Rule 424(b)(2)
                                       Registration Statement File No. 333-22341

Prospectus Supplement
(To Prospectus dated March 4, 1997)

                                3,000,000 Shares

                          ImClone Systems Incorporated

                                  Common Stock
                                 $.001 par value

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

     This  Prospectus  Supplement  relates to 3,000,000  shares of Common Stock,
$.001 par value  (the  "Common  Stock"),  of  ImClone  Systems  Incorporated,  a
Delaware corporation (the "Company"), being offered by the Company.

     The shares of Common Stock  offered  hereby are being  offered at a single,
negotiated  price.  The shares of Common Stock offered hereby may be offered and
sold to different purchasers at different times.

     The Common Stock is included on the Nasdaq National Market under the symbol
IMCL. On March 4, 1997, the closing sale price of the Common Stock was $8 1/8 on
the Nasdaq National Market, as reported by The Wall Street Journal.

THE SECURITIES  OFFERED HEREBY INVOLVE A HIGH DEGREE OF RISK. SEE "RISK FACTORS"
BEGINNING ON PAGE 6 OF THE PROSPECTUS.

THESE  SECURITIES  HAVE NOT BEEN APPROVED OR  DISAPPROVED  BY THE SECURITIES AND
EXCHANGE  COMMISSION OR ANY STATE  SECURITIES  COMMISSION NOR HAS THE SECURITIES
AND  EXCHANGE  COMMISSION  OR ANY STATE  SECURITIES  COMMISSION  PASSED UPON THE
ACCURACY OR ADEQUACY OF THIS PROSPECTUS. ANY REPRESENTATION TO THE CONTRARY IS A
CRIMINAL OFFENSE.

================================================================================
                     Price to                Brokerage             Proceeds to
                      Public                Commissions             Company(1)
- --------------------------------------------------------------------------------
Per Share             $7.875                    $0.13                 $7.745
- --------------------------------------------------------------------------------
Total               $23,625,000                $390,000             $23,235,000
================================================================================

(1)  Before deducting expenses payable by the Company, estimated at $63,000. See
     "Plan of Distribution."


             The date of this Prospectus Supplement is March 4, 1997



     Capitalized  terms used in this  Prospectus  Supplement  and not  otherwise
defined  herein  have  the  respective   meanings   provided  in  the  Company's
Prospectus, dated March 4, 1997 (the "Prospectus").

                 INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE

     In addition to the documents  incorporated  by reference and made a part of
the Company's  Prospectus,  the Company's two Current  Reports on Form 8-K, each
dated February 25, 1997, are  incorporated by reference in the  Prospectus.  See
"Incorporation of Certain Documents by Reference" in the Prospectus.

                                 USE OF PROCEEDS

     The net  proceeds  from the sale of the  shares  of  Common  Stock  offered
hereby,  after deducting estimated expenses payable by the Company in connection
with this offering and the commissions  payable by the Company to the Broker (as
defined  below),  will be  $23,172,000.  The Company  anticipates  using the net
proceeds  from this  offering  (i) to pay the costs for the Company to engage in
further  research and  development,  to continue to fund and expand its clinical
programs, and to support and expand manufacturing and (ii) for general corporate
purposes,  including  working  capital.  Pending such uses, the Company plans to
invest  such funds in  short-term  interest-bearing  obligations  of  investment
grade.

                                    DILUTION

     As of December  31,  1996,  the Company  had a net  tangible  book value of
$15,547,000,  or $.77 per share. Net tangible book value per share is determined
by dividing the net tangible book value  (tangible  assets less  liabilities) of
the Company by the number of shares of Common  Stock  outstanding  at that date.
Adjusting  such net tangible  book value to give effect to the sale of 3,000,000
shares of Common Stock offered by the Company  hereby at the offering  price set
forth  on  the  cover  of  this  Prospectus  Supplement,  and  the  receipt  and
application of the net proceeds  therefrom,  but without taking into account any
other changes in net tangible book value after  December 31, 1996, the pro forma
net  tangible  book value of the Company as of December 31, 1996 would have been
$38,719,000 or $1.67 per share. This represents an immediate increase in the net
tangible book value of $.90 per share to existing  stockholders and an immediate
dilution of $6.21 per share to new investors.  The following  table  illustrates
this per share dilution.

        Public offering price per share .............               $7.875
        Net tangible book value per share as of
                 December 31, 1996 ................ .    $.77
        Increase in net tangible book value per share
                 attributable to the offering(1).....     .90
        Pro forma net tangible book value per share
                 after the offering .................                 1.67
                                                                    ------
        Dilution per share to new investors(2).......               $ 6.21
                                                                    ======

- -----------------
(1)  After deducting  commissions  payable to the Broker and estimated  expenses
     payable  by the  Company  in  connection  with sale of the shares of Common
     Stock offered hereby.

(2)  Determined by  subtracting  the pro forma net tangible book value per share
     after the  offering  from the amount of cash paid by a new  investor  for a
     share of Common Stock.

                              PLAN OF DISTRIBUTION

     Trades to effect sales of the shares of Common Stock offered hereby will be
executed on the Nasdaq National Market by Genesis  Merchant Group Securities LLC
(the  "Broker").  The Company  has agreed to pay  brokerage  commissions  to the
Broker in connection with such trades aggregating  $390,000. It is expected that




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delivery of the shares of Common Stock, upon payment  therefor,  will be made to
the accounts of the several purchasers on or about March 7, 1997.

     The  Broker  has in the  past  provided,  and  may in the  future  provide,
investment  banking,  financial  advisory  and other  services  to the  Company.
Pursuant  to an  agreement  entered  into  between the Company and the Broker in
November 1995, subject to certain  conditions,  the Company agreed to engage the
Broker on a non-exclusive  basis as managing  underwriter or placement agent, as
the case may be, in connection with securities offerings by the Company prior to
May 2, 1997 in which the Company  uses the  services  of a financial  advisor or
intermediary.  The Broker has waived any rights it may have under such agreement
in connection with this offering.









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