Exhibit
4.15


 


ALLOS
THERAPEUTICS, INC.


 


 


and


 


 


                    ,
As Warrant Agent


 


 


FORM
OF DEBT SECURITIES

WARRANT AGREEMENT


 


 


Dated
As Of
                      


 

















 


TABLE OF CONTENTS


 


	
  ARTICLE 1

  	
  ISSUANCE OF
  WARRANTS AND EXECUTION AND  DELIVERY
  OF WARRANT CERTIFICATES

  	
   

  
	
   

  	
   

  	
   

  
	
  1.1

  	
   

  	
  Issuance of Warrants

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
  1.2

  	
   

  	
  Execution
  and Delivery of Warrant Certificates

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
  1.3

  	
   

  	
  Issuance of Warrant
  Certificates

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
  ARTICLE
  2

  	
  WARRANT
  PRICE, DURATION AND EXERCISE OF WARRANTS

  	
   

  
	
   

  	
   

  	
   

  
	
  2.1

  	
   

  	
  Warrant
  Price

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
  2.2

  	
   

  	
  Duration of Warrants

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
  2.3

  	
   

  	
  Exercise of Warrants

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
  ARTICLE
  3

  	
  OTHER
  PROVISIONS RELATING TO RIGHTS OF 
  HOLDERS OF WARRANT CERTIFICATES

  	
   

  
	
   

  	
   

  	
   

  
	
  3.1

  	
   

  	
  No
  Rights as Holders of Warrant Debt Securities Conferred by Warrants or Warrant
  Certificates

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
  3.2

  	
   

  	
  Lost,
  Stolen, Mutilated or Destroyed Warrant Certificates

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
  3.3 

  	
   

  	
  Holder
  oWarrant Certificate May Enforce Rights 

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
  3.4

  	
   

  	
  Merger, Sale,
  Conveyance or Lease

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
  3.5

  	
   

  	
  Notice to Warrantholders

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
  ARTICLE
  4

  	
  EXCHANGE
  AND TRANSFER OF WARRANT CERTIFICATES

  	
   

  
	
   

  	
   

  	
   

  
	
  4.1

  	
   

  	
  Exchange
  and Transfer of Warrant Certificates

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
  4.2

  	
   

  	
  Treatment
  of Holders of Warrant Certificates

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
  4.3

  	
   

  	
  Cancellation
  of Warrant Certificates

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
  ARTICLE 5

  	
  CONCERNING THE
  WARRANT AGENT

  	
   

  
	
   

  	
   

  	
   

  
	
  5.1

  	
   

  	
  Warrant
  Agent

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
  5.2

  	
   

  	
  Conditions
  of Warrant Agent’s Obligations

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
  5.3

  	
   

  	
  Resignation,
  Removal and Appointment of Successors

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
  ARTICLE 6

  	
  MISCELLANEOUS

  	
   

  
	
   

  	
   

  	
   

  
	
  6.1

  	
   

  	
  Amendment

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
  6.2

  	
   

  	
  Notices
  and Demands to the Company and Warrant Agent

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
  6.3

  	
   

  	
  Addresses

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
  6.4

  	
   

  	
  Governing
  Law

  	
   

  
					



 


i

















 


	
  6.5

  	
   

  	
  Delivery of Prospectus

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
  6.6

  	
   

  	
  Obtaining of
  Governmental Approvals

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
  6.7

  	
   

  	
  Persons
  Having Rights Under Warrant Agreement

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
  6.8

  	
   

  	
  Headings

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
  6.9

  	
   

  	
  Counterparts

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
  6.10

  	
   

  	
  Inspection of Agreement

  	
   

  



 


ii

















 


ALLOS THERAPEUTICS, INC.


Form of Debt Securities Warrant Agreement


 


Debt Securities Warrant Agreement, dated as
of _____________ between Allos Therapeutics, Inc.,
a Delaware corporation (the “Company”) and               ,
a [corporation] [national banking association] organized and existing under the
laws of
                 
and having a corporate trust office in                 ,
as warrant agent (the “Warrant
Agent”).


 


Whereas, the Company has entered into an indenture
dated as of
[                    
(the “Senior Indenture”),
with
                     ,
as trustee (such trustee, and any successors to such trustee, herein called the
“Senior Trustee”),
providing for the issuance from time to time of its unsubordinated debt
securities, to be issued in one or more series as provided in the Senior
Indenture (the “Debt
Securities”);]
[               
(the “Subordinated
Indenture”), with
                     ,
as trustee (such trustee, and any successors to such trustee, herein called the
“Subordinated Trustee”),
providing for the issuance from time to time of its subordinated debt
securities, to be issued in one or more series as provided in the Subordinated
Indenture (the “Debt
Securities”);]


 


Whereas, the Company proposes to sell [If Warrants
are sold with other securities – title of such other Securities being offered
(the “Other Securities”)
with] warrant certificates  evidencing
one or more warrants (the “Warrants”
or, individually, a “Warrant”)
representing the right to purchase [title of Debt Securities purchasable
through exercise of Warrants] (the “Warrant Debt Securities”), such warrant
certificates and other warrant certificates issued pursuant to this Agreement
being herein called the “Warrant
Certificates”; and


 


Whereas, the Company
desires the Warrant Agent to act on behalf of the Company, and the Warrant
Agent is willing so to act, in connection with the issuance, registration,
transfer, exchange, exercise and replacement of the Warrant Certificates, and
in this Agreement wishes to set forth, among other things, the form and
provisions of the Warrant Certificates and the terms and conditions on which
they may be issued, registered, transferred, exchanged, exercised and replaced;


 


Now, Therefore, in consideration of the
premises and of the mutual agreements herein contained, the parties hereto
agree as follows:


 


ARTICLE 1


 


ISSUANCE
OF WARRANTS AND EXECUTION AND 

DELIVERY OF WARRANT CERTIFICATES


 


1.1          Issuance
of Warrants.  [If
Warrants alone–Upon issuance, each Warrant Certificate shall evidence one or
more Warrants.]  [If Other Securities
and Warrants–Warrant Certificates shall be [initially] issued in connection
with the issuance of the Other Securities [but shall be separately transferable
on and after
                            
(the “Detachable Date”)]
[and shall not be separately transferable] and each Warrant Certificate shall


 


1

















 


evidence one or more
Warrants.]  Each Warrant evidenced
thereby shall represent the right, subject to the provisions contained herein
and therein, to purchase one Warrant Debt Security.  [If Other Securities and Warrants - Warrant Certificates shall be
initially issued in units with the Other Securities and each Warrant
Certificate included in such a unit shall evidence
                      
Warrants for each
[$                    
principal amount]
[             
shares] of Other Securities included in such unit.].


 


1.2          Execution and Delivery of Warrant
Certificates. 
Each Warrant Certificate, whenever issued, shall be in registered form
substantially in the form set forth in Exhibit A hereto, shall be dated
the date of its countersignature by the Warrant Agent and may have such
letters, numbers, or other marks of identification or designation and such
legends or endorsements printed, lithographed or engraved thereon as the
officers of the Company executing the same may approve (execution thereof to be
conclusive evidence of such approval) and as are not inconsistent with the
provisions of this Agreement, or as may be required to comply with any law or
with any rule or regulation made pursuant thereto or with any rule or regulation
of any securities exchange on which the Warrants may be listed, or to conform
to usage.  The Warrant Certificates
shall be signed on behalf of the Company by any of its present or future chief
executive officers, presidents, senior vice presidents, vice presidents, chief
financial officers, chief legal officers, treasurers, assistant treasurers,
controllers, assistant controllers, secretaries or assistant secretaries under
its corporate seal reproduced thereon. 
Such signatures may be manual or facsimile signatures of such authorized
officers and may be imprinted or otherwise reproduced on the Warrant
Certificates.  The seal of the Company
may be in the form of a facsimile thereof and may be impressed, affixed, imprinted
or otherwise reproduced on the Warrant Certificates.


 


No Warrant Certificate shall be valid for any purpose, and no Warrant
evidenced thereby shall be exercisable, until such Warrant Certificate has been
countersigned by the manual signature of the Warrant Agent.  Such signature by the Warrant Agent upon any
Warrant Certificate executed by the Company shall be conclusive evidence that
the Warrant Certificate so countersigned has been duly issued hereunder.


 


In case any officer of the Company who shall have signed any of the
Warrant Certificates either manually or by facsimile signature shall cease to
be such officer before the Warrant Certificates so signed shall have been
countersigned and delivered by the Warrant Agent, such Warrant Certificates may
be countersigned and delivered notwithstanding that the person who signed
Warrant Certificates ceased to be such officer of the Company; and any Warrant
Certificate may be signed on behalf of the Company by such persons as, at the
actual date of the execution of such Warrant Certificate, shall be the proper
officers of the Company, although at the date of the execution of this
Agreement any such person was not such officer.


 


The term “holder” or “holder of a Warrant Certificate” as used herein
shall mean any person in whose name at the time any Warrant Certificate shall
be registered upon the books to be maintained by the Warrant Agent for that
purpose [If Other Securities and Warrants are not immediately detachable - or
upon the registration of the Other Securities prior to the Detachable Date.  Prior to the Detachable Date, the Company
will, or will cause the registrar of the Other Securities to, make available at
all times to the Warrant Agent such information as to holders of the Other
Securities as may be necessary to keep the Warrant Agent’s records up to date].


 


2

















 


1.3          Issuance of Warrant Certificates.  Warrant Certificates evidencing the right to
purchase Warrant Debt Securities may be executed by the Company and delivered
to the Warrant Agent upon the execution of this Warrant Agreement or from time
to time thereafter.  The Warrant Agent
shall, upon receipt of Warrant Certificates duly executed on behalf of the
Company, countersign such Warrant Certificates and shall deliver such Warrant
Certificates to or upon the order of the Company.


 


ARTICLE 2


 


WARRANT
PRICE, DURATION AND

EXERCISE OF WARRANTS


 


2.1          Warrant
Price.  During the
period specified in Section 2.2, each Warrant shall, subject to the terms
of this Warrant Agreement and the applicable Warrant Certificate, entitle the
holder thereof, to purchase the principal amount of Warrant Debt Securities
specified in the applicable Warrant Certificate at an exercise price of
               %
of the principal amount thereof [plus accrued amortization, if any, of the
original issue discount of the Warrant Debt Securities] [plus accrued interest,
if any, from the most recent date from which interest shall have been paid on
the Warrant Debt Securities or, if no interest shall have been paid on the Warrant
Debt Securities, from the date of their initial issuance.]  [The original issue discount
($             
for each $1,000 principal amount of Warrant Debt Securities) will be amortized
at a
                     %
annual rate, computed on a[n] [semi-] annual basis [using a 360-day year
consisting of twelve 30-day months].] Such purchase price for the Warrant Debt
Securities is referred to in this Agreement as the “Warrant Price.”


 


2.2          Duration of Warrants.  Each
Warrant may be exercised in whole or in part at any time, as specified herein,
on or after [the date thereof]
[          ] and at or before
[            ]
p.m., [City] time, on                    
or such later date as the Company may designate by notice to the Warrant Agent
and the holders of Warrant Certificates mailed to their addresses as set forth
in the record books of the Warrant Agent (the “Expiration Date”).  Each Warrant not exercised at or before
[                ]
p.m., [City] time, on the Expiration Date shall become void, and all rights of
the holder of the Warrant Certificate evidencing such Warrant under this
Agreement shall cease.


 


2.3          Exercise of Warrants.


 


(a)           During the period specified in
Section 2.2, the Warrants may be exercised to purchase a whole number of
Warrant Debt Securities in registered form by providing certain information as
set forth on the reverse side of the Warrant Certificate and by paying in full,
in lawful money of the United States of America, [in cash or by certified check
or official bank check in New York Clearing House funds] [by bank wire transfer
in immediately available funds] the Warrant Price for each Warrant Debt
Security with respect to which a Warrant is being exercised to the Warrant
Agent at its corporate trust office, provided that such exercise is subject to
receipt within five business days of such payment by the Warrant Agent of the
Warrant Certificate with the form of election to purchase Warrant Debt
Securities set forth on the reverse side of the Warrant Certificate properly
completed and duly executed.  The date
on which payment in full of the Warrant Price is received by the Warrant Agent
shall, subject to


 


3

















 


receipt of the Warrant
Certificate as aforesaid, be deemed to be the date on which the Warrant is
exercised; provided, however, that if, at the date of receipt of such Warrant Certificates
and payment in full of the Warrant Price, the transfer books for the Warrant
Debt Securities purchasable upon the exercise of such Warrants shall be closed,
no such receipt of such Warrant Certificates and no such payment of such
Warrant Price shall be effective to constitute the person so designated to be
named as the holder of record of such Warrant Debt Securities on such date, but
shall be effective to constitute such person as the holder of record of such
Warrant Debt Securities for all purposes at the opening of business on the next
succeeding day on which the transfer books for the Warrant Debt Securities
purchasable upon the exercise of such Warrants shall be opened, and the
certificates for the Warrant Debt Securities in respect of which such Warrants
are then exercised shall be issuable as of the date on such next succeeding day
on which the transfer books shall next be opened, and until such date the
Company shall be under no duty to deliver any certificate for such Warrant Debt
Securities.  The Warrant Agent shall
deposit all funds received by it in payment of the Warrant Price in an account
of the Company maintained with it and shall advise the Company by telephone at
the end of each day on which a payment for the exercise of Warrants is received
of the amount so deposited to its account. 
The Warrant Agent shall promptly confirm such telephone advice to the
Company in writing.


 


(b)           The Warrant Agent shall, from time to
time, as promptly as practicable, advise the Company of (i) the number of
Warrant Debt Securities with respect to which Warrants were exercised, (ii) the
instructions of each holder of the Warrant Certificates evidencing such Warrants
with respect to delivery of the Warrant Debt Securities to which such holder is
entitled upon such exercise, (iii) delivery of Warrant Certificates evidencing
the balance, if any, of the Warrants for the remaining Warrant Debt Securities
after such exercise, and (iv) such other information as the Company or the
[Senior] [Subordinated] Trustee shall reasonably require.


 


(c)           As soon as practicable after the
exercise of any Warrant, the Company shall issue, pursuant to the Indenture, in
authorized denominations, to or upon the order of the holder of the Warrant
Certificate evidencing such Warrant, the Warrant Debt Securities to which such
holder is entitled, in fully registered form, registered in such name or names
as may be directed by such holder.  If
fewer than all of the Warrants evidenced by such Warrant Certificate were
exercised, the Company shall execute, and an authorized officer of the Warrant
Agent shall manually countersign and deliver, a new Warrant Certificate
evidencing Warrants for the number of Warrant Debt Securities remaining
unexercised.


 


(d)           The Company shall not be required to
pay any stamp or other tax or other governmental charge required to be paid in
connection with any transfer involved in the issue of the Warrant Debt
Securities, and in the event that any such transfer is involved, the Company
shall not be required to issue or deliver any Warrant Debt Securities until
such tax or other charge shall have been paid or it has been established to the
Company’s satisfaction that no such tax or other charge is due.


 


4

















 


ARTICLE 3


 


OTHER
PROVISIONS RELATING TO RIGHTS OF 

HOLDERS OF WARRANT CERTIFICATES


 


3.1          No Rights as Holders of Warrant Debt
Securities Conferred by Warrants or Warrant Certificates.  No Warrant Certificate or Warrant evidenced
thereby shall entitle the holder thereof to any of the rights of a holder of
Warrant Debt Securities, including, without limitation, the right to receive
the payment of principal of (or premium, if any) or interest, if any, on the
Warrant Debt Securities or to enforce any of the covenants in the Indenture.


 


3.2          Lost, Stolen, Mutilated or Destroyed
Warrant Certificates. 
Upon receipt by the Warrant Agent of evidence reasonably satisfactory to
it and the Company of the ownership of and the loss, theft, destruction or
mutilation of any Warrant Certificate and/or indemnity reasonably satisfactory
to the Warrant Agent and the Company and, in the case of mutilation, upon
surrender of the mutilated Warrant Certificate to the Warrant Agent for
cancellation, then, in the absence of notice to the Company or the Warrant
Agent that such Warrant Certificate has been acquired by a bona fide purchaser,
the Company shall execute, and an authorized officer of the Warrant Agent shall
manually countersign and deliver, in exchange for or in lieu of the lost,
stolen, destroyed or mutilated Warrant Certificate, a new Warrant Certificate
of the same tenor and evidencing Warrants for a like principal amount of
Warrant Debt Securities.  Upon the
issuance of any new Warrant Certificate under this Section 3.2, the
Company may require the payment of a sum sufficient to cover any tax or other
governmental charge that may be imposed in relation thereto and any other
expenses (including the fees and expenses of the Warrant Agent) in connection
therewith.  Every substitute Warrant
Certificate executed and delivered pursuant to this Section 3.2 in lieu of
any lost, stolen or destroyed Warrant Certificate shall represent an additional
contractual obligation of the Company, whether or not the lost, stolen or
destroyed Warrant Certificate shall be at any time enforceable by anyone, and
shall be entitled to the benefits of this Agreement equally and proportionately
with any and all other Warrant Certificates duly executed and delivered
hereunder.  The provisions of this
Section 3.2 are exclusive and shall preclude (to the extent lawful) all
other rights and remedies with respect to the replacement of mutilated, lost,
stolen or destroyed Warrant Certificates.


 


3.3          Holder of Warrant Certificate May
Enforce Rights.  Notwithstanding any of the provisions of
this Agreement, any holder of any Warrant Certificate, without the consent of
the Warrant Agent, the [Senior] [Subordinated] Trustee, the holder of any
Warrant Debt Securities or the holder of any other Warrant Certificate, may, in
such holder’s own behalf and for such holder’s own benefit, enforce, and may
institute and maintain any suit, action or proceeding against the Company
suitable to enforce, or otherwise in respect of, such holder’s right to
exercise the Warrants evidenced by such holder’s Warrant Certificate in the
manner provided in such holder’s Warrant Certificates and in this Agreement.


 


3.4          Merger,
Sale, Conveyance or Lease.  In case of (a) any share exchange,
merger or similar transaction of the Company with or into another person or
entity (other than a share exchange, merger or similar transaction in which the
Company is the acquiring or surviving corporation) or (b) the sale, exchange,
lease, transfer or other disposition of all or substantially all of the
properties and assets of the Company as an entirety (in any such case, a


 


5

















 


“Reorganization Event”), then, as a
condition of such Reorganization Event, lawful provisions shall be made, and
duly executed documents evidencing the same from the Company’s successor shall
be delivered to the holders of the Warrants, so that such successor shall
succeed to and be substituted for the Company, and assume all the Company’s
obligations under, this Agreement and the Warrants.  The Company shall thereupon be relieved of any further obligation
hereunder or under the Warrants, and the Company as the predecessor corporation
may thereupon or at any time thereafter be dissolved, wound up or
liquidated.  Such successor or assuming
entity thereupon may cause to be signed, and may issue either in its own name
or in the name of the Company, any or all of the Warrants issuable hereunder
which heretofore shall not have been signed by the Company, and may execute and
deliver securities in its own name, in fulfillment of its obligations to
deliver Warrant Debt Securities upon exercise of the Warrants.  All the Warrants so issued shall in all
respects have the same legal rank and benefit under this Agreement as the
Warrants theretofore or thereafter issued in accordance with the terms of this
Agreement as though all of such Warrants had been issued at the date of the
execution hereof.  In any case of any
such Reorganization Event, such changes in phraseology and form (but not in
substance) may be made in the Warrants thereafter to be issued as may be
appropriate.


 


The Warrant Agent may
receive a written opinion of legal counsel as conclusive evidence that any such
Reorganization Event complies with the provisions of this Section 3.4.


 


3.5          Notice
to Warrantholders.  In case the Company shall (a) effect any
Reorganization Event or (b) make any distribution on or in respect of the
[title of Warrant Debt Securities] in connection with the dissolution,
liquidation or winding up of the Company, then the Company shall mail to each
holder of Warrants at such holder’s address as it shall appear on the books of
the Warrant Agent, at least ten days prior to the applicable date hereinafter
specified, a notice stating the date on which such Reorganization Event,
dissolution, liquidation or winding up is expected to become effective, and the
date as of which it is expected that holders of [title of Warrant Debt
Securities] of record shall be entitled to exchange their shares of [title of
Warrant Debt Securities] for securities or other property deliverable upon such
Reorganization Event, dissolution, liquidation or winding up.  No failure to mail such notice nor any
defect therein or in the mailing thereof shall affect any such transaction.


 


ARTICLE 4


 


EXCHANGE
AND TRANSFER OF WARRANT CERTIFICATES


 


4.1          Exchange
and Transfer of Warrant Certificates.  [If Other Securities with Warrants which are
immediately detachable - Upon] [If Other Securities with Warrants which are not
immediately detachable - Prior to the Detachable Date, a Warrant Certificate
may be exchanged or transferred only together with the Other Security to which
the Warrant Certificate was initially attached, and only for the purpose of
effecting or in conjunction with an exchange or transfer of such Other
Security.  Prior to any Detachable Date,
each transfer of the Other Security shall operate also to transfer the related
Warrant Certificates.  After the
Detachable Date, upon] surrender at the corporate trust office of the Warrant
Agent, Warrant Certificates evidencing Warrants may be exchanged for Warrant
Certificates in other denominations evidencing such Warrants or the transfer
thereof may be registered in whole or in part; provided that such other
Warrant Certificates evidence Warrants for the same aggregate principal amount


 


6

















 


of Warrant Debt
Securities as the Warrant Certificates so surrendered.  The Warrant Agent shall keep, at its
corporate trust office, books in which, subject to such reasonable regulations
as it may prescribe, it shall register Warrant Certificates and exchanges and
transfers of outstanding Warrant Certificates, upon surrender of the Warrant
Certificates to the Warrant Agent at its corporate trust office for exchange or
registration of transfer, properly endorsed or accompanied by appropriate
instruments of registration of transfer and written instructions for transfer,
all in form satisfactory to the Company and the Warrant Agent.  No service charge shall be made for any
exchange or registration of transfer of Warrant Certificates, but the Company
may require payment of a sum sufficient to cover any stamp or other tax or
other governmental charge that may be imposed in connection with any such
exchange or registration of transfer. 
Whenever any Warrant Certificates are so surrendered for exchange or
registration of transfer, an authorized officer of the Warrant Agent shall
manually countersign and deliver to the person or persons entitled thereto a
Warrant Certificate or Warrant Certificates duly authorized and executed by the
Company, as so requested.  The Warrant
Agent shall not be required to effect any exchange or registration of transfer
which will result in the issuance of a Warrant Certificate evidencing a Warrant
for a fraction of a Warrant Debt Security or a number of Warrants for a whole
number of Warrant Debt Securities and a fraction of a Warrant Debt Security.  All Warrant Certificates issued upon any
exchange or registration of transfer of Warrant Certificates shall be the valid
obligations of the Company, evidencing the same obligations and entitled to the
same benefits under this Agreement as the Warrant Certificate surrendered for
such exchange or registration of transfer.


 


4.2          Treatment
of Holders of Warrant Certificates.  [If Other Securities and Warrants are not
immediately detachable–Prior to the Detachable Date, the Company, the Warrant
Agent and all other persons may treat the owner of the Other Security as the
owner of the Warrant Certificates initially attached thereto for any purpose
and as the person entitled to exercise the rights represented by the Warrants
evidenced by such Warrant Certificates, any notice to the contrary notwithstanding.  After the Detachable Date and prior to due
presentment of a Warrant Certificate for registration of transfer, the] [The]
Company, the Warrant Agent and all other persons may treat the registered holder
of a Warrant Certificate as the absolute owner thereof for any purpose and as
the person entitled to exercise the rights represented by the Warrants
evidenced thereby, any notice to the contrary notwithstanding.


 


4.3          Cancellation
of Warrant Certificates. 
Any Warrant Certificate surrendered for exchange, registration of
transfer or exercise of the Warrants evidenced thereby shall, if surrendered to
the Company, be delivered to the Warrant Agent and all Warrant Certificates
surrendered or so delivered to the Warrant Agent shall be promptly canceled by
the Warrant Agent and shall not be reissued and, except as expressly permitted
by this Agreement, no Warrant Certificate shall be issued hereunder in exchange
therefor or in lieu thereof.  The
Warrant Agent shall deliver to the Company from time to time or otherwise
dispose of canceled Warrant Certificates in a manner satisfactory to the
Company.


 


7

















 


ARTICLE 5


 


CONCERNING
THE WARRANT AGENT


 


5.1          Warrant
Agent.  The
Company hereby appoints
                      
as Warrant Agent of the Company in respect of the Warrants and the Warrant
Certificates upon the terms and subject to the conditions herein set forth, and
                    
hereby accepts such appointment.  The
Warrant Agent shall have the powers and authority granted to and conferred upon
it in the Warrant Certificates and hereby and such further power and authority
to act on behalf of the Company as the Company may hereafter grant to or confer
upon it.  All of the terms and
provisions with respect to such power and authority contained in the Warrant
Certificates are subject to and governed by the terms and provisions hereof.


 


5.2          Conditions
of Warrant Agent’s Obligations.  The Warrant Agent accepts its obligations herein set forth upon
the terms and conditions hereof, including the following to all of which the
Company agrees and to all of which the rights hereunder of the holders from
time to time of the Warrant Certificates shall be subject:


 


(a)           Compensation and Indemnification.  The Company agrees promptly to pay the
Warrant Agent the compensation to be agreed upon with the Company for all
services rendered by the Warrant Agent and to reimburse the Warrant Agent for
reasonable out-of-pocket expenses (including reasonable counsel fees) incurred
without negligence, bad faith or willful misconduct by the Warrant Agent in
connection with the services rendered hereunder by the Warrant Agent.  The Company also agrees to indemnify the
Warrant Agent for, and to hold it harmless against, any loss, liability or
expense incurred without negligence, bad faith or willful misconduct on the
part of the Warrant Agent, arising out of or in connection with its acting as
Warrant Agent hereunder, including the reasonable costs and expenses of
defending against any claim of such liability.


 


(b)           Agent for the Company.  In
acting under this Warrant Agreement and in connection with the Warrant
Certificates, the Warrant Agent is acting solely as agent of the Company and
does not assume any obligations or relationship of agency or trust for or with
any of the holders of Warrant Certificates or beneficial owners of Warrants.


 


(c)           Counsel.  The Warrant Agent may consult with counsel
satisfactory to it, which may include counsel for the Company, and the written
advice of such counsel shall be full and complete authorization and protection
in respect of any action taken, suffered or omitted by it hereunder in good
faith and in accordance with the advice of such counsel.


 


(d)           Documents.  The Warrant Agent shall be protected and
shall incur no liability for or in respect of any action taken or omitted by it
in reliance upon any Warrant Certificate, notice, direction, consent,
certificate, affidavit, statement or other paper or document reasonably
believed by it to be genuine and to have been presented or signed by the proper
parties.


 


(e)           Certain Transactions.  The Warrant Agent, and its officers,
directors and employees, may become the owner of, or acquire any interest in,
Warrants, with the same rights


 


8

















 


that it or they would
have if it were not the Warrant Agent hereunder, and, to the extent permitted
by applicable law, it or they may engage or be interested in any financial or
other transaction with the Company and may act on, or as depositary, trustee or
agent for, any committee or body of holders of Warrant Securities or other
obligations of the Company as freely as if it were not the Warrant Agent
hereunder.  Nothing in this Warrant Agreement
shall be deemed to prevent the Warrant Agent from acting as [Senior]
[Subordinated] Trustee under the [Senior] [Subordinated] Indenture.


 


(f)            No Liability for Interest.  Unless otherwise agreed with the Company,
the Warrant Agent shall have no liability for interest on any monies at any time
received by it pursuant to any of the provisions of this Agreement or of the
Warrant Certificates.


 


(g)           No Liability for Invalidity.  The Warrant Agent shall have no liability
with respect to any invalidity of this Agreement or any of the Warrant Certificates
(except as to the Warrant Agent’s countersignature thereon).


 


(h)           No Responsibility for
Representations.  The
Warrant Agent shall not be responsible for any of the recitals or
representations herein or in the Warrant Certificates (except as to the Warrant
Agent’s countersignature thereon), all of which are made solely by the Company.


 


(i)            No Implied Obligations.  The Warrant Agent shall be obligated to
perform only such duties as are herein and in the Warrant Certificates
specifically set forth and no implied duties or obligations shall be read into
this Agreement or the Warrant Certificates against the Warrant Agent.  The Warrant Agent shall not be under any
obligation to take any action hereunder which may tend to involve it in any
expense or liability, the payment of which within a reasonable time is not, in
its reasonable opinion, assured to it. 
The Warrant Agent shall not be accountable or under any duty or
responsibility for the use by the Company of any of the Warrant Certificates
authenticated by the Warrant Agent and delivered by it to the Company pursuant
to this Agreement or for the application by the Company of the proceeds of the
Warrant Certificates.  The Warrant Agent
shall have no duty or responsibility in case of any default by the Company in
the performance of its covenants or agreements contained herein or in the
Warrant Certificates or in the case of the receipt of any written demand from a
holder of a Warrant Certificate with respect to such default, including,
without limiting the generality of the foregoing, any duty or responsibility to
initiate or attempt to initiate any proceedings at law or otherwise or, except
as provided in Section 6.2 hereof, to make any demand upon the Company.


 


5.3          Resignation, Removal and Appointment
of Successors.


 


(a)           The Company agrees, for the benefit
of the holders from time to time of the Warrant Certificates, that there shall
at all times be a Warrant Agent hereunder until all the Warrants have been
exercised or are no longer exercisable.


 


(b)           The Warrant Agent may at any time
resign as agent by giving written notice to the Company of such intention on
its part, specifying the date on which its desired resignation shall become
effective; provided
that such date shall not be less than three months after the date on
which such notice is given unless the Company otherwise agrees.  The Warrant


 


9

















 


Agent hereunder may be
removed at any time by the filing with it of an instrument in writing signed by
or on behalf of the Company and specifying such removal and the intended date
when it shall become effective.  Such
resignation or removal shall take effect upon the appointment by the Company,
as hereinafter provided, of a successor Warrant Agent (which shall be a bank or
trust company authorized under the laws of the jurisdiction of its organization
to exercise corporate trust powers) and the acceptance of such appointment by
such successor Warrant Agent.  The
obligation of the Company under Section 5.2(a) shall continue to the extent set
forth therein notwithstanding the resignation or removal of the Warrant Agent.


 


(c)           In case at any time the Warrant Agent
shall resign, or shall be removed, or shall become incapable of acting, or
shall be adjudged a bankrupt or insolvent, or shall commence a voluntary case
under the Federal bankruptcy laws, as now or hereafter constituted, or under
any other applicable Federal or state bankruptcy, insolvency or similar law or
shall consent to the appointment of or taking possession by a receiver,
custodian, liquidator, assignee, trustee, sequestrator (or other similar
official) of the Warrant Agent or its property or affairs, or shall make an
assignment for the benefit of creditors, or shall admit in writing its
inability to pay its debts generally as they become due, or shall take
corporate action in furtherance of any such action, or a decree or order for
relief by a court having jurisdiction in the premises shall have been entered
in respect of the Warrant Agent in an involuntary case under the Federal
bankruptcy laws, as now or hereafter constituted, or any other applicable
Federal or state bankruptcy, insolvency or similar law, or a decree or order by
a court having jurisdiction in the premises shall have been entered for the appointment
of a receiver, custodian, liquidator, assignee, trustee, sequestrator (or
similar official) of the Warrant Agent or of its property or affairs, or any
public officer shall take charge or control of the Warrant Agent or of its
property or affairs for the purpose of rehabilitation, conservation, winding up
or liquidation, a successor Warrant Agent, qualified as aforesaid, shall be
appointed by the Company by an instrument in writing, filed with the successor
Warrant Agent.  Upon the appointment as
aforesaid of a successor Warrant Agent and acceptance by the successor Warrant
Agent of such appointment, the Warrant Agent shall cease to be Warrant Agent
hereunder.


 


(d)           Any successor Warrant Agent appointed
hereunder shall execute, acknowledge and deliver to its predecessor and to the
Company an instrument accepting such appointment hereunder, and thereupon such
successor Warrant Agent, without any further act, deed or conveyance, shall
become vested with all the authority, rights, powers, trusts, immunities,
duties and obligations of such predecessor with like effect as if originally
named as Warrant Agent hereunder, and such predecessor, upon payment of its
charges and disbursements then unpaid, shall thereupon become obligated to
transfer, deliver and pay over, and such successor Warrant Agent shall be
entitled to receive, all monies, securities and other property on deposit with
or held by such predecessor, as Warrant Agent hereunder.


 


(e)           Any corporation into which the
Warrant Agent hereunder may be merged or converted or any corporation with
which the Warrant Agent may be consolidated, or any corporation resulting from
any merger, conversion or consolidation to which the Warrant Agent shall be a
party, or any corporation to which the Warrant Agent shall sell or otherwise
transfer all or substantially all the assets and business of the Warrant Agent,
provided
that it shall be qualified as aforesaid, shall be the successor
Warrant Agent under this Agreement without the execution or filing of any paper
or any further act on the part of any of the parties hereto.


 


10

















 


ARTICLE 6


 


MISCELLANEOUS


 


6.1          Amendment.  This Agreement may be amended by the parties
hereto, without the consent of the holder of any Warrant Certificate, for the
purpose of curing any ambiguity, or of curing, correcting or supplementing any
defective provision contained herein, or making any other provisions with
respect to matters or questions arising under this Agreement as the Company and
the Warrant Agent may deem necessary or desirable; provided that such action shall not materially adversely affect
the interests of the holders of the Warrant Certificates.


 


6.2          Notices and Demands to the Company and
Warrant Agent.  If the Warrant Agent shall receive any
notice or demand addressed to the Company by the holder of a Warrant
Certificate pursuant to the provisions of the Warrant Certificates, the Warrant
Agent shall promptly forward such notice or demand to the Company.


 


6.3          Addresses. 
Any communication from the Company to the Warrant Agent with respect to
this Agreement shall be addressed to
                     ,
Attention: 
                     
and any communication from the Warrant Agent to the Company with respect to
this Agreement shall be addressed to Allos Therapeutics, Inc., 11080
CirclePoint Road, Suite 200, Westminster, Colorado 80020, Attention:  Corporate Secretary (or such other address
as shall be specified in writing by the Warrant Agent or by the Company).


 


6.4          Governing Law. 
This Agreement and each Warrant Certificate issued hereunder shall be
governed by and construed in accordance with the laws of the State of New York.


 


6.5          Delivery
of Prospectus.  The Company shall furnish to the Warrant
Agent sufficient copies of a prospectus meeting the requirements of the
Securities Act of 1933, as amended, relating to the Warrant Debt Securities
deliverable upon exercise of the Warrants (the “Prospectus”), and the Warrant Agent agrees
that upon the exercise of any Warrant, the Warrant Agent will deliver to the
holder of the Warrant Certificate evidencing such Warrant, prior to or
concurrently with the delivery of the Warrant Debt Securities issued upon such
exercise, a Prospectus.


 


The Warrant Agent shall not, by reason of any such
delivery, assume any responsibility for the accuracy or adequacy of such
Prospectus.


 


6.6          Obtaining of Governmental Approvals.  The Company will from time to time take all
action which may be necessary to obtain and keep effective any and all permits,
consents and approvals of governmental agencies and authorities and securities
act filings under United States Federal and state laws (including without
limitation a registration statement in respect of the Warrants and Warrant Debt
Securities under the Securities Act of 1933, as amended), which may be or
become requisite in connection with the issuance, sale, transfer, and delivery
of the Warrant Debt Securities issued upon exercise of the Warrants, the
issuance, sale, transfer and delivery of the Warrants or upon the expiration of
the period during which the Warrants are exercisable.


 


11

















 


6.7          Persons Having Rights Under Warrant
Agreement.  Nothing in this Agreement shall give to any
person other than the Company, the Warrant Agent and the holders of the Warrant
Certificates any right, remedy or claim under or by reason of this Agreement.


 


6.8          Headings. 
The descriptive headings of the several Articles and Sections of this
Agreement are inserted for convenience only and shall not control or affect the
meaning or construction of any of the provisions hereof.


 


6.9          Counterparts. 
This Agreement may be executed in any number of counterparts, each of
which as so executed shall be deemed to be an original, but such counterparts
shall together constitute but one and the same instrument.


 


6.10        Inspection
of Agreement.  A copy of this Agreement shall be available
at all reasonable times at the principal corporate trust office of the Warrant
Agent for inspection by the holder of any Warrant Certificate.  The Warrant Agent may require such holder to
submit his Warrant Certificate for inspection by it.


 


12

















 


In Witness Whereof, the parties hereto have
caused this Agreement to be duly executed, all as of the day and year first
above written.


 


	
   

  	
   

  	
   

  	
  Allos Therapeutics, Inc.

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
  By

  	
   

  
	
   

  	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
  Its

  	
   

  
	
   

  	
   

  	
   

  	
   

  	
   

  
	
  Attest:

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
   

  	
  , as

  
	
   

  	
   

  	
   

  	
  Warrant Agent

  	
   

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
  By

  	
   

  
	
   

  	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
  Its

  	
   

  
	
   

  	
   

  	
   

  	
   

  	
   

  
	
  Attest:

  	
   

  	
   

  	
   

  
							



 


[Signature
Page to Debt Securities Warrant Agreement]


 

















 


Exhibit A


 


FORM
OF WARRANT CERTIFICATE

[Face of Warrant Certificate]


 


	
  [Form if Warrants are attached to Other Securities
  and are not immediately detachable.

  	
   

  	
  Prior to
                         ,
  this Warrant Certificate cannot be transferred or exchanged unless attached
  to a [Title of Other Security].]

  
	
   

  	
   

  	
   

  
	
  [Form of Legend if Warrants are not immediately
  exercisable.

  	
   

  	
  Prior to
                         ,
  Warrants evidenced by this Warrant Certificate cannot be exercised.]

  



 


EXERCISABLE ONLY IF COUNTERSIGNED BY THE WARRANT

AGENT AS PROVIDED HEREIN


 


VOID AFTER
[         ] P.M., [CITY] TIME, ON
                  ,


 


ALLOS THERAPEUTICS, INC.


 


WARRANT CERTIFICATE REPRESENTING

WARRANTS TO PURCHASE

[TITLE OF WARRANT DEBT SECURITIES]


 


	
  No.
                         

  	
   

  	
   

  	
                   
  Warrants

  



 


This certifies that
                         
or registered assigns is the registered owner of the above indicated number of
Warrants, each Warrant entitling such owner [If Warrants are attached to Other
Securities and are not immediately detachable –, subject to the registered
owner qualifying as a “Holder” of this Warrant Certificate, as hereinafter
defined)] to purchase, at any time [after
[        ] p.m., [City] time, on            
and] on or before
[          ] p.m., [City]
time, on            ,
$              
principal amount of [Title of Warrant Debt Securities] (the “Warrant Debt Securities”),
of Allos Therapeutics, Inc. (the “Company”), issued or to be issued under the
Indenture (as hereinafter defined), on the following basis:  during the period from
           , through and
including
            , each
Warrant shall entitle the Holder thereof, subject to the provisions of this
Agreement, to purchase the principal amount of Warrant Debt Securities stated
in the Warrant Certificate at the warrant price (the “Warrant Price”) of
          % of the principal
amount thereof [plus accrued amortization, if any, of the original issue
discount of the Warrant Debt Securities] [plus accrued interest, if any, from
the most recent date from which interest shall have been paid on the Warrant
Debt Securities or, if no interest shall have been paid on the Warrant Debt
Securities, from the date of their original issuance].  [The original issue discount
($         for each $1,000 principal
amount of Warrant Debt Securities) will be amortized at a
            %
annual rate, computed on a[n] [semi-]annual basis [using a 360-day year
consisting of twelve 30-day months]. 
The Holder may exercise the Warrants evidenced hereby by providing
certain information set forth on the back hereof and by paying in full, in
lawful


 


A-1

















 


money of the United States of America, [in cash or by
certified check or official bank check in New York Clearing House funds] [by
bank wire transfer in immediately available funds], the Warrant Price for each
Warrant Debt Security with respect to which this Warrant is exercised to the
Warrant Agent (as hereinafter defined) and by surrendering this Warrant
Certificate, with the purchase form on the back hereof duly executed, at the
corporate trust office of [name of Warrant Agent], or its successor as warrant
agent (the “Warrant Agent”),
which is, on the date hereof, at the address specified on the reverse hereof,
and upon compliance with and subject to the conditions set forth herein and in
the Warrant Agreement (as hereinafter defined).


 


The term  “Holder”as used herein shall mean [If Warrants are attached to Other Securities
and are not immediately detachable–, prior to
                  ,
              
(the “Detachable Date”),
the registered owner of the Company’s [title of Other Securities] to which this
Warrant Certificate was initially attached, and after such Detachable Date,]
the person in whose name at the time this Warrant Certificate shall be
registered upon the books to be maintained by the Warrant Agent for that
purpose pursuant to Section 4 of the Warrant Agreement.


 


The Warrants evidenced by this Warrant Certificate may be exercised to
purchase Warrant Debt Securities in the principal amount of $1,000 or any
integral multiple thereof in registered form.  Upon any exercise of
fewer than all of the Warrants evidenced by this Warrant Certificate, there
shall be issued to the Holder hereof a new Warrant Certificate evidencing
Warrants for the aggregate principal amount of Warrant Debt Securities
remaining unexercised.


 


This Warrant Certificate is issued under and in accordance with the
Warrant Agreement dated as of
                 ,
             (the “Warrant Agreement”),
between the Company and the Warrant Agent and is subject to the terms and
provisions contained in the Warrant Agreement, to all of which terms and
provisions the Holder of this Warrant Certificate consents by acceptance hereof.  Copies
of the Warrant Agreement are on file at the above-mentioned office of the
Warrant Agent.


 


The Warrant Debt Securities to be issued and delivered upon the
exercise of Warrants evidenced by this Warrant Certificate will be issued under
and in accordance with an Indenture, [dated as of
                ,
             (the “Senior Indenture”),
between the Company and
                      ,
as trustee (such trustee, and any successors to such trustee, the “Senior Trustee”)]
[dated as of
                    ,
                ,
(the “Subordinated
Indenture”), between the Company and
                      ,
as trustee (such trustee, and any successors to such trustee, the “Subordinated Trustee”)]
and will be subject to the terms and provisions contained in the Warrant Debt
Securities and in the Indenture.  Copies of the [Senior] [Subordinated]
Indenture, including the form of the Warrant Debt Securities, are on file at
the corporate trust office of the Trustee.


 


[If Warrants are attached to Other Securities and are not immediately
detachable–Prior to the Detachable Date, this Warrant Certificate may be exchanged or
transferred only together with the [Title of Other Securities] (the “Other Securities”)
to which this Warrant Certificate was initially attached, and only for the
purpose of effecting or in conjunction with, an exchange or transfer of such
Other Security.  Additionally, on or
prior to the Detachable Date, each transfer of such Other Security on the
register of the Other Securities shall operate also to transfer this Warrant
Certificate.  After such date, transfer
of this] [If Warrants are attached to Other


 


A-2

















 


Securities and are immediately detachable – Transfer
of this] Warrant Certificate may be registered when this Warrant Certificate is
surrendered at the corporate trust office of the Warrant Agent by the
registered owner or such owner’s assigns, in the manner and subject to the
limitations provided in the Warrant Agreement.


 


[If Other Securities with Warrants which are not immediately
detachable-Except as provided in the immediately preceding paragraph, after]
[If Other Securities with Warrants which are immediately detachable or Warrants
alone–After] countersignature by the Warrant Agent and prior to the expiration
of this Warrant Certificate, this Warrant Certificate may be exchanged at the
corporate trust office of the Warrant Agent for Warrant Certificates
representing Warrants for the same aggregate principal amount of Warrant Debt
Securities.


 


This Warrant Certificate shall not entitle the Holder hereof to any of
the rights of a holder of the Warrant Debt Securities, including, without limitation, the right to receive
payments of principal of (and premium, if any) or interest, if any, on the
Warrant Debt Securities or to enforce any of the covenants of the Indenture.


 


Reference is hereby made to the further provisions of this Warrant
Certificate set forth on the reverse hereof, which further provisions shall for
all purposes have the same effect as if set forth at this place.


 


This Warrant Certificate shall not be valid or obligatory for any
purpose until countersigned by the Warrant Agent.


 


A-3

















 


In Witness Whereof,  the Company has caused this
Warrant to be executed in its name and on its behalf by the facsimile
signatures of its duly authorized officers.


 


	
  Dated:

  	
   

  	
   

  	
   

  	
  Allos Therapeutics, Inc.

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
  By

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
  Its

  	
   

  
	
  Attest:

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
  Countersigned:

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
  As Warrant Agent

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
  By

  	
   

  	
   

  	
   

  
	
   

  	
  Authorized Signature

  	
   

  	
   

  
								



 


A-4

















 


[REVERSE OF WARRANT CERTIFICATE]


 


(Instructions for Exercise of Warrants)


 


To exercise any Warrants evidenced hereby for Warrant Debt Securities
(as hereinafter defined), the Holder must pay, in lawful money of the United
States of America, [in cash or by certified check or official bank check in New
York Clearing House funds] [by bank wire transfer in immediately available
funds], the Warrant Price in full for Warrants exercised, to [Warrant Agent]
[address of Warrant Agent], Attn: 
                ,
which payment must specify the name of the Holder and the number of Warrants exercised
by such Holder.  In addition, the Holder
must complete the information required below and present this Warrant Certificate
in person or by mail (certified or registered mail is recommended) to the
Warrant Agent at the appropriate address set forth above.  This Warrant Certificate, completed and duly
executed, must be received by the Warrant Agent within five business days of
the payment.


 


(To be executed upon exercise of Warrants)


 


The undersigned hereby irrevocably elects to exercise
                
Warrants, represented by this Warrant Certificate, to purchase
$            
principal amount of the [Title of Warrant Debt Securities] (the “Warrant Debt Securities”)
of Allos Therapeutics, Inc. and represents that he has tendered payment for
such Warrant Debt Securities, in lawful money of the United States of America,
[in cash or by certified check or official bank check in New York Clearing
House funds] [by bank wire transfer in immediately available funds], to the
order of Allos Therapeutics, Inc., c/o [insert name and address of Warrant
Agent], in the amount of $                 
in accordance with the terms hereof.  The undersigned requests that said principal amount of Warrant
Debt Securities be in fully registered form in the authorized denominations,
registered in such names and delivered all as specified in accordance with the
instructions set forth below.


 


If the number of Warrants exercised is less than all the Warrants
evidenced hereby, the undersigned requests that a new Warrant Certificate
evidencing the Warrants for the aggregate principal amount of Warrant Debt
Securities remaining unexercised be issued and delivered to the undersigned
unless otherwise specified in the instructions below.


 


	
  Dated

  	
   

  	
   

  	
   

  	
  Name

  	
   

  
	
   

  	
   

  	
  (Please Print)

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
  Address

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
  (Insert Social Security or Other Identifying Number
  of Holder)

  
							



 


A-5

















 


	
  Signature Guaranteed

  	
   

  	
   

  
	
   

  	
   

  	
  Signature

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
  (Signature must conform in all respects to name of
  holder as specified on the face of this Warrant Certificate and must bear a
  signature guarantee by a bank, trust company or member broker of the New
  York, Midwest or Pacific Stock Exchange)

  



 


This Warrant may be exercised at the following
addresses:


 


	
  By hand at

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
  By mail at

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  



 


[Instructions as to form and delivery of Warrant Debt
Securities and, if applicable, Warrant Certificates evidencing Warrants for the
number of Warrant Debt Securities remaining unexercised — complete as
appropriate.]


 


A-6

















 


ASSIGNMENT


 


[Form of assignment to be executed if

Warrant Holder desires to transfer Warrant)


 


FOR VALUE RECEIVED,
                              
hereby sells, assigns and transfers unto:


 


	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
  (Please print name and address including zip code)

  	
   

  	
  Please insert Social Security or other identifying
  number

  



 


the right represented by the within Warrant to
purchase $           
aggregate principal amount of [Title of Warrant Debt Securities] of Allos
Therapeutics, Inc. to which the within Warrant relates and appoints
                 
attorney to transfer such right on the books of the Warrant Agent with full
power of substitution in the premises.


 


	
  Dated

  	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
  Signature

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
  (Signature must conform in all respects to name of
  holder as specified on the face of the Warrant)

  
	
  Signature Guaranteed

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  



 


A-7