Document:

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Exhibit 10.5

    SECOND AMENDMENT TO AMENDED AND RESTATED NORTHWEST BIOTHERAPEUTICS, INC.
 LOAN AGREEMENT, SECURITY AGREEMENT AND 10% CONVERTIBLE, SECURED PROMISSORY NOTE

      THIS SECOND AMENDMENT TO AMENDED AND RESTATED NORTHWEST BIOTHERAPEUTICS,
INC. LOAN AGREEMENT, SECURITY AGREEMENT AND 10% CONVERTIBLE, SECURED PROMISSORY
NOTE (the "Second Amendment") is made and entered into as of July 26, 2005, by
and among NORTHWEST BIOTHERAPEUTICS, INC., a Delaware corporation (the "Maker")
and Toucan Capital Fund II, L.P. (the "Holder"). This Second Amendment amends
the Note (as defined below).

                                    RECITALS

A. Section 17.6 of that certain Amended and Restated Northwest Biotherapeutics,
Inc. Loan Agreement, Security Agreement and 10% Convertible, Secured Promissory
Note, in the principal amount of $50,000.00 amended and restated as of July 30,
2004 and originally issued on February 2, 2004, by and between the Maker and the
Holder in the form attached to this Second Amendment as Exhibit A and as amended
by that First Amendment To Northwest Biotherapeutics, Inc. Loan Agreement,
Security Agreement and 10% Convertible, Secured Promissory Note in the form
attached to this Second Amendment as Exhibit B (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 to provide that the Maturity Date is
November 1, 2005.

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

3. This Second Amendment shall be governed by and construed under the laws of
the state of Delaware without giving effect to principles of conflicts of laws
of the State of Delaware or any other state.

                            [SIGNATURE PAGE FOLLOWS]

                                        1

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      IN WITNESS WHEREOF, the parties hereto have executed this SECOND AMENDMENT
TO AMENDED AND RESTATED NORTHWEST BIOTHERAPEUTICS, INC. LOAN AGREEMENT, SECURITY
AGREEMENT AND 10% CONVERTIBLE, SECURED PROMISSORY NOTE as of the date first
above written.

MAKER:

NORTHWEST BIOTHERAPEUTICS, INC.,
a Delaware corporation

By:_________________________________
Name:_______________________________
Title:______________________________

HOLDER:

Toucan Capital Fund II, L.P.

By:________________________________
   Linda Powers, Managing Director

                                        2<PAGE>

Exhibit 10.6

  SECOND AMENDMENT TO AMENDED AND RESTATED NORTHWEST BIOTHERAPEUTICS, INC. LOAN
   AGREEMENT, SECURITY AGREEMENT AND 10% CONVERTIBLE, SECURED PROMISSORY NOTE

      THIS SECOND AMENDMENT TO AMENDED AND RESTATED NORTHWEST BIOTHERAPEUTICS,
INC. LOAN AGREEMENT, SECURITY AGREEMENT AND 10% CONVERTIBLE, SECURED PROMISSORY
NOTE (the "Second Amendment") is made and entered into as of July 26, 2005, by
and among NORTHWEST BIOTHERAPEUTICS, INC., a Delaware corporation (the "Maker")
and Toucan Capital Fund II, L.P. (the "Holder"). This Second Amendment amends
the Note (as defined below).

                                    RECITALS

A. Section 17.6 of that certain Amended and Restated Northwest Biotherapeutics,
Inc. Loan Agreement, Security Agreement and 10% Convertible, Secured Promissory
Note, in the principal amount of $50,000.00 amended and restated as of July 30,
2004 and originally issued on March 1, 2004, by and between the Maker and the
Holder in the form attached to this Second Amendment as Exhibit A and as amended
by that First Amendment To Northwest Biotherapeutics, Inc. Loan Agreement,
Security Agreement and 10% Convertible, Secured Promissory Note in the form
attached to this Second Amendment as Exhibit B (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

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1. Section 1 of the Note is hereby amended to provide that the Maturity Date is
November 1, 2005.

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

3. This Second Amendment shall be governed by and construed under the laws of
the state of Delaware without giving effect to principles of conflicts of laws
of the State of Delaware or any other state.

                            [SIGNATURE PAGE FOLLOWS]

                                        2

<PAGE>

      IN WITNESS WHEREOF, the parties hereto have executed this SECOND AMENDMENT
TO AMENDED AND RESTATED NORTHWEST BIOTHERAPEUTICS, INC. LOAN AGREEMENT, SECURITY
AGREEMENT AND 10% CONVERTIBLE, SECURED PROMISSORY NOTE as of the date first
above written.

MAKER:

NORTHWEST BIOTHERAPEUTICS, INC.,
a Delaware corporation

By:_________________________________
Name:_______________________________
Title:______________________________

HOLDER:

Toucan Capital Fund II, L.P.

By:________________________________
   Linda Powers, Managing Director

                                        3<PAGE>

Exhibit 10.7

    SECOND AMENDMENT TO AMENDED AND RESTATED NORTHWEST BIOTHERAPEUTICS, INC.
 LOAN AGREEMENT, SECURITY AGREEMENT AND 10% CONVERTIBLE, SECURED PROMISSORY NOTE

      THIS SECOND AMENDMENT TO AMENDED AND RESTATED NORTHWEST BIOTHERAPEUTICS,
INC. LOAN AGREEMENT, SECURITY AGREEMENT AND 10% CONVERTIBLE, SECURED PROMISSORY
NOTE (the "Second Amendment") is made and entered into as of July 26, 2005, by
and among NORTHWEST BIOTHERAPEUTICS, INC., a Delaware corporation (the "Maker")
and Toucan Capital Fund II, L.P. (the "Holder"). This Second Amendment amends
the Note (as defined below).

                                    RECITALS

A. Section 17.6 of that certain Amended and Restated Northwest Biotherapeutics,
Inc. Loan Agreement, Security Agreement and 10% Convertible, Secured Promissory
Note, in the principal amount of $500,000.00 amended and restated as of July 30,
2004 and originally issued on April 26, 2004, by and between the Maker and the
Holder in the form attached to this Second Amendment as Exhibit A and as amended
by that First Amendment To Northwest Biotherapeutics, Inc. Loan Agreement,
Security Agreement and 10% Convertible, Secured Promissory Note in the form
attached to this Second Amendment as Exhibit B (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

<PAGE>

1. Section 1 of the Note is hereby amended to provide that the Maturity Date is
November 1, 2005.

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

3. This Second Amendment shall be governed by and construed under the laws of
the state of Delaware without giving effect to principles of conflicts of laws
of the State of Delaware or any other state.

                            [SIGNATURE PAGE FOLLOWS]

                                        2

<PAGE>

      IN WITNESS WHEREOF, the parties hereto have executed this SECOND AMENDMENT
TO AMENDED AND RESTATED NORTHWEST BIOTHERAPEUTICS, INC. LOAN AGREEMENT, SECURITY
AGREEMENT AND 10% CONVERTIBLE, SECURED PROMISSORY NOTE as of the date first
above written.

MAKER:

NORTHWEST BIOTHERAPEUTICS, INC.,
a Delaware corporation

By:_________________________________
Name:_______________________________
Title:_______________________________

HOLDER:

Toucan Capital Fund II, L.P.

By:________________________________
   Linda Powers, Managing Director

                                        3<PAGE>

Exhibit 10.8

    FIRST AMENDMENT TO AMENDED AND RESTATED NORTHWEST BIOTHERAPEUTICS, INC.
 LOAN AGREEMENT, SECURITY AGREEMENT AND 10% CONVERTIBLE, SECURED PROMISSORY NOTE

      THIS FIRST AMENDMENT TO AMENDED AND RESTATED NORTHWEST BIOTHERAPEUTICS,
INC. LOAN AGREEMENT, SECURITY AGREEMENT AND 10% CONVERTIBLE, SECURED PROMISSORY
NOTE (the "First Amendment") is made and entered into as of July 26, 2005, by
and among NORTHWEST BIOTHERAPEUTICS, INC., a Delaware corporation (the "Maker")
and Toucan Capital Fund II, L.P. (the "Holder"). This First Amendment amends the
Note (as defined below).

                                    RECITALS

A. Section 17.6 of that certain Northwest Biotherapeutics, Inc. Loan Agreement,
Security Agreement and 10% Convertible, Secured Promissory Note, in the
principal amount of $500,000.00 amended and restated as of July 30, 2004 and
originally issued on June 11, 2004, by and between the Maker and the Holder in
the form attached to this First Amendment as Exhibit A (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 to provide that the Maturity Date is
November 1, 2005.

                                        1

<PAGE>

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

3. This First Amendment shall be governed by and construed under the laws of the
state of Delaware without giving effect to principles of conflicts of laws of
the State of Delaware or any other state.

                            [SIGNATURE PAGE FOLLOWS]

                                        2

<PAGE>

      IN WITNESS WHEREOF, the parties hereto have executed this FIRST AMENDMENT
TO AMENDED AND RESTATED NORTHWEST BIOTHERAPEUTICS, INC. LOAN AGREEMENT, SECURITY
AGREEMENT AND 10% CONVERTIBLE, SECURED PROMISSORY NOTE as of the date first
above written.

MAKER:

NORTHWEST BIOTHERAPEUTICS, INC.,
a Delaware corporation

By:_________________________________
Name:_______________________________
Title:_______________________________

HOLDER:

Toucan Capital Fund II, L.P.

By:________________________________
   Linda Powers, Managing Director

                                        3

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