<PAGE>

================================================================================

                                  UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                              WASHINGTON, DC 20549

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

                                   FORM 10-Q/A

[X]      QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES
         EXCHANGE ACT OF 1934
         FOR THE QUARTERLY PERIOD ENDED SEPTEMBER 30, 2002

[ ]      TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES
         EXCHANGE ACT OF 1934
         FOR THE TRANSITION PERIOD FROM           TO

                         COMMISSION FILE NUMBER 0-19612

                          IMCLONE SYSTEMS INCORPORATED

             (Exact name of registrant as specified in its charter)

                  DELAWARE                                     04-2834797
       (State or other jurisdiction of                        (IRS employer
       incorporation or organization)                      identification no.)

       180 VARICK STREET, NEW YORK, NY                            10014
  (Address of principal executive offices)                     (Zip code)

                                 (212) 645-1405
               Registrant's telephone number, including area code

                                 NOT APPLICABLE
Former name, former address and former fiscal year, if changed since last report

         Indicate by check mark whether the registrant (1) has filed all reports
required to be filed by Section 13 or 15(d) of the Securities Exchange Act of
1934 during the preceding 12 months (or for such shorter period that the
registrant was required to file such reports), and (2) has been subject to such
filing requirements for the past 90 days.

                                 Yes [ ] No [X]

Applicable only to corporate issuers:

         Indicate the number of shares outstanding of each of the registrant's
classes of common stock, as of the latest practicable date.

             CLASS                         OUTSTANDING AS OF NOVEMBER 13, 2002
             -----                         -----------------------------------

 Common Stock, par value $.001                      73,631,262 Shares

================================================================================

<PAGE>

                                EXPLANATORY NOTE

We are filing this Amendment No. 1 to our Quarterly Report on Form 10-Q for the
quarterly period ended September 30, 2002 for the purpose of amending and
restating Item 1 of Part I, containing our unaudited consolidated financial
statements and related notes as of September 30, 2002 and for the three and nine
month periods ended September 30, 2002 and 2001. See Notes 2, 3 and 15 to the
unaudited consolidated financial statements for further discussion of the
restatement and related disclosures. We have also updated Item 2 of Part I,
Management Discussion and Analysis of Financial Condition and Results of
Operations, to give effect to the restatement. In addition, we have amended Item
6 of Part II to reflect the filing of updated certifications pursuant to 18
U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley
Act of 2002, and we have filed updated certifications pursuant to Section 302 of
the Sarbanes-Oxley Act of 2002. Other than the changes regarding the restatement
and related disclosures, no other information in this Amendment No. 1 has been
updated to reflect any subsequent information or events since the original
filing of this Form 10-Q on November 14, 2002. This Amendment should be read
together with our Annual Report on Form 10-K for the year ended December 31,
2002 filed with the U.S. Securities and Exchange Commission on June 23, 2002.

<PAGE>

                          IMCLONE SYSTEMS INCORPORATED

                                      INDEX

<TABLE>
<CAPTION>
                                                                                                           PAGE NO.
<S>                <C>                                                                                     <C>
PART I - FINANCIAL INFORMATION

    Item 1.        Financial Statements

                   Unaudited Consolidated Balance Sheets - September 30, 2002
                   and December 31, 2001..................................................................      1

                   Unaudited Consolidated Statements of Operations - Three and nine months ended
                   September 30, 2002 and 2001............................................................      2

                   Unaudited Consolidated Statements of Cash Flows - Nine months ended

                   September 30, 2002 and 2001............................................................      3

                   Notes to Unaudited Consolidated Financial Statements...................................      4

    Item 2.        Management's Discussion and Analysis of Financial Condition and Results of Operations..     18

PART II - OTHER INFORMATION

    Item 6.        Exhibits and Reports on Form 8-K.......................................................     31

                   Signatures.............................................................................     32

                   Certifications Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002...............     33
</TABLE>

<PAGE>

PART I - FINANCIAL INFORMATION

ITEM 1.  FINANCIAL STATEMENTS

                          IMCLONE SYSTEMS INCORPORATED

                           CONSOLIDATED BALANCE SHEETS
                 (IN THOUSANDS, EXCEPT PER SHARE AND SHARE DATA)
                                  (UNAUDITED)
<TABLE>
<CAPTION>
                                                                                                    SEPTEMBER 30,      DECEMBER 31,
                                                                                                        2002              2001
                                                                                                    -------------      ------------
                                                                                                      RESTATED           RESTATED
                                                                                                      (NOTE 2)           (NOTE 2)
<S>                                                                                                 <C>                <C>
                                     ASSETS

Current assets:
  Cash and cash equivalents.................................................................         $    52,432       $    38,093
  Securities available for sale.............................................................             240,649           295,893
  Prepaid expenses..........................................................................               4,272             3,891
  Amounts due from corporate partners (Note 9)..............................................              16,870             8,230
  Current portion of withholding tax assets.................................................              10,126                --
  Other current assets......................................................................               9,066             3,547
                                                                                                     -----------       -----------
      Total current assets..................................................................             333,415           349,654
                                                                                                     -----------       -----------
Property and equipment, net.................................................................             160,604           107,248
Patent costs, net...........................................................................               1,623             1,513
Deferred financing costs, net...............................................................               4,125             5,404
Note receivable.............................................................................              10,000            10,000
Withholding tax assets......................................................................                  --            13,510
Other assets................................................................................               1,018               383
                                                                                                     -----------       -----------
                                                                                                     $   510,785       $   487,712
                                                                                                     ===========       ===========
                 LIABILITIES AND STOCKHOLDERS' EQUITY (DEFICIT)

Current liabilities:
  Accounts payable..........................................................................         $    18,011       $    16,919
  Accrued expenses (including $2,270 due to Bristol-Myers Squibb Company ("BMS") at
     September 30, 2002)....................................................................              25,810            11,810
  Withholding tax liability.................................................................              38,779            38,779
  Industrial Development Revenue Bonds tax liability........................................                 929               851
  Interest payable..........................................................................               1,204             4,446
  Income taxes payable......................................................................                 550                --
  Current portion of deferred revenue (Note 9)..............................................              37,494            20,683
  Current portion of long-term debt.........................................................               2,200                --
  Current portion of long-term liabilities..................................................                 150               426
                                                                                                     -----------       -----------
      Total current liabilities.............................................................             125,127            93,914
                                                                                                     -----------       -----------
Deferred revenue, less current portion (Note 9).............................................             292,806           182,813
Long-term debt, less current portion .......................................................             240,000           242,200
Other long-term liabilities, less current portion...........................................                  55                79
                                                                                                     -----------       -----------
      Total liabilities.....................................................................             657,988           519,006
                                                                                                     -----------       -----------
Commitments and contingencies (Notes 3 and 10)
Stockholders' equity (deficit):
  Preferred stock, $1.00 par value; authorized 4,000,000 shares; reserved 1,200,000
   series B participating cumulative preferred stock........................................                  --                --
  Common stock, $.001 par value; authorized 200,000,000 shares; issued 73,588,383 and
   73,348,271 at September 30, 2002 and December 31, 2001, respectively; outstanding
   73,399,133 and 73,159,021 at September 30, 2002 and December 31, 2001, respectively......                  74                73
  Additional paid-in capital................................................................             345,474           341,735
  Accumulated deficit.......................................................................            (490,734)         (372,157)
  Treasury stock, at cost; 189,250 shares at September 30, 2002 and December 31, 2001.......              (4,100)           (4,100)
  Accumulated other comprehensive income:
    Unrealized gain on securities available for sale........................................               2,083             3,155
                                                                                                     -----------       -----------
      Total stockholders' deficit...........................................................            (147,203)          (31,294)
                                                                                                     -----------       -----------
                                                                                                     $   510,785       $   487,712
                                                                                                     ===========       ===========
</TABLE>

           See accompanying notes to consolidated financial statements

                                     Page 1

<PAGE>

                          IMCLONE SYSTEMS INCORPORATED

                      CONSOLIDATED STATEMENTS OF OPERATIONS
                      (IN THOUSANDS, EXCEPT PER SHARE DATA)
                                   (UNAUDITED)

<TABLE>
<CAPTION>
                                                                             THREE MONTHS ENDED                NINE MONTHS ENDED
                                                                                SEPTEMBER 30,                    SEPTEMBER 30,
                                                                         --------------------------       -------------------------
                                                                            2002            2001             2002           2001
                                                                         ----------      ----------       -----------    ----------
                                                                          RESTATED        RESTATED         RESTATED       RESTATED
                                                                          (NOTE 2)        (NOTE 2)         (NOTE 2)       (NOTE 2)
<S>                                                                      <C>             <C>              <C>            <C>
Revenues:
  License fees and milestone revenue (Note 9)........................    $    4,996      $    2,244       $    13,254    $   29,476
  Research and development funding and royalties.....................           622             667             1,310         1,430
  Collaborative agreement revenue (Note 9)...........................         9,416           2,818            30,586         6,713
                                                                         ----------      ----------       -----------    ----------
    Total revenues...................................................        15,034           5,729            45,150        37,619
                                                                         ----------      ----------       -----------    ----------
Operating expenses:
  Research and development...........................................        43,504          26,664           119,449        76,150
  Marketing, general and administrative..............................        12,341           5,599            36,943        15,550
  Write-down of withholding tax assets............................               --              --             3,384            --
  Industrial Development Revenue Bonds tax expense................               25              25                75            75
  Expenses associated with the BMS acquisition, stockholder and
   amended commercial agreements.....................................            --          16,050             2,250        16,050
                                                                         ----------      ----------       -----------    ----------
    Total operating expenses.........................................        55,870          48,338           162,101       107,825
                                                                         ----------      ----------       -----------    ----------
Operating loss.......................................................       (40,836)        (42,609)         (116,951)      (70,206)
                                                                         ----------      ----------       -----------    ----------
Other:
  Interest income....................................................        (2,259)         (3,244)           (7,427)      (11,071)
  Interest expense...................................................         3,162           3,535            10,003        10,051
  Loss (gain) on securities and investments..........................          (264)         (1,800)           (1,500)        2,668
                                                                         ----------      ----------       -----------    ----------
    Net interest and other expense (income)..........................           639          (1,509)            1,076         1,648
                                                                         ----------      ----------       -----------    ----------
    Loss before income taxes.........................................       (41,475)        (41,100)         (118,027)      (71,854)
    Income taxes.....................................................           550              --               550            --
                                                                         ----------      ----------       -----------    ----------
    Net loss.........................................................    $  (42,025)     $  (41,100)      $  (118,577)   $  (71,854)
                                                                         ==========      ==========       ===========    ==========
Net loss per common share:
  Basic and diluted:
    Net loss per common share........................................    $    (0.57)     $    (0.57)      $     (1.62)   $    (1.05)
                                                                         ==========      ==========       ===========    ==========
Weighted average shares outstanding..................................        73,385          71,534            73,350        68,301
                                                                         ==========      ==========       ===========    ==========
</TABLE>

           See accompanying notes to consolidated financial statements

                                     Page 2

<PAGE>

                          IMCLONE SYSTEMS INCORPORATED
                      CONSOLIDATED STATEMENTS OF CASH FLOWS
                                 (IN THOUSANDS)
                                   (UNAUDITED)

<TABLE>
<CAPTION>
                                                                                                          NINE MONTHS ENDED
                                                                                                             SEPTEMBER 30,
                                                                                                      --------------------------
                                                                                                          2002           2001
                                                                                                      ------------   -----------
                                                                                                        RESTATED       RESTATED
                                                                                                        (NOTE 2)       (NOTE 2)
<S>                                                                                                   <C>            <C>
 Cash flows from operating activities:
 Net loss.........................................................................................    $   (118,577)  $   (71,854)
 Adjustments to reconcile net loss to net cash provided by operating activities:
   Depreciation and amortization..................................................................           7,000         3,517
   Amortization of deferred financing costs.......................................................           1,279         1,279
   Expense associated with issuance of options and warrants.......................................              11           952
   Gain on securities available for sale..........................................................          (1,500)       (2,707)
   Write-down of investment in Valigen N.V........................................................              --         4,375
   Write-off of convertible promissory note receivable from A.C.T. Group, Inc.....................              --         1,000
   Accrued interest on note receivable - officer..................................................              --           (24)
   Accrued interest on notes receivable - officers and directors..................................              --          (606)
   Changes in:
     Prepaid expenses.............................................................................            (381)       (2,776)
     Amounts due from corporate partners (including amounts received from BMS of $8,377
      for the nine months ended September 30, 2002)...............................................          (8,640)           --
     Other current assets.........................................................................          (5,519)          163
     Withholding tax assets ......................................................................           3,384        (7,119)
     Other assets.................................................................................            (635)          (81)
     Interest payable.............................................................................          (3,242)       (3,237)
     Accounts payable.............................................................................           1,092        (2,244)
     Accrued expenses.............................................................................          14,000        10,306
     Withholding tax liability....................................................................              --         7,119
     Industrial Development Revenue Bonds tax liability...........................................              78            84
     Income taxes payable.........................................................................             550            --
     Deferred revenue (including amounts received from BMS of $140,000 and $200,000
      for the nine months ended September 30, 2002 and 2001, respectively)........................         126,804       203,325
     Fees potentially refundable to Merck KGaA....................................................              --       (28,000)
                                                                                                      ------------   -----------
      Net cash provided by operating activities...................................................          15,704       113,472
                                                                                                      ------------   -----------
 Cash flows from investing activities:
   Acquisitions of property and equipment.........................................................         (60,165)      (44,591)
   Purchases of securities available for sale.....................................................        (327,470)     (158,497)
   Sales and maturities of securities available for sale..........................................         383,142       130,449
   Investment in Valigen N.V......................................................................              --        (2,000)
   Loan to A.C.T. Group, Inc......................................................................              --        (1,000)
   Additions to patents...........................................................................            (243)         (593)
                                                                                                      ------------   -----------
      Net cash used in investing activities.......................................................          (4,736)      (76,232)
                                                                                                      ------------   -----------
 Cash flows from financing activities:
   Proceeds from exercise of stock options and warrants...........................................           2,751         7,333
   Proceeds from issuance of common stock under the employee stock purchase plan..................             413           531
   Proceeds from short-swing profit rule..........................................................             565            --
   Proceeds from issuance of common stock to Merck KGaA...........................................              --         3,240
   Purchase of treasury stock.....................................................................              --        (1,830)
   Payment of preferred stock dividends...........................................................              --        (5,764)
   Redemption of series A preferred stock.........................................................              --       (20,000)
   Payments of other liabilities..................................................................            (358)         (487)
                                                                                                      ------------   -----------
      Net cash provided by (used in) financing activities.........................................           3,371       (16,977)
                                                                                                      ------------   -----------
      Net increase in cash and cash equivalents...................................................          14,339        20,263
 Cash and cash equivalents at beginning of period.................................................          38,093        60,325
                                                                                                      ------------   -----------
 Cash and cash equivalents at end of period.......................................................    $     52,432   $    80,588
                                                                                                      ============   ===========
 Supplemental cash flow information:
      Cash paid for interest, including amounts capitalized of $1,441 and $1,398
       for the nine months ended September 30, 2002 and 2001, respectively........................    $     13,403   $    13,397
                                                                                                      ============   ===========
 Non-cash financing activity:
      Capital asset and lease obligation addition.................................................    $         58   $        --
                                                                                                      ============   ===========
</TABLE>

           See accompanying notes to consolidated financial statements

                                     Page 3

<PAGE>

                          IMCLONE SYSTEMS INCORPORATED

                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

                                   (UNAUDITED)

(1) BASIS OF PREPARATION

         The consolidated financial statements of ImClone Systems Incorporated
("ImClone Systems" or the "Company") as of September 30, 2002 and for the three
and nine months ended September 30, 2002 and 2001 are unaudited. In the opinion
of management, these unaudited financial statements include all adjustments,
consisting only of normal recurring adjustments, necessary for a fair
presentation. These financial statements should be read in conjunction with the
audited financial statements and notes thereto included in the Company's Annual
Report on Form 10-K for the year ended December 31, 2001, as filed with the
Securities and Exchange Commission ("SEC").

         Results for the interim periods are not necessarily indicative of
results for the full years.

         Pursuant to the guidance in Emerging Issues Task Force Issue No. 01-14,
Income Statement Characterization of Reimbursements Received for "Out-of-Pocket"
Expenses Incurred ("EITF No. 01-14"), the Company changed its classification for
corporate partner reimbursements effective January 1, 2002 to characterize such
reimbursements received for research and development and marketing expenses
incurred as collaborative agreement revenue in the consolidated statements of
operations. Prior to January 1, 2002, the Company characterized such
reimbursements as a reduction of expenses in the consolidated statements of
operations. As prescribed in EITF No. 01-14, all comparative financial
statements for prior periods have been reclassified to comply with this
guidance.

(2) RESTATEMENT OF CONSOLIDATED FINANCIAL STATEMENTS

         The Company has restated its Consolidated Balance Sheets as of
September 30, 2002 and December 31, 2001, primarily to reflect a withholding tax
liability and withholding tax assets primarily relating to the exercises of
certain non-qualified stock options and compensatory warrants described below.
The restatement includes recording withholding tax assets of $10,126,000 and
$13,510,000 as of September 30, 2002 and December 31, 2001, respectively; a
withholding tax liability of $38,779,000 as of September 30, 2002 and December
31, 2001; an Industrial Development Revenue Bonds tax liability of $929,000 and
$851,000 as of September 30, 2002 and December 31, 2001, respectively; a
cumulative increase to accumulated deficit of $29,582,000 as of September 30,
2002; and a cumulative increase to accumulated deficit of $26,120,000 as of
December 31, 2001. The $26,120,000 increase to accumulated deficit reflects the
fourth quarter 2001 write-down of the $25,269,000 asset noted below regarding
Dr. Samuel D. Waksal and $851,000 in additional tax expense and interest expense
for the years 1995 through 2001 in connection with its outstanding Industrial
Development Revenue Bonds issued in 1990 (the "1990 IDA Bonds").

         The Company has restated its Consolidated Statements of Operations for
the three and nine months ended September 30, 2002, primarily to reflect the
write-down of the $3,384,000 withholding tax asset discussed below. In addition,
the Company has restated its Consolidated Statements of Operations for the three
and nine months ended September 30, 2002 and 2001 to reflect the additional tax
expense and interest expense for the 1990 IDA Bonds. Due to the restatement, the
net loss for the three and nine months ended September 30, 2002 increased to
$42,025,000 and $118,577,000 from $41,999,000 and $115,115,000, respectively.
The basic and diluted net loss per common share increased to $1.62 from $1.57
for the nine months ended September 30, 2002, with no impact for the three
months then ended. Also due to the restatement, the net loss for the three and
nine months ended September 30, 2001 increased to $41,100,000 and $71,854,000
from $41,072,000 and $71,770,000, respectively, with no impact on the basic and
diluted net loss per common share.

         Federal and applicable state tax laws require an employer to withhold
income taxes at the time of an employee's exercise of non-qualified stock
options or warrants issued in connection with the performance of services by the
employee. An employer that does not do so is liable for the taxes not withheld
if the employee fails to pay his or her taxes for the year in which the
non-qualified stock options or warrants are exercised. In 2000 and prior years,
the Company generally did not require the withholding of federal, state or local
income taxes and in certain years, employment payroll taxes at the time of the
exercise of non-qualified stock options or warrants. Prior to 1996, the Company
did not comply with tax reporting requirements with respect to the exercise of
non-qualified stock options or warrants.

         In January 2003, the New York State Department of Taxation and Finance
("New York State") notified the Company that it was liable for the New York
State and City income taxes that were not withheld because one or more of the
Company's employees who exercised certain non-qualified stock options in 1999
and 2000 failed to pay New York State and City income taxes for those years. At
December 31, 2002, the Company recorded a gross New York State and City
withholding tax liability of approximately $6,800,000. On March 13, 2003, the
Company entered into a closing agreement with New York State, paying $4,500,000
to settle the matter.

                                     Page 4

<PAGE>
The Company believes that substantially all of the underpayment of New York
State and City income tax identified by New York State is attributable to the
exercise of non-qualified stock options by its former President and Chief
Executive Officer, Dr. Samuel D. Waksal.

         On March 13, 2003, the Company initiated discussions with the Internal
Revenue Service ("IRS") relating to federal income taxes on the exercise of
non-qualified stock options on which income tax was not properly withheld.
Although the IRS has not yet asserted that the Company is required to make a
payment with respect to such failure to withhold, the IRS may assert that such a
liability exists, and may further assert that the Company is liable for interest
and penalties. The Company has requested and received confirmation from all of
its current and substantially all of its former employees who exercised
non-qualified stock options in 1999 and 2000, on which no income tax was
withheld, that they have reported the appropriate amount of income on their tax
returns and paid the taxes shown as due on those returns. Based on this
information, the Company determined that all but an insignificant amount of
the potential liability for withholding taxes with respect to exercises of
non-qualified stock options in 1999 and 2000 is attributed to those amounts
related to Dr. Samuel D. Waksal.

         In addition, in the course of the Company's investigation into its
potential liability in respect of the non-qualified stock options described
above, the Company identified certain warrants that were granted in 1991 and
prior years to current and former officers, directors and advisors (including
the four individuals discussed herein) that the Company previously treated as
non-compensatory warrants and thus not subject to tax withholding and
information reporting requirements upon exercise. Accordingly, when exercised
in 2001 and prior years, the Company did not deduct income and payroll taxes
upon exercise or report applicable information to the taxing authorities. Based
on the information discovered in the course of the Company's recent
investigation, the Company now believes that such treatment was incorrect, and
that the exercise of such warrants by current and former officers of the
Company should have been treated in the same manner for withholding and
reporting purposes as the exercise of non-qualified stock options. The Company
has informed the relevant authorities, including the IRS and New York State, of
this matter and intends to resolve its liability in respect of these warrants
with these taxing authorities in conjunction with its resolution of the matter
described above. On June 17, 2003, New York State notified the Company that,
based on the issue identified above, they are continuing a previously conducted
audit of the Company and are evaluating the terms of the closing agreement to
determine whether or not it should be re-opened.

         On April 2, 2003, the Company received a request from the SEC for the
voluntary production of documents and information relating to the above matters.
The Company is cooperating fully with the SEC, and intends to continue to do so,
while also updating the United States Attorney's Office on an ongoing basis.

         One of the officers and directors to whom warrants were issued and
previously treated as non-compensatory warrants is Dr. Harlan W. Waksal, the
Company's Chief Scientific Officer. In June 2003, Dr. Harlan Waksal represented
that he has paid the taxes associated with the exercise of these warrants and
further agreed to indemnify the Company for any withholding taxes that may be
assessed and are attributable to the Company's failure to deduct income and
payroll taxes on all warrants and options that he or his transferee have
previously exercised, subject to the consent of Dr. Harlan W. Waksal, which can
not be unreasonably withheld.

         Two of the other officers and directors to whom warrants were issued
and previously treated as non-compensatory warrants are Dr. Samuel D. Waksal
and its former General Counsel, John B. Landes. The Company has made demands on
both of these individuals to pay the taxes associated with the exercise of these
warrants and to indemnify the Company against any liability that it may incur to
taxing authorities in respect of the warrants or non-qualified stock options
that they have previously exercised.

         The Company has recognized assets at the time of exercise relating to
the above individuals. These assets are based on the fact that individuals are
required by law to pay their personal income taxes, as well as the Company's
determination that these individuals had the means and intention to satisfy
their tax liabilities and legal claims the Company has against the individuals
both during and after their employment with the Company. The Company decided to
write-down these assets during the periods noted in the paragraph below.

         Regarding Dr. Samuel D. Waksal, the Company determined that subsequent
to its receipt of a "refusal to file" letter from the United States Food and
Drug Administration on December 28, 2001, with respect to its rolling Biologics
License Application for ERBITUX, his financial condition deteriorated and
therefore the recoverability of the asset became doubtful. Regarding Mr. Landes,
based on the limited information available to it, due to the decrease in the
Company's stock price during 2002 and corresponding decrease in the value of Mr.
Landes' ownership of the Company's securities, the Company determined that
recoverability of the asset became doubtful. Based upon these determinations,
the asset write-downs of $25,269,000 and $3,384,000 were recorded during the
fourth quarter of 2001 for Dr. Samuel D. Waksal and the second quarter of 2002
for Mr. Landes, respectively. The withholding tax liabilities relating to Dr.
Samuel D. Waksal and Mr. Landes will remain on the Company's Consolidated
Balance Sheets, until such time as these liabilities are satisfied. Should the
Company negotiate settlements with the IRS and New York State tax authorities
for amounts less than those noted above, the Company would reduce operating
expenses for the difference between the withholding tax liabilities and
settlement amounts in the period of settlement.

                                     Page 5

<PAGE>
         In April 2003, the Company discovered that it is in breach of certain
covenants in its outstanding 1990 IDA Bonds. These bonds are tax-exempt and the
Company is required to continue to use the proceeds for a qualified tax-exempt
purpose (in this case, manufacturing), until maturity. These bonds, in principal
amount of $2,200,000, bearing 11.25% annual interest, mature on May 1, 2004.
While the bond proceeds were originally used for manufacturing purposes, a
recent internal investigation concluded that in August 1995, this qualified
purpose was abandoned and the proceeds have been used for a non-qualified
purpose in later periods. As a result, the bond proceeds likely became taxable
to the bondholders in August 1995. The Company is required to indemnify the
bondholders from any taxes imposed upon them. The Company intends to attempt to
settle any tax liability directly with the relevant taxing authorities using
procedures established for that purpose. Based on the Company's understanding of
these procedures, the Company has recognized a tax liability of $929,000 and
$851,000 on the Consolidated Balance Sheets as of June 30, 2002 and December 31,
2001, respectively. The Company recorded Industrial Development Revenue Bonds
tax expense of $75,000 for the nine months ended September 30, 2002 and 2001,
and interest expense of $3,000 and $9,000 for the same periods, respectively. On
May 22, 2003, the Company notified the bond trustee of its intent to redeem in
full the bonds by repaying the principal amount plus accrued and unpaid interest
and has reclassified this debt to current liabilities on the Consolidated
Balance Sheet as of September 30, 2002. This redemption is scheduled to occur on
June 30, 2003.

                  The following tables present the impact of the restatement on
a condensed basis:

<TABLE>
<CAPTION>
                                                               SEPTEMBER 30, 2002                     DECEMBER 31, 2001
                                                       ----------------------------------     --------------------------------
                                                         AS PREVIOUSLY                        AS PREVIOUSLY
CONSOLIDATED BALANCE SHEETS                                 REPORTED        AS RESTATED          REPORTED        AS RESTATED
                                                                          ---------------                      ---------------
<S>                                                    <C>                <C>                <C>               <C>
Current portion of withholding tax assets...........   $            --    $    10,126,000    $            --   $            --
Total current assets................................       323,289,000        333,415,000        349,654,000       349,654,000
Withholding tax assets..............................                --                 --                 --        13,510,000
Total assets........................................       500,659,000        510,785,000        474,202,000       487,712,000
Withholding tax liability...........................                --         38,779,000                 --        38,779,000
Industrial Development Revenue Bonds tax liability..                --            929,000                 --           851,000
Current portion of long-term debt...................                --          2,200,000                 --                --
Total current liabilities...........................        83,219,000        125,127,000         54,284,000        93,914,000
Long-term debt, less current portion................       242,200,000        240,000,000        242,200,000       242,200,000
Total liabilities...................................       618,280,000        657,988,000        479,376,000       519,006,000
Accumulated deficit.................................      (461,152,000)      (490,734,000)      (346,037,000)     (372,157,000)
Total stockholders' deficit.........................      (117,621,000)      (147,203,000)        (5,174,000)      (31,294,000)
Total liabilities and stockholders' deficit.........   $   500,659,000    $   510,785,000    $   474,202,000   $   487,712,000
</TABLE>

<TABLE>
<CAPTION>
                                                               THREE MONTHS ENDED                    THREE MONTHS ENDED
                                                               SEPTEMBER 30, 2002                    SEPTEMBER 30, 2001
                                                       -----------------------------------   ---------------------------------
                                                         AS PREVIOUSLY                        AS PREVIOUSLY
CONSOLIDATED STATEMENTS OF OPERATIONS                       REPORTED         AS RESTATED         REPORTED        AS RESTATED
                                                                           ---------------                     ---------------
<S>                                                    <C>                 <C>               <C>               <C>
Industrial Development Revenue Bonds tax expense....   $            --     $        25,000   $            --   $        25,000
Total operating expenses............................        55,845,000          55,870,000        48,313,000        48,338,000
Operating loss......................................       (40,811,000)        (40,836,000)      (42,584,000)      (42,609,000)
Interest expense....................................         3,161,000           3,162,000         3,532,000         3,535,000
Net interest and other expense (income).............           638,000             639,000        (1,512,000)       (1,509,000)
Loss before income taxes............................       (41,449,000)        (41,475,000)      (41,072,000)      (41,100,000)
Net loss............................................   $   (41,999,000)    $   (42,025,000)  $   (41,072,000)  $   (41,100,000)
</TABLE>

<TABLE>
<CAPTION>
                                                                NINE MONTHS ENDED                     NINE MONTHS ENDED
                                                               SEPTEMBER 30, 2002                    SEPTEMBER 30, 2001
                                                       ---------------------------------     ---------------------------------
                                                         AS PREVIOUSLY                        AS PREVIOUSLY
CONSOLIDATED STATEMENTS OF OPERATIONS                       REPORTED        AS RESTATED          REPORTED        AS RESTATED
                                                                          ---------------                      ---------------
<S>                                                    <C>                <C>                <C>               <C>
Write-down of withholding tax assets...............    $            --    $     3,384,000    $            --   $            --
Industrial Development Revenue Bonds tax expense...                 --             75,000                 --            75,000
Total operating expenses...........................        158,642,000        162,101,000        107,750,000       107,825,000
Operating loss.....................................       (113,492,000)      (116,951,000)       (70,131,000)      (70,206,000)
Interest expense...................................         10,000,000         10,003,000         10,042,000        10,051,000
Net interest and other expense (income)............          1,073,000          1,076,000          1,639,000         1,648,000
Loss before income taxes...........................       (114,565,000)      (118,027,000)       (71,770,000)      (71,854,000)
Net loss...........................................    $  (115,115,000)   $  (118,577,000)   $   (71,770,000)  $   (71,854,000)
Net loss per share.................................    $         (1.57)   $         (1.62)   $         (1.05)  $         (1.05)
</TABLE>

                                     Page 6

<PAGE>
             The restatement did not impact the amounts presented in the
Consolidated Statements of Cash Flows for net cash provided by operating
activities, net cash used in investing activities or net cash provided by (used
in) financing activities, although it did impact certain components of cash
flows from operating activities.

             Amounts related to the following items are included in withholding
tax assets:

<TABLE>
<CAPTION>
                                                              SEPTEMBER 30,      DECEMBER 31,
                                                                  2002               2001
                                                            ----------------   ---------------
<S>                                                         <C>                <C>
Dr. Harlan W. Waksal*................................       $     9,958,000    $     9,958,000
John B. Landes.......................................                    --          3,384,000
Other................................................               168,000            168,000
                                                            ---------------    ---------------
                                                                 10,126,000         13,510,000
Less: Current portion                                           (10,126,000)                --
                                                            ---------------    ---------------
                                                            $            --     $   13,510,000
                                                            ===============    ===============
</TABLE>

* - In June 2003, Dr. Harlan W. Waksal represented that he has paid the taxes
associated with the exercise of these warrants and further agreed to indemnify
the Company for any withholding taxes that may be assessed and are attributable
to the Company's failure to deduct income and payroll taxes on all warrants and
options that he or his transferee has previously exercised, subject to the
consent of Dr. Harlan W. Waskal, which can not be unreasonably withheld.

             Amounts related to the following items are included in withholding
tax liability:

<TABLE>
<CAPTION>
                                                                   SEPTEMBER 30,       DECEMBER 31,
                                                                       2002                2001
                                                                 ---------------     ---------------
<S>                                                              <C>                 <C>
Withholding tax related to the exercise of stock options
  and warrants...............................................    $    38,349,000     $    38,349,000
Other........................................................            430,000             430,000
                                                                 ---------------     ---------------
                                                                 $    38,779,000     $    38,779,000
                                                                 ===============     ===============
</TABLE>

             Amounts related to the following items are included in Industrial
Development Revenue Bonds tax liability:

<TABLE>
<CAPTION>
                                                            SEPTEMBER 30,      DECEMBER 31,
                                                                2002               2001
                                                           --------------     --------------
<S>                                                        <C>                <C>
Tax related to the 1990 IDA Bonds.......................   $      687,000     $      612,000
Accrued interest on tax related to the 1990 IDA Bonds...          242,000            239,000
                                                           --------------     --------------
                                                           $      929,000     $      851,000
                                                           ==============     ==============
</TABLE>

(3) WITHHOLDING TAX CONTINGENCIES

    The Company has not recognized withholding tax liabilities in respect of
exercises of certain warrants by the Company's then-current and now-former
Chairman of the Board, Robert F. Goldhammer, the final of the four officers or
directors to whom warrants were issued and previously treated as
non-compensatory warrants. Based on the Company's investigation, the Company
believes that, although such warrants were compensatory, such warrants were
received by Mr. Goldhammer in connection with the performance of services by him
in his capacity as a director, rather than as an employee, and, as such, are not
subject to tax withholding requirements. In addition, in 1999, Mr. Goldhammer
erroneously received a portion of a stock option grant in the form of incentive
stock options, which under federal law may only be granted to employees. There
can be no assurance, however, that the taxing authorities will agree with the
Company's position and will not assert that it is liable for the failure to
withhold income and employment taxes with respect to the exercise of such
warrants and any stock options by Mr. Goldhammer. If the Company became liable
for the failure to withhold these taxes on the exercise of such warrants and any
stock options by Mr. Goldhammer, the potential liability, exclusive of any
interest or penalties, would be approximately $12,600,000.

     The Company has not recognized accruals for penalties and interest that may
be imposed with respect to the withholding tax issues described above and other
related contingencies, including the period covered by the statute of
limitations and the Company's determination of certain exercise dates because it
does not believe that losses from such contingencies are probable. With respect
to the statute of limitations, and the Company's confirmation of certain
exercise dates, while the Company does not believe a loss is probable, there is
a potential additional liability with respect to these issues that may be
asserted by a taxing authority. If taxing authorities assert such issues and
prevail related to these withholding tax issues and other related contingencies,
including penalties, the liability which could be imposed by taxing authorities
would be substantial. The potential interest on the withholding tax liability
recorded on the Company's Consolidated Balance Sheet could be up to a maximum
amount of $6,600,000 at September 30, 2002. Potential additional withholding tax
liability on other related contingencies amounts to approximately $11,000,000,
exclusive of any interest or penalties, and excluding the amount potentially
attributable to Mr. Goldhammer noted above.

(4) PROPERTY AND EQUIPMENT

    Property and equipment are recorded at cost and consist of the following:

<TABLE>
<CAPTION>
                                                        SEPTEMBER 30,       DECEMBER 31,
                                                            2002                2001
                                                       ---------------    ---------------
<S>                                                    <C>                <C>
Land..............................................     $     4,899,000    $     2,733,000
Building and building improvements................          61,420,000         50,720,000
Leasehold improvements............................           8,370,000          8,302,000
Machinery and equipment...........................          38,359,000         33,057,000
Furniture and fixtures............................           2,096,000          2,031,000
Construction in progress..........................          75,002,000         33,080,000
                                                       ---------------    ---------------
      Total cost..................................         190,146,000        129,923,000
Less accumulated depreciation and amortization....         (29,542,000)       (22,675,000)
                                                       ---------------    ---------------
Property and equipment, net.......................     $   160,604,000    $   107,248,000
                                                       ===============    ===============
</TABLE>

         The Company is building a second commercial manufacturing facility
adjacent to its product launch manufacturing facility in Somerville (Branchburg
Township), New Jersey. This new facility will be a multi-use facility with
capacity of up to 110,000 liters (production volume). The 250,000 square foot
facility will cost approximately $234,000,000, and is being built on land
purchased in July 2000. The actual cost of the new facility may change depending
upon various factors. The Company incurred approximately $64,693,000 (included
in construction in progress above), excluding capitalized interest of

                                     Page 7

<PAGE>

approximately $1,831,000, in conceptual design, engineering and pre-construction
costs through September 30, 2002. Through October 24, 2002, committed purchase
orders totaling approximately $44,593,000 have been placed for subcontracts and
equipment related to this project. In addition, $21,306,000 in engineering,
procurement, construction management and validation costs were committed. During
August 2002, the Company executed an escrow agreement with Branchburg Township
(the "Township"). The agreement required the Company to deposit $5,040,000 in an
escrow account until the Company supplies the Township with certain New Jersey
Department of Environmental Protection permits and also certain water and sewer
permits related to the construction of this facility. The escrow agreement
requires the permits to be supplied to the Township by July 1, 2003 at which
time the Company will receive back the escrow deposit. Interest that accrues on
the escrow deposit is allocated two-thirds to the Company and one-third to the
Township. The escrow deposit was requested by the Township to insure that funds
would be available to restore the site to its original condition should the
Company fail to obtain such permits required for construction at the site. The
escrow deposit, including the Company's portion of the interest, totaled
$5,052,000 at September 30, 2002 and is included in Other current assets in the
consolidated balance sheet.

         In January 2002, the Company purchased real estate consisting of a
7.5-acre parcel of land located adjacent to the Company's product launch
manufacturing facility and pilot facility in Somerville, New Jersey. The real
estate includes an existing 50,000 square foot building, 40,000 square feet of
which is warehouse space and 10,000 square feet of which is office space. The
purchase price for the property and building was approximately $7,020,000, of
which approximately $1,125,000 related to the purchase of the land and
approximately $5,895,000 related to the purchase of the building and building
improvements. The Company intends to use this property for warehousing and
material logistics for its Somerville campus. As of September 30, 2002, the
Company has incurred approximately $326,000 (included in construction in
progress above), excluding capitalized interest of approximately $2,000, for the
retrofit of this facility. The total cost for the retrofit will be approximately
$635,000.

         On May 20, 2002, the Company purchased real estate consisting of a
6.94-acre parcel of land located across the street from the Company's product
launch manufacturing facility in Somerville, New Jersey. The real estate
includes an existing building with 46,000 square feet of office space. The
purchase price for the property was approximately $4,515,000, of which
approximately $1,041,000 was related to the purchase of the land and
approximately $3,474,000 was related to the purchase of the building. The
Company intends to use this property as the administrative building for its
Somerville campus. As of September 30, 2002, the Company has incurred
approximately $2,857,000 (included in construction in progress above), excluding
capitalized interest of approximately $7,000, for the retrofit of this facility.
The total cost for the retrofit will be approximately $5,187,000.

         The process of preparing consolidated financial statements in
accordance with accounting principles generally accepted in the United States of
America requires the Company to evaluate the carrying values of its long-lived
assets. The recoverability of the carrying values of the Company's product
launch manufacturing facility, its second commercial manufacturing facility and
its warehousing and material logistics facility will depend on (1) receiving
Food and Drug Administration ("FDA") approval of our interventional therapeutic
product candidate for cancer, ERBITUX(TM), (2) receiving FDA approval of the
manufacturing facilities and (3) the Company's ability to earn sufficient
returns on ERBITUX. Based on management's current estimates, the Company expects
to recover the carrying value of such assets.

(5) CONTRACT MANUFACTURING SERVICES

         In December 1999, the Company entered into a development and
manufacturing services agreement with Lonza Biologics PLC ("Lonza"). This
agreement was amended in April 2001 to include additional services. Under the
agreement, Lonza was responsible for process development and scale-up to
manufacture ERBITUX in bulk form under current Good Manufacturing Practices
("cGMP"). These steps were taken to assure that the manufacturing process would
produce bulk material that conforms with the Company's reference material. The
Company did not incur any costs associated with this agreement during the three
months ended September 30, 2002 and $1,535,000 was incurred during the three
months ended September 30, 2001. Approximately $38,000 and $5,135,000 was
incurred in the nine months ended September 30, 2002 and 2001, respectively, and
$7,068,000 from inception through September 30, 2002. As of September 30, 2002,
Lonza has completed its responsibilities under the development and manufacturing
services agreement.

         In September 2000, the Company entered into a three-year commercial
manufacturing services agreement with Lonza relating to ERBITUX. This agreement
was amended in June 2001 and again in September 2001 to include additional
services. The total cost for services to be provided under the three-year
commercial manufacturing services agreement is approximately $87,050,000. The
Company has incurred approximately $15,578,000 in the three months ended
September 30, 2002 and a reduction to expenses of $2,475,000 in the three months
ended September 30 2001, as a result of reductions to prior billings. The
Company has incurred $30,105,000 and $2,400,000 in the nine months ended
September 30, 2002 and 2001, respectively, and $40,418,000 from inception
through September 30, 2002 for services provided under the commercial
manufacturing services agreement.

                                     Page 8

<PAGE>

         Under the December 1999 and September 2000 agreements, Lonza is
manufacturing ERBITUX at the 5,000 liter scale under cGMP and is delivering it
to the Company over a term ending no later than December 2003. The costs
associated with both of these agreements are included in research and
development expenses when incurred and will continue to be so classified until
such time as ERBITUX may be approved for sale or until the Company obtains
obligations from its corporate partners to purchase such product. In the event
of such approval or obligations from its corporate partners, the subsequent
costs associated with manufacturing ERBITUX for commercial sale will be included
in inventory and expensed when sold. In the event the Company terminates the
commercial manufacturing services agreement without cause, the Company will be
required to pay 85% of the stated costs for each of the first ten batches
cancelled, 65% of the stated costs for each of the next ten batches cancelled
and 40% of the stated costs for each of the next six batches cancelled. The
batch cancellation provisions for certain additional batches that we are
committed to purchase require the Company to pay 100% of the stated costs of
cancelled batches scheduled within six months of the cancellation, 85% of the
stated costs of cancelled batches scheduled between six and twelve months
following the cancellation and 65% of the stated costs of cancelled batches
scheduled between twelve and eighteen months following the cancellation. These
amounts are subject to mitigation should Lonza use its manufacturing capacity
caused by such termination for another customer. At September 30, 2002, the
estimated remaining future commitments under the amended commercial
manufacturing services agreement are $26,283,000 in 2002 and $20,350,000 in
2003.

         In December 2001, the Company entered into an agreement with Lonza to
manufacture ERBITUX at the 2,000 liter scale for use in clinical trials by Merck
KGaA (the "2,000L Lonza Agreement"). The costs associated with the agreement are
reimbursable by Merck KGaA and accordingly are accounted for as collaborative
agreement revenue and such costs are also included in research and development
expenses in the consolidated statement of operations. The Company has incurred
approximately $1,175,000 and $1,763,000 in the three months ended September 30,
2002 and 2001, respectively, and $4,700,000 and $1,763,000 in the nine months
ended September 30, 2002 and 2001, respectively, and $7,183,000 from inception
through September 30, 2002 for services provided under this agreement.
Approximately $588,000 and $133,000 were reimbursable by Merck KGaA at September
30, 2002 and December 31, 2001, respectively, and included in amounts due from
corporate partners in the consolidated balance sheets. As of September 30, 2002,
Lonza has completed its responsibilities under the 2,000L Lonza Agreement.

         In January 2002, the Company executed a letter of intent with Lonza to
enter into a long-term supply agreement. The long-term supply agreement would
apply to a large scale manufacturing facility that Lonza is constructing, which
would be able to produce ERBITUX in 20,000 liter batches. The Company paid Lonza
$3,250,000 upon execution of the letter of intent for the exclusive right to
negotiate a long-term supply agreement for a portion of the facility's
manufacturing capacity. During September 2002, the Company wrote-off the deposit
because the exclusive negotiation period ended on September 30, 2002, although
negotiations continued thereafter. The $3,250,000 is included in Marketing,
general and administrative expenses on the Consolidated Statement of Operations
for the three and nine months ended September 30, 2002, respectively. The
Company is currently negotiating with Lonza and a third party with the intention
of assigning to the third party any remaining rights the Company has under this
letter of intent in return for the third party's agreement to reimburse the
Company the $3,250,000 upon execution of a binding agreement with Lonza for
supply of biologics on similar terms to those negotiated with Lonza by the
Company. The Company cannot be certain that it will enter into this arrangement.

(6) INVESTMENT IN VALIGEN N.V.

         In May 2000, the Company made an equity investment in ValiGen N.V.
("ValiGen"), a private biotechnology company specializing in therapeutic target
identification and validation using the tools of genomics and gene expression
analysis. The Company purchased 705,882 shares of ValiGen's series A preferred
stock and received a five-year warrant to purchase 388,235 shares of ValiGen's
common stock at an exercise price of $12.50 per share. The aggregate purchase
price was $7,500,000. The Company assigned a value of $594,000 to the warrant
based on the Black-Scholes Pricing Model. The ValiGen series A preferred stock
contains voting rights identical to holders of ValiGen's common stock. Each
share of ValiGen series A preferred stock is convertible into one share of
ValiGen common stock. The Company may elect to convert the ValiGen series A
preferred stock at any time; provided, that the ValiGen preferred stock will
automatically convert into ValiGen common stock upon the closing of an initial
public offering of ValiGen's common stock with gross proceeds of not less than
$20,000,000. The Company also received certain protective rights and customary
registration rights under this arrangement. The Company recorded this original
investment in ValiGen using the cost method of accounting. During the second
quarter of 2001, the Company purchased 160,000 shares of ValiGen's series B
preferred stock for $2,000,000. The terms of the series B preferred stock are
substantially the same as the series A preferred stock. The investment in
ValiGen represented approximately 7% of ValiGen's outstanding equity at the time
of purchase. As of June 30, 2001, the Company had completely written-off its
investment in ValiGen based on the modified equity method of accounting.
Included in loss on securities and investments are write-downs of the Company's
investment in Valigen of $4,375,000 for the nine months ended September 30,
2001. In the spring of 2001, the Company also entered into a no-cost Discovery
Agreement with ValiGen to

                                     Page 9

<PAGE>

evaluate certain of its technology. After the Company made its investment in
Valigen, the Company's former President and Chief Executive Officer became a
member of ValiGen's Board of Directors.

(7) NET LOSS PER COMMON SHARE

         Basic and diluted net loss per common share are computed based on the
net loss for the relevant period, divided by the weighted average number of
common shares outstanding during the period. For purposes of the diluted loss
per share calculation, the exercise or conversion of all potential common shares
is not included since their effect would be anti-dilutive for all periods
presented. For the three and nine months ended September 30, 2002 and 2001, the
Company had approximately 17,937,000 and 16,037,000, respectively, potential
common shares outstanding which represent new shares which could be issued under
convertible debt, stock options and stock warrants.

(8) COMPREHENSIVE INCOME (LOSS)

         The following table reconciles net loss to comprehensive income (loss):

<TABLE>
<CAPTION>
                                                                   THREE MONTHS ENDED                   NINE MONTHS ENDED
                                                                      SEPTEMBER 30,                       SEPTEMBER 30,
                                                           ------------------------------      ----------------------------------
                                                                2002            2001                2002                2001
                                                           -------------    -------------      ---------------    ---------------
                                                              RESTATED         RESTATED            RESTATED           RESTATED
                                                              (NOTE 2)         (NOTE 2)            (NOTE 2)           (NOTE 2)
<S>                                                        <C>              <C>                <C>                <C>
 Net loss..............................................    $ (42,025,000)   $ (41,100,000)     $  (118,577,000)   $   (71,854,000)
 Other comprehensive income (loss):
   Unrealized holding gain (loss) arising during the
    period.............................................         (130,000)       1,473,000              428,000          3,427,000
   Reclassification adjustment for realized gain
    included in net loss...............................         (264,000)      (1,800,000)          (1,500,000)        (2,707,000)
                                                           -------------    -------------      ----------------   ---------------
      Total other comprehensive income (loss)..........         (394,000)        (327,000)          (1,072,000)           720,000
                                                           -------------    -------------      ----------------   ---------------
 Total comprehensive loss..............................    $ (42,419,000)   $ (41,427,000)     $  (119,649,000)   $   (71,134,000)
                                                           =============    =============      ================   ===============
</TABLE>

(9) COLLABORATIVE AGREEMENTS

(A) MERCK KGAA

         Effective April 1990, the Company entered into a development and
commercialization agreement with Merck KGaA with respect to BEC2 and the
recombinant gp75 antigen. The agreement has been amended a number of times, most
recently in December 1997. The agreement grants Merck KGaA a license, with the
right to sublicense, to make, have made, use, sell, or have sold BEC2 and gp75
outside North America. The agreement also grants Merck KGaA a license, without
the right to sublicense, to use, sell, or have sold, but not to make BEC2 within
North America in conjunction with the Company. Pursuant to the terms of the
agreement the Company has retained the rights, (1) without the right to
sublicense, to make, have made, use, sell, or have sold BEC2 in North America in
conjunction with Merck KGaA and (2) with the right to sublicense, to make, have
made, use, sell, or have sold gp75 in North America. In return, the Company has
recognized research support payments totaling $4,700,000 and is entitled to no
further research support payments under the agreement. Merck KGaA is also
required to make payments of up to $22,500,000, of which $4,000,000 has been
recognized, through September 30, 2002, based on milestones achieved in the
licensed products' development. Merck KGaA is also responsible for worldwide
costs of up to DM17,000,000 associated with a multi-site, multinational phase
III clinical trial for BEC2 in limited disease small-cell lung carcinoma. This
expense level was reached during the fourth quarter of 2000 and all expenses
incurred from that point forward are being shared 60% by Merck KGaA and 40% by
the Company. Such cost sharing applies to all expenses beyond the DM17,000,000
threshold. The Company has incurred approximately $27,000 and $8,000 in the
three months ended September 30, 2002 and 2001, respectively, and approximately
$181,000 and $130,000 in the nine months ended September 30, 2002 and 2001,
respectively, in reimbursable research and development expenses associated with
this agreement. These amounts have been recorded as research and development
expenses and also as collaborative agreement revenue in the consolidated
statements of operations. Merck KGaA is also required to pay royalties on the
eventual sales of BEC2 outside of North America, if any. Revenues from sales, if
any, of BEC2 in North America will be distributed in accordance with the terms
of a co-promotion agreement to be negotiated by the parties.

         In December 1998, the Company entered into a development and license
agreement with Merck KGaA with respect to ERBITUX. In exchange for granting
Merck KGaA exclusive rights to market ERBITUX outside of the United States and
Canada and co-development rights in Japan, the Company received through
September 30, 2002, $30,000,000 in up-front fees and early cash-based milestone
payments based on the achievement of defined milestones. In March 2001, the
Company

                                    Page 10

<PAGE>

satisfied a condition relating to obtaining certain collateral license
agreements associated with the ERBITUX development and license agreement with
Merck KGaA. The satisfaction of this condition allowed for the recognition of
$24,000,000 in previously received milestone payments and initiated revenue
recognition of the $4,000,000 up-front payment received in connection with this
agreement. An additional $30,000,000 can be received, of which $5,000,000 has
been received as of September 30, 2002, assuming the achievement of further
milestones for which Merck KGaA will receive equity in the Company. The equity
underlying these milestone payments will be priced at varying premiums to the
then-market price of the common stock depending upon the timing of the
achievement of the respective milestones. If issuing shares of common stock to
Merck KGaA would result in Merck KGaA owning greater than 19.9% of our common
stock, the milestone shares will be a non-voting preferred stock, or other
non-voting stock convertible into the Company's common stock. These convertible
securities will not have voting rights. They will be convertible at a price
determined in the same manner as the purchase price for shares of the Company's
common stock if shares of common stock were to be issued. They will not be
convertible into common stock if, as a result of the conversion, Merck KGaA
would own greater than 19.9% of the Company's common stock. This 19.9%
limitation is in place through December 2002. Merck KGaA will pay the Company a
royalty on future sales of ERBITUX outside of the United States and Canada, if
any. This agreement may be terminated by Merck KGaA in various instances,
including (1) at its discretion on any date on which a milestone is achieved (in
which case no milestone payment will be made), or (2) for a one-year period
after first commercial sale of ERBITUX in Merck KGaA's territory, upon Merck
KGaA's reasonable determination that the product is economically unfeasible (in
which case Merck KGaA is entitled to a return of 50% of the cash-based up front
fees and milestone payments then paid to date, but only out of revenues received
by ImClone, if any, based upon a royalty rate applied to the gross profit from
ERBITUX sales or a percentage of ERBITUX fees and royalties received from a
sublicensee on account of the sale of ERBITUX in the United States and Canada).
In August 2001, the Company and Merck KGaA amended this agreement to provide,
among other things, that Merck KGaA may manufacture ERBITUX for supply in its
territory and may utilize a third party to do so. The amendment further released
Merck KGaA from its obligations under the agreement relating to providing a
guaranty under a $30,000,000 credit facility relating to the build-out of the
Company's product launch manufacturing facility. In addition, the amendment
provides that the companies have co-exclusive rights to ERBITUX in Japan,
including the right to sublicense, and that Merck KGaA has waived its right of
first offer in the case of a proposed sublicense by the Company of ERBITUX in
the Company's territory. In consideration for the amendment, the Company agreed
to a reduction in royalties payable by Merck KGaA on sales of ERBITUX in Merck
KGaA's territory.

         In conjunction with Merck KGaA, the Company has expanded the trial of
ERBITUX plus radiotherapy in squamous cell carcinoma of the head and neck into
Europe, South Africa, Israel, Australia and New Zealand. In order to support
these clinical trials, Merck KGaA has agreed to purchase from the Company
ERBITUX manufactured by the Company and under the various manufacturing service
agreements with Lonza for use in this and other trials and further agreed to
reimburse the Company for one-half of the outside contract service costs
incurred with respect to this Phase III clinical trial of ERBITUX for the
treatment of head and neck cancer in combination with radiation. In September
2002, the Company entered into a binding term sheet, effective as of April 15,
2002, for the supply of ERBITUX to Merck KGaA, which replaces previous supply
arrangements. The term sheet provides for Merck KGaA to purchase bulk and
finished ERBITUX ordered from the Company during the term of the December 1998
development and license agreement at a price equal to the Company's fully loaded
manufacturing costs. The term sheet also provides for Merck KGaA to use
reasonable efforts to enter into its own contract manufacturing agreements for
supply of ERBITUX by 2004 and obligates Merck KGaA to reimburse the Company for
costs associated with transferring technology and any other services requested
by Merck KGaA relating to establishing its own manufacturing or contract
manufacturing capacity. Amounts due from Merck KGaA related to these
arrangements totaled approximately $2,704,000 and $1,503,000 at September 30,
2002 and December 31, 2001, respectively, and are included in amounts due from
corporate partners in the consolidated balance sheets. The Company recorded
collaborative agreement revenue related to these arrangements in the
consolidated statements of operations totaling approximately $1,997,000 and
$2,616,000 in the three months ended September 30, 2002, and 2001, respectively
and $14,219,000 and $6,206,000 in the nine months ended September 30, 2002, and
2001, respectively. Of these amounts, $1,470,000 and $1,170,000 in the three
months ended September 30, 2002, and 2001, and $12,323,000 and $2,593,000 in the
nine months ended September 30, 2002, and 2001, respectively, related to
reimbursable costs associated with supplying ERBITUX to Merck KGaA for use in
clinical trials. A portion of the ERBITUX sold to Merck KGaA was produced in
prior periods and the related manufacturing costs have been expensed in prior
periods when the related raw materials were purchased and the associated direct
labor and overhead was consumed or, in the case of contract manufacturing, when
such services were performed. These costs totaled $704,000 and $1,061,000 for
the three months ended September 30, 2002 and 2001, respectively and $7,051,000
and $2,464,000 for the nine months ended September 30, 2002 and 2001,
respectively. Reimbursable research and development expenses were incurred and
totaled approximately $527,000 and $1,446,000 in the three months ended
September 30, 2002 and 2001, respectively, and $1,896,000 and $3,613,000 in the
nine months ended September 30, 2002 and 2001, respectively. These amounts have
been recorded as research and development expenses and also as collaborative
agreement revenue in the consolidated statements of operations.

                                    Page 11

<PAGE>

(b) BRISTOL-MYERS SQUIBB COMPANY

         On September 19, 2001, the Company entered into an acquisition
agreement (the "Acquisition Agreement") with BMS and Bristol-Myers Squibb
Biologics Company, a Delaware corporation ("BMS Biologics"), which is a
wholly-owned subsidiary of BMS, providing for the tender offer by BMS Biologics
to purchase up to 14,392,003 shares of the Company's common stock for $70.00 per
share, net to the seller in cash. In connection with the Acquisition Agreement,
the Company entered into a stockholder agreement with BMS and BMS Biologics,
dated as of September 19, 2001 (the "Stockholder Agreement"), pursuant to which
all parties agreed to various arrangements regarding the respective rights and
obligations of each party with respect to, among other things, the ownership of
shares of the Company's common stock by BMS and BMS Biologics. Concurrent with
the execution of the Acquisition Agreement and the Stockholder Agreement, the
Company entered into a development, promotion, distribution and supply agreement
(the "Commercial Agreement") with BMS and its wholly-owned subsidiary E.R.
Squibb & Sons, L.L.C. ("E.R. Squibb"), relating to ERBITUX, pursuant to which,
among other things, the Company is co-developing and co-promoting ERBITUX in the
United States and Canada, and co-developing ERBITUX (together with Merck KGaA)
in Japan.

         On October 29, 2001, pursuant to the Acquisition Agreement, BMS
Biologics accepted for payment pursuant to the tender offer 14,392,003 shares of
the Company's common stock on a pro rata basis from all tendering shareholders
and those conditionally exercising stock options.

         On March 5, 2002, the Company amended the Commercial Agreement with
E.R. Squibb and BMS. The amendment changed certain economics of the Commercial
Agreement and has expanded the clinical and strategic roles of BMS in the
ERBITUX development program. One of the principal economic changes to the
Commercial Agreement is that the Company received $140,000,000 on March 7, 2002
and an additional payment of $60,000,000 is payable on March 5, 2003. Such
payments are in lieu of the $300,000,000 milestone payment the Company would
have received under the original terms of the agreement upon acceptance by the
FDA of the ERBITUX rolling Biologic License Application submitted for marketing
approval to treat irinotecan-refractory colorectal cancer. In addition, the
Company agreed, and has in fact, resumed construction of its second commercial
manufacturing facility as soon as reasonably practicable after the execution of
the amendment.

         In exchange for the rights granted to BMS under the amended Commercial
Agreement, the Company can receive up-front and milestone payments totaling
$900,000,000 in the aggregate, of which $200,000,000 was received on September
19, 2001, $140,000,000 was received on March 7, 2002, $60,000,000 is payable on
March 5, 2003, $250,000,000 is payable upon receipt of marketing approval from
the FDA with respect to an initial indication for ERBITUX and $250,000,000 is
payable upon receipt of marketing approval from the FDA with respect to a second
indication for ERBITUX. All such payments are non-refundable and non-creditable.
Payments received under the amended Commercial Agreement with BMS and E.R.
Squibb are being deferred and recognized as revenue based on the percentage of
actual product research and development costs incurred to date by both BMS and
the Company to the estimated total of such costs to be incurred over the term of
the Commercial Agreement. Except for the Company's expenses incurred pursuant to
a co-promotion option, E.R. Squibb is also responsible for 100% of the
distribution, sales and marketing costs in the United States and Canada, and as
between the Company and E.R. Squibb, each party will be responsible for 50% of
the distribution, sales, and marketing costs and other related costs and
expenses in Japan. The Commercial Agreement provides that E.R. Squibb shall pay
the Company a 39% distribution fee on net sales of ERBITUX by E.R. Squibb in the
United States and Canada. The Commercial Agreement also provides that the
distribution fees for the sale of ERBITUX in Japan by E.R. Squibb or the Company
shall be equal to 50% of operating profit or loss with respect to such sales for
any calendar month. In the event of an operating profit, E.R. Squibb will pay
the Company the amount of such distribution fee, and in the event of an
operating loss, the Company will credit E.R. Squibb the amount of such
distribution fee. The Commercial Agreement provides that the Company will be
responsible for the manufacture and supply of all requirements of ERBITUX in
bulk form for clinical and commercial use in the United States, Canada and Japan
and that E.R. Squibb will purchase all of its requirements of ERBITUX in bulk
form for commercial use from the Company. The Company will supply ERBITUX for
clinical use at the Company's fully burdened manufacturing cost, and will supply
ERBITUX for commercial use at the Company's fully burdened manufacturing cost
plus a mark-up of 10%. In addition to the up-front and milestone payments, the
distribution fees for the United States, Canada and Japan and the 10% mark-up on
the commercial supply of ERBITUX, E.R. Squibb is also responsible for 100% of
the cost of all clinical studies other than those studies undertaken post-launch
which are not pursuant to an Investigational New Drug Application ("INDA")
(e.g., phase IV studies), the cost of which will be shared equally between E.R.
Squibb and the Company. As between E.R. Squibb and the Company, each will be
responsible for 50% of the cost of all clinical studies in Japan.

         Unless earlier terminated pursuant to the termination rights discussed
below, the Commercial Agreement expires with regard to ERBITUX in each of the
United States, Canada and Japan on the later of September 19, 2018 and the date
on which the sale of the Product ceases to be covered by a validly issued or
pending patent in such country. The Commercial

                                    Page 12

<PAGE>

Agreement may also be terminated prior to such expiration as follows:

         -        by either party, in the event that the other party materially
                  breaches any of its material obligations under the Commercial
                  Agreement and has not cured such breach within 60 days after
                  notice;

         -        by E.R. Squibb, if the joint executive committee (the "JEC")
                  formed by BMS and the Company determines that there exists a
                  significant concern regarding a regulatory or patient safety
                  issue that would seriously impact the long-term viability of
                  all products; or

         -        by either party, in the event that the JEC does not approve
                  additional clinical studies that are required by the FDA in
                  connection with the submission of the initial regulatory
                  filing with the FDA within 90 days of receiving the formal
                  recommendation of the product development committee concerning
                  such additional clinical studies.

         The Company incurred approximately $2,250,000 during the nine months
ended September 30, 2002 in advisor fees associated with the amendment to the
Commercial Agreement with BMS and affiliates, and $16,050,000 during the nine
months ended September 30, 2001, in advisor fees associated with consummating
the acquisition agreement, the stockholder agreement and the commercial
agreement with BMS and affiliates, which have been expensed and included as a
separate line item in operating expenses in the consolidated statement of
operations.

         Amounts due from BMS related to this agreement totaled approximately
$14,106,000 and $6,714,000 at September 30, 2002 and December 31, 2001,
respectively, and are included in amounts due from corporate partners in the
consolidated balance sheets. The Company recorded collaborative agreement
revenue related to this agreement in the consolidated statements of operations
totaling approximately $7,248,000 and $15,769,000 in the three and nine months
ended September 30, 2002, respectively. Of these amounts, $2,477,000 and
$6,286,000 in the three and nine months ended September 30, 2002, respectively,
related to reimbursable costs associated with supplying ERBITUX for use in
clinical trials associated with this agreement. A portion of the ERBITUX sold to
BMS was produced in prior periods and the related manufacturing costs have been
expensed in prior periods when the related raw materials were purchased and the
associated direct labor and overhead was consumed or, in the case of contract
manufacturing, when such services were performed. These costs totaled $462,000
and $4,271,000 for the three and nine months ended September 30, 2002,
respectively. Reimbursable research and development and marketing expenses were
incurred and totaled approximately $4,771,000 and $9,483,000 in the three and
nine months ended September 30, 2002. These amounts have been recorded as
research and development and marketing, general and administrative expenses and
also as collaborative agreement revenue in the consolidated statements of
operations.

         In June 2002, the Company and BMS agreed that certain ERBITUX clinical
trial costs would in fact be borne by the Company. This resulted in the issuance
of credit memos to BMS during the nine months ended September 30, 2002 totaling
approximately $2,949,000, which ultimately reduced collaborative agreement
revenue and license fee revenue in the nine months ended September 30, 2002.

         License fees and milestone revenues consist of the following:

<TABLE>
<CAPTION>
                                                                      THREE MONTHS ENDED                 NINE MONTHS ENDED
                                                                         SEPTEMBER 30,                     SEPTEMBER 30,
                                                                ------------------------------    -----------------------------
                                                                    2002             2001             2002             2001
                                                                -------------    -------------    -------------   -------------
<S>                                                             <C>              <C>              <C>             <C>
BMS ERBITUX license fee revenue.............................    $   4,841,000    $     387,000    $  12,907,000   $     387,000
Merck KGaA ERBITUX milestone revenue........................               --        1,760,000               --      27,760,000
Merck KGaA BEC2 milestone revenue...........................               --               --               --       1,000,000
Merck KGaA ERBITUX and BEC2 license fee revenue.............           97,000           97,000          289,000         289,000
Other.......................................................           58,000               --           58,000          40,000
                                                                -------------    -------------    -------------   -------------
    Total license fees and milestone revenues...............    $   4,996,000    $   2,244,000    $  13,254,000   $  29,476,000
                                                                =============    =============    =============   =============
</TABLE>

                                    Page 13

<PAGE>

         Collaborative agreement revenue (see note 1) from corporate partners
consists of the following:

<TABLE>
<CAPTION>
                                                                            THREE MONTHS ENDED                NINE MONTHS ENDED
                                                                               SEPTEMBER 30,                    SEPTEMBER 30,
                                                                      ------------------------------   -----------------------------
                                                                          2002             2001            2002            2001
                                                                      -------------    -------------   -------------   -------------
<S>                                                                   <C>              <C>             <C>             <C>
BMS, reimbursable ERBITUX research and development
  expenses.......................................................     $   7,152,000    $          --   $  14,844,000   $          --
BMS, reimbursable ERBITUX marketing expenses.....................            96,000               --         925,000              --
Merck KGaA, reimbursable ERBITUX research and
  development expenses...........................................           527,000        1,446,000       1,896,000       3,613,000
Merck KGaA, reimbursable ERBITUX product costs for use
  in clinical trials.............................................         1,470,000        1,170,000      12,323,000       2,593,000
Merck KGaA, reimbursable administrative expenses.................           144,000          194,000         417,000         377,000
Merck KGaA, reimbursable BEC2 research and
  development expenses...........................................            27,000            8,000         181,000         130,000
                                                                      -------------    -------------   -------------   -------------
    Total collaborative agreement revenue........................     $   9,416,000    $   2,818,000   $  30,586,000   $   6,713,000
                                                                      =============    =============   =============   =============
</TABLE>

         Amounts due from corporate partners consist of the following:

<TABLE>
<CAPTION>
                                                                                                     SEPTEMBER 30,      DECEMBER 31,
                                                                                                         2002               2001
                                                                                                     -------------      ------------
<S>                                                                                                  <C>                <C>
Due from BMS, ERBITUX research and development and marketing expenses........................        $  14,106,000      $  6,714,000
Due from Merck KGaA, ERBITUX research and development and administrative expenses............            1,233,000           666,000
Due from Merck KGaA, reimbursement of ERBITUX manufacturing costs for use in clinical
  trials.....................................................................................            1,471,000           837,000
Due from Merck KGaA, BEC2 research and development expenses..................................               60,000            13,000
                                                                                                     -------------      ------------
    Total amounts due from corporate partners................................................        $  16,870,000      $  8,230,000
                                                                                                     =============      ============
</TABLE>

         Deferred revenue consists of the following:

<TABLE>
<CAPTION>
                                                                                       SEPTEMBER 30,      DECEMBER 31,
                                                                                           2002               2001
                                                                                      ---------------   ---------------
<S>                                                                                   <C>               <C>
BMS, ERBITUX Commercial Agreement........................................             $   324,539,000   $   197,447,000
Merck KGaA, ERBITUX development and license agreement....................                   3,611,000         3,778,000
Merck KGaA, BEC2 development and commercialization agreement.............                   2,150,000         2,271,000
                                                                                      ---------------   ---------------
                                                                                          330,300,000       203,496,000
Less: current portion....................................................                 (37,494,000)      (20,683,000)
                                                                                      ---------------   ---------------
                                                                                      $   292,806,000   $   182,813,000
                                                                                      ===============   ===============
</TABLE>

(10)     OTHER CONTINGENCIES

         Beginning in January 2002, a number of complaints asserting claims
under the federal securities laws against the Company and certain of its
directors and officers were filed in the U.S. District Court for the Southern
District of New York. Those actions were consolidated under the caption Irvine
v. ImClone Systems Incorporated et al., No. 02 Civ. 0109 (RO), and on September
16, 2002, a consolidated amended complaint was filed in that consolidated
action, which plaintiffs corrected in limited respects on October 22, 2002. The
corrected consolidated amended complaint names as defendants the Company, its
former chief executive officer Dr. Samuel D. Waksal, its current chief executive
officer Dr. Harlan W. Waksal, the chairman of its board of directors Robert
Goldhammer, current or former directors Richard Barth, David Kies, Paul Kopperl,
John Mendelsohn and William Miller, the Company's former general counsel John
Landes, and its vice president for marketing and sales, Ronald Martell. The
complaint asserts claims for securities fraud under sections 10(b) and 20(a) of
the Securities Exchange Act of 1934 ("the Exchange Act") and SEC Rule 10b-5, on
behalf of a purported class of persons who purchased the Company's publicly
traded securities between March 27, 2001 and January 25, 2002. The complaint
also asserts claims against Dr. Samuel D. Waksal under section 20A of the
Exchange Act on behalf of a separate purported sub-class of purchasers of the
Company's securities between December 27, 2001 and December 28, 2001. The
complaint generally alleges that various public statements made by or on behalf
of the Company or the other defendants during 2001 and early 2002 regarding the
prospects for FDA approval of ERBITUX were false or misleading when made, that
the individual defendants were allegedly aware of material non-public
information regarding the actual prospects for ERBITUX at the time that they
engaged in transactions in the Company's common stock and that members of the
purported stockholder class suffered damages when the market price of the
Company's common stock declined following disclosure of the information that
allegedly had not been previously disclosed. The complaint seeks to proceed on
behalf of the alleged class described above, seeks monetary damages in an
unspecified amount and seeks recovery of plaintiffs' costs and attorneys' fees.

                                    Page 14

<PAGE>

Under the existing schedule in that action, defendants' response to the
consolidated amended complaint is due in late November 2002.

         Separately, on September 17, 2002 an individual purchaser of the
Company's common stock filed an action on his own behalf asserting claims
against the Company, Dr. Samuel D. Waksal and Dr. Harlan W. Waksal under
sections 10(b) and 20(a) of the Exchange Act and SEC Rule 10b-5. That action is
styled Flynn v. ImClone Systems Incorporated, et al., No. 02 Civ. 7499.
Plaintiff alleges that he purchased shares on various dates in late 2001, that
various public statements made by the Company or the other defendants during
2001 regarding the prospects for FDA approval of ERBITUX were false or
misleading when made and that plaintiff relied on such allegedly false and
misleading information in making his purchases. Plaintiff seeks compensatory
damages of not less than $180,000 and punitive damages of $5 million, together
with interest, costs and attorneys' fees. Defendants' response to the complaint
is due in late November 2002.

         Beginning on January 13, 2002 and continuing thereafter, nine separate
purported shareholder derivative actions have been filed against the members of
the Board of Directors and the Company, as nominal defendant, advancing claims
based on allegations similar to the allegations in the federal securities class
action complaints. Four of these derivative cases were filed in the Delaware
Court of Chancery and have been consolidated in that court under the caption In
re ImClone Systems Incorporated Derivative Litigation, Cons. C.A. No. 19341-NC.
In addition, two purported derivative actions have been filed in the U.S.
District Court for the Southern District of New York, styled Lefanto v. Waksal,
et al., No. 02 Civ. 0163 (LLS), and Forbes v. Barth, et al., No. 02 Civ. 1400
(RO), and three purported derivative actions have been filed in New York State
Supreme Court in Manhattan, styled Boghosian v. Barth, et al., Index No.
100759/02, Johnson v. Barth, et al., Index No. 601304/02 and Henshall v. Bodnar,
et al., Index No. 603121/02. All of these actions assert claims, purportedly on
behalf of the Company, for breach of fiduciary duty by certain members of the
Board of Directors based on the allegation, among others, that certain directors
engaged in transactions in our common stock while in possession of material,
non-public information concerning the regulatory and marketing prospects for
ERBITUX or improperly disclosed such information to others. Another complaint,
purportedly asserting direct claims on behalf of a class of the Company's
shareholders but in fact asserting derivative claims that are similar to those
asserted in these nine cases, was filed in the U.S. District Court for the
Southern District of New York on February 13, 2002, styled Dunlap v. Waksal, et
al., No. 02 Civ. 1154 (RO). The Dunlap complaint asserts claims against the
Board of Directors for breach of fiduciary duty purportedly on behalf of all
persons who purchased shares of the Company's common stock prior to June 28,
2001 and then held those shares through December 6, 2001. It alleges that the
members of the purported class suffered damages as a result of holding their
shares based on allegedly false information about the financial prospects of the
Company that was disseminated during this period.

         The Company intends to vigorously defend itself against the claims
asserted in these actions, which are in their earliest stages. The Company is
unable to predict the outcome of these actions at this time. Because the Company
does not believe a loss is probable, no legal reserve has been established.

         As previously reported, the Company has received subpoenas and requests
for information in connection with investigations by the Securities and Exchange
Commission, the Subcommittee on Oversight and Investigations of the U.S. House
of Representatives Committee on Energy and Commerce, and the U.S. Department of
Justice relating to the circumstances surrounding the disclosure of the FDA
letter dated December 28, 2001 and trading in our securities by certain Company
insiders in 2001. The Company has also received subpoenas and requests for
information pertaining to document retention issues in 2001 and 2002 and to
certain communications regarding ERBITUX in 2000. The Company is cooperating in
connection with all of these inquiries and intends to continue to do so.

         On June 19, 2002, the Company received a written "Wells Notice" from
the staff of the Securities and Exchange Commission, ("the Commission")
indicating that the Staff of the Commission is considering recommending that the
Commission bring an action against the Company relating to its disclosures
immediately following the receipt of a Refusal-to-File letter from the FDA on
December 28, 2001 for its biologics license application for ERBITUX. We filed a
"Wells submission" on July 12, 2002 in response to the staff's Wells Notice. The
Company has also received permission from the Commission to file a supplemental
Wells submission, and the Company anticipates that it will make this submission
by the end of this year.

         On August 7, 2002, a federal grand jury in the Southern District of New
York returned an indictment charging Dr. Samuel D. Waksal with, inter alia,
securities fraud and conspiracy to commit securities fraud. On October 15, 2002,
Dr. Samuel D. Waksal entered a plea of guilty to several counts in that
indictment, including that on December 27, 2001 he directed a family member to
sell shares of the Company's common stock and attempted to sell shares that he
owned in advance of an expected announcement that the FDA had issued a "refusal
to file" letter with respect to the Company's application for approval of
ERBITUX. The Company received such a "refusal to file" letter from the FDA on
December 28, 2001 and announced its receipt of that letter following the close
of trading.

                                    Page 15

<PAGE>

         On August 14, 2002, after the federal grand jury indictment of Dr.
Samuel D. Waksal had been issued but before Dr. Samuel D. Waksal's guilty plea
to certain counts of that indictment, the Company filed an action in New York
State Supreme Court seeking recovery of certain compensation, including
advancement of certain defense costs, that the Company had paid to or on behalf
of Dr. Samuel D. Waksal. That action, styled ImClone Systems Incorporated v.
Samuel D. Waksal, Index No. 02/602996, is in its earliest stages.

         The Company has incurred legal fees associated with these matters
totaling approximately $9,249,000 during the nine months ended September 30,
2002. In addition, the Company has estimated and recorded a receivable totaling
$2,593,000 for a portion of the above mentioned legal fees that the Company
believes are recoverable from its insurance carriers. This receivable is
included in Other current assets in the consolidated balance sheet at September
30, 2002. In November 2002, the Company received a letter from counsel for its
primary insurance carrier asserting that Dr. Samuel D. Waksal's guilty plea
gives rise to an exclusion from insurance coverage for the Company. The Company
intends to contest this assertion.

(11)     CERTAIN RELATED PARTY TRANSACTIONS

         In September 2001 and February 2002, the Company entered into
employment agreements with six senior executive officers, including, in
September 2001, the then President and Chief Executive Officer and the then
Chief Operating Officer. The then President and Chief Executive Officer resigned
in May 2002 and the then Chief Operating Officer was appointed to President and
Chief Executive Officer. The September agreements each have three-year terms and
the February agreement has a one-year term. The February 2002 agreement was
amended in April 2002. The term of employment for the present CEO will be
automatically extended for one additional day each day during the term of
employment unless either the Company or the Executive otherwise gives notice.
The employment agreements provide for stated base salaries, minimum bonuses and
benefits aggregating $3,765,000 annually. In October 2002, the Company accepted
the resignation of an executive officer who held one of the aforementioned
employment agreements. The Company and the officer executed a separation
agreement whereby the officer will receive his stated base salary from the date
of termination through October 2003 and certain benefits including healthcare
and life insurance coverage through December 2002.

         In August 2002 and September 2002, the Company entered into one-year
agreements with two executive officers. The employment agreements provide for a
stated base salary aggregating $390,000.

         Certain transactions engaged in by the Company's former President and
Chief Executive Officer, Dr. Samuel D. Waksal, in securities of the Company were
deemed to have resulted in "short-swing profits" under Section 16 of the
Securities Exchange Act of 1934 (the "Exchange Act"). In accordance with Section
16(b) of the Exchange Act, Dr. Samuel D. Waksal has paid the Company an
aggregate amount of approximately $486,000, in March 2002, and an additional
amount of approximately $79,000 in July 2002, as disgorgement of "short-swing
profits" he was deemed to have realized. The amounts received were recorded as
an increase to additional paid-in capital.

(12)  STOCKHOLDER RIGHTS PLAN

         On February 15, 2002, the Company's Board of Directors approved a
Stockholder Rights Plan and declared a dividend of one right for each share of
its common stock outstanding at the close of business on February 19, 2002. In
connection with the Board of Directors' approval of the Stockholder Rights Plan,
Series B Participating Cumulative Preferred Stock was created. Under certain
conditions, each right entitles the holder to purchase from the Company
one-hundredth of a share of series B Participating Cumulative Preferred Stock at
an initial purchase price of $175 per share. The Stockholder Rights Plan is
designed to enhance the Board's ability to protect stockholders against, among
other things, unsolicited attempts to acquire control of the Company that do not
offer an adequate price to all of the Company's stockholders or are otherwise
not in the best interests of the Company and its stockholders.

         Subject to certain exceptions, rights become exercisable (i) on the
tenth day after public announcement that any person, entity, or group of persons
or entities has acquired ownership of 15% or more of the Company's outstanding
common stock, or (ii) 10 business days following the commencement of a tender
offer or exchange offer by any person that would, if consummated, result in such
person acquiring ownership of 15% or more of the Company's outstanding common
stock, (collectively an "Acquiring Person").

         In such event, each right holder will have the right to receive the
number of shares of common stock having a then current market value equal to two
times the aggregate exercise price of such rights. If the Company were to enter
into certain business combination or disposition transactions with an Acquiring
Person, each right holder will have the right to receive shares of common stock
of the acquiring company having a value equal to two times the aggregate
exercise price of the rights.

                                    Page 16

<PAGE>

         The Company may redeem these rights in whole at a price of $.001 per
right. The rights expire on February 15, 2012.

(13)  SEPARATION AGREEMENT

         On May 22, 2002, the Company accepted the resignation of its President
and Chief Executive Officer, Dr. Samuel D. Waksal. In connection with the
resignation, on May 24, 2002 the Company and Dr. Samuel D. Waksal executed a
separation agreement whereby Dr. Samuel D. Waksal received a lump sum payment
totaling $7,000,000 and was entitled to receive for defined periods of time the
continuation of certain benefits including health care and life insurance
coverage with an estimated cost of $283,000. The related expense of $7,283,000
is included in Marketing, general and administrative expenses in the
consolidated statement of operations for the nine months ended September 30,
2002. In addition, 1,250,000 stock option awards granted to Dr. Samuel D. Waksal
on September 19, 2001 which were exercisable at a per share exercise price of
$50.01 and constituted all outstanding stock option awards held by Dr. Samuel D.
Waksal, were deemed amended such that the unvested portion vested immediately as
of the date of termination. The amended stock option awards can be exercised at
any time until the end of the term of such awards. No compensation expense was
recorded because the fair market value of the Company's common stock was below
the $50.01 exercise price on the date the option award was amended. On August 7,
2002, a federal grand jury indicted Dr. Samuel D. Waksal. The Company has
learned that Dr. Samuel D. Waksal, in contravention of Company policy, directed
the destruction of certain of his personal records that were, or could be
perceived to be relevant to the pending government investigations. Accordingly,
on August 14, 2002, the Company filed an action against Dr. Samuel D. Waksal in
New York State Supreme Court seeking repayment of amounts paid to him by the
Company pursuant to the separation agreement, cancellation or recovery of other
benefits provided under that agreement (including cancellation of all stock
options that vested as a result of the agreement), disgorgement of amounts
previously advanced by the Company on behalf of Dr. Samuel D. Waksal for his
legal fees and expenses, and repayment of certain amounts paid under Dr. Samuel
D. Waksal's previous employment agreement. The action, styled ImClone Systems
Incorporated v. Samuel D. Waksal, Index No. 02/602996, is in its earliest
stages.

(14)  2002 STOCK OPTION PLAN

         In June 2002, the shareholders approved and the Company adopted the
2002 Stock Option Plan. The plan provides for the granting of both incentive
stock options and non-qualified stock options to purchase 3,300,000 shares of
the Company's common stock to employees, directors, consultants and advisors of
the Company. Options granted under the plan generally vest over one to five year
periods and unless earlier terminated, expire ten years from the date of grant.
Incentive stock options granted under the 2002 stock option plan may not exceed
825,000 shares of common stock, may not be granted at a price less than the fair
market value of the stock at the date of grant and may not be granted to
non-employees.


(15)  CONVERTIBLE SUBORDINATED NOTES

         In February 2000, the Company completed a private placement of
$240,000,000 in 5 1/2% Convertible Subordinated Notes due March 1, 2005, which
notes are outstanding at September 30, 2002. On May 2, 2003, the Company
informed the trustee for the Convertible Subordinated Notes of its withholding
tax issues and the delay in filing its Annual Report on Form 10-K for the year
ended December 31, 2002 and of the Company's intention to satisfy its tax
liabilities upon completion of its discussions with the relevant taxing
authorities and to file its Form 10-K as soon as possible. The indenture for the
Convertible Subordinated Notes includes covenants requiring the Company to
timely pay taxes and timely make Exchange Act filings. Under the indenture,
there can be no acceleration of payment of the notes until the Company receives
a notice of default from the trustee or a specified percentage of the note
holders and a 60-day grace period lapses. The Company has not received any such
notice. If, at some point in the future, the Company were to receive such a
notice and if it was determined at that time that the Company was not in
compliance with applicable covenants, the Company intends to and believes it
would be able to cure such non-compliance within the 60-day grace period.


                                    Page 17

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ITEM 2.    MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION
           AND RESULTS OF OPERATIONS

         As discussed in Note 2 to our Consolidated Financial Statements
included herein and below under the "Liquidity and Capital Resources" section,
we have restated our Consolidated Financial Statements for the three and nine
months ended September 30, 2002 and 2001. All amounts included in this
discussion and analysis reflect the effects of the restatement. The following
discussion and analysis by our management is provided to identify certain
significant factors that affected our financial position and operating results
during the periods included in the accompanying financial statements.

CRITICAL ACCOUNTING POLICIES

         During January 2002, the Securities and Exchange Commission ("SEC")
published a Commission Statement in the form of Financial Reporting Release No.
61, which requested that all registrants discuss their most "critical accounting
policies" in management's discussion and analysis of financial condition and
results of operations. The SEC has defined critical accounting policies as those
that are both important to the portrayal of a company's financial condition and
results, and that require management's most difficult, subjective or complex
judgments, often as a result of the need to make estimates about the effect of
matters that are inherently uncertain. While our significant accounting policies
are summarized in Note 2 to our consolidated financial statements included in
Form 10-K for the fiscal year ended December 31, 2001, we believe the following
accounting policies to be critical:

         Revenue Recognition - We adopted Staff Accounting Bulletin No. 101
("SAB 101") in the fourth quarter of 2000 with an effective date of January 1,
2000, implementing a change in accounting policy with respect to revenue
recognition. Beginning January 1, 2000, non-refundable fees received upon
entering into collaborative agreements in which the Company has continuing
involvement are recorded as deferred revenue and recognized over the estimated
service period. See Note 7.

         Payments received under the development, promotion, distribution and
supply agreement (the "Commercial Agreement") dated September 19, 2001 and as
amended on March 5, 2002 with Bristol-Myers Squibb Company ("BMS") and E.R.
Squibb & Sons, L.L.C., a Delaware limited liability company and a wholly-owned
subsidiary of BMS ("E.R. Squibb"), relating to ERBITUX, are being deferred and
recognized as revenue based upon the actual product research and development
costs incurred to date by BMS, E.R. Squibb and ImClone Systems as a percentage
of the estimated total of such costs to be incurred over the term of the
agreement. Of the $340,000,000 in upfront payments we received from BMS through
September 30, 2002, approximately $12,907,000 was recognized as revenue during
the nine months ended September 30, 2002 and $15,461,000 from the commencement
of the Commercial Agreement through September 30, 2002.

         The methodology used to recognize deferred revenue involves a number of
estimates and judgments, such as the estimate of total product research and
development costs to be incurred under the Commercial Agreement. Changes in
these estimates and judgments can have a significant effect on the size and
timing of revenue recognition.

         Non-refundable milestone payments, which represent the achievement of a
significant step in the research and development process, pursuant to
collaborative agreements other than the Commercial Agreement with BMS, are
recognized as revenue upon the achievement of the specified milestone.

         Production Costs - The costs associated with the manufacture of ERBITUX
are included in research and development expenses when incurred and will
continue to be so classified until such time as ERBITUX may be approved for sale
or until we obtain obligations from our corporate partners for supply of such
product. In the event of such approval or obligations from our corporate
partners, the subsequent costs associated with manufacturing ERBITUX for
commercial sale will be included in inventory and expensed as cost of goods sold
when sold. If ERBITUX is approved by the United States Food and Drug
Administration ("FDA"), any subsequent sale of this inventory, previously
expensed, will result in revenue from product sales with no corresponding cost
of goods sold.

         Withholding Taxes - The estimated amounts recorded in the accompanying
Consolidated Financial Statements do not include penalties and interest that may
be imposed with respect to the withholding tax issues described herein and other
related contingencies, including the period covered by the statute of
limitations and our determination of certain exercise dates because we do not
believe that losses from such contingencies are probable. With respect to the
statute of limitations, and our determination of certain exercise dates, while
we do not believe a loss is probable, there is a potential additional liability
with respect to these issues that may be asserted by a taxing authority.
However, if our assessment of these withholding tax issues and other related
contingencies is incorrect, the liability that could be imposed by taxing
authorities may be substantial. The potential interest on the withholding tax
liabilities recorded on our Consolidated Balance Sheet could be up to a maximum
amount of $6,600,000 at September 30, 2002. Potential additional withholding tax
liability on other related contingencies amount to approximately $11,000,000,
exclusive of any interest or penalties, and excluding the amount potentially
attributable to Mr. Goldhammer noted herein.

         Litigation - We are currently involved in certain legal proceedings as
discussed in "Contingencies" Note 10 to the financial statements. In accordance
with Statement of Financial Accounting Standards No. 5, no legal reserve has
been established in our financial statements for these legal proceedings because
the Company does not believe that a loss is probable. However, if in a future
period, events in any such legal proceedings render it probable that a loss will
be incurred and if such loss is reasonably estimable at that time, the
possibility exists for a material adverse impact on the operating results of
that period.

         Long-Lived Assets - We review long-lived assets for impairment when
events or changes in business conditions indicate that their full carrying value
may not be recovered. Assets are considered to be impaired and written down to
fair value if expected associated undiscounted cash flows are less than carrying
amounts. Fair value is generally determined as the present

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<PAGE>

value of the expected associated cash flows. We recently built a product launch
manufacturing facility and are building a second commercial manufacturing
facility and a material logistics and warehousing facility, which are summarized
in Note 4 to the financial statements. The product launch manufacturing facility
is dedicated to the clinical and commercial production of ERBITUX and the second
commercial manufacturing facility will be a multi-use production facility.
ERBITUX is currently being produced for clinical trials and potential
commercialization. The material logistics and warehousing facility will be a
storage location for ERBITUX. We believe that ERBITUX will ultimately be
approved for commercialization. As such, we believe that the full carrying value
of both the product launch manufacturing facility and the second commercial
manufacturing facility and the material logistics and warehouse facility will be
recovered. Changes in business conditions in the future could change our
judgments about the carrying value of these facilities, which could result in
the recognition of material impairment losses.

         Manufacturing Contracts - As summarized under "Contract Manufacturing
Services," Note 5 to the financial statements, we have entered into certain
development and manufacturing services agreements with Lonza Biologics plc
("Lonza") for the clinical and commercial production of ERBITUX. We have
commitments from Lonza to manufacture ERBITUX at the 5,000 liter scale through
December 2003. On September 30, 2002, the estimated remaining future commitments
under the amended commercial manufacturing services agreement with Lonza were
$26,283,000 in 2002 and $20,350,000 in 2003. If ERBITUX were not to receive
regulatory approval it is possible that a liability would need to be recognized
for any remaining commitments to Lonza.

         Valuation of Stock Options - We apply APB Opinion No. 25 and related
interpretations in accounting for our stock options and warrants. Accordingly,
compensation expense is recorded on the date of grant of an option to an
employee or member of the Board of Directors only if the fair market value of
the underlying stock at the time of grant exceeds the exercise price. In
addition, we have granted options to certain Scientific Advisory Board members
and outside consultants, which are required to be measured at fair value and
recognized as compensation expense in our consolidated statement of operations.
Estimating the fair value of stock options and warrants involves a number of
judgments and variables that are subject to significant change. A change in the
fair value estimate could have a significant effect on the amount of
compensation expense recognized.

RESULTS OF OPERATIONS

NINE MONTHS ENDED SEPTEMBER 30, 2002 AND 2001

REVENUES

         Revenues for the nine months ended September 30, 2002 and 2001 were
$45,150,000 and $37,619,000, respectively, an increase of $7,531,000, or 20% in
2002. Revenues for the nine months ended September 30, 2002 primarily included
$12,907,000 in license fee revenue and $15,769,000 in collaborative agreement
revenue from our amended ERBITUX Commercial Agreement with BMS and its
wholly-owned subsidiary, E.R. Squibb. The Collaborative Agreement revenue
represents certain research and development and marketing expenses that have
been incurred by us and are reimbursable by BMS as provided for in the amended
Commercial Agreement. License fee revenue from payments under this agreement (of
which $140,000,000 was received in 2002 and $200,000,000 was received in 2001)
are being recognized as revenue over the product research and development life
of ERBITUX. An additional $60,000,000 is payable on March 5, 2003, $250,000,000
is payable upon receipt of marketing approval from the FDA with respect to an
initial indication for ERBITUX and $250,000,000 is payable upon receipt of
marketing approval from the FDA with respect to a second indication for ERBITUX.
All such payments are non-refundable and non-creditable. We also recognized
$14,636,000 in collaborative agreement revenue from our ERBITUX development and
license agreement with Merck KGaA. In addition, we recognized $167,000 of the
$4,000,000 up-front payment received upon entering into this agreement with
Merck KGaA. This revenue is being recognized ratably over the anticipated life
of the agreement. Revenues for the nine months ended September 30, 2002 also
included $1,308,000 in royalty revenue from our strategic corporate alliance
with Abbott Laboratories ("Abbott") in diagnostics and $122,000 in license fee
revenue and $181,000 in collaborative agreement revenue from our strategic
corporate alliance with Merck KGaA for our principal cancer vaccine product
candidate, BEC2. Revenues for the nine months ended September 30, 2001 primarily
included $27,760,000 in milestone revenue and $6,583,000 in collaborative
agreement revenue from our ERBITUX development and license agreement with Merck
KGaA. These milestone payments were received in prior periods and were
originally recorded as fees potentially refundable to corporate partner because
they were refundable in the event a condition relating to obtaining certain
collateral license agreements was not satisfied. This condition was satisfied in
March 2001. In addition, we recognized $167,000 of the $4,000,000 up-front
payment received upon entering into this agreement. This revenue is being
recognized ratably over the anticipated life of the agreement. Revenues for the
nine months ended September 30, 2001 also included $1,428,000 in royalty revenue
from our strategic corporate alliance with Abbott in diagnostics and $1,000,000
in milestone revenues, $122,000 in license fee revenues and

                                    Page 19

<PAGE>

$130,000 of collaborative agreement revenue from our strategic corporate
alliance with Merck KGaA for BEC2. Finally, revenues for the nine months ended
September 30, 2001 also included $387,000 in license fee revenue from our
ERBITUX Commercial Agreement with BMS and its wholly-owned subsidiary, E.R.
Squibb.

OPERATING EXPENSES

         Total operating expenses for the nine months ended September 30, 2002
and 2001 were $162,101,000 and $107,825,000, respectively, an increase of
$54,276,000, or 50% in 2002. Operating expenses in the nine months ended
September 30, 2002 included $2,250,000 in advisor fees associated with
completing the amended Commercial Agreement with BMS and E.R. Squibb, operating
expenses in the nine months ended September 30, 2001 included $16,050,000, in
advisor fees associated with consummating the acquisition agreement, the
stockholder agreement and the commercial agreement (the "BMS agreements") with
BMS and affiliates.

OPERATING EXPENSES: RESEARCH AND DEVELOPMENT

         Research and development expenses for the nine months ended September
30, 2002 and 2001 were $119,449,000 and $76,150,000, respectively, an increase
of $43,299,000 or 57% in 2002. Research and development expenses for the nine
months ended September 30, 2002 and 2001, as a percentage of total operating
expenses, excluding the advisor fees associated with the amended Commercial
Agreement and the original BMS agreements, the write-down of withholding tax
assets and the Industrial Development Revenue Bonds tax expense, in the nine
months ended September 30, 2002 and 2001, were 76% and 83%, respectively.
Research and development expenses include costs associated with our in-house and
collaborative research programs, product and process development expenses, costs
to manufacture our product candidates, particularly ERBITUX, prior to any
approval that we may obtain of a product candidate for commercial sale or
obligations of our corporate partners to acquire product from us, quality
assurance and quality control costs, and costs to conduct our clinical trials
and associated regulatory activities. Research and development expenses include
costs that are reimbursable by our corporate partners. The increase in research
and development expenses for the nine months ended September 30, 2002 was
primarily attributable to (1) the costs associated with full scale production at
our product launch manufacturing facility, (2) costs related to the
manufacturing services agreements with Lonza, (3) expenditures in the functional
areas of product development and pilot plant manufacturing associated with our
other monoclonal antibodies and (4) increased expenditures associated with
discovery research. We expect research and development costs to increase in
future periods as we continue to manufacture ERBITUX prior to any approval of
the product that we may obtain for commercial use or until we receive committed
purchase obligations from our corporate partners. In the event of such approval
or committed purchase obligations from our corporate partners, the subsequent
costs associated with manufacturing ERBITUX for supply to corporate partners for
commercial use will be included in inventory and expensed as cost of goods sold
when sold. We expect research and development costs associated with discovery
research and product development also to continue to increase in future periods.

OPERATING EXPENSES: MARKETING, GENERAL AND ADMINISTRATIVE

         Marketing, general and administrative expenses include marketing and
administrative personnel costs, including related occupancy costs, additional
costs to develop internal marketing and sales capabilities, costs to pursue
arrangements with strategic corporate partners and technology licensors, and
expenses associated with applying for patent protection for our technology and
products. Marketing, general and administrative expenses also include amounts
reimbursable from our corporate partners. Marketing, general and administrative
expenses for the nine months ended September 30, 2002 and 2001 were $36,943,000
and $15,550,000, respectively, an increase of $21,393,000, or 138% in 2002. The
increase in marketing, general and administrative expenses primarily reflected
(1) the separation compensation and other post-employment benefits associated
with the resignation of our former President and Chief Executive Officer, (2)
legal expenses associated with the pending class action lawsuits, shareholder
derivative lawsuits and investigations by the SEC, the Subcommittee on Oversight
and Investigation of the U.S. House of Representatives Committee on Energy and
Commerce and the U.S. Department of Justice, (3) expenses associated with higher
public relations costs due to the factors noted in (2) above, (4) expenses
associated with higher insurance premiums with the respect to director and
officer liability insurance, (5) the write-off of an expired negotiating right
with Lonza and (6) expenses associated with general corporate activities. Other
than the legal expenses and public relations expenses components discussed in
(2) and (3) above and related costs, whose level in the future is uncertain
because it depends upon the manner in which these investigations and proceedings
progress, we expect marketing, general and administrative expenses to increase
in future periods to support our continued commercialization efforts for
ERBITUX.

OPERATING EXPENSE:  WRITE-DOWN OF WITHHOLDING TAX ASSETS

         The write-down of withholding tax assets for the nine months ended
September 30, 2002 was $3,384,000 to reflect the write-down of the asset
attributable to our former General Counsel, John B. Landes.

                                    Page 20

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Based on the limited information available to us, due to the decrease in our
stock price during 2002 and corresponding decrease in the value of Mr. Landes'
ownership of the Company's securities, we determined that recoverability of the
asset became doubtful and therefore the asset write-down was recorded during the
second quarter of 2002.

OPERATING EXPENSES: INDUSTRIAL DEVELOPMENT REVENUE BONDS TAX EXPENSE

         Industrial Development Revenue Bonds tax expense for each of the nine
months ended September 30, 2002 and 2001 was $75,000. In April 2003, we
discovered that we are in breach of tax covenants in our 1990 IDA Bonds. The
Consolidated Statements of Operations for the nine months ended September 30,
2002 and 2001 reflect additional withholding tax expense of $75,000 relating to
the 1990 IDA Bonds.

INTEREST INCOME, INTEREST EXPENSE AND OTHER (INCOME) EXPENSE

         Interest income was $7,427,000 for the nine months ended September 30,
2002 compared with $11,071,000 for the nine months ended September 30, 2001, a
decrease of $3,644,000, or 33% in 2002. The decrease was primarily attributable
to a decrease in interest rates associated with our portfolio of debt
securities.

         Interest expense was $10,003,000 and $10,051,000 for the nine months
ended September 30, 2002 and 2001, respectively, a decrease of $48,000 or 0.5%
in 2002. We have increased interest expense by $3,000 and $9,000 for the nine
months ended September 30, 2002 and 2001, respectively, versus the amounts
previously reported. These increases represent additional accrued interest on
the 1990 IDA Bonds discussed above. Interest expense was offset by the
capitalization of interest costs of $1,441,000, during the construction period
of our second commercial manufacturing facility, our administration facility and
our material logistics facility in Somerville, New Jersey, and our chemistry
facility in Brooklyn, New York, in the nine months ended September 30, 2002, and
$1,398,000 during the construction period of our product launch manufacturing
facility and our second commercial manufacturing facility in the nine months
ended September 30, 2001. Interest expense for both periods included (1)
interest on the 5-1/2% convertible subordinated notes due March 1, 2005 (the
"Convertible Subordinated Notes") issued in February 2000, (2) interest on the
outstanding 1990 IDA Bonds and (3) interest recorded on various capital lease
obligations under a 1996 financing agreement and a 1998 financing agreement with
Finova Technology Finance, Inc. ("Finova"). We recorded gains on securities and
investments of $1,500,000 and losses of $2,668,000 for the nine months ended
September 30, 2002 and 2001, respectively. The losses on securities and
investments for the nine months ended September 30, 2001 included $4,375,000 in
write-downs of our investment in ValiGen N.V. and a $1,000,000 write-off of our
convertible promissory note from A.C.T. Group, Inc.

INCOME TAXES

         Income taxes of $550,000 for the nine months ended September 30, 2002
and are the result of various tax law changes in the State of New Jersey, one of
which is the establishment of the Alternative Minimum Assessment tax ("AMA") to
which we are subject.

NET LOSSES

         We had a net loss of $118,577,000 or $1.62 per share for the nine
months ended September 30, 2002, compared with a net loss of $71,854,000 or
$1.05 per share for the nine months ended September 30, 2001. The increase in
the net loss was due to the factors noted above.

THREE MONTHS ENDED SEPTEMBER 30, 2002 AND 2001

REVENUES

         Revenues for the three months ended September 30, 2002 and 2001 were
$15,034,000 and $5,729,000, respectively, an increase of $9,305,000, or 162% in
2002. Revenues for the three months ended September 30, 2002 primarily included
$4,841,000 in license fee revenue and $7,248,000 in collaborative agreement
revenue from our amended Commercial Agreement with BMS and its wholly-owned
subsidiary, E.R. Squibb. The Collaborative Agreement revenue represents certain
research and development and marketing expenses that have been incurred by us
and are reimbursable by BMS as provided for in the amended Commercial Agreement.
License fee revenue from payments under the Commercial Agreement

                                    Page 21

<PAGE>

(of which $140,000,000 was received in 2002 and $200,000,000 was received in
2001) are being recognized over the product research and development life of
ERBITUX. We also recognized $2,141,000 in collaborative agreement revenue from
our ERBITUX development and license agreement with Merck KGaA. In addition, we
recognized $56,000 of the $4,000,000 up-front payment received upon entering
into the ERBITUX development and license agreement with Merck KGaA. This revenue
is being recognized ratably over the anticipated life of the agreement. Revenues
for the three months ended September 30, 2002 also included $620,000 in royalty
revenue from our strategic corporate alliance with Abbott in diagnostics and
$41,000 in license fee revenue and $27,000 in collaborative agreement revenue
from our strategic corporate alliance with Merck KGaA for BEC2. Revenues for the
three months ended September 30, 2001 primarily included $1,760,000 in milestone
revenue and $2,810,000 in collaborative agreement revenue from our ERBITUX
development and license agreement with Merck KGaA. In addition, we recognized
$56,000 of the $4,000,000 up-front payment received upon entering into this
agreement. This revenue is being recognized ratably over the anticipated life of
the agreement. Revenues for the three months ended September 30, 2001 also
included $667,000 in royalty revenue from our strategic corporate alliance with
Abbott in diagnostics and $41,000 in license fee revenues from our strategic
corporate alliance with Merck KGaA for BEC2. Finally, revenues for the three
months ended September 30, 2001 also included $387,000 in license fee revenue
from our ERBITUX Commercial Agreement with BMS and its wholly-owned subsidiary,
E.R. Squibb.

OPERATING EXPENSES

         Total operating expenses for the three months ended September 30, 2002
and 2001 were $55,870,000 and $48,338,000, respectively, an increase of
$7,532,000, or 16% in 2002. Operating expenses for the three months ended
September 30, 2001 included $16,050,000 in advisor fees associated with
consummating the BMS agreements with BMS and its affiliates.

OPERATING EXPENSES: RESEARCH AND DEVELOPMENT

         Research and development expenses for the three months ended September
30, 2002 and 2001 were $43,504,000 and $26,664,000, respectively, an increase of
$16,840,000 or 63% in 2002. Research and development expenses for the three
months ended September 30, 2002 and 2001 as a percentage of total operating
expenses, excluding the advisor fees associated with the BMS agreements and the
Industrial Development Revenue Bonds tax expense, in the three months ended
September 30, 2001, were 78% and 83%, respectively. Research and development
expenses include costs associated with our in-house and collaborative research
programs, product and process development expenses, costs to manufacture our
product candidates, particularly ERBITUX, prior to any approval that we may
obtain of a product candidate for commercial sale or obligations of our
corporate partners to acquire product from us, quality assurance and quality
control costs, and costs to conduct our clinical trials and associated
regulatory activities. Research and development expenses include costs that are
reimbursable by our corporate partners. The increase in research and development
expenses for the three months ended September 30, 2002 was primarily
attributable to (1) the costs associated with full scale production at our
product launch manufacturing facility, (2) costs related to the manufacturing
services agreements with Lonza, (3) expenditures in the functional areas of
product development and pilot plant manufacturing associated with other
monoclonal antibodies and (4) increased expenditures associated with discovery
research. We expect research and development costs to increase in future periods
as we continue to manufacture ERBITUX prior to any approval of the product that
we may obtain for commercial use or until we receive committed purchase
obligations from our corporate partners. In the event of such approval or
committed purchase obligations from our corporate partners, the subsequent costs
associated with manufacturing ERBITUX for supply to corporate partners for
commercial use will be included in inventory and expensed as cost of goods sold
when sold. We expect research and development costs associated with discovery
research and product development also to continue to increase in future periods.

OPERATING EXPENSES: MARKETING, GENERAL AND ADMINISTRATIVE

         Marketing, general and administrative expenses include marketing and
administrative personnel costs, including related occupancy costs, additional
costs to develop internal marketing and sales capabilities, costs to pursue
arrangements with strategic corporate partners and technology licensors, and
expenses associated with applying for patent protection for our technology and
products. Marketing, general and administrative expenses also include amounts
reimbursable from our corporate partners. Marketing, general and administrative
expenses for the three months ended September 30, 2002 and 2001 were $12,341,000
and $5,599,000, respectively, an increase of $6,742,000, or 120% in 2002. The
increase in marketing, general and administrative expenses primarily reflected
(1) legal expenses associated with the pending class action lawsuits,
shareholder derivative lawsuits and investigations by the SEC, the Subcommittee
on Oversight and Investigation of the U.S. House of Representatives Committee on
Energy and Commerce and the U.S. Department of Justice, (2) expenses associated
with higher public relations costs due to the factors noted in (1) above, (3)
expenses associated with higher insurance premiums with respect to director and
officer liability insurance, (4) the write-off of an expired negotiating right
with Lonza and (5) expenses associated with general corporate activities. Other
than the legal expenses and public relations expenses component discussed in (1)
and (2) above and related costs, whose level in the future is uncertain because
it depends upon the manner in which these investigations and proceedings
progress, we expect marketing, general and administrative expenses to

                                    Page 22

<PAGE>

increase in future periods to support our continued commercialization efforts
for ERBITUX.

OPERATING EXPENSES: INDUSTRIAL DEVELOPMENT REVENUE BONDS TAX EXPENSE

         Industrial Development Revenue Bonds tax expense for each of the three
months ended September 30, 2002 and 2001 was $25,000. In April 2003, we
discovered that we are in breach of tax covenants in our 1990 IDA Bonds. The
Consolidated Statements of Operations for the three months ended September 30,
2002 and 2001 reflect additional withholding tax expense of $25,000 relating to
the 1990 IDA Bonds.

INTEREST INCOME, INTEREST EXPENSE AND OTHER (INCOME) EXPENSE

         Interest income was $2,259,000 for the three months ended September 30,
2002 compared with $3,244,000 for the three months ended September 30, 2001, a
decrease of $985,000, or 30% in 2002. The decrease was primarily attributable to
a decrease in interest rates associated with our portfolio of debt securities.

         Interest expense was $3,162,000 and $3,535,000 for the three months
ended September 30, 2002 and 2001, respectively, a decrease of $373,000 or 11%
in 2002. We have increased interest expense by $1,000 and $3,000 for the three
months ended September 30, 2002 and 2001, respectively, versus the amounts
previously reported. These increases represent additional accrued interest on
the 1990 IDA Bonds discussed above. Interest expense was offset by the
capitalization of interest costs of $660,000 during the construction period of
our second commercial manufacturing facility, our administration facility and
our material logistics facility in Somerville, New Jersey, and our chemistry
facility in Brooklyn, New York, in the three months ended September 30, 2002,
and $278,000 during the construction period of our second commercial facility in
the three months ended September 30, 2001. Interest expense for both periods
included (1) interest on the Convertible Subordinated Notes issued in February
2000, (2) interest on the outstanding 1990 IDA Bonds and (3) interest recorded
on various capital lease obligations under a 1998 financing agreement with
Finova. We recorded gains on securities and investments of $264,000 and
$1,800,000 for the three months ended September 30, 2002 and 2001, respectively.

INCOME TAXES

         Income taxes of $550,000 for the three months ended September 30, 2002
and are the result of various tax law changes in the State of New Jersey, one of
which is the establishment of the AMA to which we are subject.

NET LOSSES

         We had a net loss of $42,025,000 or $0.57 per share for the three
months ended September 30, 2002, compared with a net loss of $41,100,000 or
$0.57 per share for the three months ended September 30, 2001. The increase in
the net loss was due to the factors noted above.

LIQUIDITY AND CAPITAL RESOURCES

         At September 30, 2002, our principal sources of liquidity consisted of
cash and cash equivalents and securities available for sale of approximately
$293,000,000. From our inception on April 26, 1984 through September 30, 2002,
we have financed our operations primarily through the following means:

         -        Public and private sales of equity securities and convertible
                  notes in financing transactions have raised approximately
                  $492,652,000 in net proceeds

         -        We have earned approximately $124,565,000 from license fees,
                  contract research and development fees, reimbursements from
                  our corporate partners and royalties from collaborative
                  partners. Additionally, we have approximately $330,300,000 in
                  deferred revenue related to up-front payments received from
                  our amended Commercial Agreement for ERBITUX with BMS, our
                  ERBITUX development and license agreement with Merck KGaA and
                  our BEC2 development and commercialization agreement with
                  Merck KGaA. These amounts are being recognized as revenue over
                  the expected lives of the respective agreements

         -        We have earned approximately $54,541,000 in interest income

         -        The sale of the IDA Bonds in each of 1985, 1986 and 1990
                  raised an aggregate of $6,300,000, the proceeds of which have
                  been used for the acquisition, construction and installation
                  of our research and development facility in New

                                    Page 23

<PAGE>

                  York City, and of which $2,200,000 is outstanding and due May
                  2004

         We may, from time to time, consider a number of strategic alternatives
designed to increase shareholder value, which could include joint ventures,
acquisitions and other forms of alliances, as well as the sale of all or part of
the Company.

         Until September 19, 2006, or earlier upon the occurrence of certain
specified events, we may not take any action that constitutes a prohibited
action under our stockholder agreement with BMS and Bristol-Myers Squibb
Biologics Company, a Delaware corporation ("BMS Biologics"), which is a
wholly-owned subsidiary of BMS, without the consent of the BMS directors. Such
prohibited actions include (i) issuing additional shares or securities
convertible into shares in excess of 21,473,002 shares of our common stock in
the aggregate, subject to certain exceptions; (ii) incurring additional
indebtedness if the total of the principal amount of such indebtedness incurred
since September 19, 2001 and then-outstanding, and the net proceeds from the
issuance of any redeemable preferred stock then-outstanding, would exceed the
amount of indebtedness outstanding as of September 19, 2001 by more than $500
million; (iii) acquiring any business if the aggregate consideration for such
acquisition, when taken together with the aggregate consideration for all other
acquisitions consummated during the previous twelve months, is in excess of 25%
of the aggregate value of the Company at the time we enter into the binding
agreement relating to such acquisition; (iv) disposing of all or any substantial
portion of our non-cash assets; (v) issuing capital stock with more than one
vote per share.

         In September 2001, we entered into the ERBITUX Commercial Agreement
with BMS and E.R. Squibb, pursuant to which, among other things, together with
E.R Squibb we are (a) co-developing and co-promoting ERBITUX in the United
States and Canada, and (b) co-developing ERBITUX (together with Merck KGaA) in
Japan. The Commercial Agreement was amended on March 5, 2002 to change certain
economics of the agreement and has expanded the clinical and strategic roles of
BMS in the ERBITUX development program. Pursuant to the amended Commercial
Agreement, we can receive up-front and milestone payments totaling $900,000,000
in the aggregate, of which $200,000,000 was received upon the signing of the
agreement. The remaining $700,000,000 in payments comprises $140,000,000 paid on
March 7, 2002, $60,000,000 payable on March 5, 2003, $250,000,000 payable upon
receipt of marketing approval from the FDA with respect to an initial indication
for ERBITUX and $250,000,000 payable upon receipt of marketing approval from the
FDA with respect to a second indication for ERBITUX. All such payments are
non-refundable and non-creditable. Except for our expenses incurred pursuant to
the co-promotion option, E.R. Squibb is responsible for 100% of the
distribution, sales and marketing costs in the United States and Canada, and
E.R. Squibb and the Company, each will be responsible for 50% of the
distribution, sales, marketing costs and other related costs and expenses in
Japan. The Commercial Agreement provides that E.R. Squibb shall pay us
distribution fees based on a percentage of annual sales of ERBITUX by E.R.
Squibb in the United States and Canada. The distribution fee is 39% of net sales
in the United States and Canada. The Commercial Agreement also provides that the
distribution fees for the sale of ERBITUX in Japan by E.R. Squibb or us shall be
equal to 50% of operating profit or loss with respect to such sales for any
calendar month. In the event of an operating profit, E.R. Squibb will pay us the
amount of such distribution fee, and in the event of an operating loss, we will
credit E.R. Squibb the amount of such distribution fee. The Commercial Agreement
provides that we will be responsible for the manufacture and supply of all
requirements of ERBITUX in bulk form for clinical and commercial use in the
United States, Canada and Japan and that E.R. Squibb will purchase all of its
requirements of ERBITUX in bulk form for commercial use from us. We will supply
ERBITUX for clinical use at our fully burdened manufacturing cost, and will
supply ERBITUX for commercial use at our fully burdened manufacturing cost plus
a mark-up of 10%. In addition to the up-front and milestone payments, the
distribution fees for the United States, Canada and Japan and the 10% mark-up on
the commercial supply of ERBITUX, E.R. Squibb is also responsible for 100% of
the cost of all clinical studies other than those studies undertaken
post-launch, which are not pursuant to an Investigational New Drug Application
("INDA") (e.g., phase IV studies), the cost of which will be shared equally
between E.R. Squibb and ImClone Systems. As between E.R. Squibb and the Company,
each will be responsible for 50% of the cost of all clinical studies in Japan.

         In February 2000, we completed a private placement of $240,000,000 in
5-1/2% convertible subordinated notes due March 1, 2005. We received net
proceeds of approximately $231,500,000, after deducting expenses associated with
the offering. Accrued interest on the notes was approximately $1,100,000 at
September 30, 2002. A holder may convert all or a portion of a note into common
stock at any time on or before March 1, 2005 at a conversion price of $55.09 per
share, subject to adjustment under certain circumstances. We may redeem some or
all of the notes prior to March 6, 2003 if specified common stock price
thresholds are met. On or after March 6, 2003, we may redeem some or all of the
notes at specified redemption prices.

         In December 1999, we entered into a development and manufacturing
services agreement with Lonza. This agreement was amended in April 2001 to
include additional services. Under the agreement, Lonza is responsible for
process development and scale-up to manufacture ERBITUX in bulk form under cGMP.
These steps were taken to assure that the manufacturing process would produce
bulk material that conforms with our reference material and to support in part,
our regulatory filing with the FDA. We incurred approximately $7,068,000 for
services provided under this agreement through

                                    Page 24

<PAGE>

September 30, 2002. Lonza has completed its responsibilities under the
development and manufacturing service agreement. In September 2000, we entered
into a three-year commercial manufacturing services agreement with Lonza
relating to ERBITUX. This agreement was amended in June 2001 and again in
September 2001 to include additional services. As of September 30, 2002, we
incurred approximately $40,418,000 for services provided under the commercial
manufacturing services agreement. Lonza is currently manufacturing ERBITUX at
the 5,000 liter scale under cGMP and is delivering it to us over a term ending
no later than December 2003. The costs associated with both of these agreements
are included in research and development expenses when incurred and will
continue to be so classified until such time as ERBITUX may be approved for sale
or until we obtain obligations from our corporate partners for supply of such
product. In the event of such approval or obligations from our corporate
partners, the subsequent costs associated with manufacturing ERBITUX for
commercial sale will be included in inventory and expensed as cost of goods sold
when sold. In the event we terminate (i.e., the cancellation of batches of bulk
product) the commercial manufacturing services agreement without cause, we will
be required to pay 85% of the stated costs for each of the first ten batches
cancelled, 65% of the stated costs for each of the next ten batches cancelled
and 40% of the stated costs for each of the next six batches cancelled. The
batch cancellation provisions for certain additional batches that we are
committed to purchase require us to pay 100% of the stated costs of cancelled
batches scheduled within six months of the cancellation, 85% of the stated costs
of cancelled batches scheduled between six and twelve months following the
cancellation and 65% of the stated costs of cancelled batches scheduled between
twelve and eighteen months following the cancellation. These amounts are subject
to mitigation should Lonza use its manufacturing capacity caused by such
termination for another customer. At September 30, 2002, the estimated remaining
future commitments under the amended commercial manufacturing services agreement
are $26,283,000 in 2002 and $20,350,000 in 2003.

         In December 2001, we entered into an agreement with Lonza to
manufacture ERBITUX at the 2,000 liter scale for use in clinical trials by Merck
KGaA. We had incurred approximately $7,183,000 for services provided under this
agreement, of which $6,595,000 was reimbursed by Merck KGaA. The remaining
$588,000 that is due from Merck KGaA is included in Amounts due from corporate
partners in the consolidated balance sheet at September 30, 2002. At September
30, 2002, there are no remaining future commitments under this agreement.

         On January 2, 2002 we executed a letter of intent with Lonza to enter
into a long-term supply agreement. The long-term supply agreement would apply to
a large scale manufacturing facility that Lonza is constructing. We expect such
facility would be able to produce ERBITUX in 20,000 liter batches. Upon
execution of the letter of intent, we paid Lonza $3,250,000 for the exclusive
right to negotiate a long-term supply agreement for a portion of the facility's
manufacturing capacity. During September 2002, we wrote-off the deposit because
the exclusive negotiation period ended on September 30, 2002, although
negotiations continued thereafter. The $3,250,000 is included in Marketing,
general and administrative expenses on the Consolidated Statement of Operations
for the three and nine months ended September 30, 2002, respectively. We are
currently negotiating with Lonza and a third party with the intention of
assigning to the third party any remaining rights we have under this letter of
intent in return for the third party's agreement to reimburse us the $3,250,000
upon execution of a binding agreement with Lonza for supply of biologics on
similar terms to those we have negotiated with Lonza. We cannot be certain that
we will enter into this arrangement.

         We cannot be certain that we will be able to enter into agreements for
commercial supply with third party manufacturers on terms acceptable to us. Even
if we are able to enter into such agreements, we cannot be certain that we will
be able to produce or obtain sufficient quantities for commercial sale of our
products. Any delays in producing or obtaining commercial quantities of our
products could have a material adverse effect on our business, financial
condition and results of operations.

         Effective April 1990, we entered into a development and
commercialization agreement with Merck KGaA with respect to BEC2 and the
recombinant gp75 antigen. The agreement has been amended a number of times, most
recently in December 1997. The agreement grants Merck KGaA a license, with the
right to sublicense, to make, have made, use, sell, or have sold BEC2 and gp75
outside North America. The agreement also grants Merck KGaA a license, without
the right to sublicense, to use, sell, or have sold, but not to make BEC2 within
North America in conjunction with ImClone Systems. Pursuant to the terms of the
agreement, we have retained the rights, (1) without the right to sublicense, to
make, have made, use, sell, or have sold BEC2 in North America in conjunction
with Merck KGaA and (2) with the right to sublicense, to make, have made, use,
sell, or have sold gp75 in North America. In return, we have recognized research
support payments totaling $4,700,000 and are entitled to no further research
support payments under the agreement. Merck KGaA is also required to make
payments of up to $22,500,000, of which $4,000,000 has been recognized, based on
milestones achieved in the licensed products' development. Merck KGaA is also
responsible for worldwide costs of up to DM17,000,000 associated with a
multi-site, multinational phase III clinical trial for BEC2 in limited disease
small-cell lung carcinoma. This expense level was reached during the fourth
quarter of 2000 and all expenses incurred from that point forward are being
shared 60% by Merck KGaA and 40% by ImClone Systems. Such cost sharing applies
to all expenses beyond the DM17,000,000 threshold. Merck KGaA is also required
to pay royalties on the eventual sales of BEC2 outside of North America, if any.
Revenues from sales, if any, of BEC2 in North America will be distributed in
accordance with the terms of a co-promotion agreement to be negotiated by

                                    Page 25

<PAGE>

the parties.

         In December 1998, we entered into a development and license agreement
with Merck KGaA with respect to ERBITUX. In exchange for granting Merck KGaA
exclusive rights to market ERBITUX outside of the United States and Canada and
co-development rights in Japan, we received through September 30, 2002,
$30,000,000 in up-front fees and early cash-based milestone payments based on
the achievement of defined milestones. An additional $30,000,000 can be
received, of which $5,000,000 has been received as of September 30, 2002,
assuming the achievement of further milestones for which Merck KGaA will receive
equity in ImClone Systems. The equity underlying these milestone payments will
be priced at varying premiums to the then-market price of the common stock
depending upon the timing of the achievement of the respective milestones. If
issuing shares of common stock to Merck KGaA would result in Merck KGaA owning
greater than 19.9% of our common stock, the milestone shares will be a
non-voting preferred stock, or other non-voting stock convertible into our
common stock. These convertible securities will not have voting rights. They
will be convertible at a price determined in the same manner as the purchase
price for shares of our common stock if shares of common stock were to be
issued. They will not be convertible into common stock if, as a result of the
conversion, Merck KGaA would own greater than 19.9% of our common stock. This
19.9% limitation is in place through December 2002. Merck KGaA will pay us a
royalty on future sales of ERBITUX outside of the United States and Canada, if
any. This agreement may be terminated by Merck KGaA in various instances,
including (1) at its discretion on any date on which a milestone is achieved (in
which case no milestone payment will be made), or (2) for a one-year period
after first commercial sale of ERBITUX in Merck KGaA's territory, upon Merck
KGaA's reasonable determination that the product is economically unfeasible (in
which case Merck KGaA is entitled to a return of 50% of the cash-based up front
fees and milestone payments then paid to date, but only out of revenues
received, if any, based upon a royalty rate applied to the gross profit from
ERBITUX sales or a percentage of ERBITUX fees and royalties from a sublicensee
on account of the sale of ERBITUX in the United States and Canada). In August
2001, ImClone Systems and Merck KGaA amended this agreement to provide, among
other things, that Merck KGaA may manufacture ERBITUX for supply in its
territory and may utilize a third party to do so. The amendment further released
Merck KGaA from its obligations under the agreement relating to providing a
guaranty under a $30,000,000 credit facility relating to the build-out of the
product launch manufacturing facility. In addition, the amendment provides that
the companies have co-exclusive rights to ERBITUX in Japan, including the right
to sublicense and Merck KGaA waived its right of first offer in the case of a
proposed sublicense by ImClone Systems of ERBITUX in ImClone Systems' territory.
In consideration for the amendment, we agreed to a reduction in royalties
payable by Merck KGaA on sales of ERBITUX in Merck KGaA's territory.

         We have obligations under various capital leases for certain
laboratory, office and computer equipment and also certain building
improvements, primarily under a 1998 financing agreement with Finova. This
agreement allowed us to finance the lease of equipment and make certain building
and leasehold improvements to existing facilities. Each lease has a fair market
value purchase option at the expiration of its 48-month term. We have entered
into six individual leases under the financing agreement with an aggregate cost
of $1,942,000. This financing arrangement is now expired.

         We rent our current New York corporate headquarters and research
facility under an operating lease that expires in December 2004. In 2000 we
completed renovations of the facility at a cost of approximately $2,800,000.

         In October 2001, we entered into a sublease for a four-story building
in downtown New York to serve as our future corporate headquarters and research
facility. The space, to be designed and improved in the future, includes between
75,000 and 100,000 square feet of usable space, depending on design, and
includes possible additional expansion space. The sublease has a term of 22
years, followed by two five-year renewal option periods. The future minimum
lease payments are approximately $50,475,000 over the term of the sublease. In
order to induce the sublandlord to enter into the sublease, we made a loan to
the sublandlord in the principal amount of a $10,000,000. The loan is secured by
a leasehold mortgage on the prime lease as well as a collateral assignment of
rents by the sublandlord. The loan is payable by the sublandlord over 20 years
and bears interest at 5-1/2% in years one through five, 6 -1/2% in years six
through ten, 7 -1/2% in years eleven through fifteen and 8 -1/2% in years
sixteen through twenty. In addition, we paid the owner a consent fee in the
amount of $500,000.

         On May 1, 2001, we entered into a lease for an approximately 4,000
square foot portion of a 15,000 square foot building known as 710 Parkside
Avenue, Brooklyn, New York and we have leased an adjacent 6,250 square foot
building known as 313-315 Clarkson Avenue, Brooklyn, New York, to serve as our
new chemistry and high throughput screening facility. The term of the lease is
for five years with five successive one-year extensions. As of September 30,
2002, we have incurred approximately $4,250,000, excluding capitalized interest
of approximately $138,000 for the retrofit of this facility to better fit our
needs. At September 30, 2002, this project is substantially complete.

         We built a new 80,000 square foot product launch manufacturing facility
adjacent to the pilot facility in Somerville, New Jersey. The product launch
manufacturing facility was built on a 5.7 acre parcel of land we purchased in
December 1999 for approximately $700,000. The product launch manufacturing
facility contains three 10,000 liter (working volume) fermenters

                                    Page 26

<PAGE>

and is dedicated to the clinical and commercial production of ERBITUX. The cost
of the facility was approximately $53,000,000, excluding capitalized interest of
approximately $1,966,000. The cost of the facility was funded from our cash
reserves, consisting primarily of the proceeds from the issuance of debt and
equity securities. The product launch manufacturing facility was ready for its
intended use and put in operation in July 2001 and we commenced depreciation at
that time.

         We have completed conceptual design and preliminary engineering plans
and are currently reviewing detailed design plans for, and proceeding with
construction of, the second commercial manufacturing facility. The second
commercial manufacturing facility will be a multi-use facility of approximately
250,000 square feet and will contain up to 10 fermenters with a total capacity
of up to 110,000 liters (working volume). The facility will be built on a 7.12
acre parcel of land that we purchased in July 2000 for approximately $950,000.
The cost of this facility, consisting of two completely fitted out suites and a
third suite with utilities only, is expected to be approximately $234,000,000,
excluding capitalized interest. The actual cost of the new facility may change
depending upon various factors. We have incurred approximately $64,693,000,
excluding capitalized interest of approximately $1,831,000, in conceptual
design, engineering, equipment and construction costs through September 30,
2002.

         On January 31, 2002 we purchased a 7.5 acre parcel of land located
adjacent to the Company's product launch manufacturing facility and pilot
facility in Somerville, New Jersey. The real estate includes an existing 50,000
square foot building, 40,000 square feet of which is warehouse space and 10,000
square feet of which is office space. The purchase price for the property and
building was approximately $7,020,000, of which approximately $1,125,000 was
related to the purchase of the land and approximately $5,895,000 was related to
the purchase of the building. We intend to use this property for warehousing and
material logistics for our Somerville campus and are in the process of
retrofitting the building to better suit our needs. We have incurred
approximately $326,000, excluding capitalized interest of approximately $2,000,
for the retrofit of this facility through September 30, 2002. The total cost for
the retrofit is expected to be approximately $635,000.

         On May 20, 2002, we purchased real estate consisting of a 6.94 acre
parcel of land located across the street from the Company's product launch
manufacturing facility in Somerville, New Jersey. The real estate includes an
existing building with 46,000 square feet of office space. The purchase price
for the property was approximately $4,515,000, of which approximately $1,041,000
was related to the purchase of the land and approximately $3,474,000 was related
to the purchase of the building. We intend to use this property as the
administrative building for the Somerville campus and are in the process of
retrofitting the building to better suit our needs. As of September 30, 2002, we
have incurred approximately $2,857,000, excluding capitalized interest of
approximately $7,000, for the retrofit of this facility. The total cost for the
retrofit is expected to be approximately $5,187,000.

         Total capital expenditures made during the nine months ended September
30, 2002 were $60,165,000 and primarily included $1,955,000 related to the
purchase of equipment for and leasehold improvement costs associated with our
corporate office and research laboratories in our New York facility, $36,110,000
related to the conceptual design, preliminary engineering plans, capitalized
interest costs and construction costs for the second commercial manufacturing
facility, $1,125,000 and $5,895,000 for the land and building, respectively, for
the purchase of and $328,000 for the retrofit of the warehousing and material
logistics building including capitalized interest, $1,041,000 and $3,474,000 for
the land and building, respectively, for the purchase of and $2,864,000 for the
retrofit of the administration building including capitalized interest,
$3,725,000 for the retrofit of the Brooklyn chemistry lab including capitalized
interest, $1,483,000 related to improving and equipping our product launch
manufacturing facility, $1,439,000 related to improving and equipping our pilot
manufacturing facility, and approximately $719,000, for updating and upgrading
our computer and telephonic software and hardware systems.

         Federal and state tax laws require an employer to withhold income taxes
at the time of an employee's exercise of non-qualified stock options or warrants
issued in connection with the performance of services by the employee. An
employer that does not do so is liable for the taxes not withheld if the
employee fails to pay his or her taxes for the year in which the non-qualified
stock options or warrants are exercised. In 2000 and prior years, we generally
did not require the withholding of federal, state or local income taxes and in
certain years, employment payroll taxes at the time of the exercise of
non-qualified stock options or warrants. Prior to 1996, we did not comply with
tax reporting requirements with respect to the exercise of non-qualified stock
options or warrants.

         In January 2003, the New York State Department of Taxation and Finance
("New York State") notified us that we were liable for the New York State and
City income taxes that were not withheld because one or more of our employees
who exercised certain non-qualified stock options in 1999 and 2000 failed to pay
New York State and City income taxes for those years. At December 31, 2002, we
recorded a gross New York State and City withholding tax liability of
approximately $6,800,000. On March 13, 2003, we entered into a closing agreement
with New York State, paying $4,500,000 to settle the matter. We believe that
substantially all of the underpayment of New York State and City income tax
identified by New York

                                    Page 27

<PAGE>

State is attributable to the exercise of non-qualified stock options by our
former President and Chief Executive Officer, Dr. Samuel D. Waksal.

     On March 13, 2003, we initiated discussions with the Internal Revenue
Service ("IRS") relating to federal income taxes on the exercise of
non-qualified stock options on which income tax was not properly withheld.
Although the IRS has not yet asserted that we are required to make a payment
with respect to such failure to withhold, the IRS may assert that such a
liability exists, and may further assert that we are liable for interest and
penalties. We have requested and received confirmation from all of our current
and substantially all of our former employees who exercised non-qualified stock
options in 1999 and 2000 on which no income tax was withheld, that they have
reported the appropriate amount of income on their tax returns and paid the
taxes shown as due on those returns. Based on this information, we determined
that all but an insignificant amount of the potential liability for withholding
taxes with respect to exercises of non-qualified stock options in 1999 and 2000
is attributed to those amounts related to Dr. Samuel D. Waksal.

     In addition, in the course of our investigation into our potential
liability in respect of the non-qualified stock options described above, we
identified certain warrants that were granted in 1991 and prior years to current
and former officers, directors and advisors (including the four individuals
discussed herein) that we previously treated as non-compensatory warrants and
thus not subject to tax withholding and information reporting requirements upon
exercise. Accordingly, when exercised in 2001 and prior years, we did not deduct
income and payroll taxes upon exercise or report applicable information to the
taxing authorities. Based on the information discovered in the course of our
recent investigation, we now believe that such treatment was incorrect, and that
the exercise of such warrants by current and former officers of the Company
should have been treated in the same manner for withholding and reporting
purposes as the exercise of non-qualified stock options. We have informed the
relevant authorities, including the IRS and New York State, of this matter and
intend to resolve our liability in respect of these warrants with these taxing
authorities in conjunction with our resolution of the matter described above. On
June 17, 2003, New York State notified us that, based on the issue identified
above, they are continuing a previously conducted audit of the Company and are
evaluating the terms of the closing agreement to determine whether or not it
should be re-opened.

    On April 2, 2003, we received a request from the SEC for the voluntary
production of documents and information relating to the above matters. We are
cooperating fully with the SEC, and intend to continue to do so, while also
updating the United States Attorney's Office on an ongoing basis.

     One of the officers and directors to whom warrants were issued and
previously treated as non-compensatory warrants is Dr. Harlan W. Waksal, the
Company's Chief Scientific Officer. In June 2003, Dr. Harlan W. Waksal
represented that he has paid the taxes associated with the exercise of these
warrants and further agreed to indemnify us for any withholding taxes that may
be assessed and are attributable to our failure to deduct income and payroll
taxes on all warrants and options that he or his transferee has previously
exercised, subject to the consent of Dr. Harlan W. Waksal, which can not be
unreasonably withheld.

    Two of the other officers and directors to whom warrants were issued and
previously treated as non-compensatory warrants are Dr. Samuel D. Waksal and our
former General Counsel, John B. Landes, who entered into a separation agreement
with us during October 2002. We have made demands on both of these individuals
to pay the taxes associated with the exercise of these warrants and certain
non-qualified stock options and to indemnify us against any liability that we
may incur to taxing authorities in respect of the warrants or non-qualified
stock options that they have previously exercised.

     The Company has not recognized withholding tax liabilities in respect of
exercises of certain warrants by our then-current and now-former Chairman of the
Board, Robert F. Goldhammer, the final of the four officers or directors to whom
warrants were issued and previously treated as non-compensatory warrants. Based
on our investigation, we believe that, although such warrants were compensatory,
that such warrants were received by Mr. Goldhammer in connection with the
performance of services by him in his capacity as a director, rather than as an
employee, and, as such, are not subject to tax withholding requirements. In
addition, in 1999, Mr. Goldhammer erroneously received a portion of a stock
option grant to him in the form of incentive stock options, which under federal
law may only be granted to employees. There can be no assurance, however, that
the taxing authorities will agree with our position and will not assert that we
were liable for the failure to withhold income and employment taxes with respect
to the exercise of such warrants and any stock options by Mr. Goldhammer. If we
were liable for the failure to withhold these taxes on the exercise of such
warrants and any stock options by Mr. Goldhammer, the potential liability,
exclusive of any interest or penalties, would be approximately $12,600,000.

    We believe that our existing cash on hand, marketable securities and amounts
to which we are entitled should enable us to maintain our current and planned
operations through 2003. We are also entitled to reimbursement for certain
marketing and research and development expenditures and certain other payments,
some of which are payable upon the achievement of

                                    Page 28

<PAGE>

research and development milestones. Such amounts include $560,000,000 in
cash-based payments of which $60,000,000 is payable on March 5, 2003, as well as
up to $25,000,000 in equity-based milestone payments under our ERBITUX
development and license agreement with Merck KGaA and up to $18,500,000 in
cash-based milestone payments under our BEC2 development agreement with Merck
KGaA. There can be no assurance that we will achieve these milestones. Our
future working capital and capital requirements will depend upon numerous
factors, including, but not limited to:

         -    progress and cost of our research and development programs,
              pre-clinical testing and clinical trials

         -    our corporate partners fulfilling their obligations to us

         -    timing and cost of seeking and obtaining regulatory approvals

         -    timing and cost of manufacturing scale-up and effective
              commercialization activities and arrangements

         -    level of resources that we devote to the development of marketing
              and sales capabilities

         -    costs involved in filing, prosecuting and enforcing patent claims

         -    technological advances

         -    legal costs and the outcome of outstanding legal proceedings and
              investigations

         -    status of competition

         -    our ability to maintain existing corporate collaborations and
              establish new collaborative arrangements with other companies to
              provide funding to support these activities

         -    the adequacy of our estimates of liabilities for tax-related
              matters discussed above

    In order to fund our capital needs after 2003, we will require significant
levels of additional capital and we intend to raise the capital through
additional arrangements with corporate partners, equity or debt financings, or
from other sources, including the proceeds of product sales, if any. There is no
assurance that we will be successful in consummating any such arrangements. If
adequate funds are not available, we may be required to significantly curtail
our planned operations.

    Below is a table that presents our contractual obligations and commercial
commitments as of September 30, 2002:

<TABLE>
<CAPTION>
                                                                 PAYMENTS DUE BY YEAR
                                        -----------------------------------------------------------------------------
                                                                                                           2005 AND
                                             TOTAL           2002           2003           2004           THEREAFTER
                                        -------------    ------------   ------------   ------------     -------------
<S>                                     <C>              <C>            <C>            <C>              <C>
Current portion of long-term debt..     $   2,200,000    $         --   $  2,200,000   $         --     $          --
Long-term debt, less current portion      240,000,000              --             --             --       240,000,000
Capital lease obligations including
  interest.........................           205,000          78,000         76,000         15,000            36,000
Operating leases...................        54,269,000         528,000      3,106,000      3,534,000        47,101,000
Construction commitments...........        65,899,000       5,008,000     32,093,000     11,401,000        17,397,000
Lonza..............................        46,633,000      26,283,000     20,350,000             --                --
                                        -------------    ------------   ------------   ------------     -------------
Total contractual cash obligations      $ 409,206,000    $ 31,897,000   $ 57,825,000   $ 14,950,000     $ 304,534,000
                                        =============    ============   ============   ============     =============
</TABLE>

    At December 31, 2001, our estimated net operating loss carryforwards for
United States Federal income tax purposes were approximately $389,742,000, which
expire at various dates from 2002 through 2021. Of our $389,742,000 in estimated
net operating loss carryforwards, we have approximately $347,798,000 (of which
$342,639,000 will carryforward to 2003) available to use in 2002, approximately
$5,159,000 available to use in each year from 2003 through 2010 and
approximately $672,000 available to use in 2011. Any of these net operating loss
carryforwards which are not utilized are available for utilization in future
years, subject to applicable statutory expiration dates. See the Company's
Annual Report on Form 10-K for the year ended December 31, 2001 filed with the
SEC.

    The estimated amount of net operating loss carryforwards at December 31,
2001 reported above represents a reduction of approximately $47,447,000 in the
amount of net operating loss carryforwards previously reported at December 31,
2001 in our Annual Report on Form 10-K. The reduction is the result of a change
in the Company's position with respect to the deductibility under Section 162(m)
of the Internal Revenue Code of certain stock options granted to certain
executive officers of the Company.

    Under Section 162(m), compensation expense in excess of $1 million per
person is not deductible and compensation expense attributable to stock options
is subject to this limit, unless the options qualify as "qualified
performance-based

                                    Page 29

<PAGE>

compensation" as defined. The reduction in the amount of the Company's net
operating loss carryforwards at December 31, 2001 reflects the Company's
position that certain options granted to executive officers do not meet the
definition of "qualified performance-based compensation".

NEW JERSEY STATE TAX LAW CHANGES

    In July 2002, the State of New Jersey ("NJ") enacted various income tax law
changes, which are retroactive to January 1, 2002. One of the provisions of the
new law is the suspension of the utilization of net operating losses for 2002
and 2003. This provision would negatively affect the Company if it generates NJ
taxable income in 2002 and 2003 because it would not be able to utilize its NJ
net operating loss carryover to offset such taxable income. A second provision
establishes the Alternative Minimum Assessment ("AMA") aimed at companies like
ours that currently pay no corporate business tax. This provision requires that
we assess an alternate tax liability with a formula that uses either reported
gross receipts or gross profits as a determining factor. We are then required to
pay the greater of the regular NJ Corporation Business Tax or the AMA. The AMA
tax paid is creditable and can be carried forward to reduce the income tax in
future periods. We have recorded a tax provision of approximately $550,000 for
the nine months ended September 30, 2002 associated with the NJ AMA.

RECENTLY ISSUED ACCOUNTING PRONOUNCEMENTS

    On August 17, 2001, Statement of Financial Accounting Standards No. 143,
"Accounting for Asset Retirement Obligations" was issued and will be effective
for the Company in the first quarter of the year ending December 31, 2003. The
new rule requires the fair value of a liability for an asset retirement
obligation to be recognized in the period in which it is incurred. When the
liability is initially recorded, a cost is capitalized by increasing the
carrying amount of the related long-lived asset. Over time, the liability is
accreted to its present value each period, and the capitalized cost is
depreciated over the useful life of the related asset. To settle the liability,
the obligation for its recorded amount is paid or a gain or loss upon settlement
is incurred. Management is analyzing this requirement to determine the effect,
if any, on the Company's financial statements.

    In July 2002, the FASB issued SFAS No. 146, Accounting for Restructuring
Costs. SFAS 146 applies to costs associated with an exit activity (including
restructuring) or with a disposal of long-lived assets. Those activities can
include eliminating or reducing product lines, terminating employees and
contracts, and relocating plant facilities or personnel. Under SFAS 146, a
company will record a liability for a cost associated with an exit or disposal
activity when that liability is incurred and can be measured at fair value. SFAS
146 will require a company to disclose information about its exit and disposal
activities, the related costs, and changes in those costs in the notes to the
interim and annual financial statements that include the period in which an exit
activity is initiated and in any subsequent period until the activity is
completed. SFAS 146 is effective prospectively for exit or disposal activities
initiated after December 31, 2002, with earlier adoption encouraged. Under SFAS
146, a company may not restate its previously issued financial statements and
the new Statement grandfathers the accounting for liabilities that a company had
previously recorded under Emerging Issues Task Force Issue 94-3. The Company is
currently evaluating the impact, if any, of adoption of this statement.

CERTAIN FACTORS AFFECTING FORWARD-LOOKING STATEMENTS--SAFE HARBOR STATEMENT

    This Form 10-Q contains "forward-looking" statements, as defined in the
Private Securities Litigation Reform Act of 1995 that are based on current
expectations, estimates and projections. Statements that are not historical
facts, including statements about our and our subsidiary's beliefs and
expectations, are forward-looking statements. These statements involve potential
risks and uncertainties; therefore, actual results may differ materially. You
are cautioned not to place undue reliance on these forward-looking statements,
which speak only as of the date on which they were made. We do not undertake any
obligation to update any forward-looking statements, whether as a result of new
information, future events or otherwise.

    Important factors that may affect these expectations include, but are not
limited to: the risks and uncertainties associated with completing pre-clinical
and clinical trials of our compounds that demonstrate such compounds' safety and
effectiveness; obtaining additional financing to support our operations;
obtaining and maintaining regulatory approval for such compounds and complying
with other governmental regulations applicable to our business; obtaining the
raw materials necessary in the development of such compounds; consummating and
maintaining collaborative arrangements with corporate partners for product
development; achieving milestones under collaborative arrangements with
corporate partners; developing the capacity to manufacture, market and sell our
products, either directly or with collaborative partners; developing market
demand for and acceptance of such products; competing effectively with other
pharmaceutical and biotechnological products; obtaining adequate reimbursement
from third party payers; attracting and retaining key personnel; legal costs and
the outcome of outstanding legal proceedings and investigations, including, but
not limited to, our investigation pertaining to tax withholding issues; avoiding
delisting of our securities on the Nasdaq Stock Market; obtaining patent
protection for discoveries and risks associated with commercial limitations
imposed by patents owned or controlled by third parties.

                                    Page 30

<PAGE>

ITEM 6. EXHIBITS AND REPORTS ON FORM 8-K

(a) Exhibits (numbered in accordance with Item 601 of Regulation S-K)

<TABLE>
<CAPTION>
EXHIBIT NO.                                 DESCRIPTION
----------                                  -----------
<S>               <C>
  10.93           Target Price Contract, dated as of July 15, 2002, between
                  ImClone Systems Incorporated and Kvaerner Process, a division
                  of Kvaerner U.S. Inc., for the Architectural, Engineering,
                  Procurement Assistance, Construction Management and Validation
                  of a Commercial Manufacturing Project in Branchburg, New
                  Jersey.

  99.11           Certification pursuant to 18 U.S.C. Section 1350, as adopted
                  pursuant to section 906 of the Sarbanes-Oxley Act of 2002.

  99.12           Certification pursuant to 18 U.S.C. Section 1350, as adopted
                  pursuant to section 906 of the Sarbanes-Oxley Act of 2002.
</TABLE>

(b) Reports on Form 8-K

    None

                                    Page 31

<PAGE>

                                   SIGNATURES

    Pursuant to the requirements of the Securities Exchange Act of 1934, the
registrant has duly caused this report to be signed on its behalf by the
undersigned thereunto duly authorized.

                           IMCLONE SYSTEMS INCORPORATED
                           (Registrant)

Date: June 23, 2003        By               /s/ DANIEL S. LYNCH
                             ---------------------------------------------------
                                              Daniel S. Lynch
                             Senior Vice President, Chief Administrative
                                Officer and Acting Chief Executive Officer

Date: June 23, 2003        By              /s/ MICHAEL J. HOWERTON
                              --------------------------------------------------
                                            Michael J. Howerton
                              Vice President, Finance and Business Development
                               Secretary and Acting Chief Financial Officer

                                    Page 32

<PAGE>

SECTION 302 CERTIFICATIONS -

                                  CERTIFICATION

I, Michael J. Howerton, Vice President, Finance and Business Development,
Secretary and Acting Chief Financial Officer of ImClone Systems Incorporated
(the "Company"), certify that:

    1. I have reviewed this Amendment No. 1 to our Quarterly Report on Form
       10-Q for the Quarter Ended September 30, 2002 of the Company;

    2. Based on my knowledge, this quarterly report does not contain any untrue
       statement of a material fact or omit to state a material fact necessary
       to make the statements made, in light of the circumstances under which
       such statements were made, not misleading with respect to the period
       covered by this quarterly report;

    3. Based on my knowledge, the financial statements, and other financial
       information included in this quarterly report, fairly present in all
       material respects the financial condition, results of operations and cash
       flows of the registrant as of, and for, the periods presented in this
       quarterly report;

    4. The registrant's other certifying officers and I are responsible for
       establishing and maintaining disclosure controls and procedures (as
       defined in Exchange Act Rules 13a-14 and 15d-14) for the registrant and
       we have:

         a)  designed such disclosure controls and procedures to ensure that
             material information relating to the registrant, including its
             consolidated subsidiaries, is made known to us by others within
             those entities, particularly during the period in which this
             quarterly report is being prepared; and

         b)  presented in this quarterly report our conclusions about the
             effectiveness of the disclosure controls and procedures based on
             our evaluation as of the Evaluation Date.

Date: June 23, 2003

                                            /s/ MICHAEL J. HOWERTON
                                            ---------------------------
                                            Michael J. Howerton
                                            Acting Chief Financial Officer

                                    Page 33

<PAGE>

                                  CERTIFICATION

I, Daniel S. Lynch, Senior Vice President, Chief Administrative Officer and
Acting Chief Executive Officer of ImClone Systems Incorporated (the "Company"),
certify that:

    1. I have reviewed this Amendment No. 1 to our Quarterly Report on Form 10-Q
       for the Quarter Ended September 30, 2002 of the Company;

    2. Based on my knowledge, this quarterly report does not contain any untrue
       statement of a material fact or omit to state a material fact necessary
       to make the statements made, in light of the circumstances under which
       such statements were made, not misleading with respect to the period
       covered by this quarterly report;

    3. Based on my knowledge, the financial statements, and other financial
       information included in this quarterly report, fairly present in all
       material respects the financial condition, results of operations and cash
       flows of the registrant as of, and for, the periods presented in this
       quarterly report;

    4. The registrant's other certifying officers and I are responsible for
       establishing and maintaining disclosure controls and procedures (as
       defined in Exchange Act Rules 13a-14 and 15d-14) for the registrant and
       we have:

         a)  designed such disclosure controls and procedures to ensure that
             material information relating to the registrant, including its
             consolidated subsidiaries, is made known to us by others within
             those entities, particularly during the period in which this
             quarterly report is being prepared; and

         b)  presented in this quarterly report our conclusions about the
             effectiveness of the disclosure controls and procedures based on
             our evaluation as of the Evaluation Date.

Date: June 23, 2003

                                            /s/ DANIEL S. LYNCH
                                            -------------------------
                                            Daniel S. Lynch
                                            Acting Chief Executive Officer

                                    Page 34