<PAGE>

  As filed with the Securities and Exchange Commission on ________________,2001
                                              Registration No. 333-___________
================================================================================
                      SECURITIES AND EXCHANGE COMMISSION
                            Washington, D.C. 20549

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

                                   FORM S-8
                            REGISTRATION STATEMENT
                                     UNDER
                          THE SECURITIES ACT OF 1933

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

                                 MEDAREX, INC.
            (Exact name of registrant as specified in its charter)

           New Jersey                                        22-2822175
(State or other jurisdiction of                           (I.R.S. Employer
 incorporation or organization)                          Identification No.)

        707 State Road, Suite 206                                08540
         Princeton, New Jersey                                (Zip Code)
(Address of Principal Executive Offices)


      MEDAREX, INC. 2001 NON-DIRECTOR/OFFICER EMPLOYEE STOCK OPTION PLAN
                           (Full title of the plan)

                              Donald L. Drakeman
                                 Medarex, Inc.
                                707 State Road
                                   Suite 206
                         Princeton, New Jersey  08540
                    (Name and address of agent for service)

                                (609) 430-2880
         (Telephone number, including area code, of agent for service)

                                  Copies to:

      W. Bradford Middlekauff, Esq.              Dwight A. Kinsey, Esq.
 Vice President, General Counsel and        Satterlee Stephens Burke & Burke LLP
             Secretary                               230 Park Avenue
         Medarex, Inc.                         New York, New York  10169
      707 State Road, Suite 206                      (212) 818-9200
     Princeton, New Jersey  08540
          (609) 430-2880


                        CALCULATION OF REGISTRATION FEE

<TABLE>
<CAPTION>

Title of Securities to be    Amount to be        Proposed maximum        Proposed maximum           Amount of
 registered                  registered (1)      offering price per      aggregate offering       registration fee
                                                     share (2)                price (2)
<S>                         <C>                <C>                     <C>                      <C>
Common Stock, $ .01 par
 value per share             500,000 shares           $27.56                $13,780,000                $3,445

====================================================================================================================
</TABLE>

(1) The registration statement also includes an indeterminable number of
    additional shares that may become issuable as a result of the anti-dilution
    adjustment provisions of the Plan.
(2) Estimated solely for the purpose of determining the registration fee
    pursuant to Rule 457(c) and (h) and based upon the average of the high and
    low sale prices of the Company's Common Stock as reported by the Nasdaq
    National Market as of February 5, 2001.
<PAGE>

                                    PART II

Item 3.   Incorporation of Documents by Reference.
-------   ---------------------------------------

          The following documents filed with the Securities and Exchange
Commission are hereby incorporated by reference:

          (a)  Annual Report on Form 10-K for the fiscal year ended December 31,
1999; (b) Quarterly Reports of the Registrant on Form 10-Q for the three month
periods ended March 31, 2000, June 30, 2000 and September 30, 2000; (c) Proxy
Statement dated April 10, 2000 for Annual Meeting of Shareholders held on May
18, 2000; and (d) the description of the Registrant's Common Stock set forth in
the Registrant's Registration Statement on Form S-3 (File No. 333-95565),
including any amendments or reports filed for the purpose of updating such
description; and

          All reports and other documents filed by the Registrant pursuant to
Sections 13(a), 13(c), 14 and 15(d) of the Securities Exchange Act of 1934, as
amended (the "Exchange Act"), after the filing hereof and prior to a filing of a
post-effective amendment which indicates that all securities offered hereby have
been sold or which deregisters all securities remaining unsold, shall be deemed
to be incorporated by reference herein and to be a part hereof from the date of
the filing of such reports and documents. Any statement contained herein or in
any document incorporated or deemed to be incorporated by reference herein shall
be deemed to be modified or superseded for purposes of this Registration
Statement to the extent that a statement contained herein or in any other
subsequent filed document which also is or is deemed to be incorporated by
reference herein modified or superseded such statement. Any such statement so
modified or superseded shall not be deemed to constitute a part of this
Registration Statement, except as so modified or superseded.

Item 4.   Description of Securities.
-------   -------------------------

          Not applicable.

Item 5.   Interests of Named Experts and Counsel.
-------   --------------------------------------

          Dwight A. Kinsey, Esq., a partner of Satterlee Stephens Burke & Burke
LLP, owns 6,000 shares of the Registrant's Common Stock. Mr. Kinsey also holds
options to purchase 40,000 shares of the Registrant's Common Stock which he
received for services rendered as Assistant Secretary of the Registrant. No
other partner or associate of the firm owns shares or holds options to purchase
shares of the Registrant having a fair market value either individually or in
the aggregate in excess of $50,000.

Item 6.   Indemnification of Directors and Officers.
-------   -----------------------------------------

          Section 14A:3-5 of The New Jersey Business Corporation Act (the
"NJBCA") empowers a New Jersey corporation to indemnify any person who is or was
a director, officer, employee or agent of the indemnifying corporation or of any
constituent corporation absorbed by the indemnifying corporation in a
consolidation or merger and any person who is or was a director, officer,
trustee, employee or agent of any other enterprise, serving as such at the
request of the indemnifying corporation, or of any such constituent corporation,
or legal representative of any such director, officer, trustee, employee or
agent (a "corporate agent"), against his expenses and liabilities incurred in
connection with any proceeding involving the corporate agent, other than a
proceeding by or in the right of the corporation, if (a) such corporate agent
acted in good faith and in a

                                     II-1
<PAGE>

manner he reasonably believed to be in or not opposed to the best interests of
the corporation and (b) with respect to any criminal proceeding, such corporate
agent had no reason to believe that his conduct was unlawful. In addition, a
corporation may indemnify such corporate agent against his expenses in
connection with any proceeding by or in the right of the corporation to procure
a judgment in its favor which involves such corporate agent by reason of his
having been such corporate agent, if he acted in good faith and in a manner he
reasonably believed to be in or not opposed to the best interests of the
corporation. However, in such proceeding no indemnification shall be provided in
respect of any claim, issue or matter as to which such corporate agent shall
have been adjudged to be liable to the corporation, unless and only to the
extent that the Superior Court of the State of New Jersey or the court in which
such proceeding was brought shall determine upon application that despite the
adjudication of liability, but in view of all circumstances of the case, such
corporate agent is fairly and reasonably entitled to indemnity for such expenses
as the Superior Court or such other court shall deem proper.

     Under the NJBCA, a corporation shall indemnify a corporate agent against
expenses to the extent that such corporate agent has been successful on the
merits or otherwise in any proceeding referred to above or in defense of any
claim, issue or matter therein.

     The indemnification and advancement of expenses provided by or granted
pursuant to the NJBCA shall not exclude any other rights, including the right to
be indemnified against liabilities and expenses incurred in proceedings by or in
the right of the corporation, to which a corporate agent may be entitled under a
certificate of incorporation, bylaw, agreement, vote of shareholders, or
otherwise; provided that no indemnification shall be made to or on behalf of a
corporate agent if a judgment or other final adjudication adverse to the
corporate agent establishes that his acts or omissions (a) were in breach of his
duty of loyalty to the corporation or its shareholders, (b) were not in good
faith or involved a knowing violation of law or (c) resulted in receipt by the
corporate agent of an improper personal benefit.

     The Restated Certificate of Incorporation, as amended, and Article XIII of
the Registrant's Amended and Restated By-Laws provide for the indemnification of
its Officers and Directors under certain circumstances and are incorporated
herein by reference.

Item  7.   Exemption from Registration Claimed.
--------   -----------------------------------

        Not applicable.

Item 8.   Exhibits.
-------   --------



 Exhibit No.                   Description
 ----------                    -----------

 4(b)             Restated Certificate of Incorporation,
                  as amended, of Medarex, Inc.
                  (Incorporated by reference to Exhibit
                  3.1 to the Registrant's Registration
                  Statement on Form S-3 (file No. 333-95565).


                                     II-2
<PAGE>

         4(c)        Medarex, Inc. Amended and Restated
                     By-Laws (Incorporated by reference to
                     Exhibit 3.2 to the Registrant's
                     Registration Statement on Form S-3
                     (File No. 333-95565).




         5           Opinion of Satterlee Stephens Burke &
                     Burke LLP as to legality of the
                     securities being registered


         10.1        Medarex, Inc. 2001 Non-Director/ Officer
                     Employee Stock Option Plan

         15          Not Applicable

         23(a)       Consent of Ernst & Young LLP

         23(b)       Consent of Satterlee Stephens Burke &
                     Burke LLP (included in opinion filed as
                     Exhibit 5)

         24          Power of Attorney (accompanies signature
                     pages to the Registration Statement)

         27          Not Applicable

         28          Not Applicable

         99          Not Applicable

Item 9.    Undertakings.
------     ------------

  The undersigned Registrant hereby undertakes as follows:

  (1)  To file, during any period in which offers or sales are being made, a
       post-effective amendment to this registration statement:

      (i)    To include any prospectus required by Section 10(a)(3) of the
             Securities Act of 1933 (the "Securities Act");

      (ii)   To reflect in the prospectus any facts or events arising after the
             effective date of the registration statement (or the most recent
             post-effective amendment thereof) which, individually or in
             aggregate, represent a fundamental change in the information set
             forth in this registration statement;

      (iii)  To include any material information with respect to the plan of
             distribution not previously disclosed in this registration
             statement or any material change to such information in this
             registration statement;

                                     II-3
<PAGE>

provided, however, that the undertakings set forth in paragraphs (i) and (ii)
--------  -------
above shall not apply if the information required to be included in a post-
effective amendment by those paragraphs is contained in periodic reports filed
with or furnished to the Securities and Exchange Commission by the Registrant
pursuant to Section 13 or Section 15(d) of the Exchange Act that are
incorporated by reference in this registration statement.

  (2)  That, for the purpose of determining any liability under the Securities
Act, each such post-effective amendment shall be deemed to be a new registration
statement relating to the securities offered therein, and the offering of such
securities at the time shall be deemed to be the initial bona fide offering
thereof.

  (3)  To remove from registration by means of a post-effective amendment any of
the securities being registered which remain unsold at the termination of the
offering.

  (4)  That, for purposes of determining any liability under the Securities Act,
each filing of the Registrant's annual report pursuant to Section 13(a) or
Section 15(d) of the Exchange Act (and, where applicable, each filing of an
employee benefit plan's annual report pursuant to Section 15(d) of the Exchange
Act) that is incorporated by reference in this registration statement shall be
deemed to be a new registration statement relating to the securities offered
therein, and the offering of such securities at that time shall be deemed to be
the initial bona fide offering thereof.

  (5)  To deliver or cause to be delivered with the prospectus, to each person
to whom the prospectus is sent or given, the latest annual report to security
holders that is incorporated by reference in the prospectus and furnished
pursuant to and meeting the requirements of Rule 14a-3 or Rule 14c-3 under the
Exchange Act; and, where interim financial information required to be presented
by Article 3 of Regulation S-X is not set forth in the prospectus, to deliver,
or cause to be delivered to each person to whom the prospectus or cause to be
delivered to each person to whom the prospectus is sent or given, the latest
quarterly report that is specifically incorporated by reference in the
prospectus to provide such interim financial information.

  (6)  Insofar as indemnification for liabilities arising under the Securities
Act may be permitted to directors, officers, and controlling persons of the
Registrant pursuant to the foregoing provisions or otherwise, the Registrant has
been advised that in the opinion of the Securities and Exchange Commission such
indemnification is against public policy as expressed in the Securities Act and
is, therefore, unenforceable. In the event that a claim for indemnification
against such liabilities (other than the payment by the Registrant of expenses
incurred or paid by a director, officer or controlling person of the Registrant
in the successful defense of any action, suit or proceeding) is asserted by such
director, officer or controlling person in connection with the securities being
registered, the Registrant will, unless in the opinion of its counsel the matter
has been settled by controlling precedent, submit to a court of appropriate
jurisdiction the question whether such indemnification by it is against public
policy as expressed in the Securities Act and will be governed by the final
adjudication of such issue.


                                     II-4
<PAGE>

                                  SIGNATURES

     Pursuant to the requirements of the Securities Act of 1933, the Registrant
certifies that it has reasonable grounds to believe that it meets all of the
requirements for filing on Form S-8 and has duly caused this registration
statement or amendment thereto to be signed on its behalf by the undersigned,
thereunto duly authorized, in the Township of Princeton, State of New Jersey, on
this 31st day of January, 2001.

                                 MEDAREX, INC.

                                 By: /s/Irwin Lerner
                                     ----------------------------------
                                     Irwin Lerner-Chairman of the Board


                               POWER OF ATTORNEY

KNOW ALL MEN BY THESE PRESENTS:

     That the undersigned officers and directors of Medarex, Inc., a New Jersey
corporation, do hereby constitute and appoint Donald L. Drakeman and Christian
S. Schade, and either of them, the lawful attorney and agent, with power and
authority to do any and all acts and things and to execute any and all
instruments which said attorney and agent, determine may be necessary or
advisable or required to enable said corporation to comply with the Securities
Act of 1933, as amended, and any rules or regulations or requirements of the
Securities and Exchange Commission in connection with this Registration
Statement. Without limiting the generality of the foregoing power of authority,
the powers granted include the power and authority to sign the names of the
undersigned officers and directors in the capacities indicated below to this
Registration Statement, to any and all amendments and supplements thereof, and
to any and all instruments or documents filed as part of or in connection with
such Registration Statement, and each of the undersigned hereby certifies and
confirms all that said attorney and agent, shall do or cause to be done by
virtue hereof. The Power of Attorney may be signed in several counterparts.

     IN WITNESS WHEREOF, the undersigned has executed this Power of Attorney as
of the dates indicated below.

     Pursuant to the requirements of the Securities Act of 1933, as amended,
this Registration Statement has been signed below by the following persons in
the capacities and on the dates indicated.

<TABLE>
<CAPTION>
              Signature                                   Title                             Date
              ---------                                   -----                             ----
<S>                                     <C>                                        <C>

/s/ Irwin Lerner                        Chairman of the Board                         January 31, 2001
--------------------------------------
Irwin Lerner

/s/ Donald L. Drakeman                  President, Chief Executive Officer and        January 31, 2001
--------------------------------------  Director (Principal Executive Officer)
Donald L. Drakeman

/s/ Michael A. Appelbaum                Executive Vice President and Director         January 31, 2001
--------------------------------------
Michael A. Appelbaum

/s/ Christian S. Schade                 Senior Vice President, Treasurer and          January 31, 2001
--------------------------------------  Chief Financial Officer (Principal
Christian S. Schade                     Financial and Accounting Officer)

/s/ Michael W. Fanger                   Director                                      January 31, 2001
--------------------------------------
Michael W. Fanger
</TABLE>
<PAGE>

/s/ Julius A. Vida                      Director               January 31, 2001
-----------------------------
Julius A. Vida

/s/ Charles R. Schaller                 Director               January 31, 2001
-----------------------------
Charles R. Schaller

/s/ W. Leigh Thompson, Jr.              Director               January 31, 2001
-----------------------------
W. Leigh Thompson, Jr.

/s/ Frederick B. Craves                 Director               January 31, 2001
-----------------------------
Frederick B. Craves
<PAGE>

                               INDEX TO EXHIBITS


<TABLE>
<CAPTION>

 Exhibit No.                   Description
 -----------                   -----------
<S>                         <C>

5                         Opinion of Satterlee Stephens Burke &
                          Burke LLP as to legality of the
                          securities being registered


10.1                      Medarex, Inc. 2001 Non-Director/Officer
                          Employees Stock Option Plan

23(a)                     Consent of Ernst & Young LLP

</TABLE>
[{"type": "S-8", "sequence": "1", "filename": "0001.txt", "description": "FORM S-8", "secsgml_size_bytes": 20468}]
{"company-data": {"conformed-name": "MEDAREX INC", "cik": "0000874255", "assigned-sic": "2836", "irs-number": "222822175", "state-of-incorporation": "NJ", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-55224", "film-number": "1528546"}, "business-address": {"street1": "707 STATE ROAD 206", "city": "PRINCETON", "state": "NJ", "zip": "08540", "phone": "9087136001"}, "mail-address": {"street1": "707 STATE ROAD 206", "city": "PRINCETON", "state": "NJ", "zip": "08540"}}
As filed with the Securities and Exchange Commission on ________________,2001
                                              Registration No. 333-___________
================================================================================
                      SECURITIES AND EXCHANGE COMMISSION
                            Washington, D.C. 20549

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

                                   FORM S-8
                            REGISTRATION STATEMENT
                                     UNDER
                          THE SECURITIES ACT OF 1933

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

                                 MEDAREX, INC.
            (Exact name of registrant as specified in its charter)

           New Jersey                                        22-2822175
(State or other jurisdiction of                           (I.R.S. Employer
 incorporation or organization)                          Identification No.)

        707 State Road, Suite 206                                08540
         Princeton, New Jersey                                (Zip Code)
(Address of Principal Executive Offices)

      MEDAREX, INC. 2001 NON-DIRECTOR/OFFICER EMPLOYEE STOCK OPTION PLAN
                           (Full title of the plan)

                              Donald L. Drakeman
                                 Medarex, Inc.
                                707 State Road
                                   Suite 206
                         Princeton, New Jersey  08540
                    (Name and address of agent for service)

                                (609) 430-2880
         (Telephone number, including area code, of agent for service)

                                  Copies to:

      W. Bradford Middlekauff, Esq.              Dwight A. Kinsey, Esq.
 Vice President, General Counsel and        Satterlee Stephens Burke & Burke LLP
             Secretary                               230 Park Avenue
         Medarex, Inc.                         New York, New York  10169
      707 State Road, Suite 206                      (212) 818-9200
     Princeton, New Jersey  08540
          (609) 430-2880

                        CALCULATION OF REGISTRATION FEE
Title of Securities to be    Amount to be        Proposed maximum        Proposed maximum           Amount of
 registered                  registered (1)      offering price per      aggregate offering       registration fee
                                                     share (2)                price (2)
Common Stock, $ .01 par
 value per share             500,000 shares           $27.56                $13,780,000                $3,445

====================================================================================================================
(1) The registration statement also includes an indeterminable number of
    additional shares that may become issuable as a result of the anti-dilution
    adjustment provisions of the Plan.
(2) Estimated solely for the purpose of determining the registration fee
    pursuant to Rule 457(c) and (h) and based upon the average of the high and
    low sale prices of the Company's Common Stock as reported by the Nasdaq
    National Market as of February 5, 2001.
PART II

Item 3.   Incorporation of Documents by Reference.
-------   ---------------------------------------

          The following documents filed with the Securities and Exchange
Commission are hereby incorporated by reference:

          (a)  Annual Report on Form 10-K for the fiscal year ended December 31,
1999; (b) Quarterly Reports of the Registrant on Form 10-Q for the three month
periods ended March 31, 2000, June 30, 2000 and September 30, 2000; (c) Proxy
Statement dated April 10, 2000 for Annual Meeting of Shareholders held on May
18, 2000; and (d) the description of the Registrant's Common Stock set forth in
the Registrant's Registration Statement on Form S-3 (File No. 333-95565),
including any amendments or reports filed for the purpose of updating such
description; and

          All reports and other documents filed by the Registrant pursuant to
Sections 13(a), 13(c), 14 and 15(d) of the Securities Exchange Act of 1934, as
amended (the "Exchange Act"), after the filing hereof and prior to a filing of a
post-effective amendment which indicates that all securities offered hereby have
been sold or which deregisters all securities remaining unsold, shall be deemed
to be incorporated by reference herein and to be a part hereof from the date of
the filing of such reports and documents. Any statement contained herein or in
any document incorporated or deemed to be incorporated by reference herein shall
be deemed to be modified or superseded for purposes of this Registration
Statement to the extent that a statement contained herein or in any other
subsequent filed document which also is or is deemed to be incorporated by
reference herein modified or superseded such statement. Any such statement so
modified or superseded shall not be deemed to constitute a part of this
Registration Statement, except as so modified or superseded.

Item 4.   Description of Securities.
-------   -------------------------

          Not applicable.

Item 5.   Interests of Named Experts and Counsel.
-------   --------------------------------------

          Dwight A. Kinsey, Esq., a partner of Satterlee Stephens Burke & Burke
LLP, owns 6,000 shares of the Registrant's Common Stock. Mr. Kinsey also holds
options to purchase 40,000 shares of the Registrant's Common Stock which he
received for services rendered as Assistant Secretary of the Registrant. No
other partner or associate of the firm owns shares or holds options to purchase
shares of the Registrant having a fair market value either individually or in
the aggregate in excess of $50,000.

Item 6.   Indemnification of Directors and Officers.
-------   -----------------------------------------

          Section 14A:3-5 of The New Jersey Business Corporation Act (the
"NJBCA") empowers a New Jersey corporation to indemnify any person who is or was
a director, officer, employee or agent of the indemnifying corporation or of any
constituent corporation absorbed by the indemnifying corporation in a
consolidation or merger and any person who is or was a director, officer,
trustee, employee or agent of any other enterprise, serving as such at the
request of the indemnifying corporation, or of any such constituent corporation,
or legal representative of any such director, officer, trustee, employee or
agent (a "corporate agent"), against his expenses and liabilities incurred in
connection with any proceeding involving the corporate agent, other than a
proceeding by or in the right of the corporation, if (a) such corporate agent
acted in good faith and in a

                                     II-1
manner he reasonably believed to be in or not opposed to the best interests of
the corporation and (b) with respect to any criminal proceeding, such corporate
agent had no reason to believe that his conduct was unlawful. In addition, a
corporation may indemnify such corporate agent against his expenses in
connection with any proceeding by or in the right of the corporation to procure
a judgment in its favor which involves such corporate agent by reason of his
having been such corporate agent, if he acted in good faith and in a manner he
reasonably believed to be in or not opposed to the best interests of the
corporation. However, in such proceeding no indemnification shall be provided in
respect of any claim, issue or matter as to which such corporate agent shall
have been adjudged to be liable to the corporation, unless and only to the
extent that the Superior Court of the State of New Jersey or the court in which
such proceeding was brought shall determine upon application that despite the
adjudication of liability, but in view of all circumstances of the case, such
corporate agent is fairly and reasonably entitled to indemnity for such expenses
as the Superior Court or such other court shall deem proper.

     Under the NJBCA, a corporation shall indemnify a corporate agent against
expenses to the extent that such corporate agent has been successful on the
merits or otherwise in any proceeding referred to above or in defense of any
claim, issue or matter therein.

     The indemnification and advancement of expenses provided by or granted
pursuant to the NJBCA shall not exclude any other rights, including the right to
be indemnified against liabilities and expenses incurred in proceedings by or in
the right of the corporation, to which a corporate agent may be entitled under a
certificate of incorporation, bylaw, agreement, vote of shareholders, or
otherwise; provided that no indemnification shall be made to or on behalf of a
corporate agent if a judgment or other final adjudication adverse to the
corporate agent establishes that his acts or omissions (a) were in breach of his
duty of loyalty to the corporation or its shareholders, (b) were not in good
faith or involved a knowing violation of law or (c) resulted in receipt by the
corporate agent of an improper personal benefit.

     The Restated Certificate of Incorporation, as amended, and Article XIII of
the Registrant's Amended and Restated By-Laws provide for the indemnification of
its Officers and Directors under certain circumstances and are incorporated
herein by reference.

Item  7.   Exemption from Registration Claimed.
--------   -----------------------------------

        Not applicable.

Item 8.   Exhibits.
-------   --------

 Exhibit No.                   Description
 ----------                    -----------

 4(b)             Restated Certificate of Incorporation,
                  as amended, of Medarex, Inc.
                  (Incorporated by reference to Exhibit
                  3.1 to the Registrant's Registration
                  Statement on Form S-3 (file No. 333-95565).

                                     II-2
4(c)        Medarex, Inc. Amended and Restated
                     By-Laws (Incorporated by reference to
                     Exhibit 3.2 to the Registrant's
                     Registration Statement on Form S-3
                     (File No. 333-95565).

         5           Opinion of Satterlee Stephens Burke &
                     Burke LLP as to legality of the
                     securities being registered

         10.1        Medarex, Inc. 2001 Non-Director/ Officer
                     Employee Stock Option Plan

         15          Not Applicable

         23(a)       Consent of Ernst & Young LLP

         23(b)       Consent of Satterlee Stephens Burke &
                     Burke LLP (included in opinion filed as
                     Exhibit 5)

         24          Power of Attorney (accompanies signature
                     pages to the Registration Statement)

         27          Not Applicable

         28          Not Applicable

         99          Not Applicable

Item 9.    Undertakings.
------     ------------

  The undersigned Registrant hereby undertakes as follows:

  (1)  To file, during any period in which offers or sales are being made, a
       post-effective amendment to this registration statement:

      (i)    To include any prospectus required by Section 10(a)(3) of the
             Securities Act of 1933 (the "Securities Act");

      (ii)   To reflect in the prospectus any facts or events arising after the
             effective date of the registration statement (or the most recent
             post-effective amendment thereof) which, individually or in
             aggregate, represent a fundamental change in the information set
             forth in this registration statement;

      (iii)  To include any material information with respect to the plan of
             distribution not previously disclosed in this registration
             statement or any material change to such information in this
             registration statement;

                                     II-3
provided, however, that the undertakings set forth in paragraphs (i) and (ii)
--------  -------
above shall not apply if the information required to be included in a post-
effective amendment by those paragraphs is contained in periodic reports filed
with or furnished to the Securities and Exchange Commission by the Registrant
pursuant to Section 13 or Section 15(d) of the Exchange Act that are
incorporated by reference in this registration statement.

  (2)  That, for the purpose of determining any liability under the Securities
Act, each such post-effective amendment shall be deemed to be a new registration
statement relating to the securities offered therein, and the offering of such
securities at the time shall be deemed to be the initial bona fide offering
thereof.

  (3)  To remove from registration by means of a post-effective amendment any of
the securities being registered which remain unsold at the termination of the
offering.

  (4)  That, for purposes of determining any liability under the Securities Act,
each filing of the Registrant's annual report pursuant to Section 13(a) or
Section 15(d) of the Exchange Act (and, where applicable, each filing of an
employee benefit plan's annual report pursuant to Section 15(d) of the Exchange
Act) that is incorporated by reference in this registration statement shall be
deemed to be a new registration statement relating to the securities offered
therein, and the offering of such securities at that time shall be deemed to be
the initial bona fide offering thereof.

  (5)  To deliver or cause to be delivered with the prospectus, to each person
to whom the prospectus is sent or given, the latest annual report to security
holders that is incorporated by reference in the prospectus and furnished
pursuant to and meeting the requirements of Rule 14a-3 or Rule 14c-3 under the
Exchange Act; and, where interim financial information required to be presented
by Article 3 of Regulation S-X is not set forth in the prospectus, to deliver,
or cause to be delivered to each person to whom the prospectus or cause to be
delivered to each person to whom the prospectus is sent or given, the latest
quarterly report that is specifically incorporated by reference in the
prospectus to provide such interim financial information.

  (6)  Insofar as indemnification for liabilities arising under the Securities
Act may be permitted to directors, officers, and controlling persons of the
Registrant pursuant to the foregoing provisions or otherwise, the Registrant has
been advised that in the opinion of the Securities and Exchange Commission such
indemnification is against public policy as expressed in the Securities Act and
is, therefore, unenforceable. In the event that a claim for indemnification
against such liabilities (other than the payment by the Registrant of expenses
incurred or paid by a director, officer or controlling person of the Registrant
in the successful defense of any action, suit or proceeding) is asserted by such
director, officer or controlling person in connection with the securities being
registered, the Registrant will, unless in the opinion of its counsel the matter
has been settled by controlling precedent, submit to a court of appropriate
jurisdiction the question whether such indemnification by it is against public
policy as expressed in the Securities Act and will be governed by the final
adjudication of such issue.

                                     II-4
SIGNATURES

     Pursuant to the requirements of the Securities Act of 1933, the Registrant
certifies that it has reasonable grounds to believe that it meets all of the
requirements for filing on Form S-8 and has duly caused this registration
statement or amendment thereto to be signed on its behalf by the undersigned,
thereunto duly authorized, in the Township of Princeton, State of New Jersey, on
this 31st day of January, 2001.

                                 MEDAREX, INC.

                                 By: /s/Irwin Lerner
                                     ----------------------------------
                                     Irwin Lerner-Chairman of the Board

                               POWER OF ATTORNEY

KNOW ALL MEN BY THESE PRESENTS:

     That the undersigned officers and directors of Medarex, Inc., a New Jersey
corporation, do hereby constitute and appoint Donald L. Drakeman and Christian
S. Schade, and either of them, the lawful attorney and agent, with power and
authority to do any and all acts and things and to execute any and all
instruments which said attorney and agent, determine may be necessary or
advisable or required to enable said corporation to comply with the Securities
Act of 1933, as amended, and any rules or regulations or requirements of the
Securities and Exchange Commission in connection with this Registration
Statement. Without limiting the generality of the foregoing power of authority,
the powers granted include the power and authority to sign the names of the
undersigned officers and directors in the capacities indicated below to this
Registration Statement, to any and all amendments and supplements thereof, and
to any and all instruments or documents filed as part of or in connection with
such Registration Statement, and each of the undersigned hereby certifies and
confirms all that said attorney and agent, shall do or cause to be done by
virtue hereof. The Power of Attorney may be signed in several counterparts.

     IN WITNESS WHEREOF, the undersigned has executed this Power of Attorney as
of the dates indicated below.

     Pursuant to the requirements of the Securities Act of 1933, as amended,
this Registration Statement has been signed below by the following persons in
the capacities and on the dates indicated.
Signature                                   Title                             Date
              ---------                                   -----                             ----
/s/ Irwin Lerner                        Chairman of the Board                         January 31, 2001
--------------------------------------
Irwin Lerner

/s/ Donald L. Drakeman                  President, Chief Executive Officer and        January 31, 2001
--------------------------------------  Director (Principal Executive Officer)
Donald L. Drakeman

/s/ Michael A. Appelbaum                Executive Vice President and Director         January 31, 2001
--------------------------------------
Michael A. Appelbaum

/s/ Christian S. Schade                 Senior Vice President, Treasurer and          January 31, 2001
--------------------------------------  Chief Financial Officer (Principal
Christian S. Schade                     Financial and Accounting Officer)

/s/ Michael W. Fanger                   Director                                      January 31, 2001
--------------------------------------
Michael W. Fanger
/s/ Julius A. Vida                      Director               January 31, 2001
-----------------------------
Julius A. Vida

/s/ Charles R. Schaller                 Director               January 31, 2001
-----------------------------
Charles R. Schaller

/s/ W. Leigh Thompson, Jr.              Director               January 31, 2001
-----------------------------
W. Leigh Thompson, Jr.

/s/ Frederick B. Craves                 Director               January 31, 2001
-----------------------------
Frederick B. Craves
INDEX TO EXHIBITS
Exhibit No.                   Description
 -----------                   -----------
5                         Opinion of Satterlee Stephens Burke &
                          Burke LLP as to legality of the
                          securities being registered

10.1                      Medarex, Inc. 2001 Non-Director/Officer
                          Employees Stock Option Plan

23(a)                     Consent of Ernst & Young LLP