<PAGE>

As filed with the Securities and Exchange Commission on June 12, 2000
                                                      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 Identification
  incorporation or organization)                             No.)

 707 State Road, Suite 206                                     08801
 Princeton, New Jersey 08540                                (Zip Code)
 (Address of Principal Executive Offices)

                     MEDAREX, INC. 2000 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:

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


<TABLE>
<CAPTION>
                                           CALCULATION OF REGISTRATION FEE
====================================================================================================================
                                                    Proposed maximum        Proposed maximum
 Title of Securities to be       Amount to be      offering price per      aggregate offering         Amount of
         registered             registered (1)         share (2)               price (2)           registration fee
--------------------------------------------------------------------------------------------------------------------
<S>                           <C>                  <C>                     <C>                     <C>
Common Stock, $ .01 par
value per share               1,000,000 shares          $ 67.625              $67,625,000              $ 17,853
====================================================================================================================
</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 June 7, 2000.
<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 Report of the Company on Form 10-Q for the three month
period ended March 31, 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-1 (File No. 33-98244), 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 3,000 shares Medarex Common Stock. Mr. Kinsey also holds options to
purchase 30,000 shares of Medarex Common Stock (20,000 shares personally and
10,000 shares as nominee for the firm of Satterlee Stephens Burke & Burke, LLP)
which he received for services rendered as an officer of Medarex. No other
partner or associate of the firm owns shares or holds options to purchase shares
of Medarex.

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 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
<PAGE>

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.

                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-1
                                (File No. 33-39956) filed on April 12, 1991).
<PAGE>

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

                10.1            Medarex, Inc.  2000 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;

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.
<PAGE>

     (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.
<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 City of Princeton, State of New Jersey, on
this 5th day of June, 2000.

                                  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
Michael A. Appelbaum, 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                                June 5, 2000
-------------------------------------
Irwin Lerner

/s/Donald L. Drakeman                        President, Chief Executive Officer and               June 5, 2000
-------------------------------------        Director (Principal Executive Officer)
Donald L. Drakeman

/s/Michael A. Appelbaum                      Executive Vice President-Finance and                 June 5, 2000
-------------------------------------        Administration, Treasurer, Chief Financial
Michael A. Applebuam                         Officer and Director (Principal Financial
                                             and Accounting Officer)

/s/Michael W. Fanger                         Director                                             June 5, 2000
-------------------------------------
Michael W. Fanger

/s/Julius A. Vida                            Director                                             June 5, 2000
-------------------------------------
Julius A. Vida

/s/Charles R. Schaller                       Director                                             June 5, 2000
-------------------------------------
Charles R. Schaller

/s/W. Leigh Thompson, Jr.                    Director                                             June 5, 2000
-------------------------------------
W. Leigh Thompson, Jr.

/s/Frederick B. Craves                       Director                                             June 5, 2000
-------------------------------------
Frederick B. Craves
</TABLE>
<PAGE>

                               INDEX TO EXHIBITS



               Exhibit No.                      Description
               -----------                      -----------
               4(b)               Restated Certificate of Incorporation,
                                  as amended, of Medarex, Inc.

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

               10.1               Medarex, Inc.  2000 Stock Option Plan

               23(a)              Consent of Ernst & Young LLP
[{"type": "S-8", "sequence": "1", "filename": "0001.txt", "description": "FORM S-8", "secsgml_size_bytes": 20891}]
{"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": "333-39084", "film-number": "653526"}, "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 June 12, 2000
                                                      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 Identification
  incorporation or organization)                             No.)

 707 State Road, Suite 206                                     08801
 Princeton, New Jersey 08540                                (Zip Code)
 (Address of Principal Executive Offices)

                     MEDAREX, INC. 2000 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                                 Dwight A. Kinsey, Esq.
Vice President, General Counsel and Secretary             Satterlee Stephens Burke & Burke LLP
               Medarex, Inc.                                        230 Park Avenue
        707 State Road, Suite 206                               New York, New York 10169
       Princeton, New Jersey 08540                                   (212) 818-9200
             (609) 430-2880
CALCULATION OF REGISTRATION FEE
====================================================================================================================
                                                    Proposed maximum        Proposed maximum
 Title of Securities to be       Amount to be      offering price per      aggregate offering         Amount of
         registered             registered (1)         share (2)               price (2)           registration fee
--------------------------------------------------------------------------------------------------------------------
Common Stock, $ .01 par
value per share               1,000,000 shares          $ 67.625              $67,625,000              $ 17,853
====================================================================================================================
(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 June 7, 2000.
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 Report of the Company on Form 10-Q for the three month
period ended March 31, 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-1 (File No. 33-98244), 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 3,000 shares Medarex Common Stock. Mr. Kinsey also holds options to
purchase 30,000 shares of Medarex Common Stock (20,000 shares personally and
10,000 shares as nominee for the firm of Satterlee Stephens Burke & Burke, LLP)
which he received for services rendered as an officer of Medarex. No other
partner or associate of the firm owns shares or holds options to purchase shares
of Medarex.

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 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.

                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-1
                                (File No. 33-39956) filed on April 12, 1991).
5               Opinion of Satterlee Stephens Burke & Burke LLP
                                as to legality of the securities being
                                registered

                10.1            Medarex, Inc.  2000 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;

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.
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 City of Princeton, State of New Jersey, on
this 5th day of June, 2000.

                                  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
Michael A. Appelbaum, 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                                June 5, 2000
-------------------------------------
Irwin Lerner

/s/Donald L. Drakeman                        President, Chief Executive Officer and               June 5, 2000
-------------------------------------        Director (Principal Executive Officer)
Donald L. Drakeman

/s/Michael A. Appelbaum                      Executive Vice President-Finance and                 June 5, 2000
-------------------------------------        Administration, Treasurer, Chief Financial
Michael A. Applebuam                         Officer and Director (Principal Financial
                                             and Accounting Officer)

/s/Michael W. Fanger                         Director                                             June 5, 2000
-------------------------------------
Michael W. Fanger

/s/Julius A. Vida                            Director                                             June 5, 2000
-------------------------------------
Julius A. Vida

/s/Charles R. Schaller                       Director                                             June 5, 2000
-------------------------------------
Charles R. Schaller

/s/W. Leigh Thompson, Jr.                    Director                                             June 5, 2000
-------------------------------------
W. Leigh Thompson, Jr.

/s/Frederick B. Craves                       Director                                             June 5, 2000
-------------------------------------
Frederick B. Craves
INDEX TO EXHIBITS

               Exhibit No.                      Description
               -----------                      -----------
               4(b)               Restated Certificate of Incorporation,
                                  as amended, of Medarex, Inc.

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

               10.1               Medarex, Inc.  2000 Stock Option Plan

               23(a)              Consent of Ernst & Young LLP