FOURTH AMENDMENT TO CONVERTIBLE SECURED PROMISSORY NOTE THIS FOURTH AMENDMENT TO CONVERTIBLE SECURED PROMISSORY NOTE (the "FOURTH AMENDMENT") is made and entered into as of July 26, 2005, by and among NORTHWEST BIOTHERAPEUTICS, INC., a Delaware...

Exhibit 10.11

                               FOURTH AMENDMENT TO
                       CONVERTIBLE SECURED PROMISSORY NOTE

      THIS FOURTH AMENDMENT TO CONVERTIBLE SECURED PROMISSORY NOTE (the "FOURTH
AMENDMENT") is made and entered into as of July 26, 2005, by and among NORTHWEST
BIOTHERAPEUTICS, INC., a Delaware corporation (the "MAKER") and ______________
(the "HOLDER"). This Amendment amends the Note (as defined below).

                                    RECITALS

A. SECTION 10 of that certain Convertible Secured Promissory Note, dated as of
November 12, 2003 and amended on April 26, 2004, April 12, 2005 and June 16,
2005, by and between the Maker and the Holder (as so amended the "NOTE"), states
that any provision of such note may be amended or waived in writing by the
Holder and the Maker; and

B. The Maker and the Holder wish to amend the Note as provided below.

                                    AGREEMENT

      NOW, THEREFORE, in consideration of these premises and for other good and
valuable consideration, the receipt and sufficiency of which are hereby
acknowledged, the parties hereto agree as follows:

1.    SECTION 1 of the Note is hereby amended and restated in its entirety as
      follows:

            "1. Maturity Date. The aggregate principal amount of this Note and
      accrued interest thereon shall be due and payable on November 15, 2005
      (such date, the "MATURITY DATE")."

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2.    All other terms and conditions of the Note shall be unaffected hereby and
      remain in full force and effect

3.    This Fourth Amendment shall be shall be governed by and construed under
      the laws of the State of Washington as applied to agreements among
      Washington residents entered into and to be performed entirely within the
      State of Washington.

4.    This Fourth Amendment may be executed in one or more counterparts, each of
      which will be deemed an original but all of which together shall
      constitute one and the same agreement.

                            [SIGNATURE PAGE FOLLOWS]

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      IN WITNESS WHEREOF, the parties hereto have executed this FOURTH AMENDMENT
TO CONVERTIBLE SECURED PROMISSORY NOTE as of the date first above written.

MAKER:

NORTHWEST BIOTHERAPEUTICS, INC.,
a Delaware corporation

By:________________________
Name:______________________
Title:_____________________

HOLDER:

___________________________
Name:

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