Document:

Form of Underwriter's Warrant

 Exhibit 4.44 
 THE COMMON SHARES FOR WHICH THIS SECURITY IS EXERCISABLE HAVE NOT BEEN AND WILL NOT BE REGISTERED UNDER THE UNITED STATES SECURITIES ACT OF 1933, AS AMENDED (THE “1933 ACT”) OR ANY APPLICABLE STATE SECURITIES LAWS. THIS
SECURITY MAY NOT BE EXERCISED WITHIN THE UNITED STATES OR ON BEHALF OF ANY U.S. PERSON (AS DEFINED IN REGULATION S UNDER THE 1933 ACT) UNLESS REGISTERED UNDER THE 1933 ACT AND ANY APPLICABLE STATE SECURITIES LAWS OR UNLESS AN EXEMPTION FROM SUCH
REGISTRATION IS AVAILABLE. 
 THE COMPENSATION OPTIONS EVIDENCED HEREBY ARE EXERCISABLE ON OR BEFORE 5:00 P. M. (TORONTO TIME) ON FEBRUARY 21, 2009,
AFTER WHICH TIME THE WARRANTS EVIDENCED HEREBY SHALL BE DEEMED TO BE VOID AND OF NO FURTHER FORCE OR EFFECT. 
  

			
	 NO.
                    
	  	February 21, 2007                    

 UNDERWRITER’S WARRANT 
 TO ACQUIRE 
 COMPENSATION UNITS OF 
 ADHEREX TECHNOLOGIES INC. 
 THIS CERTIFIES that,
for value received,                              in trust for Versant Partners Inc., 330 Bay St.,
Suite 711, Toronto, Ontario M5H 2S8 (the “Holder”), is the registered holder of
                            
(            ) Underwriter’s Warrants (the “Underwriter’s Warrants”) of Adherex Technologies Inc. (the “Corporation”), each
Underwriter’s Warrant entitling the Holder, subject to the terms and conditions set forth in this Certificate, to acquire from the Corporation, one (1) compensation unit (a “Compensation Unit”) at a price as US$0.33 per
Compensation Unit (the “Exercise Price”) at any time, and from time to time, commencing on the date hereof and continuing until 5:00 p.m. on February 21, 2009 (“Time of Expiry”). Each Compensation Unit shall,
subject to adjustment in certain events, be comprised of one common share in the capital of the Corporation (an “Option Share”) , and one-half of one common share purchase warrant (each whole warrant a “Compensation
Warrant” and collectively, the “Compensation Warrants”). 
 All capitalized terms not otherwise defined herein
shall have the meanings ascribed thereto in the underwriting and agency agreement between the Corporation and Versant Partners Inc. (the “Underwriter”), dated January 19, 2007 (the “Underwriter’s
Agreement”). 
 The Holder may exercise the Underwriter’s Warrants at any time, and from time to time, until the Time of Expiry
by completing the “Election to Exercise” attached as Schedule “A” to this Certificate. 
 In the event that the
Underwriter’s Warrants are exercised by the Holder for Compensation Units in accordance with the terms hereof, the Compensation Warrants shall have the terms and conditions set forth in the Warrant Indenture dated February 21, 2007 by and
between the Corporation and Computershare Trust Company of Canada, including the form of warrant certificate annexed thereto as Schedule “A” (the “Warrant Indenture”), which provides, among other things, that each whole
Compensation Warrant shall be exercisable by the holder for one Common Share at a price of US$0.40 on or before the date which is 3 years following the Initial Closing Date. 

	1.	Manner of Exercise of Underwriter’s Warrants. 

 The Holder may exercise the Underwriter’s Warrants to purchase, to the extent hereinafter provided, all or any part of the Compensation Units, during and until the earlier of the Time of Expiry or until all of the Underwriter’s
Warrants have been exercised. 
  

	2.	Notice of Exercise of the Underwriter’s Warrants and Payment. 

 The Underwriter’s Warrants shall be exercised in whole or in part upon providing notice in writing to the Corporation addressed to the Secretary or President of the Corporation at such place as the
Corporation’s executive office may then be located (the “Notice”), in substantially the form of the Election to Exercise appended hereto as Schedule “A” or in such other form as may be acceptable to the Corporation,
together with a certified cheque or bank draft representing the subscription price for the applicable number of Compensation Units. The “Exercise Date” shall be the date the Corporation receives the Notice and the subscription price
for the Compensation Units to be purchased. In the event the Underwriter’s Warrants are exercised in part, the Corporation shall, contemporaneously with the issuance of the Compensation Units issuable on the exercise of the Underwriter’s
Warrants so exercised, issue to the Holder Underwriter’s Warrants on identical terms in respect of that number of Compensation Units in respect of which the Holder has not exercised the Underwriter’s Warrants. These Underwriter’s
Warrants shall effectively be surrendered, only upon personal delivery hereof or, if sent by mail or other means of transmission, upon actual receipt thereof by the Corporation at the office referred to above. 
  

	3.	Rights of a Shareholder and Warrantholder. 

 As
promptly as possible and in any event within five (5) business days after receipt of the Notice and payment in full of the exercise price for the total number of Compensation Units to be purchased, the Corporation shall cause the Holder, or
such person as may be designated by the Holder, to be recorded in its register of shareholders and warrantholders, as the case may be, as holder of the number of fully paid, non-assessable Option Shares and Compensation Warrants comprising the
Compensation Units so issued (the date upon which the Holder is so recorded as registered holder being referred to in this paragraph 3 as the “Registry Date”). The Holder shall have full rights as a shareholder and warrantholder, as
the case may be, with respect to Option Shares and Compensation Warrants acquired upon the due exercise of the Underwriter’s Warrants on or after the Registry Date. The Corporation agrees to issue share certificates and warrant certificates in
respect of all Option Shares and Compensation Warrants so purchased as soon as possible after the Registry Date, and in any event within five (5) business days thereafter. 
  

	4.	Fractional Units. 

 No fractional Option Shares or
Compensation Warrants shall be issued upon exercise of any Compensation Option. If any fractional interest in an Option Share or Compensation Warrant would, except for the provisions of the first sentence of this paragraph, be deliverable upon the
exercise of a Compensation Option, the Corporation shall instead deliver to the Holder the nearest whole number of Option Shares or Compensation Warrants, as the case may be. 
  

	5.	Adjustment in Option Shares Subject to the Underwriter’s Warrants. 

  

	 	(a)	 Corporate Changes. If, at any time after the Closing Date but prior to the Time of Expiry, the Corporation shall be a party to any reorganization, merger,
dissolution or sale of all or substantially all of its assets, whether or not the Corporation is the surviving entity, as a result of which an adjustment is made to the Common Shares, the number of Option Shares issuable on exercise of each
Underwriter’s Warrant shall be adjusted so as to 

	 	 
apply to the securities to which the holders of that number of Option Shares of the Corporation subject to the unexercised Underwriter’s Warrants would
have been entitled by reason of such reorganization, merger, dissolution or sale of all or substantially all of its assets (the “Event”), and the Exercise Price in effect immediately prior to the Event shall be adjusted to reflect
such Event. 

  

	 	(b)	Subdivision or Consolidation of Shares. 

  

	 	(i)	If, at any time prior to the Time of Expiry, the Corporation shall subdivide its outstanding common shares into a greater number of shares, the Exercise Price in effect immediately
prior to such subdivision shall be proportionately reduced, and conversely, in case the outstanding common shares of the Corporation shall be consolidated into a smaller number of shares, the Exercise Price in effect immediately prior to such
consolidation shall be proportionately increased. 

  

	 	(ii)	Upon each adjustment of the Exercise Price as provided herein, the Holder shall thereafter be entitled to acquire, at the Exercise Price resulting from such adjustment, the number
of Option Shares (calculated to the nearest tenth of an Option Share) obtained by multiplying the Exercise Price in effect immediately prior to such adjustment by the number of Option Shares which may be acquired hereunder immediately prior to such
adjustment and dividing the product thereof by the Exercise Price resulting from such adjustment. 

  

	 	(c)	Change or Reclassification of Common Shares. If, at any time prior to the Time of Expiry, the Corporation shall change or reclassify its outstanding common shares into a
different class of securities, the rights to purchase Option Shares evidenced by the Underwriter’s Warrants hereunder shall be adjusted as follows so as to apply to the successor class of securities: 

  

	 	(i)	the number of the successor class of securities which the Holder shall be entitled to acquire shall be that number of the successor class of securities which a holder of that number
of Option Shares subject to the unexercised Underwriter’s Warrants immediately prior to the change or reclassification would have been entitled to by reason of such change or reclassification; and 

  

	 	(ii)	the Exercise Price in effect immediately prior to such change or reclassification shall be adjusted to reflect such change or reclassification. 

  

	 	(d)	 Rights Offering to Shareholders. If, at any time prior to the Time of Expiry, the Corporation shall fix a record date or if a date of entitlement to receive
is otherwise established (any such date being hereinafter referred to in this Subsection (d) as the “record date”) for the issuance of rights, options or warrants to all or substantially all the holders of the outstanding common
shares of the Corporation entitling them, for a period expiring not more than 45 days after such record date, to subscribe for or purchase common shares of the Corporation or securities convertible into or exchangeable for common shares at a price
per share or, as the case may be, having a conversion or exchange price per share less than 95% of the Fair Market Value (as hereinafter defined) on such record date, the Exercise Price shall be adjusted immediately after such record date to reflect
the event discussed in this section (d); common shares owned by or held for the account of the Corporation or any subsidiary of the Corporation shall be deemed not to be outstanding for the purpose of any such computation; such adjustment shall be

	 	 
made successively whenever such a record date is fixed; to the extent that any rights or warrants are not so issued or any such rights or warrants are not
exercised prior to the expiration thereof, the Exercise Price shall then be readjusted to the Exercise Price which would then be in effect if such record date had not been fixed or to the Exercise Price which would then be in effect based upon the
number of common shares or conversion or exchange rights contained in convertible or exchangeable securities actually issued upon the exercise of such rights or warrants, as the case may be. 

  

	 	(e)	Carry Over of Adjustments. No adjustment of the Exercise Price shall be made if the amount of such adjustment shall be less than 1% of the Exercise Price in effect
immediately prior to the event giving rise to the adjustment, provided, however, that in such case any adjustment that would otherwise be required then to be made shall be carried forward and shall be made at the time of and together with the next
subsequent adjustment which, together with any adjustment so carried forward, shall amount to at least 1% of the Exercise Price. 

  

	 	(f)	Notice of Adjustment. Upon any adjustment of the number of Option Shares and upon any adjustment of the Exercise Price, then and in each such case the Corporation shall give
written notice thereof to the Holder, which notice shall state the Exercise Price and the number of Option Shares or other securities subject to the unexercised Underwriter’s Warrants resulting from such adjustment, and shall set forth in
reasonable detail the method of calculation and the facts upon which such calculation is based. Upon the request of the Holder, there shall be transmitted promptly to the Holder a statement of the firm of independent chartered accountants retained
to audit the financial statements of the Corporation to the effect that such firm concurs in the Corporation’s calculation of the change. 

  

	 	(g)	Other Notices. In case at any time prior to the Time of Expiry: 

  

	 	(i)	the Corporation shall declare any dividend upon its common shares payable in common shares or other securities of the Corporation; 

  

	 	(ii)	the Corporation shall offer for subscription pro rata to the holders of its common shares any additional shares of any class or other rights; 

  

	 	(iii)	there shall be any capital reorganization or reclassification of the capital stock of the Corporation, or consolidation, amalgamation or merger of the Corporation with, or sale of
all or substantially all of its assets to, another corporation; or 

  

	 	(iv)	there shall be a voluntary or involuntary dissolution, liquidation or winding-up of the Corporation, 

 then, in any one or more of such cases, the Corporation shall give to the Holder (A) at least 10 days’ prior written notice of the date on which
a record shall be taken for such dividend, distribution or subscription rights or for determining rights to vote in respect of any such reorganization, reclassification, consolidation, amalgamation, merger, sale, dissolution, liquidation or
winding-up and (B) in the case of any such reorganization, reclassification, consolidation, amalgamation, merger, sale, dissolution, liquidation or winding-up, at least 10 days’ prior written notice of the date when the same shall take
place. Such notice in accordance with the foregoing clause (A) shall also specify, in the case of any such dividend, distribution or subscription rights, the date on which the 

 
holders of common shares shall be entitled thereto, and such notice in accordance with the foregoing clause (B) shall also specify the date on which the
holders of common shares shall be entitled to exchange their common shares for securities or other property deliverable upon such reorganization, reclassification, consolidation, amalgamation, merger, sale, dissolution, liquidation or winding-up, as
the case may be. 
  

	 	(h)	Common Shares to be Reserved. The Corporation will at all times keep available, and reserve if necessary under applicable law, out of its authorized common shares, solely for
the purpose of issue upon the exercise of the Underwriter’s Warrants, such number of common shares as shall then be issuable upon the exercise of the Underwriter’s Warrants and Compensation Warrants. The Corporation covenants and agrees
that all common shares which shall be so issuable will, upon payment of the Exercise Price, and in the case of the Compensation Warrants, upon the due and proper exercise of the Compensation Warrants and payment of the purchase price therefor, be
duly authorized and issued as fully paid and non-assessable. The Corporation will take all such actions as may be necessary to ensure that all such common shares may be so issued without violation of any applicable law or of any applicable
requirements of any exchange upon which the common shares of the Corporation may be listed or in respect of which the common shares are qualified for unlisted trading privileges. 

  

	 	(i)	Listing. The Corporation will, at its expense and as expeditiously as possible, use its reasonable commercial efforts to cause all Option Shares and common shares underlying
the Compensation Warrants issuable upon the exercise of the Underwriter’s Warrants to be duly listed on the Toronto Stock Exchange (the “TSX”) and/or any other stock exchange upon which the common shares of the Corporation may
be then listed prior to the issuance of such shares. 

  

	 	(j)	Issue Tax. The issuance of certificates for Option Shares and Compensation Warrants upon the exercise of Underwriter’s Warrants shall be made without charge to the
Holder for any issuance tax in respect thereto. 

  

	 	(k)	Fair Market Value. For the purposes of any computation hereunder, the “Fair Market Value” of the Common Shares at any date shall be Current Market Price, as defined
in the Warrant Indenture. 

  

	6.	Compensation Warrants; Adjustment to Compensation Warrants. 

 The Compensation Warrants shall be in the form of the warrant certificate annexed as Schedule “A” to the Warrant Indenture. All adjustments in connection with the Compensation Warrants shall be made in accordance with the terms of
the Warrant Indenture, whether or not these Compensation Warrants have been issued. 
  

	7.	Proceedings Prior to any Action Requiring Adjustment. 

 As a condition precedent to the taking of any action which would require an adjustment in any of the acquisition rights pursuant to any of the Underwriter’s Warrants, including the number of Common Shares which are to be received upon
the exercise thereof, the Corporation shall take any corporate action which may, in the opinion of its counsel, be necessary in order that the Corporation or a successor corporation has unissued and reserved in its authorized capital and may validly
and legally issue as fully paid and non-assessable all the securities which the holders of such Underwriter’s Warrants are entitled to receive on the full exercise thereof in accordance with the provisions hereof. 

	8.	Replacement. 

 Upon receipt of evidence satisfactory
to the Corporation of the loss, theft, destruction or mutilation of this Certificate and, if requested by the Corporation, upon delivery of a bond of indemnity satisfactory to the Corporation (or, in the case of mutilation, upon surrender of this
Agreement), the Corporation will issue to the Holder a replacement certificate (containing the same terms and conditions as this Certificate). 
  

	9.	No Further Rights. 

 Upon the exercise of the
Underwriter’s Warrants in accordance with the terms herein, the Underwriter’s Warrants so exercised will be void and of no value or effect and the Holder shall have no further rights under this Certificate, other than the right to receive
the Option Shares and Compensation Warrants duly exercised in accordance with the terms herein. The Holder will not have any rights under this Certificate after the Time of Expiry and this Certificate shall be deemed surrendered, shall be void and
of no value or effect and the Holder shall have no further rights under this Certificate and the Certificate shall be cancelled by the Corporation. 
  

	10.	No Right as Shareholder. 

 The holding of the
Underwriter’s Warrants evidenced by this Certificate shall not constitute the Holder a shareholder or warrantholder of the Corporation or entitle the Holder to any right or interest in respect thereof. 
  

	11.	United States Securities Laws. 

 The
Underwriter’s Warrants represented hereby and securities which may be acquired hereunder have not been registered under the United States Securities Act of 1933, as amended (the “U.S. Securities Act”), or the securities laws of
any state and, in the absence of such registration or the consent of the Corporation (which shall not be unreasonably withheld), may not be transferred to or exercised by or on behalf of any U.S. person or in the United States unless registered
under the U.S. Securities Act and applicable state laws. 
  

	12.	Inability to Deliver Compensation Units. 

 If for
any reason the Corporation is unable to issue and deliver the Option Shares, or Compensation Warrants as contemplated herein to the Holder the proper exercise by the Holder of the Underwriter’s Warrants evidenced hereby, the Corporation will
pay, at the option of the Holder and in complete satisfaction of its obligations hereunder, to the Holder, in cash, an amount equal to the amount, if any, by which (as applicable); 
  

	 	(l)	the Fair Market Value of such Option Shares exceeds the Exercise Price as of the Exercise Date; and/or 

  

	 	(m)	the Fair Market Value of the common shares in the capital of the Corporation underlying the Compensation Warrants exceeds the exercise price of the Compensation Warrants as of the
Exercise Date, 

 within 30 days after being requested to do so in writing by the Holder in accordance with the provisions hereof. 

	13.	Successors and Assigns. 

 This certificate shall
enure to the benefit of and be binding upon the Corporation, its successors and assigns, the Holder and, subject as hereinbefore provided, its permitted successors and assigns. 
  

	14.	Time of the Essence. 

 Time shall be of the essence
in this Agreement. 
  

	15.	Expiry Date. 

 The Underwriter’s Warrants shall
expire and all rights to purchase Compensation Units hereunder shall cease and become null and void at 5:00 p.m. (Toronto time) on February 21, 2009. 
  

	16.	Covenant. 

 Except to the extent the Corporation
participates in a merger or business combination transaction which is in the best interest of the Corporation and following which the Corporation is not a “reporting issuer”, so long as any Underwriter’s Warrants remain outstanding
the Corporation covenants that it shall use all reasonable efforts to maintain its status as a reporting issuer not in default in the Offering Jurisdictions in which it is a reporting issuer (as such term is defined in the Securities Act
(Ontario)) at the date hereof. 
  

	17.	Governing Law. 

 This Agreement and the
Underwriter’s Warrants granted hereunder shall be governed by and construed in accordance with the laws of the Province of Ontario and the laws of Canada applicable therein. 

 IN WITNESS WHEREOF the Corporation has caused this Certificate to be signed by its duly authorized
officers. 
 DATED as of February ·, 2007. 
  

			
	ADHEREX TECHNOLOGIES INC.
		
	 Per:
	 	  

		 	Authorized Signing Officer

 Schedule “A” 
 Election to Exercise 
 The undersigned hereby irrevocably elects to exercise the number of Underwriter’s
Warrants of Adherex Technologies Inc. set out below for the number of Option Shares and Compensation Warrants (or other property or securities subject thereto) as set forth below: 
  

					
			
	(n)	  	Number of Underwriter’s Warrants to be Exercised	  	  

			
	(o)	  	Number of Option Shares to be Acquired	  	  

			
	(p)	  	Number of Compensation Warrants to be Acquired	  	  

			
	(q)	  	Exercise Price (per Compensation Unit)	  	  

			
	(r)	  	Aggregate Purchase Price [(a) multiplied by (d)]	  	  

 and hereby tenders a certified cheque, bank draft or cash for such aggregate purchase price, and hereby directs
that certificate(s) evidencing such Option Shares and Compensation Warrants to be registered as indicated below. 
 Please check the applicable box:

  

					
	  ̈
	  	(i)	  	the undersigned is not a U.S. person and these Underwriter’s Warrants are not being exercised within the United States or on behalf of a U.S. person; or
			
	  ̈
	  	(ii)	  	the undersigned has delivered herewith to the Corporation a written opinion of counsel to the effect that the exercise of these Underwriter’s Warrants by the undersigned is not subject
to registration under the Securities Act of 1933, as amended, or the securities laws of any state of the United States.

 DATED this      day of
            . 
  

			
	 [NAME OF HOLDER]

		
	 Per:
	 	  

	 Name:
	 	
	 Title:
	 	

  

					
	 Direction as to Registration
	 		 	
			
	 Name of Registered Holder:
	 	  
	 	
			
	 Address of Registered Holder:Warrant Indenture

 Exhibit 4.45 
 WARRANT INDENTURE 
 ADHEREX TECHNOLOGIES INC. 
 - AND - 
 COMPUTERSHARE TRUST
COMPANY OF CANADA 
 Providing for the Issue 
 of Warrants 
 February 21, 2007 

 TABLE OF CONTENTS 
  

					
	 ARTICLE 1 INTERPRETATION
	  	2
			
	 1.1
	  	 Definitions
	  	2
	 1.2
	  	 Meaning of “outstanding” for Certain Purposes
	  	6
	 1.3
	  	 Day not a Business Day
	  	6
	 1.4
	  	 Words Importing the Singular
	  	6
	 1.5
	  	 Time of the Essence
	  	7
	 1.6
	  	 Interpretation not Affected by Headings, etc.
	  	7
	 1.7
	  	 Applicable Law
	  	7
	 1.8
	  	 Trust Indenture Legislation
	  	7
	 1.9
	  	 Severability
	  	7
	 1.10
	  	 Entire Agreement
	  	7
	 1.11
	  	 Currency and Language
	  	7
		
	 ARTICLE 2 ISSUE OF WARRANTS
	  	8
			
	 2.1
	  	 Creation and Issue of Warrants
	  	8
	 2.2
	  	 Form and Terms of Warrant Certificates
	  	8
	 2.3
	  	 Issue of Warrant Certificates
	  	8
	 2.4
	  	 Warrantholder not a Shareholder
	  	8
	 2.5
	  	 Execution of Warrant Certificates
	  	8
	 2.6
	  	 Certification by Warrant Agent
	  	9
	 2.7
	  	 Exchange of Warrant Certificates
	  	9
	 2.8
	  	 Issue in Substitution for Lost Certificates
	  	9
	 2.9
	  	 Registration and Transfer of Warrants
	  	10
	 2.10
	  	 Enforcement of Rights of Warrantholders
	  	11
	 2.11
	  	 Warrants to Rank Pari Passu
	  	12
	 2.12
	  	 Notice to Warrantholders
	  	12
	 2.13
	  	 Notice to the Company or the Warrant Agent
	  	13
	 2.14
	  	 Transfer Restrictions and Legends
	  	14
	 2.15
	  	 Reliance by the Warrant Agent
	  	17
		
	 ARTICLE 3 EXERCISE OF WARRANTS
	  	18
			
	 3.1
	  	 Method of Exercise of Warrants
	  	18
	 3.2
	  	 Effect of the Exercise of Warrants
	  	19
	 3.3
	  	 Partial Exercise of Warrants
	  	20
	 3.4
	  	 Cancellation of Warrants
	  	20
	 3.5
	  	 Expiration of Warrants
	  	20
	 3.6
	  	 Adjustment of the Exercise Price and Subscription Rights
	  	20
	 3.7
	  	 Adjustment Rules for Exercise Price
	  	25
	 3.8
	  	 Postponement of Issue of Shares, etc.
	  	27
	 3.9
	  	 Notice of Certain Events
	  	27
	 3.10
	  	 No Fractional Shares
	  	28
	 3.11
	  	 Reclassification, Reorganizations, etc.
	  	28

					
		
	 ARTICLE 4 RIGHTS AND COVENANTS OF THE COMPANY
	  	29
			
	 4.1
	  	 Optional Purchases by the Company
	  	29
	 4.2
	  	 General Covenants
	  	30
	 4.3
	  	 Securities Qualification Requirements
	  	31
	 4.4
	  	 Warrant Agent’s Remuneration and Expenses
	  	32
	 4.5
	  	 Notice to Warrantholders of Certain Events
	  	32
	 4.6
	  	 Closure of Share Transfer Books
	  	33
	 4.7
	  	 Performance of Covenants by Warrant Agent
	  	33
	 4.8
	  	 Representation and Warranty
	  	33
		
	 ARTICLE 5 MEETINGS OF WARRANTHOLDERS
	  	33
			
	 5.1
	  	 Right to Convene Meeting
	  	33
	 5.2
	  	 Notice
	  	34
	 5.3
	  	 Chairman
	  	34
	 5.4
	  	 Quorum
	  	34
	 5.5
	  	 Power to Adjourn
	  	35
	 5.6
	  	 Show of Hands
	  	35
	 5.7
	  	 Poll
	  	35
	 5.8
	  	 Voting
	  	35
	 5.9
	  	 Persons Entitled to be Present
	  	35
	 5.10
	  	 Regulations
	  	36
	 5.11
	  	 Certain Powers Exercisable by Extraordinary Resolution
	  	37
	 5.12
	  	 Definition of “Extraordinary Resolution”
	  	38
	 5.13
	  	 Resolutions Binding on all Warrantholders
	  	38
	 5.14
	  	 Holdings by Company Disregarded
	  	38
	 5.15
	  	 Minutes
	  	38
	 5.16
	  	 Powers Cumulative
	  	38
	 5.17
	  	 Instruments in Writing
	  	39
		
	 ARTICLE 6 SUPPLEMENTAL INDENTURES AND SUCCESSOR COMPANIES
	  	39
			
	 6.1
	  	 Provision for Supplemental Indenture for Certain Purposes
	  	39
	 6.2
	  	 Successor Companies
	  	40
	 6.3
	  	 Successor Body Corporate Substituted
	  	40
		
	 ARTICLE 7 CONCERNING THE WARRANT AGENT
	  	41
			
	 7.1
	  	 Rights and Duties of Warrant Agent
	  	41
	 7.2
	  	 Evidence, Experts and Advisors
	  	41
	 7.3
	  	 Documents, Moneys, etc. Held by Warrant Agent
	  	42
	 7.4
	  	 Action by Warrant Agent to Protect Interests
	  	43
	 7.5
	  	 Warrant Agent not Required to give Security
	  	43
	 7.6
	  	 Protection of Warrant Agent
	  	43
	 7.7
	  	 Replacement of Warrant Agent
	  	44
	 7.8
	  	 Conflict of Interest
	  	45
	 7.9
	  	 Acceptance of Trust
	  	45
	 7.10
	  	 Accounts
	  	46

  

 - ii - 

					
		
	 ARTICLE 8 GENERAL
	  	46
			
	 8.1
	  	 Satisfaction and Discharge of Indenture
	  	46
	 8.2
	  	 Sole Benefit of Parties and Warrantholders
	  	46
	 8.3
	  	 Discretion of Directors
	  	47
	 8.4
	  	 Privacy
	  	47
	 8.5
	  	 Counterparts and Formal Date
	  	48

 SCHEDULE “A” 
 FORM OF WARRANT CERTIFICATE 
 SCHEDULE “B” 
 FORM OF U.S. PURCHASER LETTER 
  

 - iii - 

 THIS WARRANT INDENTURE is made as of the
21st day of February, 2007. 
 BETWEEN: 
 ADHEREX TECHNOLOGIES INC., a corporation existing under the laws of Canada 
 (hereinafter the “Company”) 
 AND: 
 COMPUTERSHARE TRUST COMPANY OF CANADA, a trust company registered under the laws of Canada and duly authorized
to carry on the trust business in each Province of Canada 
 (hereinafter called the “Warrant Agent”).

 RECITALS 
 WHEREAS: 
 A. The Company and Versant Partners Inc. (the “Underwriter”) have entered into an
underwriting and agency agreement dated January 19, 2007 (the “Underwriting and Agency Agreement”), pursuant to which: (i) the Company agreed to sell and the Underwriter agreed to purchase 30,304,000 Units; and
(ii) the Underwriter agreed to conditionally offer on a best efforts basis a maximum of 45,455,000 additional Units, the whole subject to prior sales, as and when issued by the Company and accepted by the Underwriter in accordance with the
conditions contained in the Underwriting and Agency Agreement, at a price of US$0.33 per Unit. 
 B. Each Unit consists of one Common Share (as
hereinafter defined) and one-half of one Warrant (as hereinafter defined), subject to adjustment, upon the terms and conditions herein set forth; 
 C.
The Company has agreed to issue to the Underwriter underwriter’s warrants which are exercisable for up to an additional 2,272,770 Warrants. 
 D.
Each whole Warrant will entitle the holder thereof to acquire, on exercise, subject to adjustment in accordance with this Warrant Indenture (the “Indenture”), one Common Share for the Exercise Price (as hereinafter defined) at
any time before the Warrant Expiry Time (as hereinafter defined) on the Warrant Expiry Date (as hereinafter defined), all upon the terms and conditions set forth in this Indenture; 
 E. The Company proposes to issue Warrants in the manner set forth in this Indenture and is duly authorized to create and issue the Warrants and complete the transactions contemplated in this Indenture;

 F. All acts and deeds necessary have been done and performed to make the Warrants, when issued as provided in this
Indenture, legal, valid and binding upon the Company with the benefits and subject to the terms of this Indenture; 
 G. The foregoing recitals are
made by the Company and not by the Warrant Agent; and 
 H. The Warrant Agent has agreed to enter into this Indenture and to hold all rights,
interests and benefits contained herein for and on behalf of those persons who become holders of the Warrants issued pursuant to this Indenture from time to time. 
 NOW THEREFORE, in consideration of the premises and for other good and valuable consideration, the receipt and sufficiency whereof is hereby acknowledged, the Company hereby appoints the Warrant Agent as
trustee, for the Warrantholders, to hold all rights, interests and benefits contained herein for and on behalf of those persons who become holders of Warrants from time to time issued pursuant to this Indenture and the parties hereto agree as
follows: 
 ARTICLE 1 
 INTERPRETATION 
  

	1.1	Definitions 

 In this Indenture and in the Warrant
Certificates: 
 “1933 Act” means the United States Securities Act of 1933, as amended; 
 “Accredited Investor” means an “accredited investor” as that term is defined in Rule 501 of Regulation D; 
 “Applicable Legislation” means the provisions of the Canada Business Corporations Act, as from time to time amended, and any
statute of Canada or a province thereof, and the regulations and rules under any such named or other statute relating to trust indentures or the rights, duties or obligations of corporations and trustees under trust indentures as are from time to
time in force and applicable to this Indenture; 
 “auditors” of the Company means a chartered accountant or firm of
chartered accountants as may be duly appointed as auditor of the Company from time to time; 
 “business day” means a day
that is not a Saturday, Sunday or civic or statutory holiday in the City of Toronto, Ontario; 
 “Closing Date” means the
date of initial closing of the Offering as confirmed in writing by the Company; 
  

 - 2 - 

 “Convertible Securities” means securities of the Company or any other issuer that are
convertible into or exchangeable or exercisable for or otherwise carry the right to acquire Shares, and “Convertible Security” means any one of them; 
 “Corporate Reorganization” has the meaning ascribed thereto in Section 3.6(7); 
 “Current Market Price” means, at any date, (i) the volume weighted average trading price per Share at which the Shares have traded on the Exchange, or (ii) the United States dollar equivalent (calculated using the
inverse of the noon buying rate in the City of New York for cable transfers in Canadian dollars as certified for customs purposes by the Federal Reserve Bank of New York on the day prior to such date) of the volume weighted average trading price per
Share at which the Shares have traded on TSX, if TSX constitutes the principal trading market (by volume) for the Shares during the twenty consecutive trading days before such date, and the volume weighted average trading price shall be determined
by dividing the aggregate sale price (or United States dollar equivalent thereof calculated as above if applicable) of all Shares sold on the Exchange or TSX, as the case may be, during the five consecutive trading days before such date by the
number of Shares sold. Whenever the Current Market Price is required to be determined hereunder, the Company shall deliver to the Warrant Agent a certificate of an officer specifying such Current Market Price and setting out the details of its
calculation. In the event of any subsequent dispute as to the determination of the Current Market Price, the Company’s auditors shall make such determination which, absent manifest error, shall be binding for all purposes hereunder; 

“Date of Issue” means the date hereof, notwithstanding that Warrants may be issued and countersigned later than the date hereof;

 “Directors” means the board of directors of the Company for the time being and reference without more to action by the
Directors shall mean action by the Directors as a board or by any authorized committee thereof; 
 “dividends” means
dividends (payable in cash or in securities, property or assets of equivalent value) declared payable on the Shares; 
 “Dividends
Paid in the Ordinary Course” means cash dividends paid on the Shares in any financial year of the Company provided that the amount of such dividends in the aggregate does not in such financial year exceed the greater of: (i) 150% of
the aggregate amount of dividends paid by the Company on the Shares in its immediately preceding financial year; or (ii) 100% of the consolidated net income of the Company (before extraordinary items but after dividends payable on all shares
ranking prior to or on a parity with the Shares with respect to the payment of dividends) for its immediately preceding financial year, determined in accordance with generally accepted accounting principles applicable in Canada from time to time;

 “Exchange” means the American Stock Exchange; 
 “Exercise Price” means US$0.40 per Share, as adjusted in accordance with the terms of this Indenture, from time to time; 
  

 - 3 - 

 “Extraordinary Resolution” means an extraordinary resolution of Warrantholders as
defined in Section 5.12 and includes a written instrument signed by Warrantholders pursuant to the provisions of Section 5.12; 
 “Offering” means the public offering of up to 75,759,000 Units of the Company by way of short form prospectus in British Columbia, Alberta and Ontario, and by way of exempt offering in the United States; 
 “Original U.S. Purchaser” means a person that purchased the Warrants in the United States directly from the Company pursuant to a written
subscription agreement for the purchase of Units; 
 “person” means an individual, a corporation, a partnership, a government
or any department or agency thereof, a joint venture, a trust, an estate, an unincorporated organization and the heirs, executors, administrators or other legal representatives of an individual; and pronouns and other words importing persons have a
similarly extended meaning; 
 “Qualifying Jurisdictions” means the Provinces of British Columbia, Alberta and Ontario and
other jurisdictions which are agreed to by the Company and the Underwriter; 
 “Regulation D” means Regulation D under the
1933 Act; 
 “Regulation S” means Regulation S under the 1933 Act; 
 “Securities Commissions” means, collectively, the securities commissions or other securities regulatory authorities under the applicable
Securities Laws of each of the Canadian Qualifying Jurisdictions; 
 “Securities Laws” means, collectively, the applicable
securities laws of each of the Canadian Qualifying Jurisdictions and the respective regulations made and forms prescribed thereunder together with all applicable published policy statements, rules, instruments, blanket orders and rulings of the
Securities Commissions; 
 “Share Reorganization” has the meaning ascribed thereto in Section 3.6(2); 
 “Shareholder” means an owner of record of one or more Shares or shares of any other class or series of the Company; 
 “Shares” means the common shares without par value in the capital of the Company as constituted on the date hereof, provided that in the
event of any adjustment pursuant to Article 3, “Shares” will thereafter mean the shares or other securities or property resulting from such adjustment that a Warrantholder is entitled to acquire on exercise of a Warrant after
the adjustment; 
 “Subsidiary” means a corporation, a majority of the outstanding voting shares of which are owned, directly
or indirectly, by the Company, or by one or more Subsidiaries of the Company and, as used in this definition, “voting shares” means shares of a class or 

  

 - 4 - 

 
classes ordinarily entitled to vote for the election of a majority of the directors of a corporation irrespective of whether or not shares of any other class
or classes shall have or might have the right to vote for directors by reason of the happening of any contingency, whether or not such contingency shall have happened; 
 “this Indenture”, “hereto”, “herein”, “hereby”, “hereunder”, “hereof” and similar expressions refer to this
instrument and not to any particular Article, section, paragraph, clause, subdivision or other portion hereof, and include any and every instrument supplemental or ancillary hereto or in implementation hereof; 
 “Time of Exercise” means the time that surrender of the Warrant Certificate, the Warrant Exercise Form (attached hereto as part of
Schedule “A”) and payment of the Exercise Price is effected by a Warrantholder according to the provisions of Section 3.1 hereof; 
 “trading day” means a day on which the Exchange is open for business; 
 “TSX” means the Toronto
Stock Exchange; 
 “Underwriter” means Versant Partners Inc.; 
 “Unit” means a Unit of the Company, consisting of one Common Share and one-half of a Warrant, issued pursuant to the Offering at a
purchase price of US$0.33 per Unit; 
 “U.S. Person” means a U.S. person as that term is defined in Regulation S; 

“Warrant Agent” means Computershare Trust Company of Canada or any lawful successor thereto from time to time under this Indenture;

 “Warrant Certificate” means a certificate substantially in the form specified in Schedule “A” hereto evidencing
one or more Warrants; 
 “Warrant Exercise Form” means the exercise form forming part of each Warrant Certificate as more
particularly described in Section 3.1(3) hereof; 
 “Warrant Expiry Date” means the date that is three years after the
Closing Date; 
 “Warrant Expiry Time” means 5:00 p.m. (Toronto time) on the Warrant Expiry Date; 
 “Warrantholder”, “holder” or “holder of Warrants” means with respect to the Warrants, a person entered
on the register to be maintained under Section 2.9 as the registered holder of a Warrant for the time being; and 
 “Warrants” means the warrants to purchase Shares of the Company issued and certified hereunder and for the time being outstanding, each exercisable into one Share upon due exercise and payment of the Exercise Price.

  

 - 5 - 

	1.2	Meaning of “outstanding” for Certain Purposes 

 Every Warrant Certificate certified and delivered by the Warrant Agent hereunder shall be deemed to be outstanding until the Warrant Expiry Time, or until it shall be surrendered to the Warrant Agent upon the exercise thereof pursuant to
Article 3, provided however that: 
  

	 	(a)	a Warrant which has been partially exercised shall be deemed to be outstanding only to the extent of the unexercised part of the Warrant; 

  

	 	(b)	where a Warrant Certificate has been issued in substitution for a Warrant Certificate which has been lost, stolen or destroyed, only one of them shall be counted for the purpose of
determining the number of Warrants outstanding; and 

  

	 	(c)	for the purpose of any provision of this Indenture entitling holders of outstanding Warrants to vote, sign consents, requests or other instruments or take any other action under
this Indenture, Warrants owned legally or equitably by the Company or any Subsidiary thereof shall be disregarded, except that: 

  

	 	(i)	for the purpose of determining whether the Warrant Agent shall be protected in relying on any such vote, consent, request or other instrument or other action, only the Warrants of
which the Warrant Agent has notice that they are so owned by the Company or any Subsidiary shall be so disregarded; and 

  

	 	(ii)	Warrants so owned which have been pledged in good faith other than to the Company or any Subsidiary thereof shall not be so disregarded if the pledgee shall establish to the
satisfaction of the Warrant Agent the pledgee’s right to vote the Warrants in his discretion free from the control of the Company or any Subsidiary thereof, as the case may be, and the terms of the pledge thereof as to the right to vote shall
govern. 

  

	1.3	Day not a Business Day 

 If the day on or before
which any action (other than the exercise of a Warrant) would otherwise be required to be taken or is contemplated to commence hereunder is not a business day, that action will be required to be taken and such procedure will commence on or before
the requisite time on the next succeeding day that is a business day. 
  

	1.4	Words Importing the Singular 

 Words importing the
singular include the plural and vice versa and words importing a particular gender include all genders. 
  

 - 6 - 

	1.5	Time of the Essence 

 Time shall be of the essence
in this Indenture and in the Warrant Certificates. 
  

	1.6	Interpretation not Affected by Headings, etc. 

 The
division of this Indenture into Articles, and Sections and subsections, the provision of a table of contents and the insertion of headings are for convenience of reference only and shall not affect the construction or interpretation hereof.

  

	1.7	Applicable Law 

 This Indenture and the Warrant
Certificates shall be governed by and construed in accordance with the laws of the Province of Ontario and the federal laws of Canada applicable therein. 
  

	1.8	Trust Indenture Legislation 

  

	 	(1)	If and to the extent that any provision of this Indenture limits, qualifies or conflicts with a mandatory requirement of Applicable Legislation, the mandatory requirement will
prevail. 

  

	 	(2)	Each of the Company and the Warrant Agent will at all times in relation to this Indenture and any action to be taken hereunder observe and comply with and be entitled to the
benefits of Applicable Legislation. 

  

	1.9	Severability 

 In the event that any provision
hereof shall be determined to be invalid or unenforceable in any respect, such determination shall not affect such provision in any other respect or any other provision hereof, all of which shall remain in full force and effect. 
  

	1.10	Entire Agreement 

 This Indenture and the agreements
referred to herein constitute the entire agreement between the parties hereto relating to the subject matter hereof and supersede all prior and contemporaneous agreements, understandings, negotiations and discussions, whether oral or written, of the
parties and there are no general or specific warranties, representations or other agreement by or among the parties in connection with the entering into of this Indenture or the subject matter hereof except as specifically set forth herein.

  

	1.11	Currency and Language 

 Unless otherwise stated, all
dollar amounts referred to in this Indenture are references to United States dollars. The parties hereto confirm their express wish that this Indenture and all documents relating hereto be drawn up in the English language. 
  

 - 7 - 

 ARTICLE 2 
 ISSUE OF WARRANTS 
  

	2.1	Creation and Issue of Warrants 

  

	 	(1)	A total of 40,152,270 Warrants are hereby created and authorized to be issued. 

  

	 	(2)	Subject to adjustment as provided in this Indenture, each Warrant issued hereunder will entitle the holder thereof to purchase one Share at any time from and after the Date of Issue
of the Warrant to and including the Warrant Expiry Time upon payment of the Exercise Price. 

  

	2.2	Form and Terms of Warrant Certificates 

 Warrant
Certificates shall be substantially in the form set out in Schedule “A” hereto with such additions, variations or omissions as may be permitted by the provisions of this Indenture or may from time to time be agreed upon between the Company
and the Warrant Agent and shall be numbered in the manner as the Company, with the approval of the Warrant Agent, may prescribe. No Warrant Certificates representing fractional Warrants will be issued under this Indenture, and any fractional
Warrants will be rounded down to the nearest whole Warrant. 
  

	2.3	Issue of Warrant Certificates 

 Warrant Certificates
to be issued and delivered from time to time under this Indenture shall be executed by the Company and certified by the Warrant Agent pursuant to or upon the written order of the Company, without the Warrant Agent receiving any consideration
therefor. 
  

	2.4	Warrantholder not a Shareholder 

 Nothing in this
Indenture or in the ownership of a Warrant evidenced by a Warrant Certificate, or otherwise, will be construed as conferring on a Warrantholder any right or interest whatsoever as a Shareholder of the Company, including but not limited to any right
to vote at, to receive notice of, or to attend, any meeting of Shareholders or any other proceeding of the Company or any right to receive any dividend or other distribution. 
  

	2.5	Execution of Warrant Certificates 

 Warrant
Certificates may be signed by any one director or officer of the Company manually or may be engraved, lithographed or printed in facsimile and shall be dated the Date of Issue. Notwithstanding that any of the persons whose signature appears on any
Warrant Certificates as one of the officers or directors may no longer, before the certification and delivery of the Warrant Certificate, hold the official capacity in which he signed, any Warrant Certificate signed as aforesaid shall be valid and
binding upon the Company when the Warrant Certificate has been certified by the Warrant Agent in accordance with Section 2.6 and the registered holder thereof shall be entitled to the benefits of this Indenture. 
  

 - 8 - 

	2.6	Certification by Warrant Agent 

  

	 	(1)	No Warrant Certificate shall be issued, or if issued, shall be valid or entitle the holder to the benefit hereof until it has been certified by the Warrant Agent by being
countersigned by or on behalf of the Warrant Agent and the countersignature upon any Warrant Certificate shall be conclusive evidence as against the Company that the Warrant Certificate so countersigned has been duly issued hereunder and is a valid
obligation of the Company, and that the holder is entitled to the benefit hereof. 

  

	 	(2)	The countersigning by or on behalf of the Warrant Agent on any Warrant Certificate issued hereunder shall not be construed as a representation or warranty by the Warrant Agent as to
the validity of this Indenture or of the Warrants and the Warrant Agent shall in no respect be liable or answerable for the use made of any Warrant Certificate or of the consideration therefor, except as otherwise specified herein. The
countersignature of or on behalf of the Warrant Agent shall, however, be a representation and warranty by the Warrant Agent that the Warrant Certificate has been duly countersigned by or on behalf of the Warrant Agent pursuant to the provisions of
this Indenture. 

  

	2.7	Exchange of Warrant Certificates 

 The holder of a
Warrant Certificate may at any time after the date of issue thereof and before the Warrant Expiry Time, upon surrender thereof to the Warrant Agent at its principal transfer offices in the City of Toronto or at any other place that is designated by
the Company with the approval of the Warrant Agent, exchange the same for Warrant Certificates entitling the holder to subscribe in the aggregate for the same number of Shares for which the holder may subscribe under the surrendered Warrant
Certificate. On each exchange the Warrant Agent may levy a charge sufficient to reimburse it for any tax or other governmental charge required to be paid, which shall be paid by the party requesting the exchange, and, in addition, a reasonable
charge for every Warrant Certificate issued upon the exchange and such additional charge shall be paid by the Company, as a condition precedent thereto. The Company shall execute and the Warrant Agent shall certify in accordance with
Sections 2.5 and 2.6 all Warrant Certificates necessary to carry out exchanges contemplated herein. 
  

	2.8	Issue in Substitution for Lost Certificates 

  

	 	(1)	If a Warrant Certificate becomes mutilated or is lost, destroyed or stolen, the Company, subject to applicable law and subject to subsection (2), will issue and thereupon the
Warrant Agent will countersign or certify and deliver a new certificate of like denomination, date and tenor as the one mutilated, lost, destroyed or stolen in exchange for and in place of and on surrender and cancellation of the mutilated
certificate or in lieu of and in substitution for the lost, destroyed or stolen certificate, and the substituted Warrant Certificate shall entitle the holder thereof to the same rights and benefits and will bear the same legends, if any, as the
certificate being replaced and shall rank equally in accordance with its terms with all other Warrant Certificates issued or to be issued hereunder. 

  

 - 9 - 

	 	(2)	The applicant for the issue of a new certificate pursuant to this section will bear the cost of the issue thereof and in case of loss, destruction or theft will, as a condition
precedent to the issue thereof: 

  

	 	(a)	furnish to the Company and the Warrant Agent such evidence of ownership and of the loss, destruction or theft of the certificate to be replaced as is satisfactory to the Company and
to the Warrant Agent in their discretion; 

  

	 	(b)	if so required, furnish an indemnity and surety bond in amount and form satisfactory to the Company and to the Warrant Agent acting reasonably; and 

  

	 	(c)	pay the reasonable charges of the Company and the Warrant Agent in connection therewith. 

  

	2.9	Registration and Transfer of Warrants 

  

	 	(1)	The Company shall cause to be kept by and at the principal offices of the Warrant Agent in the City of Toronto and by the Warrant Agent or such other registrar as the Company, with
the approval of the Warrant Agent, may appoint, at such other place or places, if any, as the Company may designate with the approval of the Warrant Agent, registers in which shall be entered in alphabetical order the names and addresses (including
street and number, if any) of the holders of Warrants and particulars of the Warrants held by them respectively. Such registration shall be noted on the Warrant Certificates by the Warrant Agent or other registrar. 

  

	 	(2)	No transfer of a Warrant shall be valid unless made on any one of the registers upon surrender of the Warrant Certificate to the Warrant Agent or other registrar accompanied by a
written instrument of transfer in form satisfactory to the Warrant Agent or other registrar executed by the registered holder or his executors, administrators or other legal representatives or his or their attorney duly appointed by an instrument in
writing in form and execution satisfactory to the Warrant Agent or other registrar and upon compliance with such reasonable requirements, including those set forth in Section 2.14 hereof, if applicable, as the Warrant Agent or other registrar
may prescribe, nor, except in the case where a new Warrant Certificate is issued upon a transfer, unless the transfer shall have been noted by the Warrant Agent or other registrar. 

  

	 	(3)	The registered holder of Warrants may at any time and from time to time have the registration of the Warrants transferred from the register in which the registration thereof appears
to another authorized register upon compliance with such reasonable requirements as the Warrant Agent or other registrar may prescribe. 

  

	 	(4)	The Company shall also cause to be kept by and at the principal offices of the Warrant Agent in the City of Toronto and by the Warrant Agent or such other registrar as the Company
may appoint, with the approval of the Warrant Agent, at such other place or places, if any, as the Company may designate with the approval of the Warrant Agent, registers in which all transfers of Warrants and the date and other particulars of each
transfer shall be set out. 

  

 - 10 - 

	 	(5)	The transferee of Warrants shall, after the Warrant Certificate and the appropriate form of transfer are lodged with the Warrant Agent or other registrar and upon compliance with
all other conditions in that behalf required by this Indenture or by law, be entitled to be entered on one of the registers as the owner of the Warrants free from all equities or rights of set-off or counterclaim between the Company and his
transferor or any previous holder of the Warrants, save in respect of the equities of which the Company is required to take notice by statute or by order of a court of competent jurisdiction or by applicable law. The receipt by the registered holder
of Warrants of the Shares purchasable pursuant thereto will be a good discharge to the Company and the Warrant Agent therefor and neither the Company nor the Warrant Agent will be bound to inquire into the title of the holder except as aforesaid.

  

	 	(6)	Subject to applicable law, neither the Company nor the Warrant Agent nor any registrar shall be bound to take notice of or see to the execution of any trust, whether express,
implied or constructive, in respect of any Warrant or Warrant Certificate, and may transfer the same on the direction of the person registered as the holder thereof, as though that person were the beneficial owner thereof. 

 

	 	(7)	The registers required to be kept in the City of Toronto shall at all reasonable times be open for inspection by the Company or any Warrantholder. The Warrant Agent and every
registrar shall from time to time when requested to do so by the Company, by the Warrant Agent or by a Warrantholder, furnish the Warrant Agent or upon payment by the Company or Warrantholder of a reasonable fee, the Company or the Warrantholder, as
the case may be, with a list of names and addresses of holders of Warrants entered on the registers kept by them and showing the number of Warrants held by each such holder. 

  

	2.10	Enforcement of Rights of Warrantholders 

  

	 	(1)	All or any of the rights conferred upon a Warrantholder by the terms of the Warrants held by him and/or by the terms of this Indenture may be enforced by such Warrantholder by
appropriate legal proceedings, but without prejudice to the right that is hereby conferred upon the Warrant Agent and subject to the provisions of Section 7.1. The Warrant Agent shall also have the power at any time and from time to time to
institute and to maintain such suits and proceedings as it may reasonably be advised shall be necessary or advisable to preserve and protect the interests of the Warrantholder. 

  

	 	(2)	No recourse under or upon any obligation, covenant or agreement contained in this Indenture or in the Warrant Certificates shall be had against any shareholder, officer or director,
past, present or future, of the Company or of any of its Subsidiaries or of any successor corporation or any subsidiary, either directly or through the Company, or the Subsidiaries or otherwise, by any legal or equitable proceeding by virtue of any
statute or otherwise. 

  

 - 11 - 

	 	(3)	This Indenture and the Warrants issued hereunder are solely obligations of the Company and no personal liability whatsoever shall attach to or be incurred by the shareholders,
officers or directors, past, present or future, of the Company, or of any of its Subsidiaries, or any successor corporations, under or by reason of the obligations, covenants or agreements contained in this Indenture or in the Warrant Certificates;
and any personal liability of any nature whatsoever either at common law, in equity or by statute, and any right or claim against any such shareholder, officer or director are hereby expressly waived as a condition of and as consideration for the
execution of this Indenture and the issue of the Warrants. 

  

	2.11	Warrants to Rank Pari Passu 

 Except as otherwise
provided herein, all Warrants will rank pari passu, whatever may be the actual dates of issue thereof. 
  

	2.12	Notice to Warrantholders 

  

	 	(1)	Unless herein otherwise expressly provided, a notice to be given hereunder to Warrantholders will be deemed to be validly given if the notice is sent by ordinary mail or air mail,
postage prepaid, addressed to the holders or delivered by hand or prepaid courier (or so mailed to certain holders and so delivered to the other holders) at their respective addresses appearing on any of the registers above mentioned; and if in the
case of joint holders of any Warrant more than one address appears on the register in respect of the joint holding, the notice shall be addressed or delivered, as the case may be, only to the first address so appearing. The Warrant Agent shall give,
in the same manner as for Warrantholders set out above, a copy of each such notice to Versant Partners Inc., Attention: Syndication (Facsimile No. 514-845-4437, with a copy to Heenan Blaikie LLP, Attention: Sonia Yung (Facsimile
No. 416-360-8425). Any notice so given by mail or so delivered by hand shall be deemed to have been given on the fifth business day after it has been mailed or on the day upon which it has been delivered, or if sent by facsimile on the first
business day following the transmission, as the case may be. In determining under any provision hereof the date when notice of any meeting or other event must be given, the date of giving the notice shall be included and the date of the meeting or
other event shall be excluded. Accidental error or omission in giving notice or accidental failure to mail notice to any Warrantholder shall not invalidate any action or proceeding founded thereon. 

  

	 	(2)	 If, by reason of a strike, lockout or other work stoppage, actual or threatened, involving postal employees, a notice to be given to the Warrantholders hereunder
could reasonably be considered unlikely to reach or to be delayed in reaching its destination, the notice will be valid and effective only if it is published once in the Report on Business section in the national edition of The Globe and Mail
newspaper, or, if there is a disruption of circulation of that newspaper, once in an English language newspaper of general circulation and approved by the Warrant Agent in the City of Toronto and, in the case of notice convening a meeting of
Warrantholders, with such additional publications, in the same or in other cities or 

  

 - 12 - 

	 	 
both, as the Warrant Agent deems necessary for the reasonable protection of the Warrantholders or to comply with any applicable requirement of law or a stock
exchange on which the Shares are listed and if a daily newspaper of general circulation is not, for any reason, published at the time in the English language in any city, the notice may be published in any other publication available in that city as
is acceptable to the Warrant Agent. A notice so given will be deemed to have been given on the day on which it has been published in all of the cities in which publication was required (or first published in all the cities if more than one
publication in any of them is required). 

  

	 	(3)	Any mailings to or from outside of Canada shall be made by postage prepaid mail or by prepaid courier. 

  

	2.13	Notice to the Company or the Warrant Agent 

  

	 	(1)	Unless herein otherwise expressly provided, a notice to be given hereunder to the Company or the Warrant Agent will be validly given if delivered or if sent by postage prepaid mail
or if transmitted by facsimile: 

  

	 	(a)	if to the Company: 

 Adherex Technologies Inc. 

4620 Creekstone Drive, Suite 200 
 Durham, NC 27703 
  

			
	Attention:	  	Scott Murray
	Facsimile:	  	919-484-8001

 With a copy, which shall not constitute notice to the Company, to: 
 LaBarge Weinstein Professional Corporation 
 515 Legget Drive, Suite 800 
 Ottawa, Ontario K2K 3G4 
  

			
	Attention:	  	Randy Taylor
	Facsimile:	  	613-599-0018

  

	 	(b)	if to the Warrant Agent: 

 Computershare Trust Company of
Canada 
 100 University Avenue 
 9th Floor 
 Toronto, Ontario M5J 2Y1 
  

			
	Attention:	  	Manager, Corporate Trust
	Facsimile:	  	416-981-9777

  

 - 13 - 

 and any notice delivered in accordance with the foregoing will be deemed to have been received on the
date of delivery or, if mailed, on the fifth business day following the day of the mailing of the notice, or if transmitted by facsimile, on the first business day following the transmission. 
  

	 	(2)	The Company or the Warrant Agent, as the case may be, may from time to time notify the other in the manner provided in subsection (1) of a change of address which, from the
effective date of the notice and until changed by like notice, will be the address of the Company or the Warrant Agent, as the case may be, for all purposes of this Indenture. 

  

	 	(3)	If, by reason of a strike, lockout or other work stoppage, actual or threatened, involving postal employees, a notice to be given to the Warrant Agent or to the Company hereunder by
registered mail could reasonably be considered unlikely to reach or to be delayed in reaching its destination, the notice will be valid and effective only if it is delivered to an officer of the party to which it is addressed or if it is delivered
to that party at the appropriate address provided in subsection (1) by cable, facsimile, telegram, or other means of prepaid transmitted, recorded communication, and any notice delivered in accordance with the foregoing will be deemed to have
been received on the date of delivery to the officer or if delivered by cable, facsimile, telegram, telex or other means of prepaid, transmitted, recorded communication, on the first business day following the date of the sending of the notice.

  

	 	(4)	Any mailings to or from outside of Canada shall be made by registered airmail, postage prepaid or by prepaid courier. 

  

	2.14	Transfer Restrictions and Legends 

  

	 	(1)	The Warrant Agent understands and acknowledges that the Warrants and the Shares issuable upon exercise of the Warrants have not been and will not be registered under the 1933 Act or
the securities laws of any state of the United States. 

  

	 	(2)	Certificates representing Warrants issued in the United States or to a U.S. Person or on behalf of a U.S. Person and Shares issued in the United States or to a U.S. Person upon
exercise of Warrants in the United States or by or on behalf of a U.S. Person, and all certificates issued in exchange thereof or in substitution thereof, until such time as it is no longer required under the applicable requirements of the 1933 Act
or applicable U.S. state laws and regulations, shall bear the following legend: 

 “THE SECURITIES REPRESENTED HEREBY HAVE
NOT BEEN REGISTERED UNDER THE UNITED STATES SECURITIES ACT OF 1933, AS AMENDED (THE “U.S. SECURITIES ACT”), OR ANY STATE SECURITIES LAWS. THE HOLDER HEREOF, BY PURCHASING SUCH SECURITIES, AGREES FOR THE BENEFIT OF THE 

  

 - 14 - 

 
COMPANY THAT SUCH SECURITIES MAY BE OFFERED, SOLD OR OTHERWISE TRANSFERRED ONLY (A) TO ADHEREX TECHNOLOGIES INC. (THE “COMPANY”),
(B) OUTSIDE THE UNITED STATES IN ACCORDANCE WITH RULE 904 OF REGULATION S UNDER THE U.S. SECURITIES ACT AND IN COMPLIANCE WITH APPLICABLE LOCAL LAWS AND REGULATIONS, (C) WITHIN THE UNITED STATES IN ACCORDANCE WITH (1) THE EXEMPTION
FROM REGISTRATION UNDER THE U.S. SECURITIES ACT PROVIDED BY RULE 144A THEREUNDER, OR (2) THE EXEMPTION FROM REGISTRATION UNDER THE U.S. SECURITIES ACT PROVIDED BY RULE 144 THEREUNDER, IF APPLICABLE, OR (D) IN ANOTHER TRANSACTION THAT DOES
NOT REQUIRE REGISTRATION UNDER THE U.S. SECURITIES ACT OR ANY APPLICABLE STATE SECURITIES LAWS AFTER, IN THE CASE OF PROPOSED TRANSFERS PURSUANT TO CLAUSES (C) OR (D), PROVIDING A LEGAL OPINION SATISFACTORY TO THE COMPANY TO THE EFFECT THAT THE
PROPOSED TRANSFER MAY BE EFFECTED WITHOUT REGISTRATION UNDER THE U.S. SECURITIES ACT OR ANY APPLICABLE STATE SECURITIES LAWS. DELIVERY OF THIS CERTIFICATE MAY NOT CONSTITUTE “GOOD DELIVERY” IN SETTLEMENT OF TRANSACTIONS ON STOCK EXCHANGES
IN CANADA. PROVIDED THAT THE COMPANY IS A “FOREIGN ISSUER” WITHIN THE MEANING OF REGULATION S AT THE TIME OF SALE, A NEW CERTIFICATE BEARING NO LEGEND MAY BE OBTAINED FROM THE REGISTRAR AND TRANSFER AGENT OF THE COMPANY UPON DELIVERY OF
THIS CERTIFICATE AND A DULY EXECUTED DECLARATION, IN A FORM SATISFACTORY TO THE COMPANY’S REGISTRAR AND TRANSFER AGENT AND THE COMPANY, TO THE EFFECT THAT SUCH SALE OF THE SECURITIES REPRESENTED HEREBY IS BEING MADE IN COMPLIANCE WITH RULE 904
OF REGULATION S UNDER THE U.S. SECURITIES ACT.” 
 provided that: 
  

	 	(i)	 if any such securities are being sold under clause (B) of the above legend and in compliance with Canadian local laws and regulations, and provided that the
Company is a “foreign issuer” within the meaning of Regulation S at the time of sale, the legend may be removed by providing a declaration to the Company and the Warrant Agent, in the form attached as Appendix C to Schedule A to
this Indenture to the effect that the securities 

  

 - 15 - 

	 	 
are being sold in compliance with Rule 904 of Regulation S, together with any documentation as may be required by the Company or its transfer agent to the
effect that an exemption from the registration requirements of the 1933 Act is available; and 

  

	 	(ii)	if any such securities are being sold under clause (C) or (D) of the above legend, the legend may be removed by delivery to the Company and the Warrant Agent of an opinion
of counsel, of recognized standing reasonably satisfactory to the Company, that such legend is no longer required under applicable requirements of the 1933 Act or state securities laws. 

 In addition, the Warrants with the above legend will bear the following legend: 
 “THIS WARRANT AND THE SECURITIES ISSUABLE UPON EXERCISE OF THIS WARRANT HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE
“U.S. SECURITIES ACT”), OR THE SECURITIES LAWS OF ANY STATE. THIS WARRANT MAY NOT BE EXERCISED IN THE UNITED STATES OR BY OR ON BEHALF OF A PERSON IN THE UNITED STATES OR A U.S. PERSON UNLESS THE WARRANT AND THE UNDERLYING SECURITIES HAVE
BEEN REGISTERED UNDER THE U.S. SECURITIES ACT AND THE APPLICABLE SECURITIES LEGISLATION OF ANY SUCH STATE OR AN EXEMPTION FROM SUCH REGISTRATION REQUIREMENTS IS AVAILABLE. THE TERMS “UNITED STATES” AND “U.S.
PERSON” HAVE THE MEANINGS GIVEN THEM UNDER REGULATION S PROMULGATED PURSUANT TO THE U.S. SECURITIES ACT.” 
 The Company
shall use its commercial best efforts to cause the Warrant Agent to remove such legend, and to deliver a certificate which does not bear such legend, within five business days of the receipt of such a declaration or, in the case of Shares being sold
pursuant to Rule 144 under the 1933 Act, receipt of the foregoing evidence. 
  

	 	(3)	The Warrant Agent acknowledges that the Warrants evidenced by any Warrant Certificate or Share certificate issued with respect to an exercise of Warrants which includes the legend
set forth in subsection 2.14(2) above may not be transferred except pursuant to registration or compliance with exemptions therefrom under the 1933 Act and all applicable state securities laws, and the Warrant Agent agrees not to register any
transfer of the Warrants or Shares so legended unless, in addition to the other requirements set forth herein: 

  

	 	(a)	 the transferor has executed and delivered to the Warrant Agent a declaration in the form set forth in subsection 2.14(2) (or as the Company may otherwise prescribe)
to the effect that the transfer is being made 

  

 - 16 - 

	 	 
pursuant to Rule 904 of Regulation S under the 1933 Act, and in such case the Warrant Certificate or Share certificate issued to the transferee shall not
include the legend set forth in subsection 2.14(2) unless the Company has, before the issuance thereof, informed the Warrant Agent that it has ceased to be a “foreign issuer” as defined in Rule 902 under the U.S. Securities Act; or

  

	 	(b)	the transferor has delivered to the Warrant Agent and the Company an opinion of counsel to the effect that the transfer is in compliance with the requirements of the 1933 Act and
all applicable state securities laws, and the Company has confirmed in writing to the Warrant Agent that such opinion is satisfactory to the Company, and in such case the Warrant Certificate or Share certificate issued to the transferee shall
include the legend set forth in subsection 2.14(2) unless such opinion states that the legend is no longer required; or 

  

	 	(c)	the Company has confirmed in writing to the Warrant Agent that it has received other evidence satisfactory to it that the transfer is in compliance with the requirements of the 1933
Act and all applicable state securities laws, and has instructed the Warrant Agent regarding the inclusion or omission of the legend set forth in subsection 2.14(2) on the Warrant Certificate or Share certificate issued to the transferee; or

  

	 	(d)	the transferee is the Company. 

  

	2.15	Reliance by the Warrant Agent 

 The Warrant Agent
shall have no obligation to ensure or verify compliance with any applicable laws or regulatory requirements on the issue, exercise or transfer of any Warrants or any Shares issuable upon the exercise thereof, provided such issue, exercise or
transfer, as the case may be, is effected in accordance with the terms of this Agreement. The Warrant Agent shall be entitled to process all transfers and exercises of Warrants upon the presumption that such transfers or exercises are permissible
pursuant to all applicable laws and regulatory requirements. The Warrant Agent may assume for the purposes of this Agreement that any address on the register of the Warrantholders is the holder’s actual address and is also determinative as to
residency and that the address of any transferee to whom any Shares or Warrants are to be registered, as shown on the transfer document, is the transferee’s residency. The Warrant Agent shall have no obligation to ensure that legends appearing
on the Share certificates or Warrant Certificates comply with regulatory requirements or securities laws of any applicable jurisdiction, but shall ensure that the applicable legends required to be placed on the certificates evidencing the Shares and
Warrants pursuant to this Agreement are placed thereon. 
  

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 ARTICLE 3 
 EXERCISE OF WARRANTS 
  

	3.1	Method of Exercise of Warrants 

  

	 	(1)	Each Warrant may be exercised by the holder thereof at any time on or after the Date of Issue, but not after the Warrant Expiry Time, upon the terms and subject to the conditions
set forth herein. 

  

	 	(2)	Subject to and upon compliance with the provisions of this Article, the holder of any Warrant Certificate may exercise the right of purchase therein provided for by surrendering the
Warrant Certificate to the Warrant Agent at its principal transfer offices in the City of Toronto or at such additional place or places as may be designated by the Company from time to time with the approval of the Warrant Agent during normal
business hours on a business day at that place before the Warrant Expiry Time, together with the Warrant Exercise Form duly completed and executed by the holder for the number of Shares which the holder desires to purchase and payment of the
aggregate Exercise Price applicable at the time of the surrender calculated in accordance with the provisions of this Indenture. The aggregate Exercise Price for Shares subscribed for under the Warrants shall be paid by certified cheque, bank draft
or money order in lawful money of the United States payable to or to the order of the Company at the city where the Warrant Certificate is surrendered. Surrender of a Warrant Certificate with the Warrant Exercise Form duly completed and payment of
the aggregate Exercise Price will be deemed to have been effected, and Warrants shall be deemed to have been exercised, only on personal delivery thereof to, or if sent by mail or other means of transmission on actual receipt thereof by, the Warrant
Agent at one of the offices specified in this section. 

  

	 	(3)	Every Warrant Exercise Form: 

  

	 	(a)	shall be signed by the holder of the Warrant Certificate who desires to exercise in whole or in part the right of purchase therein provided for; 

  

	 	(b)	shall specify the number of Shares that the subscriber wishes to purchase (being not more than he is entitled to purchase under the Warrant Certificate), the person or persons in
whose name or names the Shares which the subscriber desires to purchase are to be issued and his or their address or addresses and the number of Shares to be issued to each such person and if more than one is so specified, the form shall have one of
the boxes in the Warrant Exercise Form checked; and 

  

	 	(c)	shall be substantially in the form set out in the Warrant Certificate. 

  

	 	(4)	 If any Shares subscribed for are to be issued to a person or persons other than the Warrantholder, the Warrantholder must pay to the Company or to the Warrant Agent
on his behalf an amount equal to all applicable transfer taxes or other government charges, and the Company will not be required to issue or deliver any 

  

 - 18 - 

	 	 
certificate evidencing any Shares unless or until that amount has been so paid or the Warrantholder has established to the satisfaction of the Company that
the taxes and charges have been paid or that no taxes or charges are owing. 

  

	 	(5)	The Warrants and the Shares issuable upon exercise thereof have not been registered under the 1933 Act or the securities law of any state of the United States, and the Warrants may
not be exercised within the United States or by or on behalf of any U.S. Person unless the Shares are registered under the 1933 Act and the securities laws of all applicable states of the United States or an exemption from such registration
requirements is available. No exercise of any Warrants shall be effective, and no certificate representing Shares shall be issued pursuant to the exercise of Warrants, unless the appropriate box on the Warrant Exercise Form is selected specifying
one of the following: 

  

	 	(a)	the holder is not in the United States or a U.S. Person, is not exercising the Warrants on behalf of a U.S. Person, and did not execute or deliver the Warrant Exercise Form in the
United States; 

  

	 	(b)	the holder is an Original U.S. Purchaser that remains an Accredited Investor and is exercising the Warrants on its own behalf and not for the account or benefit of any other person
in which case the holder shall, concurrent with exercise of the Warrants, provide a letter in substantially the form set out in Appendix “A” to the Warrant Exercise Form; or 

  

	 	(c)	the holder is resident in the United States or is a U.S. Person and provides an opinion of counsel of recognized standing in form and substance satisfactory to the Company to the
effect that registration under the 1933 Act and applicable state securities laws is not required. 

 The certificates
representing any Shares issued in connection with the exercise of Warrants pursuant to clause (b) or (c) of this Section 3.1(5) shall bear the legend set forth in Section 2.14(2) of this Indenture. No certificates for Shares
shall be registered or delivered to an address in the United States unless the holder complies with clause (b) or (c) of this Section 3.1(5). 
  

	3.2	Effect of the Exercise of Warrants 

  

	 	(1)	Subject to subsection (2) and Section 3.8, on exercise of a Warrant, the Company shall cause to be issued to the person or persons in whose name or names the Shares so
subscribed for are to be issued as specified in the Warrant Exercise Form, the number of Shares to be issued to such person or persons and such person or persons shall become a Shareholder or Shareholders of the Company in respect of those Shares
with effect from the date on which the Warrant is exercised and shall be entitled to delivery of a certificate or certificates evidencing the Shares and the Company shall cause the certificate or certificates to be mailed by first class, insured
mail or delivered as specified to such person or persons (or, if applicable, the trustee under the registered retirement savings plan which holds the Shares) at the address or addresses specified in the Warrant Exercise Form within five business
days of the date on which the Warrant is exercised. 

  

 - 19 - 

	 	(2)	Notwithstanding any provision herein contained to the contrary, the Company shall not be required to deliver certificates for Shares in any period while the share transfer books of
the Company are closed and, in the event of the exercise of any Warrant during any such period, the Shares subscribed for shall be issued and such person shall be deemed to have become the holder of record of such Shares on the date to which such
delivery of certificates for Shares may be postponed (such period not exceeding three business days after the date of the re-opening of the share transfer books). 

  

	3.3	Partial Exercise of Warrants 

 A Warrantholder may
subscribe for and purchase any lesser number of Shares than the number of Shares to which such holder is entitled upon the exercise of Warrants, in which case the Warrantholder shall be entitled to receive forthwith a new Warrant Certificate in
respect of the Shares purchasable under the original Warrant Certificate and not then subscribed for and purchased, and the Warrant Agent shall issue a new Warrant Certificate upon surrender of the Warrant Certificate, if satisfied that the new
Warrant Certificate is properly issuable. 
  

	3.4	Cancellation of Warrants 

 All Warrants exercised as
provided in Section 3.1, partially exercised as provided in Section 3.3, or exchanged for other Warrants as provided in Section 2.7 or otherwise surrendered to the Warrant Agent shall be cancelled and either held by the Warrant Agent
until termination of this Indenture or resignation of the Warrant Agent or destroyed by the Warrant Agent at the direction of the Company and, if required by the Company, the Warrant Agent shall furnish the Company with a certificate as to the
destruction. 
  

	3.5	Expiration of Warrants 

 After the Warrant Expiry
Time, all rights under this Indenture and under any Warrant that has not been exercised shall wholly cease and terminate and the Warrant Certificate therefor shall be wholly void and of no effect. 
  

	3.6	Adjustment of the Exercise Price and Subscription Rights 

  

	 	(1)	In this section, the terms “record date” and “effective date” where used herein, shall mean the close of business on the relevant date.

  

	 	(2)	If and whenever at any time from the date hereof until the Warrant Expiry Time, the Company: 

  

	 	(a)	subdivides, redivides or changes the outstanding Shares into a greater number of shares, 

  

 - 20 - 

	 	(b)	combines, consolidates or reduces the outstanding Shares into a lesser number of shares, or 

  

	 	(c)	issues Shares or Convertible Securities to all or substantially all of the holders of Shares by way of stock dividend or other distribution, other than the issue from time to time
of Shares or Convertible Securities by way of stock dividend to Shareholders who elect to receive Shares or Convertible Securities in lieu of a Dividend Paid in the Ordinary Course; 

 (each of such events being herein called a “Share Reorganization”), the Exercise Price will be adjusted effective immediately on the
record date for the dividend or, in the case of a subdivision, redivision, change, combination, consolidation or reduction, effective immediately on the record date, or the effective date if no record date is fixed, to the number that is the product
of: 
  

	 	(d)	the Exercise Price in effect immediately before that effective date or record date; and 

  

	 	(e)	the fraction of which: 

  

	 	(i)	the numerator is the total number of Shares outstanding on that effective date or record date before giving effect to the Share Reorganization, and 

  

	 	(ii)	the denominator is the total number of Shares that are or would be outstanding immediately after that effective date or record date after giving effect to the Share Reorganization
and assuming all Convertible Securities issued as part of the Share Reorganization had then been converted into or exchanged for Shares or all rights to acquire Shares had then been exercised. 

 For the purpose of determining the number of Shares outstanding at any particular time there shall be included that number of Shares which would have
resulted from the conversion or exchange at that time of all Convertible Securities of the Company (other than any Convertible Securities issued to holders of Shares by way of a stock dividend or other distribution and otherwise included in
computing the denominator in clause (ii) hereof). Shares (and Shares issuable upon conversion or exchange of Convertible Securities) issued or to be issued under a Share Reorganization shall be deemed to be outstanding on the record date or
effective date for such Share Reorganization for the purpose of calculating the number of outstanding Shares under subsections (3) and (5). To the extent that any Convertible Securities issued to holders of Shares by way of a stock dividend or
other distribution are not so converted or exchanged into or for Shares before the expiration of the right to do so, the conversion price shall then be readjusted to the conversion price which would then be in effect based upon the number of Shares
actually issued upon the conversion or exchange of the Convertible Securities. 
  

 - 21 - 

	 	(3)	If and whenever at any time from the date hereof to the Warrant Expiry Time, the Company shall fix a record date for the issuance or distribution of rights, options or warrants to
all or substantially all of the holders of the outstanding Shares entitling them, for a period expiring not more than 45 days after the record date, to subscribe for or purchase Shares or Convertible Securities at a price per Share (or having a
conversion price per Share) less than 95% of the Current Market Price on the record date (any such issuance being herein called a “Rights Offering”), the Exercise Price will be adjusted on the record date for the Rights Offering to
the number which is the product of the Exercise Price in effect immediately before the record date and the fraction: 

  

	 	(i)	the numerator of which shall be the total of (A) the number of Shares outstanding immediately before the record date and (B) a number of Shares equal to the number arrived
at by multiplying the total number of additional Shares offered for subscription or purchase under the Rights Offering or into or for which the total number of Convertible Securities so offered under the Rights Offering are convertible or
exchangeable by the quotient obtained by dividing the purchase or subscription price for each Share offered for subscription or purchase or the conversion price for each Convertible Security so offered by such Current Market Price for the Shares,
and 

  

	 	(ii)	the denominator of which shall be the total number of Shares outstanding immediately before such record date plus the total number of additional Shares offered for subscription or
purchase under the Rights Offering or into or for which the total number of Convertible Securities so offered under the Rights Offering are convertible or exchangeable. 

 The adjustment shall be made successively whenever a record date is fixed, and shall become effective immediately after the record date for determination
of shareholders entitled to receive such Shares or Convertible Securities, provided that if two or more such record dates or dates of announcement, as applicable, referred to in subsection (3) are fixed within a period of 35 trading days,
the adjustment shall be made successively as if each of such record dates occurred on the earliest of such record dates. To the extent that any rights, options or warrants are not so issued or any of the rights, options or warrants so issued are not
exercised before the expiration thereof, or any Convertible Securities are not so converted into or exchanged for Shares before the expiration of the right to do so, the Exercise Price will be readjusted to the Exercise Price in effect immediately
before the record date, and the Exercise Price will be further adjusted based upon the number of additional Shares actually delivered upon the exercise of the rights, options or warrants, or issued upon the conversion or exchange of the Convertible
Securities, as the case may be. 
  

 - 22 - 

	 	(4)	If and whenever at any time from the date hereof to the Warrant Expiry Time, the Company shall fix a record date for the issue of rights, options or warrants to all or substantially
all the holders of the outstanding Shares entitling them, for a period expiring not more than 45 days after such record date, to subscribe for or purchase Shares or Convertible Securities at a price per Share (or having a conversion price per Share)
not less than 95% of the Current Market Price on the record date, the Exercise Price will not be adjusted. 

  

	 	(5)	If and whenever at any time from the date hereof to the Warrant Expiry Time the Company shall fix a record date for the making of an issue or distribution to all or substantially
all the holders of its outstanding Shares of (a) shares or securities of any class, excluding Shares or Convertible Securities referred to in paragraph 2(a), whether of the Company or any other corporation, or (b) rights, options or
warrants, excluding those referred to in subsection (3) or (4), or (c) evidences of its indebtedness, or (d) property, cash or other assets, excluding Dividends Paid in the Ordinary Course or property distributed in lieu thereof at
the option of the Shareholders (any of such events being herein called a “Special Distribution”) then, in each such case, the Exercise Price shall be adjusted on the record date to the number that is the product of the Exercise
Price in effect immediately before the record date and the fraction: 

  

	 	(i)	the numerator of which shall be the total number of Shares outstanding immediately before the record date multiplied by the Current Market Price on the day immediately before such
record date, less the aggregate fair market value (as determined by the Directors, subject to prior written approval of the Exchange which determination, absent manifest error, shall be conclusive) of the shares or rights, options or warrants or
evidence of indebtedness or property, cash or assets so distributed pursuant to such Special Distribution, and 

  

	 	(ii)	the denominator of which shall be the total number of Shares outstanding immediately before the record date multiplied by such Current Market Price. 

 The adjustment shall be made successively whenever a record date is fixed, and shall become effective immediately after the record date for the
determination of Shareholders entitled to receive such Special Distribution, provided that if two or more such record dates or dates of announcement, as applicable, referred to in subsection (5) are fixed within a period of 35 trading
days, the adjustment shall be made successively as if each of such record dates occurred on the earliest of such record dates. To the extent that any Special Distribution is not so made, the Exercise Price shall then be readjusted to the Exercise
Price which would then be in effect if the record date had not been fixed or to the Exercise Price which would then be in effect based upon the shares or rights, options or warrants or evidences of indebtedness or property, cash or assets actually
distributed, as the case may be. 
  

 - 23 - 

	 	(6)	On any adjustment of the Exercise Price pursuant to subsection (2), (3) or (5), including any readjustment, the number of Shares purchasable on exercise of a Warrant will be
adjusted, effective at the same time as the adjustment of the Exercise Price, by multiplying the number of Shares so purchasable immediately before the adjustment by a fraction, the numerator of which shall be the Exercise Price in effect
immediately before the adjustment and the denominator of which shall be the Exercise Price resulting from such adjustment. 

  

	 	(7)	Subject to the prior written approval of the Exchange and TSX (if required), if and whenever at any time from the date hereof to the Warrant Expiry Time there is:

  

	 	(a)	a reclassification or redesignation of the Shares outstanding, a change of Shares into other shares or securities, or any other capital reorganization of the Company except as
described in subsections (2), (3) and (5), 

  

	 	(b)	a consolidation, merger, arrangement or amalgamation of the Company with or into another body corporate or other entity resulting in a reclassification or redesignation of
outstanding Shares or a change of Shares into other shares or securities, or 

  

	 	(c)	a transaction whereby all or substantially all the Company’s undertaking and assets become the property of another corporation or other entity, 

 (any of those events being herein called a “Corporate Reorganization”), a holder who thereafter exercises Warrants will be entitled to
receive and will accept, for the Exercise Price then in effect, in lieu of the Shares (and any other securities to which Warrantholders are then entitled on the exercise of Warrants) to which he would otherwise have been entitled on exercise
immediately before the Corporate Reorganization, the kind and amount of shares or other securities or property (including cash) that he would have been entitled to receive as a result of the Corporate Reorganization if, on the effective date
thereof, he had been the holder of the number of Shares (and any other securities to which Warrantholders are then entitled on the exercise of Warrants) to which he would have been entitled on the exercise of the Warrant or Warrants immediately
before the Corporate Reorganization. 
  

	 	(8)	As a condition precedent to taking any action that would require an adjustment pursuant to subsection (7), the Company will take all action that, in the opinion of counsel, is
necessary in order that the Company, any successor or any successor to its assets and undertaking, shall be obligated to and may validly and legally issue as fully paid and non-assessable all the Shares or other shares or securities or property to
which Warrantholders will be entitled on the exercise of Warrants thereafter. 

  

	 	(9)	 Subject to the prior written consent of the Exchange and TSX (if required), if necessary as a result of any Corporate Reorganization, appropriate adjustments will
be made in the application of the provisions set forth in this Article 3 with 

  

 - 24 - 

	 	 
respect to the rights and interests of Warrantholders to the end that the provisions set forth in this Article 3 will thereafter correspondingly be made
applicable as nearly as may reasonably be possible to any shares or other securities or property thereafter deliverable on the exercise of a Warrant. Any such adjustment will be made by and set forth in an amendment hereto approved by the Directors
and by the Warrant Agent, each acting reasonably, and will for all purposes, absent manifest error, be conclusively deemed to be an appropriate adjustment. 

  

	 	(10)	Subject to the prior written consent of the Exchange and TSX (if required), if the purchase price provided for in any right, warrant or option issued in connection with a Rights
Offering is decreased, or the conversion price for Convertible Securities issued in connection with a Share Reorganization is increased, the Exercise Price shall forthwith be changed to whatever Exercise Price would have been obtained had the
adjustment made in connection with the issuance of all such rights, warrants, options or Convertible Securities been made upon the basis of the purchase price as so decreased or the conversion price as so increased, provided that the provisions of
this subparagraph shall not apply to any increase or decrease resulting from provisions in any rights, warrants, options or securities designed to prevent dilution if the increase or decrease shall not have been proportionately greater than the
change, if any, in the Exercise Price to be made at the same time pursuant to the provisions of this section. 

  

	 	(11)	Subject to the prior written consent of the Exchange and TSX (if required), if and whenever at any time before the Warrant Expiry Time the Company shall take any action affecting or
relating to the Warrants, other than any action described in this section, which in the opinion of the Warrant Agent, acting reasonably and in good faith, based upon the advice of counsel, would prejudicially affect the rights of any holders of
Warrants, the Exercise Price will be adjusted in such manner, if any, and at such time, as the Warrant Agent, may in its sole discretion determine to be equitable in the circumstances to such holders. 

  

	3.7	Adjustment Rules for Exercise Price 

 The following
rules and procedures will be applicable to adjustments made pursuant to Section 3.6: 
  

	 	(a)	the adjustments and readjustments provided for in Section 3.6 shall be cumulative and, subject to paragraph (b), will apply (without duplication) to successive issues,
subdivisions, combinations, consolidations, distributions and other events that require an adjustment; 

  

	 	(b)	no adjustment in the Exercise Price, or resulting adjustment in the number of Shares issuable on exercise of Warrants, will be made unless the adjustment would result in a change of
at least one percent (1%) in the prevailing Exercise Price and the number of Shares purchasable upon the exercise of the Warrants would change by at least one one-hundredth of a Share; provided, that any adjustment that would have been required
to be made except for the provisions of this paragraph will be carried forward and taken into account in the next adjustment; 

  

 - 25 - 

	 	(c)	no adjustment will be made in respect of an event described in paragraph 3.6(2)(b) or subsections 3.6(3) or 3.6(5) if the Warrantholders are entitled to participate in the event on
the same terms, mutatis mutandis, as if they had exercised their Warrants immediately before the effective date of or record date for the event, such participation being subject to the prior written consent of the Exchange and TSX;

  

	 	(d)	for the purposes of subsections (2), (3) and (5) of Section 3.6, there will be deemed not to be outstanding: 

  

	 	(i)	any Share owned by or held for the account of the Company, 

  

	 	(ii)	any Share owned by or held for the account of any Subsidiary of the Company; 

  

	 	(e)	subject to the prior written consent of the Exchange and TSX (if required), any dispute that arises at any time with respect to any adjustment pursuant to this Indenture will be
conclusively determined (as between the Company, the Warrantholders, the Warrant Agent and all transfer agents and shareholders of the Company) by the auditor of the Company or, if the auditor of the Company is unable or unwilling to act, by such
firm of independent chartered accountants as is selected by the Directors and is acceptable to the Warrant Agent and any determination by them, absent manifest error, will be binding on the Company, the Warrantholders, the Warrant Agent and all
transfer agents and Shareholders of the Company, and the Company shall notify the Warrantholders thereof; 

  

	 	(f)	in the absence of a resolution of the Directors fixing the record date for an event referred to in Section 3.6, the Company will be deemed to have fixed as the record date
therefor the date on which the event is effected or such other date as may be required by law; 

  

	 	(g)	subject to the prior written consent of the Exchange and TSX (if required), as a condition precedent to the taking of any action which would require an adjustment in any of the
rights under the Warrants, the Company will take any action which, in the opinion of counsel to the Company, may be necessary in order that the Company, or any successor to the Company or successor to the undertaking or assets of the Company will be
obligated to and may validly and legally issue all the Shares or securities which the holders of the Warrants would be entitled to receive thereafter and to exercise such Warrants in accordance with the provisions hereof; 

 

	 	(h)	 subject to Sections 7.2 and 7.3, the Warrant Agent shall not at any time be under any duty or responsibility to any Warrantholder to determine whether any facts
exist which may require any adjustment contemplated 

  

 - 26 - 

	 	 
by Section 3.6, or with respect to the nature or extent of any such adjustment made, or with respect to the method employed in making same. The Warrant
Agent shall not be accountable for the validity or value of any Shares delivered upon the exercise or deemed exercise of any Warrants and shall not be responsible for any failure of the Company to make any payment, or to issue or deliver any
securities or certificates represented hereby upon the exercise or deemed exercise of any Warrants; and 

  

	 	(i)	subject to the prior written consent of the Exchange and TSX (if required), if the Company, after the date hereof, shall take any action affecting any Shares which in the opinion of
the Directors acting reasonably and in good faith would materially affect the rights of Warrantholders, the Exercise Price and number of Shares issuable upon exercise of Warrants shall be adjusted in such manner, if any, and at such time, as the
Directors, in their sole discretion acting reasonably and in good faith, may determine to be equitable in the circumstances to adjust the rights of the Warrantholders to protect against dilution in accordance with the intent and purposes of
Section 3.6 and Section 3.7. Failure of the taking of action by the Directors so as to provide for an adjustment in the Exercise Price before the effective date of any action by the Company affecting the Shares shall be conclusive evidence
(absent manifest error) that the Directors have determined that it is equitable to make no adjustment in the circumstances, subject to the prior written consent of the Exchange and TSX (if required). 

  

	3.8	Postponement of Issue of Shares, etc. 

 In any case
in which Section 3.6 requires an adjustment to take effect immediately after the effective date of or record date for an event, and a Warrant is exercised after that date and before the consummation of the event (which in the case of rights,
options and warrants will be the date the rights, options and warrants are issued), the Company may postpone until consummation issuing to the Warrantholder such of the Shares, securities or property to which he is entitled if the Warrant had been
exercised immediately before that date, provided however, that the Company will deliver to the Warrantholder an appropriate instrument evidencing such holder’s right to receive such additional Shares, securities or property upon the occurrence
and consummation of such event and the right to receive any dividend or other distribution in respect of such additional Shares, securities or property declared in favour of the holders of record of Shares or of such securities or property on or
after that date or such later date as such holder would, but for the provisions of this Section, have become the holder of record of such additional Shares or of such securities or property pursuant to Section 3.6. 
  

	3.9	Notice of Certain Events 

  

	 	(1)	At least 14 days before the effective date of or record date for any event referred to in Section 3.6, other than a subdivision or consolidation of the Shares, that
requires or might require an adjustment in the subscription rights pursuant to a Warrant, including the Exercise Price and the number of Shares purchasable on exercise of a Warrant, the Company will: 

  

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	 	(a)	file with the Warrant Agent a certificate of the Company specifying the particulars of the event and, to the extent determinable, any adjustment required and the computation of the
adjustment, and 

  

	 	(b)	give notice to the Warrantholders of the particulars of the event and, to the extent, determinable, any adjustment required. 

 The notice need only set forth particulars as have been determined at the date that notice is given. 
  

	 	(2)	If any adjustment for which a notice pursuant to subsection (1) is given is not then determinable, the Company will promptly after the adjustment is determinable:

  

	 	(a)	file with the Warrant Agent a certificate of the Company showing the computation of the adjustment, and 

  

	 	(b)	give notice to the Warrantholders of the adjustment. 

  

	 	(3)	In the event of a subdivision or consolidation of the Shares, the Company will, before giving effect thereto, file with the Warrant Agent a certificate of the Company specifying the
particulars of the subdivision or consolidation and specifying the number of Shares purchasable upon exercise of a Warrant after giving effect to such subdivision or consolidation. 

  

	3.10	No Fractional Shares 

 The Company will not,
pursuant to Section 3.6 or under any other circumstances, be obligated to issue any fraction of a Share upon the exercise of a Warrant or Warrants. Subscriptions for fractional Shares will not be accepted as such and will be deemed to be a
subscription for the next smallest whole number of Shares. To the extent that the holder of one or more Warrants would otherwise have been entitled to receive on the exercise or partial exercise thereof a fraction of a Share, that holder may
exercise such right in respect of the fraction only in combination with another Warrant or Warrants that in the aggregate entitle the holder to purchase a whole number of Shares. If not so exercised, the Company shall not pay any amounts to the
holder in satisfaction of the right to otherwise have received a fraction of a Share. 
  

	3.11	Reclassification, Reorganizations, etc. 

  

	 	(1)	In case of: 

  

	 	(a)	any reclassifications or change of the Shares (other than a change in par value, or from par value to no par value, or from no par value to par value, or as a result of a
subdivision or consolidation); 

  

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	 	(b)	any amalgamation, consolidation or merger of the Company with, or amalgamation, consolidation or merger of the Company into, any other corporation (other than an amalgamation,
consolidation or merger in which the Company is the continuing corporation and which does not result in any reclassification or change, other than as aforesaid, of the Shares); 

  

	 	(c)	a reorganization of the Company; or 

  

	 	(d)	any sale, transfer or other disposition of all or substantially all of the assets of the Company, 

 the Company or the corporation formed by the amalgamation or the corporation into which the Company shall have been merged or been consolidated or the
reorganized Company, or the corporation which shall have acquired such assets, as the case may be, shall execute and deliver to the Warrant Agent a supplemental indenture providing that the holder of each Warrant then outstanding shall have the
right thereafter (until the Warrant Expiry Time) to exercise Warrants only into the kind and amount of shares and other securities and property (including cash) receivable upon such reclassification, change, amalgamation, consolidation, merger,
reorganization, sale, transfer or other disposition by a holder of the number of Shares which were purchasable upon the exercise of the Warrants had the Warrants been exercised immediately before the reclassification, change, amalgamation,
consolidation, merger, reorganization, sale, transfer or other disposition. 
  

	 	(2)	The supplemental indenture shall provide for adjustments which shall be as nearly equivalent as may be practicable to the adjustments provided for in this Article.

  

	 	(3)	The provisions of this section shall apply to successive reclassifications, changes, amalgamations, consolidations, mergers, reorganizations, sales, transfers or other dispositions.

 ARTICLE 4 
 RIGHTS AND COVENANTS OF THE COMPANY 
  

	4.1	Optional Purchases by the Company 

 The Company may
from time to time purchase, by private contract or otherwise, any of the Warrants. Any such purchase shall be made at the lowest price or prices at which, in the opinion of the directors, such Warrants are then obtainable, plus reasonable costs of
purchase, and may be made in such manner, from such persons and on such other terms as the Company, in its sole discretion, may negotiate. Any Warrant Certificates representing the Warrants purchased pursuant to this Section 4.1 shall forthwith
be delivered to and cancelled by the Warrant Agent. No Warrants shall be issued in replacement thereof. If required by the Company, the Warrant Agent will furnish the Company with a certificate as to such cancellation. 
  

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	4.2	General Covenants 

 The Company represents, warrants
and covenants with the Warrant Agent for the benefit of the Warrantholders that: 
  

	 	(a)	except to the extent the Company participates in a merger or business combination transaction which is in the best interest of the Company, it will at all times maintain its
existence, carry on and conduct its business as currently carried on, and keep or cause to be kept proper books of account in accordance with generally accepted accounting principles; 

  

	 	(b)	it is duly authorized to create and issue the Warrants to be issued hereunder and the Warrant Certificates when issued and certified as herein provided will be legal, valid, binding
and enforceable obligations of the Company; 

  

	 	(c)	subject to the provisions of this Indenture, it will cause the Shares from time to time subscribed for and purchased pursuant to the exercise of Warrants and the certificates
representing such Shares to be duly issued and delivered in accordance with the Warrants and the terms hereof; 

  

	 	(d)	at all times while any Warrants are outstanding it shall reserve and there shall remain unissued and conditionally allotted out of its authorized capital a number of Shares
sufficient to enable the Company to meet its obligations to issue Shares on the exercise of Warrants outstanding hereunder from time to time; 

  

	 	(e)	upon the exercise by the holder of any Warrant of the right of purchase provided for therein and herein and upon payment of the Exercise Price applicable thereto for each Share in
respect of which the right of purchase is so exercised, all Shares issuable upon the exercise shall be issued as fully paid and non-assessable; 

  

	 	(f)	it will use its commercially reasonable best efforts to ensure that the Shares issuable upon exercise of the Warrants will be listed for trading on the Exchange and TSX and any
other stock exchange on which the Shares are then listed and posted for trading upon their issue 

  

	 	(g)	except to the extent the Company participates in a merger or business combination transaction which is in the best interest of the Company and following which the Company is not a
“reporting issuer”, the Company will use its commercially reasonable best efforts to maintain its status as a “reporting issuer” (or the equivalent thereof) not in default of the requirements of the Securities Laws in each of the
Qualifying Jurisdictions that have such a concept to the date that is two years following the date hereof; 

  

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	 	(h)	the issue of the Warrants does not and will not result in a breach by the Company of, and does not and will not create a state of facts which, after notice or lapse of time or both,
will result in a breach by the Company of any applicable laws, and does not and will not conflict with any of the terms, conditions or provisions of the articles of incorporation of the Company, as amended, or any material trust indenture, loan
agreement or any other agreement or instrument to which the Company is a party or by which it is contractually bound on the date of this Indenture; 

  

	 	(i)	it shall do, execute, acknowledge and deliver or cause to be done, executed, acknowledged or delivered all other acts, deeds and assurances in law as the Warrant Agent may
reasonably require for better accomplishing and effecting the intentions and provisions of this Indenture; 

	 	

	 	(j)	it will make all requisite filings under applicable laws and regulations, including, without limitation, Securities Laws; 

	 	

	 	(k)	with respect to any notices to be given or other acts to be performed or which may be given or performed by the Warrant Agent under or pursuant to this Indenture, the Company shall
provide to the Warrant Agent in a timely manner all such information and documents as the Warrant Agent may reasonably request and are within the knowledge or control of the Company in order to verify the factual circumstances relating to such
notices or acts and, if requested, such notices or acts and, if requested, such information and documents shall be certified as correct by an officer of the Company; and 

	 	

	 	(l)	generally, it will well and truly perform and carry out all of the acts or things to be done by it as provided in this Indenture and will not take any action which might reasonably
be expected to deprive holders of Warrants their rights to acquire Shares on the exercise thereof. 

  

	4.3	Securities Qualification Requirements 

  

	 	(1)	If, in the opinion of either counsel to the Warrant Agent or counsel to the Company, any instrument is required to be filed with, or any permission, order or ruling is required to
be obtained from, any securities administrator or any other step is required under any federal or provincial law of Canada or any other Qualifying Jurisdiction before the Shares may be issued or delivered to an initial Warrantholder on the exercise
of the Warrants or resold by such Warrantholder, the Company covenants that it will use its commercially reasonable best efforts to file such instrument, obtain such permission, order or ruling or take all such other actions, at its expense, as is
required or appropriate in the circumstances. 

  

	 	(2)	The Company will give written notice of the issue of Shares pursuant to the exercise of Warrants, in such detail as may be required, to each securities administrator in each
jurisdiction in which there is legislation requiring the giving of any such notice. 

  

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	4.4	Warrant Agent’s Remuneration and Expenses 

 The
Company will pay to the Warrant Agent from time to time such reasonable remuneration for its services hereunder as are set out in the “Schedule of Fees” entered into between the Company and the Warrant Agent dated January 26, 2007, or
as may otherwise be agreed upon between the Company and the Warrant Agent and will pay or reimburse the Warrant Agent upon its request for all reasonable out-of-pocket expenses, disbursements and advances properly incurred or made by the Warrant
Agent in the administration or execution of the trusts hereby created (including the reasonable compensation and the disbursements of its counsel and all other advisors and assistants not regularly in its employ), both before any default hereunder
and thereafter until all duties of the Warrant Agent shall be finally and fully performed, except any such expense, disbursement or advance as may arise from the gross negligence or fraud of the Warrant Agent, its servants or its agents or other
advisors or assistants aforesaid. Any amount owing under this Section and unpaid thirty (30) days after request for such payment, will bear interest from the expiration of such thirty (30) days at a rate per annum equal to the then current
rate charged by the Warrant Agent, payable on demand. 
  

	4.5	Notice to Warrantholders of Certain Events 

 The
Company covenants with the Warrant Agent for the benefit of the Warrant Agent and the Warrantholders that, so long as any of the Warrants are outstanding, it will not: 
  

	 	(a)	pay any dividend payable in shares of any class to the holders of its Shares or make any other distribution (other than a cash distribution made as a Dividend Paid in the Ordinary
Course) to the holders of its Shares; 

  

	 	(b)	offer to the holders of its Shares rights to subscribe for or to purchase any Shares or shares of any class or any other securities, rights, warrants or options;

  

	 	(c)	make any repayment of capital on, or distribution of evidences of indebtedness on any of its assets (excluding cash dividends) to the holders of, its Shares;

  

	 	(d)	amalgamate, consolidate or merge with any other person or sell or lease the whole or substantially the whole of its assets or undertaking; 

  

	 	(e)	effect any subdivision, redivision, consolidation, reduction or reclassification of its Shares; or 

  

	 	(f)	liquidate, dissolve or wind-up, 

 unless, in each such case, the Company
shall have given notice, in the manner specified in Section 2.12, to each Warrantholder, of the action proposed to be taken and the date on which: (i) the books of the Company shall close or a record shall be taken for such dividend,
repayment, 

  

 - 32 - 

 
distribution, subscription rights or other rights, warrants or securities; or (ii) such subdivision, redivision, consolidation, reduction,
reclassification, amalgamation, merger, sale or lease, dissolution, liquidation or winding-up shall take place, as the case may be, provided that the Company shall only be required to specify in the notice those particulars of the action as shall
have been fixed and determined at the date on which the notice is given. The notice shall also specify the date as of which the holders of Shares of record shall participate in the dividend, repayment, distribution, subscription of rights or other
rights, warrants or securities, subdivision, redivision, consolidation, reduction, reclassification or shall be entitled to exchange their Shares for securities or other property deliverable upon such reclassification, amalgamation, merger, sale or
lease, other disposition, dissolution, liquidation or winding-up, as the case may be. The notice shall be given, with respect to the actions described above not less than 14 days before the record date or the date on which the Company’s
transfer books are to be closed with respect thereto. 
  

	4.6	Closure of Share Transfer Books 

 The Company
further covenants and agrees that it will not during the period of any notice given under Section 4.5 close its share transfer books or take any other corporate action which might deprive the Warrantholders of the opportunity of exercising
their Warrants; provided that nothing contained in this section shall be deemed to affect the right of the Company to do or take part in any of the things referred to in Section 4.5 or to pay any cash dividends on the shares of any class or
classes in its capital from time to time outstanding. 
  

	4.7	Performance of Covenants by Warrant Agent 

 If the
Company shall fail to perform any of its covenants contained in this Indenture, the Warrant Agent may notify the Warrantholders of the failure on the part of the Company or may itself perform any of the said covenants capable of being performed by
it, but shall be under no obligation to do so or to notify the Warrantholders. All sums expended or advanced by the Warrant Agent in so doing shall be repayable as provided in Section 4.4. No performance, expenditure or advance by the Warrant
Agent shall be deemed to relieve the Company of any default hereunder. 
  

	4.8	Representation and Warranty 

 The Company represents
and warrants to the Warrant Agent and the holders of the Warrants and/or Shares that it is a “foreign issuer” as that term is defined in Regulation S. 
 ARTICLE 5 
 MEETINGS OF WARRANTHOLDERS 
  

	5.1	Right to Convene Meeting 

  

	 	(1)	 The Warrant Agent or the Company may at any time and from time to time, and the Warrant Agent shall on receipt of a requisition in writing signed by the holders of
Warrants sufficient to purchase not less than 20% of the aggregate number of Shares which would be purchased under the Warrants then outstanding and upon being indemnified and funded to its reasonable satisfaction by the 

  

 - 33 - 

	 	 
Company or by the Warrantholders signing the requisition against the costs which may be incurred in connection with the calling and holding of the meeting,
convene a meeting of the Warrantholders. 

  

	 	(2)	If the Warrant Agent fails to convene a meeting within seven days after receipt of the requisition and indemnity referred to in subsection (1), the Company or the Warrantholders, as
the case may be, may convene the meeting. 

  

	 	(3)	Every meeting of Warrantholders shall be held in the City of Toronto, Ontario or at such other place as the Warrant Agent shall determine. 

  

	5.2	Notice 

  

	 	(1)	At least ten business days’ prior notice specifying the place, day and hour of meeting and the general nature of business to be transacted shall be given before any meeting of
Warrantholders but it shall not be necessary to specify in the notice the terms of any resolution to be proposed. 

  

	 	(2)	Notice of a meeting of Warrantholders shall be given to the Warrantholders in the manner provided in Section 2.12. Notice shall be given to the Company unless the meeting is
convened by the Company and to the Warrant Agent unless the meeting is convened by the Warrant Agent. Any accidental omission in the notice of a meeting shall not invalidate any resolution passed at the meeting. 

  

	5.3	Chairman 

 The person, who need not be a
Warrantholder, nominated in writing by the Warrant Agent shall be entitled to act as the chairman at any meeting of Warrantholders, but if no such person is nominated or if the person nominated shall not be present within 15 minutes after the time
appointed for holding the meeting, the Warrantholders present in person or by proxy shall choose a person present to be chairman. 
  

	5.4	Quorum 

  

	 	(1)	At any meeting of the Warrantholders a quorum shall consist of two or more Warrantholders present in person or by proxy holding not less than 20% of the Warrants then outstanding.

  

	 	(2)	If a quorum of the Warrantholders is not present within half an hour from the time fixed for holding any meeting, the meeting, if convened by Warrantholders or by a requisition of
Warrantholders, shall be dissolved; but if otherwise convened, the meeting shall stand adjourned without notice to the same day in the next week following (unless that day is not a business day, in which case the meeting shall stand adjourned to the
next business day thereafter) at the same time and place. At the adjourned meeting, the Warrantholders present in person or by proxy shall form a quorum and may transact the business for which the meeting was originally convened notwithstanding that
they may not hold 20% of the Warrants then outstanding. 

  

 - 34 - 

	5.5	Power to Adjourn 

 The chairman of any meeting at
which a quorum of Warrantholders is present may, with the consent of the meeting, adjourn any meeting and no notice of the adjournment need be given except such notice, if any, as the meeting may prescribe. 
  

	5.6	Show of Hands 

 Every question submitted to a
meeting other than a question to be resolved by an Extraordinary Resolution shall be decided in the first place by a majority of the votes given on a show of hands and unless a poll is duly demanded as herein provided, a declaration by the chairman
that a resolution has been carried or carried unanimously or by a particular majority or lost or not carried by a particular majority shall be conclusive evidence of that fact. 
  

	5.7	Poll 

 On every Extraordinary Resolution to be
passed at a meeting and on any other question submitted to a meeting when directed by the chairman or when demanded by one or more of the Warrantholders acting in person or by proxy, a poll shall be taken in the manner as the chairman shall direct.
Questions other than those to be resolved by Extraordinary Resolution shall, if a poll be taken, be decided by the votes of the holders of a majority of the Warrants represented at the meeting and voted on the poll. If at any meeting a poll is so
demanded as aforesaid on the election of a chairman or on a question of adjournment, it shall be taken forthwith. If at any meeting a poll is so demanded on any other question, or an Extraordinary Resolution is to be voted upon, a poll shall be
taken in such manner and either at once or after an adjournment as the chairman directs. The result of a poll shall be deemed to be the decision of the meeting at which the poll was demanded and shall be binding on all holders of Warrants.

  

	5.8	Voting 

 On a show of hands, every person who is
present and entitled to vote, whether as a Warrantholder or as proxy for one or more absent Warrantholders or both, shall have one vote. On a poll, each Warrantholder present in person or represented by a proxy duly appointed by instrument in
writing shall be entitled to one vote in respect of each Share purchasable under Warrants of which he shall then be the holder. A proxy need not be a Warrantholder. The chairman of any meeting shall be entitled both on a show of hands and on a poll
to vote in respect of the Warrants, if any, held or represented by him but shall not be entitled to a casting vote in the case of an equality of votes. 
  

	5.9	Persons Entitled to be Present 

 The Company and the
Warrant Agent by their respective officers and directors and the counsel of the Company and the Warrant Agent may attend any meeting of Warrantholders but shall have no vote as such. 
  

 - 35 - 

	5.10	Regulations 

 The Warrant Agent, or the Company with
the approval of the Warrant Agent, may from time to time make or vary such regulations as it shall think fit providing for and governing the following: 
  

	 	(a)	the issue of voting certificates: 

  

	 	(i)	by any bank, trust company or other depository approved by the Warrant Agent, certifying that specified Warrants have been deposited with it by a named holder and will remain on
deposit until after the meeting; or 

  

	 	(ii)	by any bank, trust company, insurance company, governmental department or agency approved by the Warrant Agent, certifying that it is the holder of specified Warrants and will
continue to hold the same until after the meeting, 

 which voting certificates shall entitle the holders named therein to be
present and vote at any meeting and at any adjournment thereof or to appoint a proxy or proxies to represent them and vote for them at any meeting and at any adjournment thereof, in the same manner and with the same effect as though the holders
named in the voting certificates were the actual holders of the specified Warrants; 
  

	 	(b)	the form of the instrument appointing a proxy (which shall be in writing), the manner in which the same shall be executed and the form of any authority under which a person executes
a proxy on behalf of a Warrantholder; 

  

	 	(c)	the deposit certificates, instruments appointing proxies or authorities at such place or places as the Warrant Agent (or the Company or Warrantholders in case the meeting is
convened by the Company or the Warrantholders, as the case may be) may in the notice convening the meeting direct and the time (if any) before the holding of the meeting or adjourned meeting at which the same shall be deposited;

  

	 	(d)	the deposit of voting certificates or instruments appointing proxies at some place or places other than the place at which the meeting is to be held and for particulars of the
voting certificates or instruments appointing proxies to be cabled or telegraphed or notified by other means of communication before the meeting to the Company or to the Warrant Agent and for the voting of voting certificates and proxies so
deposited as if the voting certificates or the instruments themselves were produced at the meeting or deposited at any other place required pursuant to subsection (c); and 

  

	 	(e)	generally for the calling of meetings of Warrantholders and the conduct of business thereat. 

  

 - 36 - 

 Any regulations so made shall be binding and effective and votes given in accordance therewith shall be valid and shall
be counted. Except as the regulations may provide, the only persons who shall be recognized at any meeting as the holders of any Warrants, or as entitled to vote or to be present at the meeting in respect thereof, shall be registered Warrantholders
and persons whom registered Warrantholders have by instrument in writing duly appointed as their proxies. 
  

	5.11	Certain Powers Exercisable by Extraordinary Resolution 

 In addition to all other powers conferred on them by the other provisions of this Indenture or by law but subject to obtaining the approval of the Exchange, the Warrantholders shall have the following powers, exercisable from time to time
by Extraordinary Resolution: 
  

	 	(a)	power to agree to any amendment, modification, abrogation, alteration, compromise or arrangement of the rights of Warrantholders or the Warrant Agent in that capacity or on behalf
of the Warrantholders against the Company whether the rights arise under this Indenture or otherwise; 

  

	 	(b)	power to agree to any change in or omission from the provisions of the Warrant Certificate and this Indenture or any ancillary or supplemental instrument which may be agreed to by
the Company and to authorize the Warrant Agent to concur in and execute any ancillary or supplemental indenture embodying any change or omission; 

  

	 	(c)	power to require the Warrant Agent, subject to compliance with Section 7.3, to enforce any of the obligations of the Company under this Indenture or any supplemental instrument
or to enforce any of the rights of the Warrantholders in any manner specified in an Extraordinary Resolution or to refrain from enforcing any such covenant or right, upon the Warrant Agent being furnished with such funding and indemnity as it may in
its discretion reasonably require; 

  

	 	(d)	power to remove the Warrant Agent or its successor or successors in office and to appoint a new Warrant Agent or Warrant Agents to take the place of the Warrant Agent or Warrant
Agents so removed, in each case with consent of the Company which consent shall not be unreasonably withheld; 

  

	 	(e)	power to waive and direct the Warrant Agent to waive any default on the part of the Company in complying with any provision of this Indenture either unconditionally or upon
conditions specified in the Extraordinary Resolution; 

  

	 	(f)	power to restrain any Warrantholder from taking or instituting or continuing any suit, action or proceeding against the Company for the enforcement of any of the obligations of the
Company under this Indenture or to enforce any right of the Warrantholders; and 

  

 - 37 - 

	 	(g)	power to amend, alter or repeal any Extraordinary Resolution previously passed or consented to by Warrantholders. 

  

	5.12	Definition of “Extraordinary Resolution” 

 The expression “Extraordinary Resolution” when used in this Indenture means a resolution passed at a meeting (including an adjourned meeting) of Warrantholders duly convened and held in accordance with the provisions of
this Indenture at which a quorum is present and carried by the affirmative vote of not less than 66 2/3% of the votes given on a poll or by the consent in writing, which may be in one or more instruments, of the holders of not less than 66 2/3% of
the Warrants then outstanding. 
  

	5.13	Resolutions Binding on all Warrantholders 

 Every
resolution and every Extraordinary Resolution duly passed at a meeting of the Warrantholders duly convened and held or any consent in writing having the effect of an Extraordinary Resolution shall be binding upon all the Warrantholders (including
their successors and assigns) whether or not present or represented or voting at the meting or signatories to the consent, as the case may be, and each of the Warrantholders and the Warrant Agent, subject to the provisions for its indemnity
contained in this Indenture, shall be bound to give effect thereto. 
  

	5.14	Holdings by Company Disregarded 

 In determining
whether the requisite number of Warrantholders are present for the purpose of obtaining a quorum or have voted or consented to any resolution, Extraordinary Resolution, consent, waiver or other action under this Indenture, Warrants owned by the
Company or any Subsidiary of the Company shall be deemed to be not outstanding. 
  

	5.15	Minutes 

 Minutes of all resolutions and proceedings
at every meeting of Warrantholders shall be made and duly entered in books to be provided for that purpose by the Warrant Agent at the expense of the Company and any minutes if purporting to be signed by the chairman of the meeting, or by the
chairman of the next succeeding meeting of Warrantholders, shall be prima facie evidence of the matters therein stated and, until the contrary is proved, every meeting for which minutes have been made shall be deemed to have been duly
convened and held and all resolutions passed or proceedings taken thereat to have been duly passed and taken. 
  

	5.16	Powers Cumulative 

 Any one or more of the powers or
combination of the powers in this Indenture exercisable by the Warrantholders by Extraordinary Resolution or otherwise may be exercised from time to time and the exercise of any one or more of the powers or any combination of powers from time to
time shall not be deemed to exhaust the rights of the Warrantholders to exercise the same or any other power or powers or combination of powers then or any power or powers or combinations of powers thereafter. 
  

 - 38 - 

	5.17	Instruments in Writing 

 All actions that may be
taken and all powers that may be exercised by the Warrantholders at a meeting held as hereinbefore in this Article provided may also be taken and exercised by Warrantholders entitled to acquire 66 2/3% of the aggregate number of Shares that can be
acquired pursuant to all the then outstanding Warrants by an instrument in writing signed in one or more counterparts by Warrantholders in person or by attorney duly appointed in writing and the expression “resolution” or
“Extraordinary Resolution” when used in this Indenture shall include an instrument so signed. 
 ARTICLE 6 

SUPPLEMENTAL INDENTURES AND SUCCESSOR COMPANIES 
  

	6.1	Provision for Supplemental Indenture for Certain Purposes 

 From time to time the Company and the Warrant Agent may, subject to the provisions of this Indenture and the obtaining of the prior written consent of the Exchange and the TSX, if necessary, and shall, when so directed by this Indenture,
execute and deliver by their proper officers or directors, as the case may be, indentures or instruments supplemental hereto, which thereafter shall form part hereof, for any one or more or all of the following purposes: 
  

	 	(a)	adding hereto such additional covenants and enforcement provisions as in the opinion of counsel are necessary or advisable and are not in the opinion of the Warrant Agent, based on
the advice of counsel, prejudicial to the interest of the Warrantholders as a group; 

  

	 	(b)	giving effect to any Extraordinary Resolution passed as provided in Article 5; 

  

	 	(c)	making any modification in the form of Warrant Certificate which, in the opinion of the Warrant Agent, based on the advice of counsel, does not affect the substance thereof;

  

	 	(d)	making any additions to, deletions from or alterations of the provisions of this Indenture which, in the opinion of the Warrant Agent based on the advice of counsel, do not
materially and adversely affect the interests of the Warrantholders and are necessary or advisable in order to incorporate, reflect or comply with any Applicable Legislation; 

  

	 	(e)	modifying any of the provisions of this Indenture or relieving the Company from any of the obligations, conditions or restrictions herein contained, provided that no such
modification or relief shall be or become operative or effective if in the opinion of the Warrant Agent, based on the advice of counsel, the modification or relief materially impairs any of the rights of the Warrantholders, as a group, or of the
Warrant Agent, and provided that the Warrant Agent may in its sole discretion decline to enter into any supplemental indenture which in its opinion may not afford adequate protection to the Warrant Agent when the same shall become operative;

  

 - 39 - 

	 	(f)	for any other purpose not inconsistent with the terms of this Indenture, including the correction or rectification of any ambiguities, defective provisions, errors or omissions
herein, provided that in the opinion of the Warrant Agent, based on the advice of counsel, the rights of the Warrant Agent or of the Warrantholders, as a group, are in no way prejudiced thereby; and 

  

	 	(g)	setting forth any adjustments resulting from the application of the provisions of Article 3 hereof. 

  

	6.2	Successor Companies 

 Subject to Section 3.9,
nothing in this Indenture shall prevent any consolidation, reorganization, amalgamation, arrangement or merger of the Company with or into any other body corporate, bodies corporate, or person, or a conveyance or transfer of all or substantially all
the property and assets of the Company as an entirety to any body corporate or person lawfully entitled to acquire and operate the same; provided, however, that the body corporate formed by such consolidation, amalgamation or arrangement or into
which such merger shall have been made or the person which acquires by conveyance or transfer all or substantially all the property and assets of the Company as an entirety shall execute and deliver to the Warrant Agent before or contemporaneously
with such consolidation, reorganization, amalgamation, arrangement, merger, conveyance or transfer and as a condition precedent thereto, an agreement supplemental hereto wherein the due and punctual performance and observance of all the covenants
and conditions of this Indenture to be performed or observed by the Company shall be assumed by such successor body corporate or person. The Warrant Agent shall be entitled to receive and shall be fully protected in relying upon an opinion of
counsel that any such consolidation, reorganization, amalgamation, arrangement, merger, conveyance or transfer and any supplemental agreement executed in connection therewith, complies with the provisions of this section. 
  

	6.3	Successor Body Corporate Substituted 

 Subject to
Section 3.9, in case the Company, pursuant to Section 6.2 hereof, shall be consolidated, amalgamated, reorganized, arranged or merged with or into any other body corporate or bodies corporate or person or shall convey or transfer all or
substantially all of the property and assets of the Company as an entirety to another body corporate or person, the successor body corporate or person formed by such consolidation, reorganization, arrangement or amalgamation or into which the
Company shall have been merged or which shall have received a conveyance or transfer as aforesaid shall succeed to and be substituted for the Company hereunder with the same effect as nearly as may be possible as if it had been named herein as the
party of the first part. Such changes may be made in the Warrants as may be appropriate in view of such consolidation, amalgamation, reorganization, arrangement, merger, conveyance or transfer. 
  

 - 40 - 

 ARTICLE 7 
 CONCERNING THE WARRANT AGENT 
  

	7.1	Rights and Duties of Warrant Agent 

  

	 	(1)	In the exercise of the rights, duties and obligations prescribed or conferred by the terms of this Indenture, the Warrant Agent will act honestly and in good faith with a view to
the best interests of the Warrantholders and will exercise that degree of care, diligence and skill that a reasonably prudent Warrant Agent would exercise in comparable circumstances. 

  

	 	(2)	No provision of this Indenture will be construed to relieve the Warrant Agent from liability for its own negligent action, its own negligent failure to act, or its own wilful
misconduct or bad faith. 

  

	 	(3)	The obligation of the Warrant Agent to commence or continue any action or proceeding for the purpose of enforcing any rights of the Warrant Agent or the Warrantholders hereunder
shall be conditional upon the Warrantholders furnishing, when required by notice in writing by the Warrant Agent, sufficient funds to commence or continue such act, action or proceeding and an indemnity reasonably satisfactory to the Warrant Agent
to protect and hold harmless the Warrant Agent against the costs, charges and expenses and liabilities to be incurred thereto and any loss and damage it may suffer by reason thereof. 

  

	 	(4)	No provision of this Indenture shall require the Warrant Agent to expend or risk its own funds or otherwise incur financial liability in the performance of any of its duties or in
the exercise of any of its rights or powers. 

  

	 	(5)	The Warrant Agent may, before commencing or at any time during the continuance of such act, action or proceeding require the Warrantholders at whose instance it is acting to deposit
with the Warrant Agent the Warrant Certificates held by them, for which Warrant Certificates the Warrant Agent shall issue receipts. 

  

	7.2	Evidence, Experts and Advisors 

  

	 	(1)	In addition to the reports, certificates, opinions and other evidence required by this Indenture, the Company will furnish to the Warrant Agent such additional evidence of
compliance with any provision hereof and in such form as is prescribed by Applicable Legislation or as the Warrant Agent reasonably requires by written notice to the Company. 

  

	 	(2)	In the exercise of any right or duty hereunder the Warrant Agent, if it is acting in good faith, may rely, as to the truth of any statement or the accuracy of any opinion expressed
therein, on any statutory declaration, opinion, report, certificate or other evidence furnished to the Warrant Agent pursuant to a provision hereof or Applicable Legislation or pursuant to a request of the Warrant Agent. 

  

 - 41 - 

	 	(3)	Whenever Applicable Legislation requires that evidence referred to in subsection (1) be in the form of a statutory declaration, the Warrant Agent may accept the statutory
declaration in lieu of a certificate of the Company required by any provision hereof. 

  

	 	(4)	Any statutory declaration may be made by one or more officers or Directors of the Company. 

  

	 	(5)	Proof of the execution of an instrument in writing by a Warrantholder may be made by the certificate of a notary public, or other officer with similar powers, that the person
signing the instrument acknowledged to him the execution thereof, or by an affidavit of a witness to the execution, or in any other manner that the Warrant Agent considers adequate. 

  

	 	(6)	The Warrant Agent may employ or retain such counsel, accountants, engineers, appraisers or other experts or advisers as it reasonably requires for the purpose of discharging its
duties hereunder and may pay reasonable remuneration for all services so performed by any of them payable by the Company in accordance with Section 4.4, without taxation of costs of any counsel and will not be responsible for any misconduct or
negligence on the part of any of them who has been selected with due care by the Warrant Agent. 

  

	 	(7)	The Warrant Agent may as a condition precedent to any action to be taken by it under this Indenture require such opinions, statutory declarations, reports, certificates or other
evidence as it, acting reasonably, considers necessary or advisable in the circumstances. 

  

	7.3	Documents, Moneys, etc. Held by Warrant Agent 

  

	 	(1)	Any security, document of title or other instrument that may be at any time held by the Warrant Agent subject to the terms hereof may be placed in the deposit vaults of the Warrant
Agent or of any Schedule I Canadian chartered bank or deposited for safekeeping with such bank. 

  

	 	(2)	Unless herein otherwise expressly provided, any money held pending the application or withdrawal thereof under any provision of this Indenture may be deposited in the name of the
Warrant Agent in any Schedule I Canadian chartered bank at the rate of interest (if any) then current on similar deposits or: 

  

	 	(a)	deposited in the deposit department of the Warrant Agent or of any other loan or trust company authorized to accept deposits under the laws of Canada or a province thereof, or

  

	 	(b)	with the consent of the Company may be invested in United States dollar denominated securities issued or guaranteed by the Government of Canada or a province thereof or in United
States dollar denominated obligations, maturing not more than one year from the date of investment, of any Schedule I Canadian chartered bank or loan or trust company. 

  

 - 42 - 

	 	(3)	All interest or other income received by the Warrant Agent in respect of deposits in investment will belong to the Company. 

  

	7.4	Action by Warrant Agent to Protect Interests 

 The
Warrant Agent shall have power to institute and to maintain such actions and proceedings as it may consider necessary or expedient to preserve or protect its interests and the interests of the Warrantholders. 
  

	7.5	Warrant Agent not Required to give Security 

 The
Warrant Agent shall not be required to give any bond or security in respect of the execution of the terms and powers of this Indenture or otherwise in respect of the premises. 
  

	7.6	Protection of Warrant Agent 

 By way of supplement
to the provisions of any law for the time being relating to the Warrant Agent, it is expressly declared and agreed that: 
  

	 	(a)	the Warrant Agent shall not be liable for or by reason of any representations, statements of fact or recitals in this Indenture (except the representation contained in
Section 7.8 and by virtue of the countersignature of the Warrant Agent on the Warrant Certificates) or required to verify the same, but all such representations, statements or recitals are and shall be deemed to be made by the Company;

  

	 	(b)	the Warrant Agent shall not be obligated to see or to require evidence of registration (a filing or renewal thereof) of this Indenture or any instrument ancillary or supplemental
hereto; 

  

	 	(c)	the Warrant Agent shall not be bound to give notice to any person or persons of the execution hereof; 

  

	 	(d)	the Warrant Agent shall not incur any liability or responsibility whatever or be in any way responsible for the consequence of any breach on the part of the Company of any
obligation herein contained or of any acts of the directors, officers, employees or agents of the Company; 

  

	 	(e)	the Company shall indemnify and hold harmless the Warrant Agent and its employees, directors and officers from and against any and all liabilities, losses, costs, claims, actions or
demands whatsoever which may be brought against the Warrant Agent or which it may suffer or incur as a result of or arising out of the performance of its duties and obligations under this Indenture, save only in the event of the gross negligence or
fraud of the Warrant Agent. It is understood and agreed that this indemnification shall survive the termination or discharge of this Indenture or the resignation of the Warrant Agent; 

  

 - 43 - 

	 	(f)	the Warrant Agent shall not be bound to give any notice or to do or take any act, action or proceeding by virtue of the powers conferred on it hereby unless and until it shall have
been required so to do under the terms hereof nor shall the Warrant Agent be required to take notice of any default of the Company hereunder unless and until notified in writing of the default (which notice must specify the nature of the default)
and, in the absence of that notice, the Warrant Agent may for all purposes hereunder conclusively assume that no default by the Company hereunder has occurred. The giving of any notice shall in no way limit the discretion of the Warrant Agent
hereunder as to whether any action is required to be taken in respect of any default hereunder; 

  

	 	(g)	the Warrant Agent is not at any time under any duty or responsibility to a Warrantholder to determine whether any facts exist which require any adjustment contemplated by
Section 3.6 or with respect to the nature or extent of any such adjustment when made, or with respect to the method employed in making the same; 

  

	 	(h)	the Warrant Agent is not accountable with respect to the validity or value (or the kind or amount) of any Shares or other securities or property which may at any time be issued or
delivered upon the exercise of the rights attaching to any Warrant; and 

  

	 	(i)	the Warrant Agent is not responsible for any failure of the Company to make any cash payment or any failure of the Company to issue, transfer or deliver Shares or certificates for
the same upon the exercise and surrender of any Warrants for the purpose of the exercise of such rights or to comply with any of the covenants contained in this Section 7. 

  

	7.7	Replacement of Warrant Agent 

  

	 	(1)	The Warrant Agent may resign its agency and be discharged from all further duties and liabilities hereunder, except as otherwise provided in this Indenture, by giving to the Company
and the Warrantholders not less than 90 days’ notice in writing or, if a new Warrant Agent has been appointed, such shorter notice as the Company accepts as sufficient. 

  

	 	(2)	The Warrantholders by Extraordinary Resolution may at any time remove the Warrant Agent and appoint a new Warrant Agent. 

  

	 	(3)	If the Warrant Agent so resigns or is so removed or is dissolved, becomes bankrupt, goes into liquidation or otherwise becomes incapable of acting hereunder, the Company will
forthwith appoint a new Warrant Agent unless a new Warrant Agent has already been appointed by the Warrantholders. 

  

	 	(4)	Failing appointment by the Company, the retiring Warrant Agent or any Warrantholder may apply to the Court of Ontario for the appointment of a new Warrant Agent.

  

 - 44 - 

	 	(5)	Any new Warrant Agent so appointed by the Company or by the Court will be subject to removal by Extraordinary Resolution of the Warrantholders. 

  

	 	(6)	Any new Warrant Agent appointed under any provision of this section must be a corporation authorized to carry on the business of a trust company in the Qualifying Jurisdictions in
Canada. 

  

	 	(7)	On any appointment, the new Warrant Agent will be vested with the same powers, rights, duties and responsibilities as if it had been originally named herein as Warrant Agent without
any further assurance, conveyance, act or deed, but there will be immediately executed, at the expense of the Company, all such conveyances or other instruments as, in the opinion of counsel, are necessary or advisable for the purpose of assuring
the powers, rights, duties and responsibilities to the new Warrant Agent. 

  

	 	(8)	On the appointment of a new Warrant Agent, the Company will promptly give notice thereof to the Warrantholders. 

  

	 	(9)	A corporation into or with which the Warrant Agent is merged or consolidated or amalgamated, or a corporation succeeding to the trust business of the Warrant Agent, will be the
successor to the Warrant Agent hereunder without any further act on its part or on the part of any party hereto if the corporation would be eligible for appointment as a new Warrant Agent under subsection (6). 

  

	 	(10)	A Warrant Certificate certified but not delivered by a predecessor Warrant Agent may be delivered by the new or successor Warrant Agent in the name of the predecessor Warrant Agent
or successor Warrant Agent. 

  

	7.8	Conflict of Interest 

  

	 	(1)	The Warrant Agent represents to the Company that at the time of the execution and delivery hereof no material conflict of interest exists between its role as a fiduciary hereunder
and its role in any other capacity and if a material conflict of interest arises hereafter it will, within 90 days after ascertaining that it has a material conflict of interest, either eliminate the conflict of interest or resign its agency
hereunder. 

  

	 	(2)	Subject to subsection (1), the Warrant Agent in its personal or any other capacity may buy, lend upon and deal in securities of the Company and generally may contract and enter
into financial transactions with the Company or any subsidiary of the Company without being liable to account for any profit made thereby. 

  

	7.9	Acceptance of Trust 

 The Warrant Agent hereby
accepts the agency in this Indenture declared and provided for and agrees to perform them on the terms and conditions herein set forth and agrees to hold all rights, interests and benefits contained herein for and on behalf of those persons who
become holders of Warrants from time to time issued pursuant to this Indenture. 
  

 - 45 - 

	7.10	Accounts 

  

	 	(1)	The Company hereby represents to the Warrant Agent that any account to be opened by, or interest to held by, the Warrant Agent in connection with this Indenture, for or to the
credit of the Company, either (i) is not intended to be used by or on behalf of any third party; or (ii) is intended to be used by or on behalf of a third party, in which case the Company agrees to complete and execute forthwith a
declaration in the form prescribed by the Warrant Agent as to the particulars of such third party. 

  

	 	(2)	The Warrant Agent shall retain the right not to act and shall not be liable for refusing to act if, due to a lack of information or for any other reason whatsoever, the Warrant
Agent, in its sole judgment, determines that such act might cause it to be in non-compliance with any applicable anti-money laundering or anti-terrorist legislation, regulation or guideline. Further, should the Warrant Agent, in its sole judgment,
determine at any time that its acting under this Indenture has resulted in its being in non-compliance with any applicable anti-money laundering or anti-terrorist legislation, regulation or guideline, then it shall have the right to resign on 10
days written notice to the Company, provided (i) that the Warrant Agent’s written notice shall describe the circumstances of such non-compliance; and (ii) that if such circumstances are rectified to the Warrant Agent’s
satisfaction within such 10 day period, then such resignation shall not be effective. 

 ARTICLE 8 
 GENERAL 
  

	8.1	Satisfaction and Discharge of Indenture 

 This
Indenture shall expire and terminate on the earlier of: 
  

	 	(a)	the date by which there has been delivered to the Warrant Agent for exercise or destruction all Warrant Certificates theretofore certified hereunder, or 

  

	 	(b)	the 61st day following the Warrant Expiry Date, 

 and if all Shares
required to be issued in compliance with the provisions hereof have been issued and delivered hereunder, this Indenture will cease to be of further effect and the Warrant Agent, on demand of and at the cost and expense of the Company and on delivery
to the Warrant Agent of a certificate of the Company stating that all conditions precedent to the satisfaction and discharge of this Indenture have been complied with and on payment to the Warrant Agent of the fees and other remuneration payable to
the Warrant Agent, will execute proper instruments acknowledging satisfaction of and discharging this Indenture. 
  

	8.2	Sole Benefit of Parties and Warrantholders 

 Nothing
in this Indenture expressed or implied will give or be construed to give to any person other than the parties hereto and the Warrantholders, as the case may be, any legal or equitable right, remedy or claim under this Indenture, or under any
covenant or provision herein contained, all covenants and provisions being for the sole benefit of the parties hereto and the Warrantholders. 
  

 - 46 - 

	8.3	Discretion of Directors 

 Any matter provided herein
to be determined by the Directors will be determined by the Directors in their sole discretion and a determination so made, absent manifest error, will be conclusive. 
  

	8.4	Privacy 

 The parties acknowledge that federal
and/or provincial legislation that addresses the protection of individuals’ personal information (collectively, “Privacy Laws”) applies to obligations and activities under this Indenture. Despite any other provision of this
Indenture, neither party shall take or direct any action that would contravene, or cause the other party to contravene, applicable Privacy Laws. The Company shall, before transferring or causing to be transferred personal information to the Warrant
Agent, obtain and retain required consents of the relevant individuals to the collection, use and disclosure of their personal information, or shall have determined that such consents either have previously been given upon which the parties can rely
or are not required under the Privacy Laws. The Warrant Agent shall use commercially reasonable efforts to ensure that its services hereunder comply with Privacy Laws. Specifically, the Warrant Agent agrees: (a) to have a designated chief
privacy officer; (b) to maintain policies and procedures to protect personal information and to receive and respond to any privacy complaint or inquiry; (c) to use personal information solely for the purposes of providing its services
under or ancillary to this Indenture and not to use it for any other purpose except with the consent of or direction from the Company or the individual involved; (d) not to sell or otherwise improperly disclose personal information to any third
party; and (e) to employ administrative, physical and technological safeguards to reasonably secure and protect personal information against loss, theft, or unauthorized access, use or modification. 
  

 - 47 - 

	8.5	Counterparts and Formal Date 

 This Indenture may be
executed in several counterparts, each of which when so executed will be deemed to be an original, and the counterparts together will constitute one and the same instrument and notwithstanding the date of their execution will be deemed to bear the
date set out at the top of the first page of this Indenture. 
 IN WITNESS WHEREOF the parties hereto have executed this Indenture as of the
date first written above. 
  

			
	ADHEREX TECHNOLOGIES INC.
		
	By:	 	  

		 	Authorized Signatory
	
	COMPUTERSHARE TRUST COMPANY OF CANADA
		
	By:	 	  

		 	Authorized Signatory
		
	By:	 	  

		 	Authorized Signatory

  

 - 48 - 

 SCHEDULE “A” TO INDENTURE 
 Form of Warrant Certificate to be issued to Warrantholders 
 This Certificate, and the Warrants
evidenced hereby, will be void and of no value unless exercised on or before 5:00 p.m. (Toronto time) on February 21, 2010. 
 (Insert
U.S. Legend in s.2.14(2) if necessary) 
 ADHEREX TECHNOLOGIES INC. 
  

			
		  	CUSIP No.: 00686R150
		  	ISIN No.: CA00686R1507
		
	NO. ·	  	· WARRANTS        

 WARRANT TO PURCHASE COMMON SHARES 
 THIS IS TO CERTIFY THAT for value received ·, the
registered holder hereof is entitled for each whole Warrant represented hereby to purchase one fully paid and non-assessable common share (“Common Share”) in the capital of Adherex Technologies Inc. (the “Company”)
at a price per share of US$0.40, subject to adjustment as hereinafter referred to. 
 Such right to purchase may be exercised by the
registered holder hereof at any time on the date of issue hereof up to and including 5:00 p.m. (Toronto time) on February 21, 2010 (the “Warrant Expiry Time”) by surrender of this Warrant Certificate to Computershare Trust
Company of Canada (the “Warrant Agent”) at the principal transfer offices of the Warrant Agent in Toronto, Ontario, together with the subscription form attached hereto as Appendix A duly executed and completed for the number of
Common Shares which the holder hereof is entitled to purchase and the purchase price of such Common Shares as herein provided. 
 This
Warrant Certificate and such payment shall be deemed not to have been surrendered and made except upon personal delivery thereof or, if sent by post or other means of transmission, upon actual receipt thereof by the Warrant Agent at the office
specified above. 
 The purchase price of Common Shares subscribed for hereunder shall be paid by certified cheque, money order or bank draft
in lawful money of the United States payable to the order of the Company at par in the city where this Warrant Certificate is delivered. 
 Certificates for the Common Shares subscribed for will be mailed to the persons specified in the subscription form at their respective addresses specified therein or, if so specified in such subscription form, delivered to such persons at
the office where the applicable Warrant Certificate was surrendered, when the transfer registers of the Company have been open for five business days after the due surrender of such Warrant Certificate and payment as aforesaid. In the event of a
purchase of a number of Common Shares fewer than the number which can be purchased pursuant to this Warrant Certificate, the holder shall be entitled to receive without charge a new Warrant Certificate in respect of the balance of such Warrants.

 This Warrant Certificate and other Warrant Certificates are issued under and pursuant to a certain
warrant indenture (herein referred to as the “Indenture”) dated February 21, 2007 between the Company and the Warrant Agent, to which Indenture and any instruments supplemental thereto reference is hereby made for a description
of the terms and conditions upon which such Warrant Certificates are issued and are to be held all to the same effect as if the provisions of the Indenture and all instruments supplemental thereto were herein set forth, to all of which provisions
the holder of this Warrant Certificate by acceptance hereof assents. The Company will furnish to the holder of this Warrant Certificate, upon request and without charge, a copy of the Indenture. Capitalized terms not otherwise defined herein have
the meaning ascribed to them in the Indenture. 
 Subject to the Company’s right to purchase the Warrants under the Indenture and to any
restriction under applicable law or policy of any applicable regulatory body, the Warrants and Warrants Certificates and the rights thereunder shall only be transferable by the registered holder hereof in compliance with the conditions prescribed in
the Indenture and the due completion, execution and delivery of a Transfer Form (in the form attached hereto as Appendix B) in accordance with the terms of the Indenture. THE TRANSFER OF THE WARRANTS EVIDENCED HEREBY MAY BE RESTRICTED BY
APPLICABLE SECURITIES LAWS. HOLDERS ARE ADVISED TO CONSULT THEIR LEGAL COUNSEL IN THIS REGARD. 
 Neither the Warrants evidenced by this
Warrant Certificate nor the Common Shares issuable upon the exercise thereof have been or will be registered under the United States Securities Act of 1933, as amended (the “U.S. Securities Act”), and may not be offered or
sold to a person in the United States, except pursuant to an exemption from registration under the U.S. Securities Act. Compliance with the securities laws of any jurisdiction is the responsibility of the holder of this Warrant Certificate or its
transferee. Accordingly, all certificates representing the Common Shares issued to a U.S. Person or to any person in the United States upon exercise of this Warrant Certificate will have the following legend endorsed thereon: 
 “THE SECURITIES REPRESENTED HEREBY HAVE NOT BEEN REGISTERED UNDER THE UNITED STATES SECURITIES ACT OF 1933, AS AMENDED (THE “U.S. SECURITIES
ACT”), OR ANY STATE SECURITIES LAWS. THE HOLDER HEREOF, BY PURCHASING SUCH SECURITIES, AGREES FOR THE BENEFIT OF THE COMPANY THAT SUCH SECURITIES MAY BE OFFERED, SOLD OR OTHERWISE TRANSFERRED ONLY (A) TO ADHEREX TECHNOLOGIES INC. (THE
“COMPANY”), (B) OUTSIDE THE UNITED STATES IN ACCORDANCE WITH RULE 904 OF REGULATION S UNDER THE U.S. SECURITIES ACT AND IN COMPLIANCE WITH APPLICABLE LOCAL LAWS AND REGULATIONS, (C) WITHIN THE UNITED STATES IN ACCORDANCE WITH
(1) THE EXEMPTION FROM REGISTRATION UNDER THE U.S. SECURITIES ACT PROVIDED BY RULE 144A THEREUNDER, OR (2) THE EXEMPTION FROM REGISTRATION UNDER THE U.S. SECURITIES ACT PROVIDED BY RULE 144 THEREUNDER, IF APPLICABLE, OR (D) IN ANOTHER
TRANSACTION THAT DOES NOT REQUIRE REGISTRATION UNDER THE U.S. SECURITIES ACT OR ANY APPLICABLE STATE SECURITIES LAWS AFTER, IN THE CASE OF PROPOSED TRANSFERS 

  

 - 2 - 

 
PURSUANT TO CLAUSES (C) OR (D), PROVIDING A LEGAL OPINION SATISFACTORY TO THE COMPANY TO THE EFFECT THAT THE PROPOSED TRANSFER MAY BE EFFECTED WITHOUT
REGISTRATION UNDER THE U.S. SECURITIES ACT OR ANY APPLICABLE STATE SECURITIES LAWS. DELIVERY OF THIS CERTIFICATE MAY NOT CONSTITUTE “GOOD DELIVERY” IN SETTLEMENT OF TRANSACTIONS ON STOCK EXCHANGES IN CANADA. PROVIDED THAT THE COMPANY IS A
“FOREIGN ISSUER” WITHIN THE MEANING OF REGULATION S AT THE TIME OF SALE, A NEW CERTIFICATE BEARING NO LEGEND MAY BE OBTAINED FROM THE REGISTRAR AND TRANSFER AGENT OF THE COMPANY UPON DELIVERY OF THIS CERTIFICATE AND A DULY EXECUTED
DECLARATION, IN A FORM SATISFACTORY TO THE COMPANY’S REGISTRAR AND TRANSFER AGENT AND THE COMPANY, TO THE EFFECT THAT SUCH SALE OF THE SECURITIES REPRESENTED HEREBY IS BEING MADE IN COMPLIANCE WITH RULE 904 OF REGULATION S UNDER THE U.S.
SECURITIES ACT.” 
 provided that: 
  

	 	(i)	if any such securities are being sold under clause (B) of the above legend and in compliance with Canadian local laws and regulations, and provided that the Company is a
“foreign issuer” within the meaning of Regulation S at the time of sale, the legend may be removed by providing a declaration to the Company and Computershare Trust Company of Canada, as registrar and transfer agent, in the form attached
as Appendix C to this Warrant Certificate to the effect that the Shares are being sold in compliance with Rule 904 of Regulation S, together with any documentation as may be required by the Company or its transfer agent to the effect that an
exemption from the registration requirements of the U.S. Securities Act is available; and 

  

	 	(ii)	if any such securities are being sold under clause (C) or (D) of the above legend, the legend may be removed by delivery to the Company and Computershare Trust Company of
Canada of an opinion of counsel, of recognized standing reasonably satisfactory to the Company, that such legend is no longer required under applicable requirements of the U.S. Securities Act or state securities laws. 

 The holding of this Warrant Certificate shall not constitute the holder hereof a holder of Common Shares nor entitle him to any right of interest in
respect thereof. 
 The Indenture provides for adjustment in the number of Common Shares to be delivered upon the exercise of the right of
purchase hereby granted and to the Exercise Price in certain events therein set forth. 
 The Indenture contains provisions making binding
upon all holders of Warrants outstanding thereunder resolutions passed at meetings of such holders held in accordance with such provisions by the warrantholders entitled to purchase a specified majority of the Common Shares which may be purchased
pursuant to all then outstanding Warrants. 
  

 - 3 - 

 The holder of this Warrant Certificate may at any time up to and including the Warrant Expiry Time upon
the surrender hereof to the Warrant Agent at its principal transfer offices in Toronto, Ontario, and payment of any charges provided for in the Indenture, exchange this Warrant Certificate for other Warrant Certificates entitling the holder to
subscribe in the aggregate for the same number of Common Shares as is expressed in this Warrant Certificate. 
 This Warrant Certificate
shall not be valid for any purpose whatever unless and until it has been countersigned by the Warrant Agent for the time being under the Indenture. 
 Nothing contained herein or in the Indenture shall confer any right upon the holder hereof or any other person to subscribe for or purchase any Common Shares of the Company at any time subsequent to the Warrant Expiry Time. After the
Warrant Expiry Time this Warrant Certificate and all rights thereunder shall be void and of no value. 
 Time is of the essence hereof.

 IN WITNESS WHEREOF this Warrant Certificate has been executed on behalf of Adherex Technologies Inc. as of the
     day of             , 2007. 
  

							
		 		 	ADHEREX TECHNOLOGIES INC.
				
		 		 	By:	 	  

			
		 		 	Countersigned:
			
		 		 	COMPUTERSHARE TRUST COMPANY OF CANADA
				
	 Dated:
	 	  
	 	By:	 	  

  

 - 4 - 

 APPENDIX “A” TO WARRANT CERTIFICATE 
 EXERCISE FORM 
 By Mail, Registered Mail, by Hand or
by Courier 
  

	TO:	Computershare Trust Company of Canada 

 100 University
Avenue 
 9th Floor 
 Toronto, Ontario M5J 2Y1 
 The undersigned registered holder of the within Warrant Certificate, subject to that certain warrant indenture (the “Indenture”) dated
as of February 21, 2007 between Adherex Technologies Inc. (the “Company”) and Computershare Trust Company of Canada, as Warrant Agent, hereby: 
  

	 	a)	subscribes for                          common
shares (“Common Shares”) (or such number of Common Shares or other securities or property to which such subscription entitles the undersigned in lieu thereof or in addition thereto under the Indenture) of the Company at the price
per share of US$0.40 (or such adjusted price which may be in effect under the provisions of the Indenture) and in payment of the exercise price encloses a certified cheque, money order or bank draft, in any case in lawful money of the United States
payable to “Adherex Technologies Inc.”; and 

  

	 	b)	delivers herewith the above-mentioned Warrant Certificate entitling the undersigned to subscribe for the above-mentioned number of Common Shares.

 The undersigned hereby directs that the said Common Shares be registered as follows: 
  

					
	 Name(s) in full
	 	 Address(es)
 (including Postal Code)
	 	 Number(s) of
 Common Shares

 The undersigned represents that it (A) has had access to such current public information
concerning the Company as it considered necessary in connection with its investment decision, and (B) understands that the securities issuable upon exercise hereof have not and will not be registered under the United States Securities Act of
1933, as amended (the “U.S. Securities Act”). 
 The undersigned represents, warrants and certifies as follows (one of the
following must be checked): 
 A.     ̈ The undersigned holder at the time of exercise of this Warrant (i) is not in the United States as defined in Regulation S under the U.S. Securities Act (“Regulation S”); (ii) is not a U.S. Person as defined in
Regulation S; (iii) is not exercising this Warrant on behalf of, or for the account or benefit of a U.S. Person or a person in the United States; and (iv) did not receive an offer to exercise this Warrant or execute or deliver this
Subscription Form in the United States, and has, in all other respects, complied with the terms of Regulation S or any successor rule or regulation. 
  

 - 5 - 

 B.     ̈ The undersigned holder was the original purchaser of the Warrant being exercised directly from the Company and is resident in the United States or is a U.S. Person who is a resident of the jurisdiction referred to in
the address appearing below, and is an accredited investor (an “Accredited Investor”) as such term is described in Regulation D under the U.S. Securities Act and has completed the U.S. Accredited Investor Status Certificate in
the form attached to this Exercise Form as Exhibit “A”; or 
 C.     ̈ The undersigned holder is resident in the United States or is a U.S. Person and has delivered to the Company and the Company’s transfer agent an opinion of counsel (which will
not be sufficient unless it is in form and substance satisfactory to the Company) or such other evidence satisfactory to the Company to the effect that with respect to the securities to be delivered upon exercise of this Warrant, the issuance of
such securities has been registered under the U.S. Securities Act and applicable state securities laws or an exemption from the registration requirements of the U.S. Securities Act and applicable state securities laws is available. 
 The undersigned holder understands that unless box A above is checked, the certificate representing the Common Shares will bear a legend in the form required by the
Warrant Certificate restricting transfer without registration under or exemption from the U.S. Securities Act and applicable state securities laws. 
 Note: Certificates representing Common Shares will not be registered or delivered to an address in the United States unless box B or C above is checked. 
 If the undersigned has indicated that the undersigned is an Accredited Investor by marking box B above, the undersigned represents and warrants to the Company that: 
  

	1.	the undersigned has such knowledge and experience in financial and business matters as to be capable of evaluating the merits and risks of an investment in the Common Shares
subscribed for herein, and the undersigned is able to bear the economic risk of loss of his or her entire investment; 

  

	2.	the undersigned is: (i) purchasing the Common Shares for his or her own account or for the account of one or more Accredited Investors with respect to which the undersigned is
exercising sole investment discretion, and not on behalf of any other person; (ii) is purchasing the Common Shares for investment purposes only and not with a view to resale, distribution or other disposition in violation of United States
federal or state securities laws; and (iii) in the case of the purchase by the undersigned of the Common Shares as agent or trustee for any other person or persons (each a “Beneficial Owner”), the undersigned holder has due and
proper authority to act as agent or trustee for and on behalf of each such Beneficial Owner in connection with the transactions contemplated hereby; provided that: (y) if the undersigned holder, or any Beneficial Owner, is a Company or a
partnership, syndicate, trust or other form of unincorporated organization, the undersigned holder or each such Beneficial Owner was not incorporated or created solely, nor is it being used primarily to permit purchases without a prospectus or
registration statement under applicable law; and (z) each Beneficial Owner, if any, is an Accredited Investor; and 

  

 - 6 - 

	3.	the undersigned has not exercised the Warrants as a result of any form of general solicitation or general advertising, including advertisements, articles, notices or other
communications published in any newspaper, magazine or similar media or broadcast over radio, television or other form of telecommunications, or any seminar or meeting whose attendees have been invited by general solicitation or general advertising.

 If the undersigned has indicated that the undersigned is an Accredited Investor by marking box B above, the undersigned also acknowledges
and agrees that: 
  

	1.	the Company has provided to the undersigned the opportunity to ask questions and receive answers concerning the terms and conditions of the offering, and the undersigned has had
access to such information concerning the Company as he or she has considered necessary or appropriate in connection with his or her investment decision to acquire the Common Shares subscribed for herein; 

  

	2.	if the undersigned decides to offer, sell or otherwise transfer any of the Common Shares subscribed for herein, the undersigned must not, and will not, offer, sell or otherwise
transfer any of such Common Shares directly or indirectly, unless: 

  

	 	(a)	the sale is to the Company; 

  

	 	(b)	the sale is made outside the United States in a transaction meeting the requirements of Rule 904 of Regulation S under the U.S. Securities Act and in compliance with applicable
local laws and regulations; 

  

	 	(c)	the sale is made pursuant to the exemption from the registration requirements under the U.S. Securities Act provided by Rule 144, if available, thereunder and in accordance with any
applicable state securities or “blue sky” laws; or 

  

	 	(d)	the Common Shares subscribed for herein are sold in a transaction that does not require registration under the U.S. Securities Act or any applicable state laws and regulations
governing the offer and sale of securities, 

 and, in the case of (c) or (d), it has prior to such sale furnished to the
Company an opinion of counsel reasonably satisfactory to the Company confirming that such sale is exempt from the registration requirements of the U.S. Securities Act; 
  

	3.	the Common Shares subscribed for herein are “restricted securities” under applicable federal securities laws and that the U.S. Securities Act and the rules of the United
States Securities and Exchange Commission provide in substance that the undersigned may dispose of the Common Shares only pursuant to an effective registration statement under the U.S. Securities Act or an exemption therefrom;

  

	4.	the Company has no obligation to register any of the Common Shares subscribed for herein or to take action so as to permit sales pursuant to the U.S. Securities Act (including Rule
144 thereunder); 

  

	5.	 the certificates representing the Common Shares subscribed for herein (and any certificates issued in exchange or substitution for such Common Shares) will bear a

  

 - 7 - 

	 	 
legend, in the form required by the certificate representing the Warrants, stating that such securities have not been registered under the U.S. Securities
Act or the securities laws of any state of the United States and may not be offered for sale or sold unless registered under the U.S. Securities Act and the securities laws of all applicable states of the United States or an exemption from such
registration requirements is available; and 

  

	6.	it consents to the Company making a notation on its records or giving instructions to any transfer agent of the Company in order to implement the restrictions on transfer set forth
and described in this Subscription Form. 

 DATED this      day of
            , 20    . 
 Signature of Warrantholder guaranteed
by: 
  

					
			
	  
	 		 	  

		 		 	(Signature of Warrantholder)
			
	  
	 		 	
			
		 		 	  

		 		 	(Print Name of Warrantholder)*
			
		 		 	  

			
		 		 	  

			
		 		 	  

		 		 	(Address of Warrantholder in full)

 (*The name of the Warrantholder must correspond with the name upon the face of the certificate in every particular
and the Company reserves the right to require reasonable assurance that such signature is genuine and effective.) 
  

 - 8 - 

 Instructions 
  

	1.	The registered holder may exercise its right to receive Common Shares by completing this form and surrendering this form and the Warrant Certificate representing the Warrants being
exercised along with a certified cheque, money order or bank draft in lawful money of the United States payable to the order of the Company at par in an amount equal to the exercise price applicable at the time of such surrender in respect of each
Common Share which the Warrantholder desires to acquire (being not more than those which the Warrantholder is entitled to acquire pursuant to the Warrants represented by the Warrant Certificate so surrendered) to Computershare Trust Company of
Canada, at its principal offices at: 

 By Mail, Registered Mail, by Hand or by Courier 
 Computershare Trust Company of Canada 100 University Avenue 
 9th Floor 
 Toronto, Ontario M5J 2Y1 
  

	2.	The certificates will be mailed by registered mail to the address appearing in this Exercise Form. 

  

	3.	If Common Shares are issued to a person other than the registered Warrantholder, the signature of that person must be signature guaranteed by a Schedule 1 Canadian Chartered Bank or
a major trust company or by a medallion signature guarantee from a member of a recognized signature medallion guarantee program and the Transfer Form must be completed. 

  

	4.	If the Exercise Form is signed by a trustee, executor, administrator, curator, guardian, attorney, officer of a corporation or any person acting in a fiduciary or representative
capacity, the Warrant Certificate must be accompanied by evidence of authority to sign satisfactory to the Warrant Agent and the Company. 

 The Warrants will expire at 5:00 p.m. (Toronto Time) on February 21, 2010 and must be exercised before that time, otherwise the same shall expire and be void and of no value. 
  

 - 9 - 

 EXHIBIT “A” TO THE WARRANT EXERCISE FORM 
 U.S. ACCREDITED INVESTOR STATUS CERTIFICATE 
 In
connection with the exercise of certain outstanding warrants of ADHEREX TECHNOLOGIES INC. (the “Company”) by the holder, the holder hereby represents and warrants to the Company that the holder, and each beneficial owner (each a
“Beneficial Owner”), if any, on whose behalf the holder is exercising such warrants, satisfies one or more of the following categories of Accredited Investor (please write “U/H” for the undersigned holder, and
“B/O” for each beneficial owner, if any, on each line that applies): 
  

	            (1)    	Any bank as defined in Section 3(a)(2) of the U.S. Securities Act of 1933, as amended (the “1933 Act”), or any savings and loan association or other
institution as defined in Section 3(a)(5)(A) of the 1933 Act whether acting in its individual or fiduciary capacity; any broker or dealer registered pursuant to Section 15 of the U.S. Securities Exchange Act of 1934; or any insurance
company as defined in Section 2(a)(13) of the 1933 Act; any investment company registered under the U.S. Investment Company Act of 1940 or a business development company as defined in Section 2(a)(48) of that Act; any Small Business
Investment Company licensed by the U.S. Small Business Administration under Section 301(c) or (d) of the U.S. Small Business Investment Act of 1958; any 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 US$5,000,000; any employee benefit plan within the meaning of the U.S. 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 US$5,000,000, or, if a self-directed plan, with investment decisions made solely by persons that are “accredited investors” (as such term is defined in Rule 501 of Regulation D of the 1933 Act);

  

	            (2)    	Any private business development company as defined in Section 202(a)(22) of the U.S. Investment Advisers Act of 1940; 

  

	            (3)    	Any organization described in Section 501(c)(3) of the U.S. Internal Revenue Code, corporation, Massachusetts or similar business trust, or partnership, not formed for the
specific purpose of acquiring the securities offered, with total assets in excess of US$5,000,000; 

  

	            (4)    	Any trust with total assets in excess of US$5,000,000, not formed for the specific purpose of acquiring the securities offered, whose purchase is directed by a sophisticated person
(being defined as a person who has such knowledge and experience in financial and business matters that he or she is capable of evaluating the merits and risks of the prospective investment); 

  

 - 10 - 

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

  

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

  

	            (7)    	Any entity in which all of the equity owners are Accredited Investors by virtue of satisfying one or more of the definitions above in paragraphs (1) through (6).

  

 - 11 - 

 APPENDIX “B” TO THE WARRANT CERTIFICATE 
 TRANSFER FORM 
 FOR value received I/we (the
“Transferor”) hereby sell, assign, and transfer unto: 
  

			
	  
	(Name of Transferee)
	  
	(Address of Transferee)
	  
	  
	  
		  	(Social Insurance Number)
	  	  	Warrants of
	(Quantity & Class)	  	

 ADHEREX TECHNOLOGIES INC. (the “Company”) 
  

			
	represented by:	 	  

	(List Certificate Numbers)
	
	and the undersigned hereby irrevocably constitutes and appoints:
	  

	(Leave Blank)

 the attorney to transfer the said Warrants on the books of the Company with full power of substitution in the
premises. 
 The Transferor hereby certifies that (check either A or B): 
  

	            (A)    	The sale of the Warrants is being made in an offshore transaction outside of the United States in reliance on Rule 904 of Regulation S under the U.S. Securities Act of 1933, as
amended (the “1933 Act”), and certifies that: 

  

	 	(1)	the Transferor is not an “affiliate” (as defined in Rule 405 under the 1933 Act) of the Company, or a “distributor”, as defined in Regulation S, or an
affiliate of a “distributor”; 

  

	 	(2)	the offer of such securities was not made to a person in the United States and either at the time the buy order was originated, the transferee was outside the United States, or the
Transferor and any person acting on the Transferor’s behalf reasonably believe that the transferee was outside the United States; 

  

 - 12 - 

	 	(3)	neither the Transferor nor any person acting on the Transferor’s behalf engaged in any directed selling efforts in connection with the offer and sale of the Warrants;

  

	 	(4)	the sale is bona fide and not for the purpose of “washing off” the resale restrictions imposed because the Warrants are “restricted securities” (as such term is
defined in Rule 144(a)(3) under the 1933 Act); 

  

	 	(5)	the Transferor does not intend to replace the securities sold in reliance on Rule 904 of the 1933 Act with fungible unrestricted securities; and 

  

	 	(6)	the contemplated sale is not a transaction, or part of a series of transactions which, although in technical compliance with Regulation S, is part of a plan or a scheme to
evade the registration provisions of the 1933 Act. 

  

	            (B)    	This transfer of Warrants is being completed pursuant to an exemption from the registration requirements of the 1933 Act, in which case the Transferor has delivered or caused to be
delivered by the Transferee a written opinion of U.S. legal counsel acceptable to the Company to the effect that the transfer of the Warrants is exempt from the registration requirements of the 1933 Act. 

 DATED this      day of             , 20    .

 Signature Guaranteed By: 
  

	
	  

	 (Signature of Warrantholder)

	  

	 (Name of Warrantholder, Please Print)

	  

	 (Capacity of Authorized Representative)

 Instructions: 
  

	1.	The signature on this assignment must correspond with the name as written upon the face of the certificate, in every particular, without alteration or enlargement, or change
whatever. 

  

	2.	The signature must be guaranteed by a Canadian schedule 1 chartered bank, major Trust Company or by a member firm of an acceptable Medallion Signature Guarantee Program (STAMP,
SEMP, MSP). The stamp must bear the words “Signature Medallion Guaranteed”. 

  

 - 13 - 

	3.	In the United States of America, signature guarantees must be done by members of a Medallion Signature Guarantee Program only. Signature guarantees are not accepted from Treasury
Branches, Credit Unions or Caisses Populaires unless they are members of an acceptable Medallion Program. 

 TRANSFEREE ACKNOWLEDGMENT

 In connection with this transfer (check one), the undersigned transferee (the “Transferee”) certifies that (check either A or B):

  

	            (A)    	The Transferee hereby certifies that (i) it was not offered the Warrants while in the United States and did not execute this certificate while within the United States; and
(ii) it is not a U.S. Person or a person within the United States and it is not acquiring any of the Warrants on behalf of a U.S. Person or any person within the United States. 

  

	            (B)    	The Transferor or Transferee is delivering a written opinion of U.S. Counsel acceptable to the Company to the effect that this transfer of Warrants has been registered under the
1933 Act or is exempt from registration thereunder. 

  

					
	  
	 		 	
	(Signature of Transferee)	 		 	
	  
	 		 	  

	Date	 		 	Print full name

 The Warrants and the securities issuable upon exercise of the Warrants shall only be transferable in accordance
with applicable laws. The Warrants may only be exercised in the manner required by the Warrant Certificate and the Exercise Form attached thereto. Any securities acquired pursuant to this exercise of Warrants shall be subject to applicable hold
periods and any certificate representing such securities will bear restrictive legends, each in accordance with the Warrant Indenture dated February 21, 2007, between the Company and Computershare Trust Company of Canada that governs the
Warrants and the Warrant Certificate. 
  

 - 14 - 

 APPENDIX “C” TO THE WARRANT CERTIFICATE 
 FORM OF DECLARATION FOR REMOVAL OF LEGEND 
  

	TO:	COMPUTERSHARE TRUST COMPANY OF CANADA 

 as registrar and
transfer agent for Common Shares of 
 ADHEREX TECHNOLOGIES INC. 
 The undersigned (a) acknowledges that the sale of the securities of ADHEREX TECHNOLOGIES INC. (the “Company”) to which this declaration relates is being made in reliance on Rule 904 of Regulation
S under the United States Securities Act of 1933, as amended (the “U.S. Securities Act”) and (b) certifies that (1) the undersigned is not an affiliate (as that term is defined in Rule 405 under the U.S. Securities Act) of
the Company or a “distributor” (as that term is defined in Regulation S under the U.S. Securities Act), (2) the offer of such securities was not made to a person in the United States and either (A) at the time the buy order was
originated, the buyer was outside the United States, or the undersigned and any person acting on its behalf reasonably believed that the buyer was outside the United States, or (B) the transaction was executed in, on or through the facilities
of the applicable Canadian stock exchanges designated in Regulation S or any other Designated Offshore Securities Market as defined in Regulation S under the U.S. Securities Act and neither the undersigned nor any person acting on its behalf knows
that the transaction has been prearranged with a buyer in the United States, (3) neither the undersigned nor any affiliate of the undersigned nor any person acting on any of their behalf has engaged or will engage in any directed selling
efforts in the United States in connection with the offer and sale of such securities, (4) the sale is bona fide and not for the purpose of “washing off” the resale restrictions imposed because the securities are “restricted
securities” (as such term is defined in Rule 144(a)(3) under the U.S. Securities Act) and (5) the contemplated sale is not a transaction, or part of a series of transactions which, although in technical compliance with Regulation S under
the U.S. Securities Act, is part of a plan or scheme to evade the registration provisions of the U.S. Securities Act. Terms used herein have the meanings given to them by Regulation S under the U.S. Securities Act. 
  

									
	Dated:	 	  
	 		 		 	  

		 		 		 		 	Name of Seller
					
		 		 		 	By:	 	  

		 		 		 	Name:	 	
		 		 		 	Title:	 	

 Affirmation by Seller’s Broker-Dealer 
 We have read the foregoing representations of our customer,
                                        
     (the “Seller”), dated
                                        
    , with regard to our sale, for such Seller’s account, of the
                                        
     Shares, represented by certificate number
                                        
     (the “Shares”), of the Company described therein, and on behalf of ourselves we certify and affirm that (A) we have no knowledge that the transaction had been prearranged with a buyer in the United
States, (B) the transaction was executed on or through the facilities of the Toronto 

 
Stock Exchange and (C) neither we, nor any person acting on our behalf, engaged in any directed selling efforts in connection with the offer and sale of
such Securities. Terms used herein have the meanings given to them by Regulation S. 
  

			
	  

	Name of Firm
		
	By:	 	  

		 	Authorized Officer

  

 - 2 - 

 SCHEDULE “B” TO INDENTURE 
 Form of Letter to be Delivered by 
 Original U.S. Purchaser upon  
 Exercise of Warrants 
 Adherex Technologies Inc.

 - and to - 
 Computershare Trust Company of Canada, as
Warrant Agent 
 Dear Sirs: 
 We are delivering this letter in
connection with the purchase of common shares (the “Shares”) of Adherex Technologies Inc. (the “Company”) upon the exercise of warrants of the Company (the “Warrants”), issued under the warrant
indenture dated as of February 21, 2007 between the Company and Computershare Trust Company of Canada. 
 We hereby confirm that: 
  

	(a)	we are an “accredited investor” within the meaning of Rule 501(a) of Regulation D under the United States Securities Act of 1933 (the “U.S. Securities
Act”); 

  

	(b)	we are purchasing the Shares for our own account; 

  

	(c)	we have such knowledge and experience in financial and business matters that we are capable of evaluating the merits and risks of purchasing the Shares; 

  

	(d)	we are not acquiring the Shares with a view to distribution thereof or with any present intention of offering or selling any of the Shares, except (A) to the Company,
(B) outside the United States in accordance with Rule 904 under the U.S. Securities Act or (C) inside the United States (1) in accordance with Rule 144A under the U.S. Securities Act and in compliance with applicable state securities
laws or (2) in accordance with Rule 144 under the U.S. Securities Act, if applicable, and in compliance with applicable state securities laws; 

  

	(e)	we acknowledge that we have had access to such financial and other information as we deem necessary in connection with our decision to purchase the Shares; and

  

	(f)	we acknowledge that we are not purchasing the Shares as a result of any general solicitation or general advertising, including advertisements, articles, notices or other
communications published in any newspaper, magazine or similar media or broadcast over radio, television, or any seminar or meeting whose attendees have been invited by general solicitation or general advertising. 

 We understand that the Shares are being offered in a transaction not involving any public offering within the United States within the meaning of U.S. Securities Act and
that the Shares have not been and will not be registered under the U.S. Securities Act. We further understand that any Shares acquired by us will be in the form of definitive physical certificates and that such certificates will bear a legend
reflecting the substance of paragraph (d) above. 

 We acknowledge that you will rely upon our confirmations, acknowledgements and agreements set forth herein, and we agree
to notify you promptly in writing if any of our representations or warranties herein ceases to be accurate or complete. 
  

			
		 	  

		 	    (Name of Purchaser)
		
	By:	 	  

	Name:	 	
	Title:	 	

  

 - 2 -

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