EXHIBIT 4.6


THE
SECURITIES REPRESENTED HEREBY HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT
OF 1933, AS AMENDED (THE “ACT”), OR UNDER THE SECURITIES LAWS OF ANY
STATE.  THESE SECURITIES ARE SUBJECT TO
RESTRICTIONS ON TRANSFERABILITY AND RESALE AND MAY NOT BE TRANSFERRED OR RESOLD
EXCEPT AS PERMITTED UNDER THE ACT AND THE APPLICABLE STATE SECURITIES LAWS,
PURSUANT TO REGISTRATION OR EXEMPTION THEREFROM.  THE ISSUER OF THESE SECURITIES MAY REQUIRE AN
OPINION OF COUNSEL IN FORM AND SUBSTANCE SATISFACTORY TO THE ISSUER TO THE
EFFECT THAT ANY PROPOSED TRANSFER OR RESALE IS IN COMPLIANCE WITH THE ACT AND
ANY APPLICABLE STATE SECURITIES LAWS.


COMMON STOCK PURCHASE WARRANT


	
  Warrant No. CS-[   ]

  	
   

  	
  100,000 Shares

  



July 24, 2006


RIGEL PHARMACEUTICALS, INC.


WARRANT FOR
THE PURCHASE OF SHARES OF COMMON STOCK


1.             Issuance.  For value received, this Warrant is issued to
KWACKER LIMITED,
a corporation organized and existing under the laws of England, by RIGEL PHARMACEUTICALS, INC.,
a Delaware corporation (hereinafter with its successors called the “Company”), in partial consideration for
that certain Amendment No. Three to Build-to-Suit Lease, dated as of the
date hereof, between the Company and Slough BTC, LLC, as landlord (“Amendment Three”).


2.             Purchase
Price; Number of Shares. 
The registered holder of this Warrant (the “Holder”), commencing on the date hereof, is entitled upon
surrender of this Warrant with the subscription form annexed hereto duly
executed, at the principal office of the Company, to purchase from the Company
one hundred thousand (100,000) fully paid and nonassessable shares (the “Shares”) of common stock, $.001 par value
per share, of the Company (the “Common Stock”),
at a price per share of $0.57 (the “Purchase
Price”).  Until such time as
this Warrant is exercised in full or expires, the Purchase Price and the
securities issuable upon exercise of this Warrant are subject to adjustment as
hereinafter provided.  The person or
persons under whose name or names any certificate representing shares of Common
Stock is issued hereunder shall be deemed to have become the holder of record
of the shares represented thereby as at the close of business on the date this
Warrant is exercised with respect to such shares, whether or not the transfer
books of the Company shall be closed.


3.             Payment
of Purchase Price.  The
Purchase Price may be paid (i) in cash or by check; (ii) by the
surrender by the Holder to the Company of any promissory notes or other
obligations issued by the Company, with all such notes and obligations so
surrendered being credited against the Purchase Price in an amount equal to the
principal amount thereof plus accrued interest to the date of surrender; or
(iii) by any combination of the foregoing.


4.             Net
Issue Election.  The
Holder may elect to receive, without the payment by the Holder of any
additional consideration, shares of Common Stock equal to the value of this
Warrant or any portion hereof by the surrender of this Warrant or such portion
to the Company, with the net issue election notice annexed hereto duly
executed, at the principal office of the Company.  Thereupon, the Company shall issue to the
Holder such number of fully paid and nonassessable shares of Common Stock as is
computed using the following formula:


	
  

  	
  X=

  	
  Y (A – B)

  	
   

  
	
  A

  	
   

  



 


	
  where:

  	
   

  	
  X =

  	
  the number of shares of Common Stock to be issued to
  the Holder pursuant to this Section 4.

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
  Y =

  	
  the number of shares of Common Stock covered by this
  Warrant in respect of which the

  



 









 



 


	
  

  	
   

  	
   

  	
  net issue election is made pursuant to this
  Section 4.

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
  A =

  	
  the Fair Market Value (defined below) of one share
  of Common Stock, as determined at the time the net issue election is made
  pursuant to this Section 4.

  
	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
  B =

  	
  the Purchase Price in effect under this Warrant at
  the time the net issue election is made pursuant to this Section 4.

  



 


“Fair
Market Value” of a share of Common Stock as of a particular
date (the “Determination Date”) shall mean the
average of the closing or last reported sale prices of the Common Stock as
reported on the Nasdaq National Market over the 30-day period ending five
business days prior to the Determination Date;
provided, however, that (i) if the Common Stock is neither
traded on the Nasdaq National Market nor on a national securities exchange,
then Fair Market Value shall be the average of the closing or last reported
sale prices of the Common Stock over the 30-day period ending five business
days prior to the Determination Date reflected in the over-the-counter market,
as reported by the National Quotation Bureau, Inc. or any organization
performing a similar function, or if closing prices are not then routinely
reported for the over-the-counter market, the average of the last bid and asked
prices of the Common Stock over the 30-day period ending five business days
prior to the Determination Date, and (ii) if there is no public market for
the Common Stock, then Fair Market Value shall be determined in good faith by
the Company’s Board of Directors.


5.             Partial
Exercise.  This Warrant
may be exercised in part, and the Holder shall be entitled to receive a new
warrant, which shall be dated as of the date of this Warrant, covering the
number of shares in respect of which this Warrant shall not have been
exercised.


6.             Fractional
Shares.  In no event
shall any fractional share of Common Stock be issued upon any exercise of this
Warrant.  If, upon exercise of this
Warrant as an entirety, the Holder would, except as provided in this
Section 6, be entitled to receive a fractional share of Common Stock, then
the Company shall pay in lieu thereof, the Fair Market Value of such fractional
share in cash.


7.             Expiration
Date.  This Warrant or
any Successor Warrant (as defined in Section 10 below) shall remain
exercisable until the close of business on July 24, 2013, when it shall expire
and thereafter be void.


8.             Reserved
Shares; Valid Issuance. 
The Company covenants that it will at all times from and after the date
hereof reserve and keep available such number of its authorized shares of
Common Stock, free from all preemptive or similar rights therein, as will be
sufficient to permit the exercise of this Warrant in full into shares of Common
Stock upon such exercise.  The Company
further covenants that such shares as may be issued pursuant to such exercise
will, upon issuance, be duly and validly issued, fully paid and nonassessable
and free from all taxes, liens and charges with respect to the issuance
thereof.


9.             Stock
Splits and Dividends. 
If after the date hereof the Company shall subdivide the Common Stock,
by split-up or otherwise, or combine the Common Stock, or issue additional
shares of Common Stock in payment of a stock dividend on the Common Stock, the
number of shares of Common Stock issuable on the exercise of this Warrant shall
forthwith be proportionately increased in the case of a subdivision or stock
dividend, or proportionately decreased in the case of a combination, and the Purchase
Price shall forthwith be proportionately decreased in the case of a subdivision
or stock dividend, or proportionately increased in the case of a combination.


10.          Mergers and Reclassifications.


(a)           If after the date hereof the Company
shall enter into any Reorganization (as hereinafter defined), then, as a
condition of such Reorganization, lawful provisions shall be made, and duly
executed documents evidencing the same from the Company or its successor shall
be delivered to the Holder (a “Successor Warrant”),
so that the Holder shall thereafter have the right to purchase, at a total
price not to exceed that payable upon the exercise of this Warrant in full, the
kind and amount of shares of stock and other securities and property receivable
upon such Reorganization by a holder of the number of shares of Common Stock
which might have been purchased by the Holder immediately prior to such
Reorganization, and in any such case appropriate provisions shall be made









 



 


with respect to the rights and interest of the Holder
to the end that the provisions hereof (including without limitation, provisions
for the adjustment of the Purchase Price and the number of shares issuable
hereunder and the provisions relating to the net issue election) shall
thereafter be applicable in relation to any shares of stock or other securities
and property thereafter deliverable upon exercise hereof.


 (b)          For the
purposes of this Section 10:


(i)            the term “Acquisition
Transaction” shall include without limitation any consolidation of the
Company with, or merger of the Company into, another corporation or other
business organization (other than a merger in which the Company is the
surviving corporation and which does not result in any reclassification or
change of the outstanding Common Stock); and


(ii)           the term “Reorganization”
shall include without limitation any reclassification, capital reorganization
or change of the Common Stock (other than as a result of a subdivision,
combination or stock dividend provided for in Section 9 hereof), an
Acquisition Transaction, or any sale or conveyance to another corporation or
other business organization of all or substantially all of the assets of the
Company.


11.          Certificate
of Adjustment. 
Whenever the Purchase Price is adjusted, as herein provided, the Company
shall promptly deliver to the Holder a certificate of the Company’s Chief
Financial Officer setting forth the Purchase Price after such adjustment and
setting forth a brief statement of the facts requiring such adjustment.


12.          Notices of Record Date, Etc.  In the event of:


(a)           any
taking by the Company of a record of the holders of any class of securities for
the purpose of determining the holders thereof who are entitled to receive any
dividend or other distribution, or any right to subscribe for, purchase, sell
or otherwise acquire or dispose of any shares of stock of any class or any
other securities or property, or to receive any other right;


(b)           any
reclassification of the capital stock of the Company, capital reorganization of
the Company, consolidation or merger involving the Company, or sale or
conveyance of all or substantially all of its assets; or


(c)           any
voluntary or involuntary dissolution, liquidation or winding-up of the Company;


then
in each such event the Company will provide or cause to be provided to the
Holder a written notice thereof.  Such
notice shall be provided at least fifteen (15) calendar days prior to the
date specified in such notice on which any such action is to be taken.


13.          Representations,
Warranties and Covenants. 
This Warrant is issued and delivered by the Company and accepted by each
Holder on the basis of the following representations, warranties and covenants
made by the Company:


(a)           The
Company has all necessary authority to issue, execute and deliver this Warrant
and to perform its obligations hereunder. 
This Warrant has been duly authorized, issued, executed and delivered by
the Company and is the valid and binding obligation of the Company, enforceable
in accordance with its terms, except as enforceability may be limited by
bankruptcy, insolvency, reorganization or other similar laws of general
application affecting the enforcement of Holder’s rights or by general equity
principles or public policy concerns.


(b)           The
shares of Common Stock issuable upon the exercise of this Warrant have been
duly authorized and reserved for issuance by the Company and, when issued in
accordance with the terms hereof, will be validly issued, fully paid and
nonassessable.


(c)           The
issuance, execution and delivery of this Warrant do not, and the issuance of
the shares of Common Stock upon the exercise of this Warrant in accordance with
the terms hereof will not, (i) violate or contravene the Company’s Amended
and Restated Certificate of Incorporation or by-laws, or any law, statute,









 



 


regulation, rule, judgment or order applicable to the
Company, (ii) violate, contravene or result in a breach or default under
any material contract, agreement or instrument to which the Company is a party
or by which the Company or any of its assets are bound or (iii) require
the consent or approval of or the filing of any notice or registration with any
person or entity.


14.          Amendment
and Waiver.  The terms
of this Warrant may be amended, modified or waived only with the written
consent of the party against which enforcement of the same is sought.


15.          Representations
and Covenants of the Holder. 
This Common Stock Purchase Warrant has been entered into by the Company
in reliance upon the following representations and covenants of the Holder, which
by its acceptance hereof the Holder hereby confirms:


(a)           Investment
Purpose.  The right to
acquire Common Stock or the Common Stock issuable upon exercise of the Holder’s
rights contained herein will be acquired for investment and not with a view to
the sale or distribution of any part thereof, and the Holder has no present
intention of selling or engaging in any public distribution of the same except
pursuant to a registration or exemption.


(b)           Accredited
Investor.  Holder is an
“accredited investor” within the meaning of the Securities and Exchange
Commission’s Rule 501 of Regulation D, as presently in effect.


(c)           Private
Issue.  The Holder
understands (i) that the Common Stock issuable upon exercise of the Holder’s
rights contained herein is not registered under the 1933 Act or qualified under
applicable state securities laws on the ground that the issuance contemplated
by this Warrant will be exempt from the registration and qualifications
requirements thereof and (ii) that the Company’s reliance on such
exemption is predicated on the representations set forth in this
Section 15.


(d)           Financial
Risk.  The Holder has
such knowledge and experience in financial and business matters as to be
capable of evaluating the merits and risks of its investment and has the
ability to bear the economic risks of its investment.


16.          Notices, Transfers, Etc.


(a)           Any
notice or written communication required or permitted to be given to the Holder
may be given by certified mall or delivered to the Holder at the address most recently
provided by the Holder to the Company.


(b)           Subject
to compliance with applicable federal and state securities laws, this Warrant
may be transferred by the Holder with respect to any or all of the shares
purchasable hereunder.  Upon surrender of
this Warrant to the Company, together with the assignment notice annexed hereto
duly executed, for transfer of this Warrant as an entirety by the Holder, the
Company shall issue a new warrant of the same denomination to the assignee.  Upon surrender of this Warrant to the
Company, together with the assignment hereof properly endorsed, by the Holder
for transfer with respect to a portion of the shares of Common Stock
purchasable hereunder, the Company shall issue a new warrant to the assignee,
in such denomination as shall be requested by the Holder hereof, and shall
issue to such Holder a new warrant covering the number of shares in respect of
which this Warrant shall not have been transferred.


(c)           In
case this Warrant shall be mutilated, lost, stolen or destroyed, the Company
shall issue a new warrant of like tenor and denomination and deliver the same
(i) in exchange and substitution for and upon surrender and cancellation
of any mutilated Warrant or (ii) in lieu of any Warrant lost, stolen or
destroyed, upon receipt of an affidavit of the Holder or other evidence
reasonably satisfactory to the Company of the loss, theft or destruction of
such Warrant and an indemnification of loss by the Holder in favor of the
Company.


17.          Transfer
to Comply with the Securities Act of 1933.   This Warrant may not be exercised and neither
this Warrant nor any of the Shares, nor any interest in either, may be offered,
sold, assigned, pledged, hypothecated, encumbered or in any other manner
transferred or disposed of, in whole or in part, except in









 



 


compliance with applicable United States federal and
state securities laws and the terms and conditions hereof.  Each Warrant shall bear a legend in
substantially the same form as the legend set forth on the first page of this
Warrant.  Each certificate for Shares
issued upon exercise of this Warrant, unless at the time of exercise such
Shares are acquired pursuant to a registration statement that has been declared
effective under the Securities Act of 1933, as amended (the “Securities Act”),
and applicable blue sky laws, shall bear a legend substantially in the
following form:


THE SECURITIES
REPRESENTED HEREBY HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933,
AS AMENDED (THE “ACT”), OR UNDER THE SECURITIES LAWS OF ANY STATE.  THESE SECURITIES ARE SUBJECT TO RESTRICTIONS
ON TRANSFERABILITY AND RESALE AND MAY NOT BE TRANSFERRED OR RESOLD EXCEPT AS
PERMITTED UNDER THE ACT AND THE APPLICABLE STATE SECURITIES LAWS, PURSUANT TO
REGISTRATION OR EXEMPTION THEREFROM.  THE
ISSUER OF THESE SECURITIES MAY REQUIRE AN OPINION OF COUNSEL IN FORM AND
SUBSTANCE SATISFACTORY TO THE ISSUER TO THE EFFECT THAT ANY PROPOSED TRANSFER
OR RESALE IS IN COMPLIANCE WITH THE ACT AND ANY APPLICABLE STATE SECURITIES
LAWS.


Any certificate for any Shares issued at any time in exchange or
substitution for any certificate for any Shares bearing such legend (except a
new certificate for any Shares issued after the acquisition of such Shares
pursuant to a registration statement that has been declared effective under the
Securities Act) shall also bear such legend unless, in the opinion of counsel
for the Company, the Shares represented thereby need no longer be subject to
the restriction contained herein.  The
provisions of this Section 17 shall be binding upon all subsequent holders
of certificates for Shares bearing the above legend and all subsequent holders
of this Warrant, if any.


18.          Rights
of Holder.  Holder shall not, by virtue hereof, be
entitled to any rights of a stockholder of the Company, either at law or equity,
and the rights of Holder are limited to those expressed in this Warrant.  Nothing contained in this Warrant shall be
construed as conferring upon Holder hereof the right to vote or to consent or
to receive notice as a stockholder of the Company on any matters or with
respect to any rights whatsoever as a stockholder of the Company.  No dividends or interest shall be payable or
accrued in respect of this Warrant or the interest represented hereby or the
Shares purchasable hereunder until, and only to the extent that, this Warrant
shall have been exercised in accordance with its terms.


19.  “Market Stand Off” Agreement.  Holder hereby agrees not to sell, transfer,
make any short sale of, grant any option for the purchase of, or enter into any
hedging or similar transaction with the same economic effect as a sale of, any
Common Stock (or other securities) of the Company held by Holder for a period
specified by a representative of the underwriters of Common Stock (or other
securities) of the Company not to exceed ninety (90) days following the
effective date of a registration statement of the Company filed under the
Securities Act; provided that all
officers and directors of the Company and each holder of that number of shares
of Common Stock equal to or greater than the number of Shares then issuable
upon exercise of this Warrant enter into similar agreements.


20.          No
Impairment.  The
Company will not, by amendment of its Certificate or through any
reclassification, capital reorganization, consolidation, merger, sale or
conveyance of assets, dissolution, liquidation, issue or sale of securities or
any other voluntary action, avoid or seek to avoid the observance or
performance of any of the terms of this Warrant, but will at all times in good
faith assist in the carrying out of all such terms and in the taking of all
such action as may be necessary or appropriate in order to protect the rights
of the Holder.


21.          Governing
Law.  The provisions
and terms of this Warrant shall be governed by and construed in accordance with
the internal laws of the State of California.


22.          Successors
and Assigns.  This
Warrant shall be binding upon the Company’s successors and assigns and shall
inure to the benefit of the Holder’s successors, legal representatives and
permitted assigns.


23.          Business
Days.  If the last or
appointed day for the taking of any action required or the expiration of any
rights granted herein shall be a Saturday or Sunday or a legal holiday in
California, then such action may be









 



 


taken or right may be exercised on the next succeeding
day which is not a Saturday or Sunday or such a legal holiday.


IN WITNESS WHEREOF, the Company has duly caused this Warrant to
be signed by its duly authorized officer and to be dated as of the date first
written above.


	
  

  	
  Company:

  
	
   

  	
   

  
	
   

  	
  RIGEL
  PHARMACEUTICALS, INC.

  
	
   

  	
   

  
	
   

  	
  By:

  	
  /s/ James M. Gower 

  
	
   

  	
   

  	
  James M. Gower 

  
	
   

  	
   

  	
  Chief Executive Officer

  



 









 



 


SUBSCRIPTION


	
  To:

  	
   

  	
   

  	
  Date:

  	
   

  



 


The undersigned hereby subscribes for                
shares of Common Stock covered by this Warrant. 
The certificate(s) for such shares shall be issued in the name of the
undersigned or as otherwise indicated below:


	
  

  	
   

  
	
   

  	
  Signature

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  Name for Registration

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  Mailing Address

  



 


 


NET ISSUE
ELECTION NOTICE


	
  To:

  	
   

  	
   

  	
  Date:

  	
   

  



 


The undersigned hereby elects under Section 4 to
surrender the right to purchase                    
shares of Common Stock pursuant to this Warrant.  The certificate(s) for such shares issuable
upon such net issue election shall be issued in the name of the undersigned or
as otherwise indicated below:


	
  

  	
   

  
	
   

  	
  Signature

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  Name for Registration

  
	
   

  	
   

  
	
   

  	
   

  
	
   

  	
  Mailing Address

  



 















 


 


ASSIGNMENT


	
  For value received
                                         
  hereby sells, assigns and transfers unto
                                                      

  
	
   

  
	
  [Please print or
  type the name and address of Assignee]

  
	
   

  
	
  the within Warrant, and does
  hereby irrevocably constitute and appoint
                     
                 
  its attorney to transfer the within Warrant on the books of the within named
  Company with full power of substitution on the premises.

  



 


	
  Dated:

  	
   

  	
   

  	
   

  	
   

  
	
   

  
	
   

  
	
   

  
	
   

  
	
  In the Presence of: