting
      any
      similar provisions of) the Transaction Documents, whenever any Purchaser
      exercises a right, election, demand or option under a Transaction Document
      and
      the Company does not timely perform its related obligations within the periods
      therein provided, then such Purchaser may rescind or withdraw, in its sole
      discretion from time to time upon written notice to the Company, any relevant
      notice, demand or election in whole or in part without prejudice to its future
      actions and rights.

     

    6.13 Replacement
      of Securities.
      If any
      certificate or instrument evidencing any Securities is mutilated, lost, stolen
      or destroyed, the Company shall issue or cause to be issued in exchange and
      substitution for and upon cancellation thereof, or in lieu of and substitution
      therefor, a new certificate or instrument, but only upon receipt of evidence
      reasonably satisfactory to the Company and the Transfer Agent of such loss,
      theft or destruction and the execution by the holder thereof of a customary
      lost
      certificate affidavit of that fact and an agreement to indemnify and hold
      harmless the Company and the Transfer Agent for any losses in connection
      therewith or, if required by the Transfer Agent, a bond in such form and amount
      as is reasonably required by the Transfer Agent. The applicants for a new
      certificate or instrument under such circumstances shall also pay any reasonable
      third-party costs associated with the issuance of such replacement Securities.
      If a replacement certificate or instrument evidencing any Securities is
      requested due to a mutilation thereof, the Company may require delivery of
      such
      mutilated certificate or instrument as a condition precedent to any issuance
      of
      a replacement.

     

    6.14 Intentionally
      Omitted.
      

     

    6.15 Intentionally
      Omitted.
      

     

    6.16 Adjustments
      in Share Numbers and Prices.
      In the
      event of any stock split, subdivision, dividend or distribution payable in
      shares of Common Stock (or other securities or rights convertible into, or
      entitling the holder thereof to receive directly or indirectly shares of Common
      Stock), combination or other similar recapitalization or event occurring after
      the date hereof, each reference in any Transaction Document to a number of
      shares or a price per share shall be deemed to be amended to appropriately
      account for such event. 

     

    6.17 Independent
      Nature of Purchasers' Obligations and Rights.
      The
      obligations of each Purchaser under any Transaction Document are several and
      not
      joint with the obligations of any other Purchaser, and no Purchaser shall be
      responsible in any way for the performance of the obligations of any other
      Purchaser under any Transaction Document. The decision of each Purchaser to
      purchase Securities pursuant to the Transaction Documents has been made by
      such
      Purchaser independently of any other Purchaser and independently of any
      information, materials, statements or opinions as to the business, affairs,
      operations, assets, properties, liabilities, results of operations, condition
      (financial or otherwise) or prospects of the Company which may have been made
      or
      given by any other Purchaser or by any agent or employee of any other Purchaser,
      and no Purchaser and any of its agents or employees shall have any liability
      to
      any other Purchaser (or any other Person) relating to or arising from any such
      information, materials, statement or opinions. Nothing contained herein or
      in
      any Transaction Document, and no action taken by any Purchaser pursuant thereto,
      shall be deemed to constitute the Purchasers as a partnership, an association,
      a
      joint venture or any other kind of entity, or create a presumption that the
      Purchasers are in any way acting in concert or as a group with respect to such
      obligations or the transactions contemplated by the Transaction Documents.
      Each
      Purchaser acknowledges that no other Purchaser has acted as agent for such
      Purchaser in connection with making its investment hereunder and that no
      Purchaser will be acting as agent of such Purchaser in connection with
      monitoring its investment in the Securities or enforcing its rights under the
      Transaction Documents. Each Purchaser shall be entitled to independently protect
      and enforce its rights, including without limitation the rights arising out
      of
      this Agreement or out of the other Transaction Documents, and it shall not
      be
      necessary for any other Purchaser to be joined as an additional party in any
      proceeding for such purpose. The Company acknowledges that each of the
      Purchasers has been provided with the same Transaction Documents for the purpose
      of closing a transaction with multiple Purchasers and not because it was
      required or requested to do so by any Purchaser. The Company’s obligations to
      each Purchaser under this Agreement are identical to its obligations to each
      other Purchaser other than such differences resulting solely from the number
      of
      Securities purchased by such Purchaser, but regardless of whether such
      obligations are memorialized herein or in another agreement between the Company
      and a Purchaser.

     

    
      
        
          
          

        

        
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    6.18 Termination.
      This
      Agreement may be terminated and the sale and purchase of the Shares and the
      Warrants abandoned at any time prior to the Closing by either the Company or
      any
      Purchaser (with respect to itself only) upon written notice to the other, if
      the
      Closing has not been consummated on or prior to 5:00 p.m. (New York City time)
      on the Outside Date; provided,
      however,
      that
      the right to terminate this Agreement under this Section
      6.18
      shall
      not be available to any Person whose failure to comply with its obligations
      under this Agreement has been the cause of or resulted in the failure of the
      Closing to occur on or before such time. Nothing in this Section
      6.18
      shall be
      deemed to release any party from any liability for any breach by such party
      of
      the terms and provisions of this Agreement or the other Transaction Documents
      or
      to impair the right of any party to compel specific performance by any other
      party of its obligations under this Agreement or the other Transaction
      Documents. In the event of a termination pursuant to this Section, the Company
      shall promptly notify all non-terminating Purchasers. Upon a termination in
      accordance with this Section, the Company and the terminating Purchaser(s)
      shall
      not have any further obligation or liability (including arising from such
      termination) to the other, and no Purchaser will have any liability to any
      other
      Purchaser under the Transaction Documents as a result therefrom.

     

    
      
        
          
          

        

        
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    IN
      WITNESS WHEREOF, the parties hereto have caused this Securities Purchase
      Agreement to be duly executed by their respective authorized signatories as
      of
      the date first indicated above.

     

    
      	 	 	 
	 	
              ZIOPHARM
                ONCOLOGY, INC.

            
	 
 	 
 	 
 
	
            	By:  	
            
	 	
              
                

              

              Name:

              Title: 

            

    

     

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      OF PAGE INTENTIONALLY LEFT BLANK]

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      PAGES FOR PURCHASERS FOLLOW]

    

    
      
        
          
          

        

        
          
          

          
            

          

        

         

      

    

     

    
      	 	 	 
	 	
              NAME
                OF PURCHASER: ____________________________

            
	 
 	 
 	 
 
	
            	By:  	
            
	 	
              
                

              

              Name:

              Title: 

            

    

     

    Purchase
      Price (Subscription Amount): $ ____________________  

     

    Number
      of
      Shares to be acquired: __________________________

    Underlying
      Shares subject to Warrant: ______________________

    (20.0%
      of
      the number of Shares to be acquired) 

     

    Tax
      ID
      No.: ___________________________________________  

     

    Address
      for Notice: 

     

    ____________________________________________________

    ____________________________________________________

    ____________________________________________________

     

    Telephone
      No.: ________________________________________

     

    Facsimile
      No.: ________________________________________

     

    Attention:
      ___________________________________________

    

    

    Delivery
      Instructions:

    (if
      different than above)

    

    c/o:
      ________________________________________

    

    Street:
      ______________________________________

    ______________________________________

     

     

    City/State/Zip:________________________________

    

    Attention:
      ___________________________________

    

    Telephone
      No.: _______________________________

    

    
      
        
          
          

        

        
          
          

          
            

          

        

         

      

    

    

    EXHIBITS:
      

     

    A:
       Form
      of
      Warrant 

     

    B:
       Form
      of
      Registration Rights Agreement

     

    C-1:
       Accredited
      Investor Questionnaire

     

    C-2: Stock
      Certificate Questionnaire

     

    D:
       Form
      of
      Opinion of Company Counsel

     

    E:
       Irrevocable
      Transfer
      Agent Instructions

     

    F: Wire
      Instructions

     

    SCHEDULES:
      

     

    3.1(c)
      Authorization; Enforcement

     

    3.1(e)
      Filings, Consents and Approvals 

     

    3.1(w)
      Certain Fees 

    

    
      
        
          
          

        

        
          
          

          
            

          

        

         

      

    

     

    EXHIBIT
      A

     

    Form
      of
      Warrant

    

    
      
        
          
          

        

        
          
          

          
            

          

        

         

      

    

    

    EXHIBIT
      B

     

    Form
      of
      Registration Rights Agreement

    

    
      
        
          
          

        

        
          
          

          
            

          

        

         

      

    

    

    Instruction
      Sheet for Exhibits C 

    

    (to
      be
      read in conjunction with the entire Securities Purchase Agreement and
      Registration Rights Agreement) 

    

    A.
       Complete
      the following items in the Securities Purchase Agreement and/or Registration
      Rights Agreement: 

    

    1.
        Provide
      the information regarding the Purchaser requested on the signature page.
 The
       Securities
      Purchase Agreement must be executed by an individual authorized to bind
the
      Purchaser. 

    

    2.
        Exhibit
      C-1
      -
      Accredited Investor Questionnaire: 

    

    Provide
      the information requested by the
      Accredited Investor Questionnaire

    

    3.  
       Exhibit
      C-2
      - Stock
      Certificate Questionnaire

    

    Provide
      the information requested by the
      Stock
      Certificate Questionnaire

    

    4.  
        Annex
      B
      to the
      Registration Rights Agreement—Selling
      Securityholder Notice and Questionnaire

    

    Provide
      the information requested by the Selling Securityholder Notice and
      Questionnaire

    

    5. 
        Return
      the signed Securities Purchase Agreement and Registration Rights Agreement to:
      

    

    Basil
      Christakos

    Paramount
      BioCapital, Inc.

    787
      Seventh Avenue

    48th
      Floor

    New
      York,
      NY 10019

    Tel:
      (212) 554-4364

    Fax:
      (212) 554-4355

    Email:
      bchristakos@paramountbio.com

    

    
      	
              B.
                

            	
              Instructions
                regarding the transfer of funds for the purchase of Securities is
                set
                forth on Exhibit
                F
                to
                the Securities Purchase Agreement. 

            

    

     

    
      
        
          
          

        

        
          
          

          
            

          

        

         

      

    

    

    EXHIBIT
      C-1

    

    ACCREDITED
      INVESTOR QUESTIONNAIRE

    

    (ALL
      INFORMATION WILL BE TREATED CONFIDENTIALLY)

    

    To: ZIOPHARM
      Oncology, Inc.

    

    This
      Investor Questionnaire (“Questionnaire”)
      must
      be completed by each potential investor in connection with the offer and sale
      of
      the shares of the common stock, par value $0.001 per share, and shares of common
      stock that may be issued upon exercise of certain warrants (collectively, the
      “Securities”),
      of
      ZIOPHARM Oncology, Inc., a Delaware corporation (the “Corporation”).
      The
      Securities are being offered and sold by the Corporation without registration
      under the Securities Act of 1933, as amended (the “Act”),
      and
      the securities laws of certain states, in reliance on the exemptions contained
      in Section 4(2) of the Act and on Regulation D promulgated thereunder and
      in reliance on similar exemptions under applicable state laws. The Corporation
      must determine that a potential investor meets certain suitability requirements
      before offering or selling Securities to such investor. The purpose of this
      Questionnaire is to assure the Corporation that each investor will meet the
      applicable suitability requirements. The information supplied by you will be
      used in determining whether you meet such criteria, and reliance upon the
      private offering exemptions from registration is based in part on the
      information herein supplied.

     

    This
      Questionnaire does not constitute an offer to sell or a solicitation of an
      offer
      to buy any security. Your answers will be kept strictly confidential. However,
      by signing this Questionnaire, you will be authorizing the Corporation to
      provide a completed copy of this Questionnaire to such parties as the
      Corporation deems appropriate in order to ensure that the offer and sale of
      the
      Securities will not result in a violation of the Act or the securities laws
      of
      any state and that you otherwise satisfy the suitability standards applicable
      to
      purchasers of the Securities. All potential investors must answer all applicable
      questions and complete, date and sign this Questionnaire. Please print or type
      your responses and attach additional sheets of paper if necessary to complete
      your answers to any item.

     

    PART
      A. BACKGROUND
      INFORMATION

    

    Name
      of
      Beneficial Owner of the Securities:  

    
      

    

    Business
      Address:  

    
      

    

    (Number
      and Street) 

     

    
      

    

    
      	
              (City)

            	
              (State)

            	
              (Zip
                Code)

            

    

    

    

    Telephone
      Number: (___)   

    
      

    

     

    If
      a corporation, partnership, limited liability company, trust or other
      entity:

    

    Type
      of
      entity:  

    
      

    

    

    State
      of
      formation:______________________ Approximate
      Date of formation: ____________________

    

    Set
      forth
      in the space provided below the (i) state(s), if any, in the United States
      in which you maintained your principal office during the past two years and
      the
      dates during which you maintained your office in each state, and
      (ii) state(s), if any, in which you pay income taxes:

    

    
      
        
          
          

        

        
          
          

          
            

          

        

         

      

    

     

    Were
      you
      formed for the purpose of investing in the securities being
      offered?

    

    Yes
      ____ No
      ____

    

    If
      an individual:

    

    Residence
      Address: 

    
      

    

    (Number
      and Street)

     

    
      

    

    
      	
              (City)

            	
              (State)

            	
              (Zip
                Code)

            

    

    

     

    Telephone
      Number: (___)   

    
      

    

    

    Age:
      __________ Citizenship:
      ____________ Where
      registered to vote: _______________ 

    

    Set
      forth
      in the space provided below the state(s), if any, in the United States in which
      you maintained your residence during the past two years and the dates during
      which you resided in each state:

    
 

    

    Are
      you a
      director or executive officer of the Corporation?

    

    Yes
      ____ No
      ____

    

    PART
      B. ACCREDITED
      INVESTOR QUESTIONNAIRE

     

    In
      order
      for the Company to offer and sell the Securities in conformance with state
      and
      federal securities laws, the following information must be obtained regarding
      your investor status. Please initial
      each category applicable
      to you as a Purchaser of Securities of the Company. 

     

    
      	 	__ (1)	
              A
                bank as defined in Section 3(a)(2) of the Securities Act, or any
                savings
                and loan  association
                or other institution as defined in Section 3(a)(5)(A) of the Securities
                Act  whether
                acting in its individual or fiduciary capacity;

            

      	 	 	 

      	 	__ (2)	
              A
                broker or dealer registered pursuant to Section 15 of the Securities
                Exchange Act  of
                1934; 

            

      	 	 	 

      	 	
              __
                (3) 

            	
              An
                insurance company as defined in Section 2(13) of the Securities Act;
                

            

    

    

    
      	 	
              __
                (4) 

            	
              An
                investment company registered under the Investment Company Act of
                1940 or
                a business development company as defined in Section 2(a)(48) of
                that Act;
                

            

    

    

    
      	 	
              __
                (5) 

            	
              A
                Small Business Investment Company licensed by the U.S. Small Business
                Administration under Section 301(c) or (d) of the Small Business
                Investment Act of 1958; 

            

    

    

    
      
        
          
          

        

        
          
          

          
            

          

        

         

      

    

     

    
      	 	
              __
                (6)

            	
              A
                plan established and maintained by a state, its political subdivisions,
                or
                any agency or instrumentality of a state or its political subdivisions,
                for the benefit of its employees, if such plan has total assets in
                excess
                of $5,000,000; 

            

    

    

    
      	 	
              __
                (7) 

            	
              An
                employee benefit plan within the meaning of the Employee Retirement
                Income
                Security Act of 1974, if the investment decision is made by a plan
                fiduciary, as defined in Section 3(21) of such act, which is either
                a
                bank, savings and loan association, insurance company, or registered
                investment adviser, or if the employee benefit plan has total assets
                in
                excess of $5,000,000 or, if a self-directed plan, with investment
                decisions made solely by persons that are accredited investors;
                

            

    

    

    
      	 	
              __
                (8) 

            	
              A
                private business development company as defined in Section 202(a)(22)
                of
                the Investment Advisers Act of
                1940;

            

    

     

    
      	 	
              __
                (9) 

            	
              An
                organization described in Section 501(c)(3) of the Internal Revenue
                Code,
                a corporation, Massachusetts or similar business trust, or partnership,
                not formed for the specific purpose of acquiring the Securities,
                with
                total assets in excess of $5,000,000; 

            

      	 	 	 

      	 	__ (10) 	
              A
                trust, with total assets in excess of $5,000,000, not formed for
                the
                specific purpose of acquiring the Securities, whose purchase is directed
                by a sophisticated person who has such knowledge and experience in
                financial and business matters that such person is capable of evaluating
                the merits and risks of investing in the
                Company;

            

      	 	 	 

      	 	__(11)	
              A
                natural person whose individual net worth, or joint net worth with
                that
                person’s spouse,
                at the time of his purchase exceeds
                $1,000,000;

            

      	 	 	 

      	 	__(12) 	
              A
                natural person who had an individual income in excess of $200,000
                in each
                of the two
                most recent years, or joint income with that person’s spouse in excess
                of  $300,000,
                in each of those years, and has a reasonable expectation of reaching
                the same
                income level in the current year;

            

    

     

    
      	 	
              __(13)

            	
              An
                executive officer or director of the
                Company

            

      	 	 	 

      	 	__(14)	
               An
                entity in which all of the equity owners qualify under any of the
                above
                subparagraphs. If the undersigned belongs to this investor category
                only,
                list the equity owners of the undersigned, and the investor category
                which
                each such equity owner satisfies: 

            

    

     

    (Continue
      on a separate piece of paper, if necessary.) 

    

    
      
        
          
          

        

        
          
          

          
            

          

        

         

      

    

    
 

    A. FOR
      EXECUTION BY AN INDIVIDUAL:

    
      
        
          	 	 	 	 
	
                  
                  

                	
                   

                	
                  By 

                	
                
	
                  
Date	 	Print
                  Name: 	
                  
                    

                  

                   

                  
                    
 

                

        

    

    

    B. FOR
      EXECUTION BY AN ENTITY:

     

    
      	 	 	
              
              

              Entity
                Name: 

            	
               

              
                
 

            
	
              
              

            	
               

            	
              By 

            	
            
	
              
Date	 	
              Print
                Name: 

            	
              
                

              

               

              
                

              

            
	 	 	Title: 	
               

              
                
 

            

    

     

    C. ADDITIONAL
      SIGNATURES (if required by partnership, corporation or trust
      document):

     

    
      
        	 	 	
                
                

                Entity
                  Name: 

              	
                 

                
                  
 

              
	
                
                

              	
                 

              	
                By 

              	
              
	
                
Date	 	
                Print
                  Name: 

              	
                
                  

                

                 

                
                  

                

              
	 	 	Title: 	
                 

                
                  
 

              
	 	 	 	 

      

      
        	 	 	
                
                

                Entity
                  Name: 

              	
                 

                
                  
 

              
	
                
                

              	
                 

              	
                By 

              	
              
	
                
Date	 	
                Print
                  Name: 

              	
                
                  
 

                
                  
 

              
	 	 	Title: 	
                 

                
                  
 

              

      

    
      
        
          
          

        

        
          
          

          
            

          

        

         

      

    

    

    EXHIBIT
      C-2

     

    Stock
      Certificate Questionnaire

     

    Pursuant
      to Section 2.2(b) of the Agreement, please provide us with the following
      information:

     

    
      	
              1.

            	
              The
                exact name that the Securities are to be registered in (this is the
                name
                that will appear on the stock certificate(s)). You may use a nominee
                name
                if appropriate:

            	 
	 	 	 
	
              2.

            	
              The
                relationship between the Purchaser of the Securities and the Registered
                Holder listed in response to Item 1 above:

            	 
	 	 	 
	
              3.

            	
              The
                mailing address, telephone and telecopy number of the Registered
                Holder
                listed in response to Item 1 above:

            	 
	 	 	 
	 	 	 
	 	 	 
	 	 	 
	 	 	 
	
              4.

            	
              The
                Tax Identification Number (or, if an individual, the Social Security
                Number) of the Registered Holder listed in response to Item 1
                above:

            	 

    

    

    
      
        
          
          

        

        
          
          

          
            

          

        

         

      

    

     

    EXHIBIT
      D

     

    Form
      of
      Opinion of Company Counsel

     

    
      
        
          
          

        

        
          
          

          
            

          

        

         

      

    

    
       

      EXHIBIT
        E

    

     

    Form
      of
      Irrevocable Transfer Agent Instructions

     

    As
      of
      February __, 2007

     

    American
      Stock Transfer and Trust Company

    6201
      15
      Avenue

    Brooklyn
      New York 11129

    Attn:
      _________________

     

    Ladies
      and Gentlemen: 

     

          Reference
      is made to that certain Securities Purchase Agreement, dated as of February
      __,
      2007 (the “Agreement”),
      by
      and among ZIOPHARM Oncology, Inc. a Delaware corporation (the “Company”),
      and
      the purchasers named on the signature pages thereto (collectively, the
“Holders”),
      pursuant to which the Company is issuing to the Holders shares (the
“Shares”)
      of
      Common Stock of the Company, par value $0.001 per share (the “Common
      Stock”),
      and
      warrants (the “Warrants”),
      which
      are exercisable into shares of Common Stock. 

     

          This
      letter shall serve as our irrevocable authorization and direction to you
      (provided that you are the transfer agent of the Company at such time and the
      conditions set forth in this letter are satisfied): 

     

           (i)  to
      issue
      shares of Common Stock upon transfer or resale of the Shares; and 

     

           (ii)  to
      issue
      shares of Common Stock upon the exercise of the Warrants (the “Warrant
      Shares”)
      to or
      upon the order of a Holder from time to time upon delivery to you of a properly
      completed and duly executed Exercise Notice, in the form attached hereto as
      Annex I,
      which
      has been acknowledged by the Company as indicated by the signature of a duly
      authorized officer of the Company thereon together with indication of receipt
      of
      the exercise price therefor. 

    

          You
      acknowledge and agree that so long as you have previously received
      (a) written confirmation from the Company’s legal counsel that either
      (1) a registration statement covering resales of the Shares and the Warrant
      Shares has been declared effective by the Securities and Exchange Commission
      (the “Commission”)
      under
      the Securities Act of 1933, as amended (the “Securities
      Act”),
      or
      (2) the Shares and the Warrant Shares are eligible for sale in conformity
      with Rule 144 under the Securities Act (“Rule 144”)
      and
      (b) if applicable, a copy of such registration statement, then, unless
      otherwise required by law, as soon as reasonably practicable following your
      receipt of Shares or Warrant Shares, you shall issue the certificates
      representing the Shares and the Warrant Shares so sold to the Holders or their
      transferees, as the case may be, registered in the names of such Holders or
      transferees, as the case may be, and such certificates shall not bear any legend
      restricting transfer of the Shares and the Warrant Shares thereby and should
      not
      be subject to any stop-transfer restriction; provided,
      however,
      that if
      such Shares and Warrant Shares are not registered for resale under the
      Securities Act or able to be sold under Rule 144, then the certificates for
      such
      Shares and/or Warrant Shares shall bear the following legend:

     

    THE
      SECURITIES REPRESENTED BY THIS CERTIFICATE HAVE NOT BEEN REGISTERED UNDER THE
      SECURITIES ACT OF 1933, AS AMENDED, OR APPLICABLE STATE SECURITIES LAWS. THE
      SECURITIES MAY NOT BE OFFERED FOR SALE, SOLD, TRANSFERRED OR ASSIGNED (I) IN
      THE
      ABSENCE OF (A) AN EFFECTIVE REGISTRATION STATEMENT FOR THE SECURITIES UNDER
      THE
      SECURITIES ACT OF 1933, AS AMENDED, OR (B) AN OPINION OF COUNSEL, IN A GENERALLY
      ACCEPTABLE FORM, THAT REGISTRATION IS NOT REQUIRED UNDER SAID ACT OR (II) UNLESS
      SOLD PURSUANT TO RULE 144 OR RULE 144A UNDER SAID ACT. NOTWITHSTANDING THE
      FOREGOING, THE SECURITIES MAY BE PLEDGED IN CONNECTION WITH A BONA FIDE MARGIN
      ACCOUNT OR OTHER LOAN OR FINANCING ARRANGEMENT SECURED BY THE
      SECURITIES.

     

          A
      form of
      written confirmation (to be used in connection with any sale) from the Company’s
      outside legal counsel that a registration statement covering resales of the
      Shares and the Warrant Shares has been declared effective by the Commission
      under the Securities Act is attached hereto as Annex II.
      

     

          Please
      be
      advised that the Holders are relying upon this letter as an inducement to enter
      into the Agreement and, accordingly, each Holder is a third party beneficiary
      to
      these instructions. 

     

          Please
      execute this letter in the space indicated to acknowledge your agreement to
      act
      in accordance with these instructions. 

    

    Very
      truly yours,

    

    ZIOPHARM
      ONCOLOGY, INC.

     

    By:
      __________________________________

    Name:
      ________________________________

    Title:
      ________________________________

    

    

    Acknowledged
      and Agreed:

    

    AMERICAN
      STOCK TRANSFER & TRUST COMPANY

    

    By:
      __________________________________

    Name:
      ________________________________ 

    Title:
      ________________________________

     

    Date:
      _________________, 2007

    

    
      
        
          
          

        

        
          
          

          
            

          

        

         

      

    

     

    Annex
      I 

     

    Form
      of
      Exercise Notice 

     

    (To
      be
      executed by the Holder to exercise the right to purchase shares 

    of
      Common
      Stock under the foregoing Warrants) 

     

    To:
       ZIOPHARM
      Oncology, Inc.

    

    (1) The
      undersigned hereby elects to purchase _________ shares of Common Stock pursuant
      to the above-referenced Warrant. Capitalized terms used herein and not otherwise
      defined herein have the respective meanings set forth in the Warrant.

      

    (2) The
      Holder intends that payment of the Exercise Price shall be made as (check
      one):

    

    o              Cash
      Exercise under Section 10

    

    o 
Cashless
      Exercise under Section 10

    

    (3) If
      the
      Holder has elected a Cash Exercise, the holder shall pay the sum of $_______
      to
      the Company in accordance with the terms of the Warrant.

    

    (4) Pursuant
      to this Exercise Notice, the Company shall deliver to the Holder _____________
      Warrant Shares in accordance with the terms of the Warrant.

     

    (5) By
      its
      delivery of this Exercise Notice, the undersigned represents and warrants to
      the
      Company that in giving effect to the exercise evidenced hereby, the Holder
      will
      not beneficially own in excess of the number of shares of Common Stock (as
      determined in accordance with Section 13(d) of the Securities Exchange Act
      of
      1934) permitted to be owned under Section 11 of this Warrant to which this
      notice relates. 

    

     

    Dated:_______________,
      _____ 

     

    Name
      of
      Holder: ________________________

     

     

    By:_________________________________

    Name:
      ______________________________

    Title:
      _______________________________

    

    (Signature
      must conform in all respects to name of Holder as specified on the face of
      the
      Warrant)

    

    
      
        
          
          

        

        
          
          

          
            

          

        

         

      

    

     

    Acknowledgement
      

     

          The
      Company hereby acknowledges this Exercise Notice and receipt of the appropriate
      exercise price and hereby directs American Stock Transfer & Trust Company to
      issue the above indicated number of shares of Common Stock in accordance with
      the Transfer Agent Instructions dated February __ 2007, from the Company and
      acknowledged and agreed to by American Stock Transfer & Trust Company.

    
       

      ZIOPHARM
        ONCOLOGY, INC.

       

      By:
        __________________________________  

      Name:
        ________________________________

      Title:
        ________________________________

    

     

    
      
        
          
          

        

        
          
          

          
            

          

        

         

      

    

     

    Annex
      II

     

    Form
      of
      Notice of Effectiveness of Registration Statement 

    
      	
               

            	
               

            	
               

            
	
              American
                Stock Transfer and Trust Company

              6201
                15 Avenue

              Brooklyn
                New York 11129

              Attn:
                _________________

            
	
               

            	
               

            	
               

            
	
               
                

            	
               

            	
              Re:
                ZIOPHARM
                Oncology, Inc.

            

    

     

    Ladies
      and Gentlemen: 

     

             We
      are
      counsel to ZIOPHARM Oncology, Inc. a Delaware corporation (the “Company”),
      and
      have represented the Company in connection with that certain Securities Purchase
      Agreement, dated as of February __, 2007, entered into by and among the Company
      and the buyers named therein (collectively, the “Purchasers”)
      pursuant to which the Company issued to the Purchasers shares of the Company’s
      Common Stock, $0.001 par value per share (the “Common
      Stock”),
      and
      warrants exercisable for shares of Common Stock (the “Warrants”).
      Pursuant to that certain Registration Rights Agreement of even date, the Company
      agreed to register the resale of the Common Stock, including the shares of
      Common Stock issuable upon exercise of the Warrants (collectively, the
“Registrable
      Securities”),
      under
      the Securities Act of 1933, as amended (the “Securities
      Act”).
      In
      connection with the Company’s obligations under the Registration Rights
      Agreement, on                     ,
      2007,
      the Company filed a Registration Statement on Form S-3 (File
      No. 333-                    )
      (the
“Registration
      Statement”)
      with
      the Securities and Exchange Commission (the “Commission”)
      relating to the Registrable Securities which names each of the Purchasers as
      a
      selling shareholder thereunder. 

     

            In
      connection with the foregoing, we advise you that a member of the Commission’s
      staff has advised us by telephone that the Commission has entered an order
      declaring the Registration Statement effective under the Securities Act at
      ____
      [a.m.][p.m.] on __________, 200_, and we have no knowledge, after telephonic
      inquiry of a member of the staff, that any stop order suspending its
      effectiveness has been issued or that any proceedings for that purpose are
      pending before, or threatened by, the Commission and the Registrable Securities
      are available for resale under the Securities Act pursuant to the Registration
      Statement. 

     

          This
      letter shall serve as our standing notice to you that the Common Stock may
      be
      freely transferred by the Purchasers pursuant to the Registration Statement.
      You
      need not require further letters from us to effect any future legend-free
      issuance or reissuance of shares of Common Stock to the Purchasers or the
      transferees of the Purchasers, as the case may be, as contemplated by the
      Company’s Irrevocable Transfer Agent Instructions dated February __, 2007. This
      letter shall serve as our standing instructions with regard to this matter.
      

    

    
      
        
          
          

        

        
          
          

          
            

          

        

         

      

    

    

    
      	
               

            	
               

            	
               

            	
               

            	
               

            
	
               

            	
               

            	
              Very
                truly yours,

            
	
               

            	
               

            	
               

            	
               

            	
               

            
	
               

            	
               

            	
              MASLON
                EDELMAN BORMAN & BRAND, LLP

            
	
               

            	
               

            	
               

            	
               

            	
               

            
	
               
                

            	
               

            	
              By:

            	
               

            	
               

            
	
               
                

            	
               

            	
               

            	
               

            	
              
                

              

            

    

    CC:         Purchasers

    Oppenheimer
      & Co. Inc.

    Griffin
      Securities, Inc.

    Paramount
      BioCapital, Inc.

    

    
      
        
          
          

        

        
          4

          
            

          

        

         

      

    

     

    EXHIBIT
      F

     

    WIRE
      INSTRUCTIONS

     

    
      
        
          
          

        

        
          5

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