EXHIBIT 4.1

                        COMMON STOCK PURCHASE WARRANT(1)

THE SECURITIES REPRESENTED BY THIS CERTIFICATE HAVE BEEN ACQUIRED FOR INVESTMENT
AND HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE
"ACT"), OR ANY APPLICABLE STATE SECURITIES LAW. SUCH SECURITIES MAY NOT BE SOLD
OR TRANSFERRED IN THE ABSENCE OF SUCH REGISTRATION OR AN EXEMPTION UNDER THE ACT
AND ANY APPLICABLE STATE SECURITIES LAW.

NUMBER OF SHARES:  100,000                                   WARRANT NO. _____
(SUBJECT TO ADJUSTMENT)                                          APRIL 7, 2004

                              IMMUNOMEDICS, INC.

                        COMMON STOCK PURCHASE WARRANT

              Void after the date set forth in Section 3 herein

      This Common Stock Purchase Warrant (the "Warrant") entitles Amgen Inc.,
(together with its permitted transferees, the "Holder"), for value received, to
purchase from IMMUNOMEDICS, INC., a Delaware corporation (the "Company"), up to
100,000 fully paid and nonassessable shares of the Company's common stock, par
value $0.01 per share ("Common Stock"), subject to adjustment and vesting as set
forth herein (the "Warrant Shares"). This Warrant shall be exercisable, if at
all, at a price equal to $16.00 per share, subject to adjustment as set forth
herein (the "Exercise Price"). This Warrant also is subject to the following
terms and conditions:

      1. EXERCISE OF WARRANT. Subject to the terms and conditions hereof, this
Warrant may be exercised at the option of the Holder in whole or in part at any
time from and after the date hereof and before the date of expiration set forth
in Section 3 below. Exercise shall be by presentation and surrender to the
Company at its principal office of this Warrant and the subscription form
annexed hereto as Exhibit I, executed by the Holder, together with payment to
the Company in accordance with Section 2 hereof in an amount equal to the
product of the Exercise Price multiplied by the number of Warrant Shares being
purchased upon such exercise.


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      (1)   LEGEND: IN THIS DOCUMENT, [*] CONNOTES MATERIAL THAT HAS BEEN
            OMITTED PURSUANT TO A REQUEST FOR CONFIDENTIAL TREATMENT OF THE
            SAME. SUCH OMITTED MATERIAL HAS BEEN FILED WITH THE SECURITIES AND
            EXCHANGE COMMISSION ON A CONFIDENTIAL BASIS.


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If this Warrant is exercised in part only, the Company shall, promptly after
presentation of this Warrant upon such exercise, execute and deliver a new
Warrant, dated as of the date hereof, evidencing the right of the Holder to
purchase the balance of the Warrant Shares purchasable hereunder upon the same
terms and conditions herein set forth. Upon and as of receipt by the Company of
such properly completed and duly executed subscription form accompanied by
payment as herein provided, the Holder shall be deemed to be the holder of
record of the Warrant Shares issuable upon such exercise, notwithstanding that
the stock transfer books of the Company shall then be closed or that
certificates representing such Warrant Shares shall not then actually be
delivered to the Holder. Certificates for the Warrant Shares so purchased,
together with any other securities or property to which the Holder is entitled
upon such exercise, shall be delivered to the Holder by the Company's transfer
agent at the Company's expense promptly after this Warrant has been exercised
(and in any event within 30 days). Each stock certificate so delivered shall be
in such denominations of Warrant Shares as may be requested by the Holder and
shall be registered as set forth in the applicable subscription form.

      2. PAYMENT OF EXERCISE PRICE. The Exercise Price for the Warrant Shares
being purchased may be paid in cash or by check payable to the Company or wire
transfer of immediately available funds.

      3. EXPIRATION DATE. This Warrant shall expire on April 6, 2009 (or in the
event that April 6, 2009 is not a business day, the next succeeding business
day).

      4. ADJUSTMENT OF EXERCISE PRICE AND NUMBER OF WARRANT SHARES. The number
and kind of securities purchasable upon the exercise of this Warrant and the
Exercise Price shall be subject to adjustment from time to time upon the
happening of certain events as follows:

            4.1 SUBDIVISION OR COMBINATION OF STOCK. If at any time or from time
to time after the date hereof the Company shall subdivide its outstanding shares
of Common Stock, the Exercise Price in effect immediately prior to such
subdivision shall be reduced proportionately and the number of shares of Common
Stock (calculated to the nearest whole share) shall be increased
proportionately, and conversely, in the event the outstanding shares of Common
Stock shall be combined into a smaller number of shares, the Exercise Price in
effect immediately prior to such combination shall be increased proportionately
and the number of shares of Common Stock (calculated to the nearest whole share)
shall be decreased proportionately.

            4.2 ADJUSTMENT FOR STOCK DIVIDENDS. If at any time the Company shall
declare a dividend payable in Common Stock or securities convertible into shares
of Common Stock or make any other distribution upon any class or series of stock
of the Company payable in shares of Common Stock or securities convertible into
shares of Common Stock, the Exercise Price and the number of shares to be
obtained upon exercise of this Warrant shall be adjusted proportionately to
reflect the issuance of any shares of Common Stock or convertible securities, as
the case may be, issuable in payment of such dividend or distribution.

            4.3 REORGANIZATION, RECLASSIFICATION, CONSOLIDATION, MERGER OR SALE.
In the event of any reorganization of the capital stock of the Company, a
consolidation or merger of


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the Company with another corporation (other than a merger in which the Company
is the surviving corporation and the stockholders of the Company prior to such
merger own at least a majority of the outstanding capital stock of the surviving
corporation after such merger), the sale of all or substantially all of the
Company's assets or any transaction involving the transfer of a majority of the
voting power over the capital stock of the Company effected in a manner such
that holders of Common Stock shall be entitled to receive stock, securities, or
other assets or property, then, as a condition of such reorganization,
reclassification, consolidation, merger, sale or transaction, lawful and
adequate provision shall be made whereby the Holder shall have the right to
purchase and receive (in lieu of the shares of the Common Stock immediately
theretofore purchasable and receivable upon the exercise of the rights
represented hereby) such shares of Common 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. In any such reorganization, consolidation,
merger, sale or transaction, including successive events of such nature,
appropriate provision shall be made with respect to the rights and interests of
the Holder such that the provisions hereof (including, without limitation,
provisions for adjustments of the Exercise Price and of the number of shares
purchasable and receivable upon the exercise of this Warrant) thereafter shall
be applicable, as nearly practicable, in relation to any shares of stock,
securities or assets thereafter deliverable upon the exercise hereof and,
promptly following any such reclassification, consolidation, merger, sale or
lease, the successor corporation (if other than the Company) resulting from such
reclassification, consolidation or merger or the corporation purchasing or
leasing such assets shall assume by a supplemental warrant agreement, executed
and mailed or delivered to the Holder at the last address thereof appearing on
the books of Company, the obligation to deliver to the Holder such shares of
stock, securities or assets as, in accordance with the foregoing provisions, the
Holder may be entitled to purchase.

            4.4 ADJUSTMENT OF NUMBER OF WARRANT SHARES. Upon each adjustment in
the Exercise Price pursuant to any provisions of this Section 4, the number of
Warrant Shares purchasable hereunder at that Exercise Price shall be adjusted,
to the nearest whole share, to the product obtained by multiplying such number
of shares purchasable immediately prior to such adjustment in the Exercise Price
by a fraction, the numerator of which shall be the Exercise Price immediately
prior to such adjustment and the denominator of which shall be the Exercise
Price immediately thereafter.

            4.5 MINIMAL ADJUSTMENTS. No adjustment in the Exercise Price and/or
the number of shares of Common Stock subject to this Warrant shall be made if
such adjustment would result in a change in the number of shares represented by
this Warrant of less than one (1) share (the "Adjustment Threshold Amount"). Any
adjustment not made because the Adjustment Threshold Amount is not satisfied
shall be carried forward and made, together with any subsequent adjustments, at
such time as (a) the aggregate amount of all such adjustments is equal to at
least the Adjustment Threshold Amount or (b) the Warrant is exercised.

            4.6 CERTIFICATE AS TO ADJUSTMENTS. Upon the occurrence of each
adjustment or readjustment of the Exercise Price pursuant to this Section 4, the
Warrant shall, without any action on the part of the Holder, be adjusted in
accordance with this Section 4, and the Company


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<PAGE>

shall promptly compute such adjustment or readjustment in accordance with the
terms hereof and prepare and furnish to the Holder a certificate signed by the
Company's chief financial officer setting forth such adjustment or readjustment,
showing in detail the facts upon which such adjustment or readjustment is based.

            4.7 WAIVER OF ADJUSTMENTS. Any adjustment of the Exercise Price
 otherwise required to be made hereunder may be waived with the written consent
 of the Holder and the Company.

      5. NOTICES OF RECORD DATE. In the case of any dividend or distribution,
the adjustment(s) provided for in Section 4 shall become effective immediately
after the date of the issuance or distribution of the shares of Common Stock
and, in the case of any subdivision or combination, the adjustment(s) provided
for in Section 4 shall become effective immediately after the effective date of
such action.

      6. 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 (i) if the Common Stock is not at the time of such determination
publicly traded, the fair market value as determined in good faith by the Board
of Directors of the Company or (ii) if the Common Stock is at the time of such
determination publicly traded, the market price of the Common Stock (the market
price determined, for any date, as the average of the closing prices of the
Common Stock on the Nasdaq National Market (or such other principal securities
exchange or automated quotation system upon which the Common Stock may then be
listed for public trading) for the five immediately preceding trading days on
such exchange).

      7. LOST, STOLEN OR DESTROYED WARRANT. Upon receipt by the Company of
evidence reasonably satisfactory to it of loss, theft, destruction or mutilation
of this Warrant and, in the case of loss, theft or destruction, of reasonably
satisfactory indemnification, or, in the case of mutilation, upon surrender of
this Warrant, the Company, at its expense, will execute and deliver, or instruct
the transfer agent, if any, to execute and deliver, a new Warrant of like tenor
and date, and any such lost, stolen or destroyed Warrant thereupon shall become
void.

      8. ISSUE TAX. The issuance of certificates for shares of Common Stock upon
the exercise of this Warrant shall be made without charge to the Holder for any
issue tax or other tax in respect thereof; provided, however, that the Company
shall not be required to pay any tax that 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 current Holder of the Warrant being exercised.

      9. SHARES TO BE FULLY PAID; RESERVATION OF SHARES. The Company covenants
and agrees that all Warrant Shares which may be issued upon the exercise of this
Warrant will, upon issuance, be validly issued, fully paid and nonassessable and
free from all preemptive or any similar rights and free of any liens or
encumbrances arising through the Company, other than restrictions of transfer
under any state and federal securities laws, as applicable. The Company further
covenants and agrees that during the period within which this Warrant may be
exercised the Company will at all times have authorized and reserved, for the
purpose of issue or transfer


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<PAGE>

upon exercise of this Warrant, a sufficient number of authorized but unissued
shares of Common Stock, 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 or automated quotation system
upon which the Common Stock is listed.

      10. NO IMPAIRMENT. The Company will not, by amendment of its Certificate
of Incorporation or bylaws, or through reorganization, consolidation, merger,
dissolution, issue or sale of securities, sale of assets 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 of this Warrant against
impairment. Without limiting the generality of the foregoing, the Company (a)
will not increase the par value of any shares of stock issuable upon the
exercise of this Warrant above the amount payable therefor upon such exercise,
and (b) will take all such action as may be necessary or appropriate in order
that the Company may validly and legally issue fully paid and non-assessable
shares of Common Stock upon exercise of this Warrant.

      11. NOTICES.

            All notices and other communications required or permitted hereunder
shall be effective upon receipt and shall be in writing and may be delivered in
person, by facsimile, overnight delivery service or U.S. mail, in which event it
may be mailed by first-class, certified or registered, postage prepaid,
addressed:

            if to the Holder, at



                  Amgen Inc.
                  One Amgen Center Drive
                  Thousand Oaks, CA  91320-1789
                  Attention:  Corporate Secretary
                  Fax:  (805) 447-1010

            or



            if to the Company, at



                  Immunomedics, Inc.
                  300 American Road
                  Morris Plains, New Jersey 07950
                  Attention:


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<PAGE>

               Fax:

            with a copy to

               Heller Ehrman White & McAuliffe LLP
               4350 La Jolla Village Drive
               San Diego, California 92122Attention:  Richard A. Kaufman, Esq.
               Fax:  (858) 450-8499

or in any case at such other address as the Holder or the Company shall have
furnished to the other in writing.

      12. RESTRICTIONS ON TRANSFER OF WARRANT SHARES; TRANSFERABILITY; REGISTER.

            12.1 The Holder shall not sell Warrant Shares, either under a
registration statement or otherwise, until the date that is 31 days after the
date of exercise of the Warrant.

            12.2 Prior to the time the Holder first exercises this Warrant, this
Warrant and all rights hereunder are transferable (to the extent permitted under
the Act), in whole, upon surrender of this Warrant with a properly executed
assignment (in the form of Exhibit II hereto) at the principal office of the
Company (or, if another office or agency has been designated by the Company for
such purpose, then at such other office or agency). The Warrant Shares may be
offered, resold, pledged or otherwise transferred from the Holder to a
transferee either (i) pursuant to an effective registration statement as
contemplated under Section 13, or (ii) in a transaction meeting the requirements
of Rule 144 under the Act ("Rule 144") or otherwise in accordance with the Act
and the applicable securities laws of any state of the United States or any
other applicable jurisdiction.

            12.3 The Company will maintain a register containing the name and
address of the Holder of this Warrant. The Holder may change its address as
shown on the warrant register by written notice to the Company requesting such
change.

      13. REGISTRATION RIGHTS.

            13.1 HOLDER INCIDENTAL REGISTRATION. Subject to Section 13.5, if the
Company files a registration statement under the Act (other than a registration
statement on Form S-4 or S-8 or any successor or similar forms) registering an
underwritten offering of Common Stock for cash consideration on any form that
also would permit the registration of the Warrant Shares and any shares of
common stock that may be issued or distributed with respect to, or in exchange
for, the Warrant Shares (the "Registrable Securities") and such filing is to be
on its behalf and/or on behalf of selling holders of the Company's securities,
the Company shall each such time promptly give the Holder written notice of its
intent to make such filing, setting forth the date on which the Company proposes
to file such registration statement, and advising the Holder of its right to
have Registrable Securities included in such registration. The Company will
select the managing underwriter and all other underwriters in any underwritten
offering pursuant to this


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<PAGE>

Section 13.1. Upon the written request of the Holder received by the Company no
later than ten (10) days after the date of the Company's notice, the Company
shall use commercially reasonable efforts to cause to be registered under the
Act all of the Registrable Securities that the Holder has so requested to be
registered; provided that if, at any time after giving written notice of its
intention to register any securities and prior to the effective date of the
registration statement filed in connection with such registration, the Company
shall determine for any reason not to proceed with the proposed registration of
the securities to be sold by it, the Company may, at its election, give written
notice of such determination to the Holder and, thereupon, shall be relieved of
its obligation to register any Registrable Securities in connection with such
registration (but not from its obligation to pay the registration expenses
pursuant to Section 13.4 in connection therewith). If, in the written opinion of
the managing underwriter, the total amount of such securities to be so
registered, including such Registrable Securities, will exceed the maximum
amount of the Company's securities that can be marketed either (a) at a price
reasonably related to the then current market value of such securities, or (b)
without otherwise materially and adversely affecting the entire offering, then
the Company shall include in such registration first (1st), all the securities
the Company proposes to sell for its own account or is required to register on
behalf of any third party exercising demand registration rights and without
having the adverse effect referred to above, and second (2nd), all Registrable
Securities requested to be included in such registration by the Holder pursuant
to this Section 13.1 and all shares of Common Stock requested to be included by
third parties exercising the rights similar to those granted in this Section
13.1, up to the number which the Company has been advised can be sold in such
offering without having either of the adverse effects referred to above. The
number of such Registrable Securities requested to be included in such
registration by the Holder pursuant to this Section 13.1 shall be limited to
such extent and shall be allocated pro rata among the Holder and third parties
exercising rights similar to those granted in this Section 13.1 on the basis of
the relative number of Registrable Securities the Holder has requested to be
included in such registration and the number of shares of Common Stock requested
to be included in such registration by such third parties.

            13.2 OBLIGATIONS OF THE COMPANY. Whenever the Company has filed a
registration statement pursuant to Section 13.1 that registers Registrable
Securities under the Act, the Company will:

            (a) furnish the Holder with a reasonable numbers of copies of the
Registration Statement and any Prospectus included therein (including each
preliminary Prospectus and any amendments or supplements thereto (including all
exhibits and documents incorporated by reference) in conformity with the
requirements of the Act);

            (b) use commercially reasonable efforts to register or qualify the
Registrable Securities covered by such Registration Statement under such other
securities or Blue Sky laws of such jurisdictions within the United States as
the Holder shall request for the distribution of the Registrable Securities
covered by the Registration Statement; provided, however, that the Company shall
not be required in connection therewith or as a condition thereto to qualify to
do business in or to file a general consent to service of process in any
jurisdiction wherein it would not but for the requirements of this paragraph (b)
be obligated to do so;


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<PAGE>

            (c) promptly notify the Holder (1) when such Registration Statement,
amendment, supplement or post-effective amendment has been filed, and, with
respect to such Registration Statement or any post-effective amendment, when the
same has become effective, (2) of any comments by the SEC or by any Blue Sky or
securities commissioner or regulator of any state with respect thereto, (3) of
the issuance by the SEC of any stop order suspending the effectiveness of such
Registration Statement or the initiation or threatening of any proceedings for
that purpose, or (4) of the receipt by the Company of any notification with
respect to the suspension of the qualification of the Registrable Securities for
sale in any jurisdiction or the initiation or threatening of any proceeding for
such purpose;

            (d) provide the Holder and not more than one outside counsel for the
Holder the opportunity to participate in the preparation of such Registration
Statement, each Prospectus included therein or filed with the SEC, and each
amendment or supplement thereto, and (a) promptly incorporate in a Prospectus
supplement or post-effective amendment such information as the Holder or the
Holder's counsel reasonably determine is necessary and appropriate to be
included therein, (b) make all required filings of such Prospectus supplement or
such post-effective amendment as soon as practicable after the Company has
received notification of the matters to be incorporated in such Prospectus
supplement or post-effective amendment, and (c) supplement or make amendments to
such Registration Statement;

            (e) cooperate with the Holder to facilitate the timely preparation
and delivery of certificates representing Registrable Securities to be sold, and
enable such Registrable Securities to be in such denominations and registered in
such names as Holder may request at least five Business Days prior to any sale
of the Registrable Securities;

            (f) otherwise comply with all applicable rules and regulations of
the SEC, and make available to its security holders, as soon as reasonably
practicable, but not later than eighteen months after the effective date of the
Registration Statement, an earnings statement covering the period of at least
twelve months beginning with the first full month after the effective date of
such Registration Statement, which earnings statement shall satisfy the
provisions of Section 11(a) of the Securities Act; and

            (g) use commercially reasonable efforts to list the Registrable
Securities covered by such Registration Statement with any securities exchange
on which the Common Stock of the Company is then listed.

            13.4 FURNISH INFORMATION. It shall be a condition precedent to the
obligations of the Company to take any action pursuant to this Warrant that the
Holder shall furnish to the Company such information regarding itself, the
Registrable Securities held by it, and the intended method of disposition of
such securities as the Company shall reasonably request in writing and as shall
be required in connection with the action to be taken by the Company.

            13.5 EXPENSES OF REGISTRATION. All expenses other than underwriting
discounts and commissions incurred in connection with registrations, filings or
qualifications of Registrable Securities pursuant to Section 13.1, including
without limitation all registration, filing and qualification fees, word
processing, duplicating, printers' and accounting fees


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<PAGE>

(including the expenses of any special audits or "cold comfort" letters required
by or incident to such performance and compliance), fees of the NASD or listing
fees, messenger and delivery expenses, all fees and expenses of complying with
state securities or Blue Sky laws, and fees and disbursements of counsel for the
Company and one outside legal counsel for the Holder, hired to review and
oversee any offering [*], shall be borne by the Company. The Holder shall bear
and pay the underwriting commissions and discounts applicable to the Registrable
Securities offered for its account in connection with any regulations, filings
and qualifications made pursuant to this Warrant.

            13.6 UNDERWRITING REQUIREMENTS. In connection with any underwritten
offering, the Company shall not be required under Section 13.1 to include
Registrable Securities in such underwritten offering unless the Holder accepts
the terms of the underwriting of such offering that have been reasonably agreed
upon between the Company and the underwriters selected by the Company in
accordance with the terms of this Warrant.

            13.7 INDEMNIFICATION. For the purpose of this Section 13.7:

            (a) the term "Selling Stockholder" shall include the Holder and any
"affiliate" (as such term is defined in Rule 144) of the Holder, and their
respective permitted transferees and assigns;

            (b) the term "untrue statement" shall, with respect to any
Registration Statement, include any untrue statement or alleged untrue statement
of a material fact contained in the related Registration Statement, or any
omission or alleged omission to state in the related Registration Statement a
material fact required to be stated therein or necessary to make the statements
therein, not misleading, and, with respect to any Prospectus, include any untrue
statement or alleged untrue statement of a material fact contained in the
related Prospectus, or any omission or alleged omission to state in the related
Prospectus a material fact required to be stated therein or necessary to make
the statements therein, in the light of the circumstances under which they were
made, not misleading.

            (i) The Company agrees to indemnify and hold harmless the Selling
            Stockholder (and each person, if any, who controls the Selling
            Stockholder within the meaning of Section 15 of the Securities Act,
            each officer of the Selling Stockholder and each director of the
            Selling Stockholder) from and against any losses, claims, damages or
            liabilities to which the Selling Stockholder (or any such officer,
            director or controlling person) may become subject (under the
            Securities Act or otherwise) insofar as such losses, claims, damages
            or liabilities (or actions or proceedings in respect thereof) arise
            out of, or are based upon (i) any untrue statement or (ii) any
            failure by the Company to fulfill any undertaking included in the
            related Registration Statement, and the Company will reimburse the
            Selling Stockholder promptly as incurred for any legal or other
            expenses reasonably incurred in investigating, defending or
            preparing to defend any such action, proceeding or claim, provided,
            however, that the Company shall not be liable in any such case to
            the extent that such loss, claim, damage or liability (A) arises out
            of, or is based upon, an untrue statement made in conformity with
            written information furnished to the Company by the Selling
            Stockholder


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<PAGE>

            specifically for use in preparation of the Registration Statement or
            Prospectus (which has not been subsequently corrected or
            supplemented), (B) results directly from the failure of the Selling
            Stockholder to comply in all material respects with its covenants
            and agreements contained in Section 13 hereof respecting sale of the
            Warrant Shares, or (C) arises out of any statement or omission in
            any Prospectus that is corrected in any subsequent Prospectus that
            was delivered to the Selling Stockholder prior to the pertinent sale
            or sales by the Selling Stockholder.

            (ii) The Selling Stockholder agrees to indemnify and hold harmless
            the Company (and each person, if any, who controls the Company
            within the meaning of Section 15 of the Securities Act, each officer
            of the Company and each director of the Company) from and against
            any losses, claims, damages or liabilities to which the Company (or
            any such officer, director or controlling person) may become subject
            (under the Securities Act or otherwise), insofar as such losses,
            claims, damages or liabilities (or actions or proceedings in respect
            thereof) arise out of, or are based upon, any untrue statement if
            such untrue statement was made in conformity with written
            information furnished by the Selling Stockholder specifically for
            use in preparation of the Registration Statement or Prospectus, and
            the Selling Stockholder will reimburse the Company promptly as
            incurred for any legal or other expenses reasonably incurred in
            investigating, defending or preparing to defend any such action,
            proceeding or claim, provided, however, that the Selling Stockholder
            need not indemnify any of the aforementioned indemnitees for such
            losses, claims, damages or liabilities arising from any statement or
            omission in any Prospectus that is corrected in any subsequent
            Prospectus if the subsequent Prospectus was furnished to the person
            or entity asserting the loss, claim, damage or liability prior to
            the pertinent transaction or transactions; provided, further, that
            the Selling Stockholder's obligation to indemnify the Company shall
            be limited to the net amount received by the Selling Stockholder
            from the sale of the Warrant Shares to which the loss related.

            (iii) Promptly after receipt by any indemnified person of a notice
            of a claim or the beginning of any action in respect of which
            indemnity is to be sought against an indemnifying person pursuant to
            this Section 13.7, such indemnified person shall notify the
            indemnifying person in writing of such claim or of the commencement
            of such action, but the omission to so notify the indemnifying party
            will not relieve it from any liability which it may have to any
            indemnified party under this Section 13.7 (except to the extent that
            such omission materially and adversely affects the indemnifying
            party's ability to defend such action) or from any liability
            otherwise than under this Section 13.7. Subject to the provisions
            hereinafter stated, in case any such action shall be brought against
            an indemnified person, the indemnifying person shall be entitled to
            participate therein, and, to the extent that it shall elect by
            written notice delivered to the indemnified party promptly after
            receiving the aforesaid notice from such indemnified party, shall be
            entitled to assume the defense thereof, with counsel reasonably
            satisfactory to such indemnified person. After notice from the
            indemnifying person to such indemnified person of its election to
            assume the defense thereof, such indemnifying person shall not be
            liable to such indemnified


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<PAGE>

            person for any legal expenses subsequently incurred by such
            indemnified person in connection with the defense thereof, provided,
            however, that if there exists or shall exist a conflict of interest
            that would make it inappropriate, in the opinion of counsel to the
            indemnified person, for the same counsel to represent both the
            indemnified person and such indemnifying person or any "affiliate"
            or "associate" (as those terms are defined in Rule 405 promulgated
            under the Securities Act) thereof, the indemnified person shall be
            entitled to retain its own counsel at the expense of such
            indemnifying person; provided, however, that no indemnifying person
            shall be responsible for the fees and expenses of more than one
            separate counsel (together with appropriate local counsel) for all
            indemnified parties. In no event shall any indemnifying person be
            liable in respect of any amounts paid in settlement of any action
            unless the indemnifying person shall have approved the terms of such
            settlement; provided that such consent shall not be unreasonably
            withheld. No indemnifying person shall, without the prior written
            consent of the indemnified person, effect any settlement of any
            pending or threatened proceeding in respect of which any indemnified
            person is or could have been a party and indemnification could have
            been sought hereunder by such indemnified person, unless such
            settlement includes an unconditional release of such indemnified
            person from all liability on claims that are the subject matter of
            such proceeding.

            (iv) If the indemnification provided for in this Section 13.7 is
            unavailable to or insufficient to hold harmless an indemnified party
            under subsection (i) or (ii) above in respect of any losses, claims,
            damages or liabilities (or actions or proceedings in respect
            thereof) referred to therein, then each indemnifying party shall
            contribute to the amount paid or payable by such indemnified party
            as a result of such losses, claims, damages or liabilities (or
            actions in respect thereof) in such proportion as is appropriate to
            reflect the relative fault of the Company on the one hand and the
            Selling Stockholder on the other in connection with the statements
            or omissions or other matters which resulted in such losses, claims,
            damages or liabilities (or actions in respect thereof), as well as
            any other relevant equitable considerations. The relative fault
            shall be determined by reference to, among other things, in the case
            of an untrue statement, whether the untrue statement relates to
            information supplied by the Company on the one hand or the Selling
            Stockholder on the other and the parties' relative intent,
            knowledge, access to information and opportunity to correct or
            prevent such untrue statement. The Company and the Selling
            Stockholder agree that it would not be just and equitable if
            contribution pursuant to this subsection (iv) were determined by pro
            rata allocation (even if Selling Stockholder were treated as one
            entity for such purpose) or by any other method of allocation which
            does not take into account the equitable considerations referred to
            above in this subsection (iv). The amount paid or payable by an
            indemnified party as a result of the losses, claims, damages or
            liabilities (or actions in respect thereof) referred to above in
            this subsection (iv) shall be deemed to include any reasonable legal
            or other expenses reasonably incurred by such indemnified party in
            connection with investigating or defending any such action or claim.
            Notwithstanding the provisions of this subsection (iv), Selling
            Stockholder shall not be required to contribute any amount in excess
            of


                                       11
<PAGE>

            the amount by which the net amount received by Selling Stockholder
            from the sale of the Warrant Shares to which such loss relates
            exceeds the amount of any damages which Selling Stockholder has
            otherwise been required to pay by reason of such untrue statement.
            No person guilty of fraudulent misrepresentation (within the meaning
            of Section 11(f) of the Securities Act) shall be entitled to
            contribution from any person who was not guilty of such fraudulent
            misrepresentation. Selling Stockholder's obligations in this
            subsection to contribute are several in proportion to their sales of
            Warrant Shares to which such loss relates and not joint.

            (v) The parties to this Warrant hereby acknowledge that they are
            sophisticated business persons who were represented by counsel
            during the negotiations regarding the provisions hereof including,
            without limitation, the provisions of this Section 13.7, and are
            fully informed regarding said provisions. They further acknowledge
            that the provisions of this Section 13.7 fairly allocate the risks
            in light of the ability of the parties to investigate the Company
            and its business in order to assure that adequate disclosure is made
            in the Registration Statement as required by the Securities Act and
            the Securities Exchange Act of 1934, as amended (the "Exchange
            Act"). The parties are advised that federal or state public policy
            as interpreted by the courts in certain jurisdictions may be
            contrary to certain of the provisions of this Section 13.7, and the
            parties hereto hereby expressly waive and relinquish any right or
            ability to assert such public policy as a defense to a claim under
            this Section 13.7 and further agree not to attempt to assert any
            such defense.

            13.8 INFORMATION AVAILABLE. So long as a Registration Statement is
effective covering the resale of Warrant Shares owned by the Holder, the Company
will furnish to the Holder, upon its request:

            (a) as soon as practicable after it is available, one copy of (i)
its Annual Report to Stockholders (which Annual Report shall contain financial
statements audited in accordance with generally accepted accounting principles
by a national firm of certified public accountants), (ii) its Annual Report on
Form 10-K and amendments, if any, and (iii) its Quarterly Reports on Form 10-Q
and amendments, if any (the foregoing, in each case, excluding exhibits, unless
specifically requested by the Holder); and

            (b) promptly upon the request of the Holder, an adequate number of
copies of the Prospectuses to supply to any other party requiring such
Prospectuses.

            13.9 COMPANY REPORTS FILED UNDER THE EXCHANGE ACT. With a view to
making available to the Holder the benefits of Rule 144 and other rules or
regulations of the SEC that may permit the Holder to sell the Warrant Shares
without registration, for the first two years after the Holder first exercises
this Warrant, the Company covenants and agrees to (a) comply with all of the
reporting requirements of the Exchange Act applicable to it and shall comply
with all other public information reporting requirements of the SEC that are
conditions to the availability of Rule 144 for the sale of the Warrant Shares
and (b) furnish to the Holder, upon request, a written statement by the Company
that it has complied with the reporting requirements


                                       12
<PAGE>

of Rule 144, the Act and the Securities Exchange Act of 1934, and such other
information as may be reasonably requested in order to avail the Holder of any
rule or regulation of the SEC that permits the selling of any such Warrant
Shares without registration.

      14. AMENDMENT. This Warrant is irrevocable and non-cancelable. The terms
of this Warrant may be amended, modified or waived only with the written consent
of the Company and the Holder.

      15. GOVERNING LAW. This Warrant shall be governed by and construed in
accordance with the laws of the State of Delaware, as such laws are applied to
contracts entered into and wholly to be performed within the State of Delaware.


                                       13
<PAGE>

      IN WITNESS WHEREOF, the Company has executed this Warrant as of
April 7, 2004.

                                          IMMUNOMEDICS, INC.

                                          By: /s/ Cynthia L. Sullivan
                                             -----------------------------------
                                             Name:  Cynthia L. Sullivan
                                             Title: President & CEO


AGREED AND ACCEPTED BY:

AMGEN INC.

By:  /s/ Roger M. Perlmutter
   ---------------------------------
   Name:  Roger M. Perlmutter
   Title: Executive Vice President,
          Research and Development


                                       14
<PAGE>

                                                                       EXHIBIT I

                                 SUBSCRIPTION



Date:___________________________________



________________________________________

________________________________________

________________________________________


      The undersigned, the Holder of the attached Warrant, irrevocably elects to
exercise the purchase right represented by such Warrant to purchase
_________________ shares of common stock, par value $0.01 per share, of the
Company. Simultaneously with the delivery of this subscription form, the
undersigned has made provision for the payment of $________ to the Company (via
[wire transfer] [enclosed check]) representing the Exercise Price. The
certificate(s) for such shares shall be issued in the name of the Holder or as
otherwise indicated below:


                                          ______________________________________
                                          Holder's Signature



                                          ______________________________________
                                          Name for Registration

                                          ______________________________________
                                          Mailing Address

                                          ______________________________________

                                          ______________________________________


                                      I-1
<PAGE>

                                                                      EXHIBIT II



                               ASSIGNMENT FORM

      FOR VALUE RECEIVED, ________________________________________ hereby sells,
assigns and transfers all of the rights of the undersigned under the attached
Warrant (No. ____) with respect to the number of shares of common stock, par
value $0.01 per share, of Immunomedics, Inc. covered thereby set forth below,
unto:

Name of Assignee            Address                    No. of Shares
----------------            -------                    -------------




Dated:_____________________         Signature:________________________________

Signature Guaranteed:

By: _______________________

The signature should be guaranteed by an eligible guarantor institution (banks,
stockbrokers, savings and loan associations and credit unions with membership in
an approved signature guarantee medallion program) pursuant to Rule 17Ad-15
under the Securities Exchange Act of 1934.


                                      I-2