<PAGE>


                                                                     EXHIBIT 4.5

THE SECURITIES REPRESENTED BY THIS CERTIFICATE HAVE BEEN ACQUIRED FOR INVESTMENT
AND HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933 OR ANY STATE
SECURITIES LAWS. SUCH SECURITIES MAY NOT BE SOLD OR TRANSFERRED IN THE ABSENCE
OF SUCH REGISTRATION OR AN EXEMPTION THEREFROM UNDER SAID ACT AND ANY APPLICABLE
STATE SECURITIES LAWS.

                      FORM OF WARRANT TO PURCHASE __ SHARES

                               OF COMMON STOCK OF

                       HOLLIS-EDEN PHARMACEUTICALS, INC.
                         (Void after December 11, 2003)

          This certifies that ____, having an address of ____ (the "Holder"),
for value received, is entitled to purchase from Hollis-Eden Pharmaceuticals,
Inc., a Delaware corporation (the "Company"), having a place of business at 9333
Genesee Avenue, Suite 200, San Diego, California 92121, a maximum of __ fully
paid and nonassessable shares of the Company's Common Stock ("Common Stock") for
cash at a price of $12.00 per share (the "Stock Purchase Price"), at any time or
from time to time up to and including 5:00 p.m. (Pacific time) on December 11,
2003 (the "Expiration Date"), upon surrender to the Company at its principal
office (or at such other location as the Company may advise the Holder in
writing) of this Warrant properly endorsed with the Notice of Exercise attached
hereto as Exhibit A (the "Notice of Exercise") duly completed and signed and
upon payment in cash of the aggregate Stock Purchase Price for the number of
shares for which this Warrant is being exercised determined in accordance with
the provisions hereof. The Stock Purchase Price and the number of shares
purchasable hereunder are subject to adjustment as provided in Section 3 of this
Warrant.

          This Warrant is subject to the following terms and conditions:

          1. Exercise; Issuance of Certificates; Payment for Shares. This
Warrant is exercisable at the option of the holder of record hereof, at any time
or from time to time, up to the Expiration Date for all or any part of the
shares of Common Stock subject to this Warrant. The Company agrees that the
shares of Common Stock purchased under this Warrant shall be and are deemed to
be issued to the Holder hereof as the record owner of such shares as of the
close of business on the date on which this Warrant shall have been surrendered,
properly endorsed, together with a completed Notice of Exercise, and payment
made for such shares. Certificates for the shares of Common Stock so purchased,
together with any other securities or property to which the Holder hereof is
entitled upon such exercise, shall be delivered to the Holder hereof by the
Company at the Company's expense within a reasonable time after the rights
represented by this Warrant have been so exercised. In case of a purchase of
less than all the shares which may be purchased under this Warrant, the Company
shall cancel this Warrant and execute and deliver a new Warrant or Warrants of
like tenor for the balance of the shares purchasable under the Warrant
surrendered upon such purchase to the Holder hereof within a reasonable time.
Each stock certificate so delivered shall be in such denominations of Common
Stock as may be requested by the Holder hereof and shall be registered in the
name or names as nominated by such Holder.

                                       1.

<PAGE>


     2. Shares to be Fully Paid; Reservation of Shares. The Company covenants
and agrees that all shares of Common Stock which may be issued upon the exercise
of the rights represented by this Warrant will, upon issuance, be duly
authorized, validly issued, fully paid and nonassessable and free from all
preemptive rights of any stockholder and free of all taxes, liens and charges
with respect to the issue thereof. The Company further covenants and agrees
that, during the period within which the rights represented by this Warrant may
be exercised, the Company will at all times have authorized and reserved, for
the purpose of issue or transfer upon exercise of the subscription rights
evidenced by this Warrant, a sufficient number of shares of authorized but
unissued Common Stock, or other securities and property, when and as required to
provide for the exercise of the rights represented by this Warrant. The Company
will take all such action as may be necessary to assure that such shares of
Common Stock may be issued as provided herein without violation of any
applicable law or regulation, or of any requirements of any domestic securities
exchange upon which the Common Stock may be listed. The Company will not take
any action which would result in any adjustment of the Stock Purchase Price (as
set forth in Section 3 hereof) if the total number of shares of Common Stock
issuable after such action upon exercise of all outstanding options, warrants
and convertible securities, together with all shares of Common Stock then
outstanding, would exceed the total number of shares of Common Stock then
authorized by the Company's Certificate of Incorporation.

     3. Adjustment of Stock Purchase Price and Number of Shares. The Stock
Purchase Price and the number of shares purchasable upon the exercise of this
Warrant shall be subject to adjustment from time to time upon the occurrence of
certain events described in this Section 3. Upon each adjustment of the Stock
Purchase Price, the Holder of this Warrant shall thereafter be entitled to
purchase, at the Stock Purchase Price resulting from such adjustment, the number
of shares obtained by multiplying the Stock Purchase Price in effect immediately
prior to such adjustment by the number of shares purchasable pursuant hereto
immediately prior to such adjustment, and dividing the product thereof by the
Stock Purchase Price resulting from such adjustment.

          3.1 Subdivision or Combination of Stock. In case the Company shall at
any time subdivide its outstanding shares of Common Stock into a greater number
of shares, the Stock Purchase Price in effect immediately prior to such
subdivision shall be proportionately reduced, and conversely, in case the
outstanding shares of Common Stock of the Company shall be combined into a
smaller number of shares, the Stock Purchase Price in effect immediately prior
to such combination shall be proportionately increased.

          3.2 Dividends in Common Stock, Other Stock, Property,
Reclassification. If at any time or from time to time the Holders of Common
Stock (or any shares of stock or other securities at the time receivable upon
the exercise of this Warrant) shall have received or become entitled to receive,
without payment therefore:

               (a) Common Stock or any shares of stock or other securities which
are at any time directly or indirectly convertible into or exchangeable for
Common Stock, or any rights or options to subscribe for, purchase or otherwise
acquire any of the foregoing by way of dividend or other distribution, or

                                       2.

<PAGE>

               (b) Common Stock or additional stock or other securities or
property (including cash) by way of spinoff, split-up, reclassification,
combination of shares or similar corporate rearrangement (other than shares of
Common Stock issued as a stock split or adjustments in respect of which shall be
covered by the terms of Section 3.1 above), then and in each such case, the
Holder hereof shall, upon the exercise of this Warrant, be entitled to receive,
in addition to the number of shares of Common Stock receivable thereupon, and
without payment of any additional consideration therefor, the amount of stock
and other securities and property (including cash in the case referred to in
this clause (b)) which such Holder would hold on the date of such exercise had
he been the holder of record of such Common Stock as of the date on which
holders of Common Stock received or became entitled to receive such shares or
all other additional stock and other securities and property.

     3.3 Reorganization, Reclassification, Consolidation, Merger or Sale. If any
recapitalization, reclassification or reorganization of the capital stock of the
Company, or any consolidation or merger of the Company with another corporation,
or the sale of all or substantially all of its assets or other transaction shall
be effected in such a way that holders of Common Stock shall be entitled to
receive stock, securities, or other assets or property (a "Transaction"), then,
as a condition of such Transaction, lawful and adequate provisions shall be made
by the Company whereby the Holder hereof shall thereafter have the right to
purchase and receive (in lieu of the shares of the Common Stock of the Company
immediately theretofore purchasable and receivable upon the exercise of the
rights represented hereby) such shares of stock, securities or other assets or
property as may be issued or payable with respect to or in exchange for a number
of outstanding shares of such Common Stock equal to the number of shares of such
stock immediately theretofore purchasable and receivable upon the exercise of
the rights represented hereby; provided, however, that in the event the fair
market value of the stock, securities or other assets or property (determined in
good faith by the Board of Directors of the Company) issuable or payable with
respect to one share of the Common Stock of the Company immediately theretofore
purchasable and receivable upon the exercise of the rights represented hereby is
in excess of the Stock Purchase Price hereof effective at the time of a merger
and securities received in such reorganization, if any, are publicly traded,
then this Warrant shall expire unless exercised prior to such Transaction. In
the event of any Transaction, appropriate provision shall be made by the Company
with respect to the rights and interests of the Holder of this Warrant to the
end that the provisions hereof (including, without limitation, provisions for
adjustments of the Stock Purchase Price and of the number of shares purchasable
and receivable upon the exercise of this Warrant) shall thereafter be
applicable, in relation to any shares of stock, securities or assets thereafter
deliverable upon the exercise hereof.

     3.4 Certain Events. If any change in the outstanding Common Stock of the
Company or any other event occurs as to which the other provisions of this
Section 3 are not strictly applicable or if strictly applicable would not fairly
protect the purchase rights of the Holder of the Warrant in accordance with such
provisions, then the Board of Directors of the Company shall make an adjustment
in the number and class of shares available under the Warrant, the Stock
Purchase Price or the application of such provisions, so as to protect such
purchase rights as aforesaid. The adjustment shall be such as will give the
Holder of the Warrant upon exercise for the same aggregate Stock Purchase Price
the total number, class and kind of shares as he would have owned had the
Warrant been exercised prior to the event and had he continued to hold such
shares until after the event requiring adjustment.

                                       3.

<PAGE>

     3.5  Notices of Change.

          (a) Within 60 days after any adjustment in the number or class of
shares subject to this Warrant and of the Stock Purchase Price, the Company
shall give written notice thereof to the Holder, setting forth in reasonable
detail and certifying the calculation of such adjustment.

          (b) The Company shall also give written notice to the Holder at least
10 business days prior to the date on which a Transaction shall take place.

     4. Issue Tax. The issuance of certificates for shares of Common Stock upon
the exercise of the Warrant shall be made without charge to the Holder of the
Warrant for any issue tax (other than any applicable income taxes for which the
Company may make requisite withholdings) in respect thereof; 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 issuance and delivery of any certificate
in a name other than that of the then Holder of the Warrant being exercised.

     5. Closing of Books. The Company will at no time close its transfer books
against the transfer of any warrant or of any shares of Common Stock issued or
issuable upon the exercise of any warrant in any manner which interferes with
the timely exercise of this Warrant.

     6. No Voting or Dividend Rights; Limitation of Liability. Nothing contained
in this Warrant shall be construed as conferring upon the Holder hereof the
right to vote or to consent or to receive notice as a stockholder of the Company
or any other matters or 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. No
provisions hereof, in the absence of affirmative action by the holder to
purchase shares of Common Stock, and no mere enumeration herein of the rights or
privileges of the holder hereof, shall give rise to any liability of such Holder
for the Stock Purchase Price or as a stockholder of the Company, whether such
liability is asserted by the Company or by its creditors.

     7. Warrants Non-Transferable. Neither this Warrant nor any of Holder's
rights hereunder are transferable, in whole or in part, to any third party,
unless such transfer is made to an employee, affiliate or shareholder of Holder
with notice thereof to the Company. Any attempted assignment or transfer in
violation of the foregoing will be void.

     8. Rights and Obligations Survive Exercise of Warrant. The rights and
obligations of the Company, of the holder of this Warrant and of the holder of
shares of Common Stock issued upon exercise of this Warrant shall survive the
exercise of this Warrant.

     9.   Modification and Waiver.  This Warrant and any provision hereof may be
changed, waived, discharged or terminated only by an instrument in writing
signed by the party against which enforcement of the same is sought.

                                       4.

<PAGE>

     10.  Registration Rights.  Holder shall be entitled to the registration
rights provided in that certain Stock and Warrant Purchase Agreement, dated
December 11, 2001, between Holder and the Company.

     11. Notices. Any notice, request or other document required or permitted to
be given or delivered to the holder hereof or the Company shall be delivered or
shall be sent by certified mail, postage prepaid, to each such holder at its
address as shown on the books of the Company or to the Company at the address
indicated therefor in the first paragraph of this Warrant or such other address
as either may from time to time provide to the other.

     12. Binding Effect on Successors. This Warrant shall be binding upon any
corporation succeeding the Company by merger, consolidation or acquisition of
all or substantially all of the Company's assets. All of the obligations of the
Company relating to the Common Stock issuable upon the exercise of this Warrant
shall survive the exercise and termination of this Warrant.

     13. Descriptive Headings and Governing Law. The description headings of the
several sections and paragraphs of this Warrant are inserted for convenience
only and do not constitute a part of this Warrant. This Warrant shall be
construed and enforced in accordance with, and the rights of the parties shall
be governed by, the laws of the State of Delaware.

     14. Lost Warrants. The Company represents and warrants to the Holder hereof
that upon receipt of evidence reasonably satisfactory to the Company of the
loss, theft, destruction, or mutilation of this Warrant and, in the case of any
such loss, theft or destruction, upon receipt of an indemnity reasonably
satisfactory to the Company, or in the case of any such mutilation upon
surrender and cancellation of such Warrant, the Company, at its expense, will
make and deliver a new Warrant, of like tenor, in lieu of the lost, stolen,
destroyed or mutilated Warrant.

     15. Fractional Shares. No fractional shares shall be issued upon exercise
of this Warrant. The Company shall, in lieu of issuing any fractional share, pay
the holder entitled to such fraction a sum in cash equal to such fraction
multiplied by the then effective Stock Purchase Price.

                                       5.

<PAGE>

     In Witness Whereof, the Company has caused this Warrant to be duly executed
by its officers, thereunto duly authorized this 11/th/ day of December, 2001.

                                    Hollis-Eden Pharmaceuticals, Inc.,
                                    a Delaware corporation


                                    By:_____________________________

                                    Name: Daniel D. Burgess

                                    Title: Chief Financial Officer and Chief
                                    Operating Officer

                                       6.

<PAGE>

                                    EXHIBIT A

                                SUBSCRIPTION FORM

                                                        Date:  _________________
Hollis-Eden Pharmaceuticals, Inc.
9333 Genesee Avenue, Suite 200
San Diego, CA 92121

Attn:  Secretary

Ladies and Gentlemen:

[_]    The undersigned hereby elects to exercise the warrant issued to it by
       Hollis-Eden Pharmaceuticals, Inc. (the "Company") and dated December 11,
       2001 (the "Warrant") and to purchase thereunder
       __________________________________ shares of the Common Stock of the
       Company (the "Shares") at a purchase price of $12.00 per Share or an
       aggregate purchase price of __________________________________ Dollars
       ($__________) (the "Purchase Price").

[_]    The undersigned hereby elects to convert _______________________ percent
       (____%) of the value of the Warrant pursuant to the provisions of Section
       2 of the Warrant.

       Pursuant to the terms of the Warrant the undersigned has delivered the
Purchase Price herewith in full in cash or by certified check or wire transfer.

                                    Very truly yours,

                                    -----------------------------------
                                    Signature

                                    -----------------------------------
                                    Printed Name

<PAGE>

                                   SCHEDULE 1

                                   ----------


The Company has entered into Warrant Agreements with each of the investors set
forth below. Such agreements are identical to the Form of Warrant Agreement to
which this Schedule 1 is attached, except as to the parties thereto and the
number of shares issuable pursuant to each warrant.

<TABLE>
<CAPTION>


                         INVESTOR NAME                            NUMBER OF SHARES
                                                                  ISSUABLE PURSUANT
                                                                     TO WARRANT
          <S>                                                     <C>

          Vertical Ventures Investments LLC                            50,000
          Rochdale Investment Management, LLC                           5,556
          Jackson Square Partners, L.P.                                 7,500
          ANDA Partnership                                              7,500
          BlackRock Funds, Micro-Cap Equity Portfolio                  36,667
          BlackRock Funds, Global Science and Technology
          Portfolio                                                    10,000
          The Lynch Foundation                                          2,778
          Clarion Capital Corporation                                   4,000
          Clarion Partners, L.P.                                        2,000
          Clarion Offshore Fund Ltd.                                    2,000
</TABLE>