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Exhibit 10.5.1

AMENDMENT TO THE ESCROW AGREEMENT(the
Amendment)

**THIS AMENDMENT**,
is made and entered into as of April 2, 2009, by and among MabCure Inc.(the Company), Dr. Amnon Gonenne (the Executive), and, Clark
Wilson LLP(the Escrow Agent). (Together the Parties, and each
individually, a Party).

WHEREAS, the Company, the
Executive and the Escrow Agent entered into an Escrow Agreement dated July 7,
2008 (the Agreement); and

WHEREAS, the Parties are
interested in amending the Agreement to clarify the intent of the Parties and to
correct a mistake in the description of the Subject Shares, while leaving the
Agreements remaining terms and conditions in full force and effect.

**NOW THEREFORE**,
the Parties hereby agree to amend the Agreement as follows:

1. Except as specifically modified by this Amendment, the terms
and conditions of the Agreement shall remain in full force and effect and shall
continue to govern the business relationship among the Parties. The effective
date of this Amendment shall be the date of the Agreement. In the event of any
inconsistency between the terms of this Amendment and the terms of the
Agreement, the terms of this Amendment shall control.

2. The capitalized terms used in this Amendment shall have the
meanings ascribed to them in the Agreement, unless defined otherwise herein.

3. Section 1.1 of the Agreement, entitled Definitions, shall
be amended as follows:

(a) Sub-section (k), defining the term
Executive Services, shall be deleted from Section 1.1, and replaced with the
following new sub-section (k):

| | (k) | Lapsing Repurchase Right shall have the meaning
      ascribed thereto in the Purchase Agreement, as amended;
| | ---- | ----------------------------------------------------------------------------------------------------------------

(b) Sub-Section (m), defining the term
Vesting Shares, shall be amended by replacing the term Vesting Shares with
the term Repurchase Shares.

(c) A new sub-section (n) shall be
added to Section 1.1 as follows:

| | (n) | Trigger Event shall have the meaning ascribed
      thereto in the Purchase Agreement, as amended.
| | ---- | -----------------------------------------------------------------------------------------------------

4. The third line of Section 3.2 of the Agreement shall be
amended to read as follows: . . . the Certificates representing the Repurchase
Shares that have been released from the Lapsing Repurchase Right pursuant to the
provisions of Section 4.1 hereof . . . 

5. Section 4 of the Agreement shall be deleted and replaced
with the following amended Section 4:

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| | 4.  | RELEASE OF THE REPURCHASE SHARES FROM THE LAPSING
      REPURCHASE RIGHT                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          
| | --- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
| |     |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   
| | 4.1 | The Executive agrees and acknowledges that 75% of the
      Subject Shares (i.e. 4,807,200 shares, as adjusted to include any
      Dividend Securities distributed in respect thereof; the "Repurchase
      Shares") shall be released from the Lapsing Repurchase Right and shall
      be no longer subject thereto over an 18 month period from the Closing in
      three 6-month intervals (each an "Interval"), such that 1/3 of the
      Repurchase Shares (i.e. 1,602,400 shares) shall be released from
      the Lapsing Repurchase Right at the end of each Interval, provided that at
      each respective Interval the Executive continues to be retained by the
      Company pursuant to Employment Agreement. All of the Repurchase Shares
      shall be released from the Lapsing Repurchase Right and no longer subject
      thereto upon the expiration of the Employment Term. Notwithstanding any
      other provision hereof, the Executive hereby acknowledges and agrees that,
      in the event of a Trigger Event, upon the Companys exercise of the
      Lapsing Repurchase Right, the Escrow Agent is hereby authorized and
      directed to deliver the remaining Repurchase Shares that are subject to
      the Lapsing Repurchase Right to the Company.
| |     |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   
| | 4.2 | Notwithstanding the foregoing, if, prior to the 18-month
      anniversary of the Closing: (a) the Company terminates the services of the
      Executive without "cause"; or (b) in the event of a "change of control" of
      the Company, then all the Repurchase Shares not yet released from the
      Lapsing Repurchase Right shall be released immediately from the Lapsing
      Repurchase Right and shall no longer be subject thereto. Furthermore, and
      notwithstanding the foregoing, if, prior to the 18-month anniversary of
      the Closing, the Executive is unable to substantially perform his duties
      according to the terms of the Employment Agreement by reason of his death
      or "Disability", then the number of Repurchase Shares that would have been
      released from the Lapsing Repurchase Right at the next proceeding Interval
      shall be released immediately from the Lapsing Repurchase Right and shall
      no longer be subject thereto.                                                                                                                                                                                                                                                                                           

6. This Amendment and the Agreement constitute the entire
agreement among the Parties with respect to the subject matter herein and
therein, and supersede all prior agreements and understandings among the Parties
with respect to the subject mater hereof or thereof.

**IN WITNESS
HEREOF**, the Parties have executed this Amendment.

|MabCure Inc.          | Clark Wilson LLP    
|--------------------- | --------------------
|                      |                     
|                      |                     
|/s/ Itshak Zivan      | /s/ Bernard Pinsky  
|Name: Itshak Zivan    | Name: Bernard Pinsky
|Title: Director       | Title: Lawyer       
|Date: March 18, 2009  | Date: April 2, 2009 
|                      |                     
|                      |                     
|Dr. Amnon Gonenne     |                     
|                      |                     
|/s/ Dr. Amnon Gonenne |                     
|Date: April 1, 2009   |                     

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