<PAGE>
                                                                     Exhibit 4.3

THIS WARRANT AND THE SECURITIES REPRESENTED HEREBY OR ACQUIRABLE UPON EXERCISE
HEREOF HAVE NOT REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED, AND MAY
NOT BE OFFERED, SOLD, ASSIGNED OR TRANSFERRED, IN THE ABSENCE OF AN EFFECTIVE
REGISTRATION STATEMENT UNDER SAID ACT OR UNLESS THE COMPANY HAS RECEIVED AN
OPINION OF COUNSEL REASONABLY SATISFACTORY TO THE COMPANY THAT REGISTRATION
UNDER SAID ACT IS NOT REQUIRED.

                         SPECTRUM PHARMACEUTICALS, INC.

                                     WARRANT

DATED: SEPTEMBER 20, 2005                                       NUMBER: SPPI 335

     Spectrum Pharmaceuticals, Inc., a Delaware corporation (the "Company"),
hereby certifies that, for value received, JOHN T. MOORE or his registered
assigns ("Holder"), is entitled, subject to the terms set forth below, to
purchase from the Company up to a total of 120,000 shares of Common Stock, $.001
par value per share (the "Common Stock"), of the Company (each such share, a
"Warrant Share" and all such shares, the "Warrant Shares") at an exercise price
equal to $5.13 per share (as adjusted from time to time as provided in Section
7, the "Exercise Price"), at any time from and including September 20, 2005 (the
"Effective Date") through and including September 19, 2013 (the "Expiration
Date"), in accordance with the vesting schedule set forth in Section 3 (b),
subject to the following terms and conditions:

     1. Registration of Warrant. The Company shall register this Warrant upon
records to be maintained by the Company for that purpose (the "Warrant
Register"), in the name of the record Holder hereof from time to time. The
Company may deem and treat the registered Holder of this Warrant as the absolute
owner hereof for the purpose of any exercise hereof or any distribution to the
Holder, and for all other purposes, and the Company shall not be affected by
notice to the contrary.

     2. Registration of Transfers and Exchanges.

          (a) This Warrant may not be sold, transferred, assigned, pledged,
hypothecated or otherwise disposed, directly or indirectly, in whole or in part,
without the prior written consent of the Company. Any attempted sale, transfer,
assignment, pledge, hypothecation or other disposition of this Warrant, or any
portion thereof, shall be void and without any force or effect; provided,
however, that, subject to compliance with any applicable securities laws, the
Holder may transfer this Warrant, or any portion thereof, without the prior
written consent of the Company, if such transfer is to (i) a spouse, child,
grandchild, parent, sibling or custodian or trustee for the benefit of any such
relatives, or (ii) any shareholder or affiliate entity.

          (b) The Company shall register the transfer of any portion of this
Warrant in conformance with Section 2(a) in the Warrant Register, upon surrender
of this Warrant, with the Form of Assignment attached hereto duly completed and
signed, to the Company at the office specified in or pursuant to Section 10.
Upon any such registration or


                                        1

<PAGE>

transfer, a new warrant to purchase Common Stock, in substantially the form of
this Warrant (any such new warrant, a "New Warrant"), evidencing the portion of
this Warrant so transferred shall be issued to the transferee and a New Warrant
evidencing the remaining portion of this Warrant not so transferred, if any,
shall be issued to the transferring Holder. The acceptance of the New Warrant by
the transferee thereof shall be deemed the acceptance of such transferee of all
of the rights and obligations of a holder of this Warrant.

          (c) This Warrant is exchangeable, upon the surrender hereof by the
Holder to the office of the Company specified in or pursuant to Section 10 for
one or more New Warrants, evidencing in the aggregate the right to purchase the
number of Warrant Shares which may then be purchased hereunder.

          (d) Unless the resale of the Warrant Shares has been registered under
the Securities Act of 1933, as amended, each certificate for Warrant Shares
initially issued upon the exercise of this Warrant, and each certificate for
Warrant Shares issued to any subsequent transferee of any such certificate,
shall be stamped or otherwise imprinted with a legend in substantially the
following form:

          "THE SECURITIES REPRESENTED BY THIS CERTIFICATE HAVE NOT BEEN
          REGISTERED UNDER THE SECURITIES ACT OF 1933 AS AMENDED, AND MAY NOT BE
          OFFERED, SOLD, ASSIGNED OR TRANSFERRED, IN THE ABSENCE OF AN EFFECTIVE
          REGISTRATION STATEMENT UNDER SAID ACT OR UNLESS THE COMPANY HAS
          RECEIVED AN OPINION OF COUNSEL REASONABLY SATISFACTORY TO THE COMPANY
          THAT REGISTRATION UNDER SAID ACT IS NOT REQUIRED."

     3. Duration and Exercise of Warrant.

          (a) This Warrant shall be exercisable by the then registered Holder on
any business day before 5:00 P.M., California time, at any time and from time to
time on or after the Effective Date to and including the Expiration Date. At
5:00 P.M., California time on the Expiration Date, the portion of this Warrant
not exercised prior thereto shall be and become void and of no value.

          (b) This Warrant shall vest in accordance with the following schedule:

               a.   20,000 shares shall vest and become exercisable upon the
                    first anniversary of the grant date of the warrant.

               b.   40,000 shares shall vest and become exercisable upon the
                    second anniversary of the grant date of the warrant.

               c.   60,000 shares shall vest and become exercisable upon the
                    third anniversary of the grant date of the warrant.


                                        2

<PAGE>

               In the event that the Consulting Agreement dated September 20,
               2005, by and between the Company and JTM Consulting, Inc.,
               expires or is terminated by either party prior to any vesting
               date, no further vesting will occur following such termination.

          (c) Upon surrender of this Warrant, with the Form of Election to
Purchase attached hereto duly completed and signed, to the Company at its
address for notice set forth in Section 10 and upon payment of the Exercise
Price multiplied by the number of Warrant Shares that the Holder intends to
purchase hereunder, in the manner provided hereunder, all as specified by the
Holder in the Form of Election to Purchase, the Company shall promptly (and in
any event, within four business days) issue or cause to be issued and cause to
be delivered to or upon the written order of the Holder and in such name or
names as the Holder may designate, a certificate for the Warrant Shares issuable
upon such exercise. Any person so designated by the Holder to receive Warrant
Shares shall be deemed to have become holder of record of such Warrant Shares as
of the Date of Exercise of this Warrant.

          A. "Date of Exercise" means the date on which the Company shall have
received (i) this Warrant (or any New Warrant, as applicable), with the Form of
Election to Purchase attached hereto (or attached to such New Warrant)
appropriately completed and duly signed, and (ii) payment of the Exercise Price
for the number of Warrant Shares so indicated by the holder hereof to be
purchased.

          (c) This Warrant shall be exercisable, either in its entirety or, from
time to time, for a portion of the number of Warrant Shares. If less than all of
the Warrant Shares which may be purchased under this Warrant are exercised at
any time, the Company shall issue or cause to be issued, at its expense, a New
Warrant evidencing the right to purchase the remaining number of Warrant Shares
for which no exercise has been evidenced by this Warrant.

          (d) Prior to the exercise of this Warrant, the Holder shall not be
entitled to any rights as a stockholder of the Company with respect to the
Warrant Shares, including (without limitation) the right to vote such shares,
receive dividends or other distributions thereon or be notified of stockholder
meetings (except as otherwise set forth in Section 7(f) herein).

          (e) If by the tenth business day after a Date of Exercise the Company
fails to deliver the required number of Warrant Shares in the manner required
pursuant to Section 3(b), then the Holder will have the right to rescind such
exercise.

     4. Payment of Taxes. The Company will pay any documentary stamp taxes
attributable to the issuance of Warrant Shares upon the exercise of this
Warrant; provided, however, that the Company shall not be required to pay any
tax which may be payable in respect of any transfer involved in the registration
of any certificates for Warrant Shares or Warrants in a name other than that of
the Holder. The Holder shall be responsible for all other tax liability that may
arise as a result of holding or transferring this Warrant or receiving Warrant
Shares upon exercise hereof.


                                        3

<PAGE>

     5. Replacement of Warrant. If this Warrant is mutilated, lost, stolen or
destroyed, the Company shall issue or cause to be issued in exchange and
substitution for and upon cancellation hereof, or in lieu of and substitution
for this Warrant, a New Warrant, but only upon receipt of evidence reasonably
satisfactory to the Company of such loss, theft or destruction and indemnity, if
requested, satisfactory to it. Applicants for a New Warrant under such
circumstances shall also comply with such other reasonable regulations and
procedures and pay such other reasonable charges as the Company may prescribe.

     6. Reservation of Warrant Shares. The Company covenants that it will at all
times reserve and keep available out of the aggregate of its authorized but
unissued Common Stock, solely for the purpose of enabling it to issue Warrant
Shares upon exercise of this Warrant as herein provided, the number of Warrant
Shares which are then issuable and deliverable upon the exercise of this entire
Warrant, free from preemptive rights or any other actual contingent purchase
rights of persons other than the Holder. The Company covenants that all Warrant
Shares that shall be so issuable and deliverable shall, upon issuance and the
payment of the applicable Exercise Price in accordance with the terms hereof, be
duly authorized, validly issued and fully paid and nonassessable.

     7. Certain Adjustments. The Exercise Price and number of Warrant Shares
issuable upon exercise of this Warrant are subject to adjustment from time to
time as set forth in this Section 7. Upon each such adjustment of the Exercise
Price pursuant to this Section 7, the Holder shall thereafter prior to the
Expiration Date be entitled to purchase, at the Exercise Price resulting from
such adjustment, the number of Warrant Shares obtained by multiplying the
Exercise Price in effect immediately prior to such adjustment by the number of
Warrant Shares issuable upon exercise of this Warrant immediately prior to such
adjustment and dividing the product thereof by the Exercise Price resulting from
such adjustment.

          (a) If the Company, at any time while this Warrant is outstanding, (i)
shall pay a stock dividend (except scheduled dividends paid on outstanding
preferred stock which contain a stated dividend rate) or otherwise make a
distribution or distributions on shares of its Common Stock payable in shares of
Common Stock, (ii) subdivide outstanding shares of Common Stock into a larger
number of shares, or (iii) combine outstanding shares of Common Stock into a
smaller number of shares, the Exercise Price shall be multiplied by a fraction
of which the numerator shall be the number of shares of Common Stock (excluding
treasury shares, if any) outstanding before such event and the denominator shall
be the number of shares of Common Stock (excluding treasury shares, if any)
outstanding after such event. Any adjustment made pursuant to this Section shall
become effective immediately after the record date for the determination of
stockholders entitled to receive such dividend or distribution and shall become
effective immediately after the effective date in the case of a subdivision or
combination, and shall apply to successive subdivisions and combinations.

          (b) In case of any reclassification of the Common Stock, any
consolidation or merger of the Company with or into another person, the sale or
transfer of all or substantially all of the assets of the Company or any
compulsory share exchange pursuant to which the Common Stock is converted into
other securities, cash or property, then the Holder shall have the right
thereafter to exercise this Warrant only into the shares of stock and other


                                        4

<PAGE>

securities and property receivable upon or deemed to be held by holders of
Common Stock following such reclassification, consolidation, merger, sale,
transfer or share exchange, and the Holder shall be entitled upon such event to
receive such amount of securities or property equal to the amount of Warrant
Shares such Holder would have been entitled to had such Holder exercised this
Warrant immediately prior to such reclassification, consolidation, merger, sale,
transfer or share exchange. The terms of any such consolidation, merger, sale,
transfer or share exchange shall include such terms so as to continue to give to
the Holder the right to receive the securities or property set forth in this
Section 7(b) upon any exercise following any such reclassification,
consolidation, merger, sale, transfer or share exchange.

          (c) If the Company, at any time while this Warrant is outstanding,
shall distribute to all holders of Common Stock (and not to holders of this
Warrant) evidences of its indebtedness or assets or rights or warrants to
subscribe for or purchase any security (excluding those referred to in Sections
7(a), and (b)), other than as part of its dissolution or liquidation or the
winding up of its affairs, then in each such case the Exercise Price shall be
determined by multiplying the Exercise Price in effect immediately prior to the
record date fixed for determination of stockholders entitled to receive such
distribution by a fraction of which the denominator shall be the fair market
value of a share of Common Stock determined as of the record date mentioned
above, and of which the numerator shall be the fair market value of a share of
Common Stock determined as of such record date less the fair market value at
such record date of the portion of such assets or evidence of indebtedness so
distributed applicable to one outstanding share of Common Stock as determined by
the Company's independent certified public accountants that regularly examines
the financial statements of the Company (an "Appraiser").

          (d) For the purposes of this Section 7, the following clauses shall
also be applicable:

               (i)  Record Date. In case the Company shall take a record of the
                    holders of its Common Stock for the purpose of entitling
                    them (A) to receive a dividend or other distribution payable
                    in Common Stock or in securities convertible or exchangeable
                    into shares of Common Stock, or (B) to subscribe for or
                    purchase Common Stock or securities convertible or
                    exchangeable into shares of Common Stock, then such record
                    date shall be deemed to be the date of the issue or sale of
                    the shares of Common Stock deemed to have been issued or
                    sold upon the declaration of such dividend or the making of
                    such other distribution or the date of the granting of such
                    right of subscription or purchase, as the case may be.

               (ii) Treasury Shares. The number of shares of Common Stock
                    outstanding at any given time shall not include shares owned
                    or held by or for the account of the Company, and


                                        5

<PAGE>

                    the disposition of any such shares shall be considered an
                    issue or sale of Common Stock.

          (e) All calculations under this Section 7 shall be made to the nearest
cent or the nearest 1/100th of a share, as the case may be.

          (f) If:

               (i)  the Company shall declare a dividend (or any other
                    distribution) on its Common Stock; or

               (ii) the Company shall declare a special nonrecurring cash
                    dividend on or a redemption of its Common Stock; or

               (iii) the Company shall authorize the granting to all holders of
                    the Common Stock rights or warrants to subscribe for or
                    purchase any shares of capital stock of any class or of any
                    rights; or

               (iv) the approval of any stockholders of the Company shall be
                    required in connection with any reclassification of the
                    Common Stock of the Company, any consolidation or merger to
                    which the Company is a party, any sale or transfer of all or
                    substantially all of the assets of the Company, or any
                    compulsory share exchange whereby the Common Stock is
                    converted into other securities, cash or property; or

               (v)  the Company shall authorize the voluntary dissolution,
                    liquidation or winding up of the affairs of the Company,

then the Company shall cause to be mailed to each Holder at their last addresses
as they shall appear upon the Warrant Register, at least 30 calendar days prior
to the applicable record or effective date hereinafter specified, a notice
stating (x) the date on which a record is to be taken for the purpose of such
dividend, distribution, redemption, rights or warrants, or if a record is not to
be taken, the date as of which the holders of Common Stock of record to be
entitled to such dividend, distributions, redemption, rights or warrants are to
be determined or (y) the date on which such reclassification, consolidation,
merger, sale, transfer or share exchange is expected to become effective or
close, and the date as of which it is expected that holders of Common Stock of
record shall be entitled to exchange their shares of Common Stock for
securities, cash or other property deliverable upon such reclassification,
consolidation, merger, sale, transfer, share exchange, dissolution, liquidation
or winding up; provided, however, that the failure to mail such notice or any
defect therein or in the mailing thereof shall not affect the validity of the
corporate action required to be specified in such notice.


                                        6

<PAGE>

     8. Payment of Exercise Price. The Holder shall pay the Exercise Price in
immediately available funds by certified check or bank draft payable to the
order of the Company or by wire transfer to an account designated by the
Company.

     9. Fractional Shares. The Company shall not be required to issue or cause
to be issued fractional Warrant Shares on the exercise of this Warrant. The
number of full Warrant Shares which shall be issuable upon the exercise of this
Warrant shall be computed on the basis of the aggregate number of Warrant Shares
purchasable on exercise of this Warrant so presented. If any fraction of a
Warrant Share would, except for the provisions of this Section 9, be issuable on
the exercise of this Warrant, the Company shall pay an amount in cash equal to
the Exercise Price multiplied by such fraction.

     10. Notices. Any and all notices or other communications or deliveries
hereunder shall be in writing and shall be deemed given and effective on the
earliest of (i) the date of transmission, if such notice or communication is
delivered via facsimile at the facsimile telephone number specified in this
Section prior to 5:00 p.m. (California time) on a business day, (ii) the
business day after the date of transmission, if such notice or communication is
delivered via facsimile at the facsimile telephone number specified in this
Section later than 5:00 p.m. (California time) on any date and earlier than
11:59 p.m. (California time) on such date, (iii) the business day following the
date of mailing, if sent by nationally recognized overnight courier service, or
(iv) upon actual receipt by the party to whom such notice is required to be
given. The addresses for such communications shall be: (i) if to the Company, to
157 Technology Drive, Irvine, CA 92618, Attention: CEO, or to facsimile no.
(949) 788-6706, or (ii) if to the Holder, to the Holder at the address or
facsimile number appearing on the Warrant Register or such other address or
facsimile number as the Holder may provide to the Company in accordance with
this Section 10.

     11. Warrant Agent. The Company shall serve as warrant agent under this
Warrant. The Company may appoint a new warrant agent upon notice to the Holder
in accordance with Section 10. Any corporation into which the Company may be
merged or any corporation resulting from any consolidation to which the Company
shall be a party or any corporation to which the Company transfers substantially
all of its corporate assets shall be a successor warrant agent under this
Warrant without any further act. Any such successor warrant agent shall promptly
cause notice of its succession as warrant agent to be mailed (by first class
mail, postage prepaid) to the Holder at the Holder's last address as shown on
the Warrant Register.

     12. Representations and Warranties of Holder. By accepting this Warrant,
Holder represents and warrants to the Company that the statements contained in
this Section 12 are correct and complete as of the date first written above.

          (a) Business or Financial Expertise. Holder has either (i) a
pre-existing personal or business relationship with the Company or any of its
officers, directors or controlling persons that is of a nature and duration
which enables Holder to be aware of the character, business acumen and general
business and financial circumstances of the Company or (ii) by reason of
Holder's business or financial expertise or the business or financial experience
of his


                                        7

<PAGE>

professional advisors who are unaffiliated with and who are not compensated by
the Company or any affiliate or selling agent of the Company, directly or
indirectly, the capacity to protect his own interests in connection with his
acquisition of the Warrant and the underlying Warrant Shares. Holder is an
"accredited investor" as defined in Rule 501 of Regulation D of the Securities
Act of 1933, as amended (the "Securities Act").

          (b) Awareness; No Distribution. Holder has had the opportunity to ask
questions about the Company's business affairs and financial condition, and has
acquired sufficient information about the Company to reach an informed and
knowledgeable decision to acquire the Warrant and underlying Warrant Shares.
Holder is acquiring the Warrant and underlying Warrant Shares for his own
account for investment purposes only and not with a view to, or for the resale
in connection with, any "distribution" thereof for purposes of the Securities
Act. Holder recognizes that the Warrant and underlying Warrant Shares are a
speculative investment involving a high degree of risk of loss and that Holder
could lose the entire amount of its investment. Holder is able to bear the
economic risk of this investment and at the present time could afford a complete
loss of this investment.

          (c) No Registration. Holder understands that the Warrant and
underlying Warrant Shares will be issued without registration under the
Securities Act and without qualification and/or registration under applicable
state securities laws ("Blue Sky Laws") in reliance upon specific exemptions
therefrom, which exemptions depend upon, among other things, the bona fide
nature of its investment intent as expressed herein. In this connection, Holder
understands that, in the view of the SEC, the statutory basis for such exemption
may be unavailable if its representations were predicated solely upon a present
intention to hold the Warrant and underlying Warrant Shares for the minimum
capital gains period specified under tax statutes, for a deferred sale, for or
until an increase or decrease in the market price of the Warrant Shares, or for
a period of one year or any other fixed period in the future.

          (d) Legend. Holder further understands that the Warrant Shares must be
held indefinitely unless subsequently registered and/or qualified under the
Securities Act and under the Blue Sky Laws or unless an exemption from
registration and/or qualification is otherwise available. Moreover, John Moore
understands that the Company is under no obligation to register and/or qualify
the Warrant Shares. In addition, Holder understands that the certificate
evidencing the Warrant Shares will be imprinted with a legend in substantially
the form as follows which prohibits the transfer of the Warrant Shares unless
they are registered and/or qualified or such registration and/or qualification
is not required in the opinion of counsel for Holder.

          THE SECURITIES REPRESENTED BY THIS CERTIFICATE HAVE NOT BEEN
          REGISTERED UNDER THE SECURITIES ACT OF 1933 AS AMENDED, AND MAY NOT BE
          OFFERED, SOLD, ASSIGNED OR TRANSFERRED, IN THE ABSENCE OF AN EFFECTIVE
          REGISTRATION STATEMENT UNDER SAID ACT OR UNLESS THE COMPANY HAS
          RECEIVED AN OPINION OF COUNSEL REASONABLY SATISFACTORY TO THE COMPANY
          THAT REGISTRATION UNDER SAID ACT IS NOT REQUIRED.


                                        8

<PAGE>

          (e) Rule 144. Holder is aware of the provisions of Rule 144,
promulgated under the Securities Act, which, in substance, permits limited
public resale of "restricted securities" acquired, directly or indirectly, from
the issuer thereof (or from an affiliate of such issuer), in a non-public
offering subject to the satisfaction of certain conditions. Holder understands
that the Warrant Shares constitute "restricted securities" for the purposes of
Rule 144.

          (f) No Public Market. Holder further understands that at the time it
wishes to sell the Warrant Shares there may be no public market upon which to
make such a sale.

          (g) Risk. Holder further understands that in the event all of the
requirements of Rule 144 are not satisfied, registration under the Securities
Act, compliance with Regulation A, or some other registration exemption will be
required; and that, notwithstanding the fact that Rule 144 is not exclusive, the
Staff of the SEC has expressed its opinion that persons proposing to sell
private placement securities other than in a registered offering and otherwise
than pursuant to Rule 144 will have a substantial burden of proof in
establishing that an exemption from registration is available for such offers or
sales, and that such persons and their respective brokers who participate in
such transactions do so at their own risk.

     13. Miscellaneous.

          (a) This Warrant shall be binding on and inure to the benefit of the
parties hereto and their respective successors and permitted assigns. This
Warrant may be amended only in writing signed by the Company and the Holder and
their successors and assigns.

          (b) Subject to Section 13(a), above, nothing in this Warrant shall be
construed to give to any person or corporation other than the Company and the
Holder any legal or equitable right, remedy or cause under this Warrant. This
Warrant shall inure to the sole and exclusive benefit of the Company and the
Holder.

          (c) This Warrant shall be governed by and construed and enforced in
accordance with the internal laws of the State of California without regard to
the principles of conflicts of law thereof. The Company and the Holder hereby
irrevocably submit to the exclusive jurisdiction of the state and federal courts
sitting in Orange County, California, for the adjudication of any dispute
hereunder or in connection herewith or with any transaction contemplated hereby
or discussed herein, and hereby irrevocably waives, and agrees not to assert in
any suit, action or proceeding, any claim that it is not personally subject to
the jurisdiction of any such court, or that such suit, action or proceeding is
improper. Each of the Company and the Holder hereby irrevocably waives personal
service of process and consents to process being served in any such suit, action
or proceeding by receiving a copy thereof sent to it at the address in effect
for notices to it under this instrument and in the manner set forth in Section
10 above, and agrees that such service shall constitute good and sufficient
service of process and notice thereof. Nothing contained herein shall be deemed
to limit in any way any right to serve process in any manner permitted by law.


                                        9

<PAGE>

          (d) The headings herein are for convenience only, do not constitute a
part of this Warrant and shall not be deemed to limit or affect any of the
provisions hereof.

          (e) In case any one or more of the provisions of this Warrant shall be
invalid or unenforceable in any respect, the validity and enforceability of the
remaining terms and provisions of this Warrant shall not in any way be affected
or impaired thereby and the parties will attempt in good faith to agree upon a
valid and enforceable provision which shall be a commercially reasonable
substitute therefor, and upon so agreeing, shall incorporate such substitute
provision in this Warrant.

     IN WITNESS WHEREOF, the Company has caused this Warrant to be duly executed
by its authorized officer as of the date first indicated above.

                                    SPECTRUM PHARMACEUTICALS, INC.


                                    By: /s/ Rajesh C. Shrotriya, M.D.
                                        ----------------------------------------
                                    Name: Rajesh C. Shrotriya, M.D.
                                    Title: Chief Executive Officer and President


                                       10

<PAGE>

                          FORM OF ELECTION TO PURCHASE

     (To be executed by the Holder to exercise the right to purchase shares
                  of Common Stock under the foregoing Warrant)

To Spectrum Pharmaceuticals, Inc.:

     In accordance with the Warrant enclosed with this Form of Election to
Purchase, the undersigned hereby irrevocably elects to purchase __________
shares of Common Stock ("Common Stock"), $.001 par value per share, of Spectrum
Pharmaceuticals, Inc. (the "Company") encloses herewith $__________ in cash,
certified or official bank check or checks, which sum represents the aggregate
Exercise Price (as defined in the Warrant) for the number of shares of Common
Stock to which this Form of Election to Purchase relates, together with any
applicable taxes payable by the undersigned pursuant to the Warrant.

     The undersigned requests that certificates for the shares of Common Stock
issuable upon this exercise be issued in the name of:

PLEASE INSERT SOCIAL SECURITY OR
TAX IDENTIFICATION NUMBER:
                                     -------------------------------------------

--------------------------------------------------------------------------------
                         (Please print name and address)

     If the number of shares of Common Stock issuable upon this exercise shall
not be all of the shares of Common Stock which the undersigned is entitled to
purchase in accordance with the enclosed Warrant, the undersigned requests that
a New Warrant (as defined in the Warrant) evidencing the right to purchase the
shares of Common Stock not issuable pursuant to the exercise evidenced hereby be
issued in the name of and delivered to:

--------------------------------------------------------------------------------
                        (Please print name and address)

     By signing below, the Holder represents and warrants to the Company that
the statements contained in Section 12 are true and correct as of the date
hereof, as if given on the date hereof.

Dated:           ,                   Name of Holder:
       ----------  ----
                                     (Print)


                                     -------------------------------------------
                                     (By:)

                                     -------------------------------------------
                                     (Name:)

                                     -------------------------------------------
                                     (Title:)


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


                                       11

<PAGE>

                               FORM OF ASSIGNMENT

           [To be completed and signed only upon transfer of Warrant]

     FOR VALUE RECEIVED, the undersigned hereby sells, assigns and transfers
unto ____________________ the right represented by the Warrant enclosed with
this Form of Assignment to purchase __________ shares of Common Stock of
Spectrum Pharmaceuticals, Inc. to which the Warrant relates and appoints
____________________ attorney to transfer said right on the books of Spectrum
Pharmaceuticals, Inc. with full power of substitution in the premises.


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

                                     -------------------------------------------
                                     Address of Transferee

                                     -------------------------------------------

                                     -------------------------------------------

In the presence of:

----------------------------------


                                       12