Exhibit
        4.2




**FIRST
        AMENDMENT TO**
 **SENIOR
        CONVERTIBLE PROMISSORY NOTE**


THIS
        FIRST AMENDMENT TO SENIOR CONVERTIBLE PROMISSORY NOTE (“ **Amendment** ”)
        is
        entered into as of March __, 2008, by and between **VIOQUEST
        PHARMACEUTICALS, INC.** ,
        a
        Delaware corporation (the “ **Company** ”),
        and
        the undersigned, constituting the holders of not less than a majority of
        the
        then outstanding principal amount of those certain Senior Convertible Promissory
        Notes (as amended, the “ **Notes** ”),
        issued on June 29, 2007 and July 3, 2007, on behalf of all of the holders
        of the
        Notes or their assigns (“ **Holders** ”),
        to
        amend, as set forth herein, the terms of all of the outstanding
        Notes.




A.  The
      Company issued the Notes pursuant to the terms of that certain Note and Warrant
      Purchase Agreement (the “ **Purchase
      Agreement** ”),
      dated
      June 29, 2007 or July 3, 2007, by and between the Company and each of the
      Holders.




B.  Section
      13 of the Notes provides that any section of the Notes may be amended by the
      consent of the Holders of not less than a majority of the then outstanding
      principal amount of the Notes (the “ **Majority
      Holders** ”)
      except
      for any amendment, modification or waiver of the terms and conditions of the
      Notes that would adversely affect the Holders’ rights with respect to: (i) the
      date by which the Notes must be repaid, or (ii) the rate at which interest
      accrues under the Notes, or any amendment or modification to Section 4.1 of
      the
      Notes.




C.  The
      Company wishes to amend the Notes, upon receipt of the consent of the Majority
      Holders, to, among other things, amend the mandatory conversion provisions
      contained in Section 2 of the Notes.




D.  The
      Company and the Holders wish to reduce their agreement to writing in the form
      of
      this Amendment.




NOW,
        THEREFORE, the
        parties hereto hereby agree as follows:


1.  **Amendment** .
      Section
      2 of the Notes is hereby deleted in its entirety and replaced with the following
      text:




2.  Mandatory
      Conversion .




2.1  Upon
      the
      closing of a New Securities Offering, (i) all principal and accrued but unpaid
      interest on this Note shall be automatically converted into shares of the
      Company’s newly-designated Series B Convertible Preferred Stock, par value
      $0.001 per share (the “ Series
      B Preferred Stock ”),
      at a
      conversion ratio of one (1) share of Series B Preferred Stock for every $1,000
      of unpaid principal and accrued interest due under this Note as of the closing
      of the New Securities Offering, and (ii), each holder of shares of Series B
      Preferred Stock (each, a “ Series
      B Holder ”)
      shall
      be granted the right, exercisable at any time on and after the closing of the
      Offering but on or prior to April 1, 2008 (the “ Exercise
      Period ”),
      to
      convert shares of Series B Preferred Stock into New Securities pursuant to
      Section 2.2 hereof (the “ Series
      B Participation Right ”).




2.2  At
      any
      time during the Exercise Period, a Series B Holder may elect to exercise such
      holder’s Series B Participation Right by delivering to the Company a duly
      executed binding subscription agreement for the purchase of New Securities,
      including the additional signature page thereto, duly completed in accordance
      with the terms of such subscription agreement (together with the applicable
      purchase price for such New Securities), and upon such delivery the Company
      shall convert shares of Series B Preferred Stock held by, or deliverable by
      the
      Company upon surrender by the Holder of the Note to, such Series B Holder into
      New Securities on the following basis: for every $1,000 of New Securities
      purchased by such Series B Holder in the New Securities Offering during the
      Exercise Period, the Company shall convert, for no additional consideration,
      one
      (1) share of Series B Preferred Stock into one (1) share of Series A Preferred
      Stock and a warrant to purchase a number of shares of the Common Stock (as
      defined below) equal to 50% of the number of shares of Common Stock into which
      one (1) share of Series A Preferred Stock may be converted as of the closing
      of
      the New Securities Offering.












2.3  Upon
      conversion of this Note in accordance with the terms of this Sections 2.1 and/or
      2.2, the applicable amount of outstanding principal and accrued unpaid interest
      of the Note shall be converted without any further action by the Holder and
      whether or not the Note is surrendered to the Company or its transfer agent.
      The
      Company shall not be obligated to issue certificates evidencing the New
      Securities or Series B Preferred Stock, as applicable, unless the Note is either
      delivered to the Company or its transfer agent, or the Holder notifies the
      Company or its transfer agent that such Note has been lost, stolen or destroyed
      and executes an agreement satisfactory to the Company to indemnify the Company
      from any loss incurred by it in connection with such Note. The Company shall,
      as
      soon as practicable after such delivery, or such agreement and indemnification,
      issue and deliver to such Holder of such Note, a certificate or certificates
      for
      the securities to which the Holder shall be entitled. Such conversion shall
      be
      deemed to have been made upon the close of the New Securities Offering. The
      person or persons entitled to receive securities issuable upon such conversion
      shall be treated for all purposes as the record holder or holders of such
      securities on such date.




2.4  For
      purposes of this Note, the term “ New
      Securities Offering ”
shall
      mean the Company’s private offering to a limited number of “accredited
      investors,” as that term is defined by Rule 501(a) of Regulation D of the
      Securities Act, of shares of the Company’s newly-designated Series A Convertible
      Preferred Stock, par value $0.001 per share (the “ Series
      A Preferred Stock ”),
      and
      warrants (“ Warrants ”
and,
      together with the Series A Preferred Stock, the “ New
      Securities ”)
      to
      purchase shares of Common Stock, for an aggregate purchase price of at least
      $500,000, pursuant to that certain Confidential Private Placement Memorandum,
      dated as of February 28, 2008, as it may be amended, restated, supplemented
      or
      otherwise modified from time to time.




2.  Pursuant
      to the Section 13 of the Notes, this Amendment shall only be effective upon
      the
      Company’s receipt of executed counterparts by the Majority Holders, and upon
      such receipt this Amendment shall be binding upon all of the Holders as if
      they
      had executed a counterpart hereto. Any Holder executing this Amendment shall
      be
      deemed to have consented to its terms and provisions with respect to the
      original principal balance of all the Notes nominally held by such Holder,
      whether or not such Holder exercises, in whole or in part, the Series B
      Participation Rights granted herein.




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3.  Except
      as
      explicitly amended by this Amendment, all of the terms and conditions of the
      Notes shall remain in full force and effect.




4.  Upon
      execution hereof by the Majority Holders, the Company will distribute a fully
      executed copy of this Amendment, and each of the Holders shall permanently
      attach this Amendment to its respective Note(s), making it a part thereof.
      Notwithstanding Section 6.12(b) of the Purchase Agreement, the Majority Holders,
      by executing and delivering this Amendment, hereby consent to the distribution
      of their executed counterparts to all of the Holders.




5.  This
      Amendment may be executed in any number of counterparts, each of which when
      so
      executed and delivered shall be deemed an original and all of which
      counterparts, taken together, shall constitute one and the same instrument.
      Delivery by fax or an e-mail file attachment of any counterpart signature to
      this Amendment shall be deemed to be an original and considered valid and
      binding to the same extent as delivered original signatures. ****




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      of page intentionally left blank; signature page follows* ]




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IN
        WITNESS WHEREOF, the undersigned parties have executed this First Amendment
        to
        Senior Convertible Promissory Note as of the date first written
        above.




**Company:**Vioquest
                Pharmaceuticals, Inc.:By:Name:Title:**Holder:**By:Name:Title:





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