SCHEDULE 14A
           Proxy Statement Pursuant to Section 14(a) of the Securities
                     Exchange Act of 1934 (Amendment No. __)


Filed by the Registrant                     [ ]

Filed by a Party other than the Registrant  [x]

Check the appropriate box:

[ ] Preliminary Proxy Statement
[ ] Confidential, for Use of the Commission Only (as permitted by
    Rule 14a-6(e)(2))
[ ] Definitive Proxy Statement
[X] Definitive Additional Materials
[ ] Soliciting Material Pursuant to ss. 240.14a-12

                          IMCLONE SYSTEMS INCORPORATED

                (Name of Registrant as Specified In Its Charter)

                                  CARL C. ICAHN
                               ALEXANDER J. DENNER
                                PETER S. LIEBERT
                                 BARBERRY CORP.
                         HIGH RIVER LIMITED PARTNERSHIP
                                       AND
                             HOPPER INVESTMENTS LLC

    (Name of Person(s) Filing Proxy Statement, if other than the Registrant)

Payment of Filing Fee (check the appropriate box):

[X] No fee required.

[ ] Fee computed on table below per Exchange Act Rule 14a-6(i)(4) and 0-11.

     1)   Title of each class of securities to which transaction applies:

     2)   Aggregate number of securities to which transaction applies:

     3)   Per unit price or other underlying value of transaction computed
          pursuant to Exchange Act Rule 0-11 (set forth the amount on which the
          filing fee is calculated and state how it was determined):

     4)   Proposed maximum aggregate value of transaction:

     5)   Total fee paid:

[ ] Fee paid previously with preliminary materials.

[ ] Check box if any part of the fee is offset as provided by Exchange Act
    Rule 0-11(a)(2) and identify the filing for which the offsetting fee was
    paid previously. Identify the previous filing by registration statement
    number, or the Form or Schedule and the date of its filing.

     1) Amount Previously Paid:

     2) Form, Schedule or Registration Statement No.:

     3) Filing Party:

     4) Date Filed:





On October 6, 2006, Institutional Shareholder Services ("ISS") "M&A Insight" put
out a note to clients discussing Carl Icahn's recent activism at ImClone Systems
Incorporated. On October 9, 2006, ISS spoke with Mr. Icahn to get his version of
the events  surrounding  the Consent  Solicitation  and  subsequently  Mr. Icahn
provided written comments to Chris Young on a draft of the attached note. A copy
of the M&A Insight Note  summarizing  the October 9, 2006  conversation is filed
herewith as Exhibit 1.



                                                                       EXHIBIT 1


INSTITUTIONAL SHAREHOLDER SERVICES

                                M&A Insight Note

Issuer: ImClone Systems (IMCL)/"A Conversation with Carl Icahn"
Date: October 18, 2006

On Oct. 6, M&A Insight put out a note to clients  discussing Carl Icahn's recent
activism at ImClone Systems  (IMCL).  In the note, we indicated that Mr. Icahn's
actions  (including  seeking the  resignation  of board  chairman David Kies and
launching a consent  solicitation  to gain control of the board)  appeared to be
rather  aggressive  in  light  of the  recent  settlement  reached  by  the  two
combatants. We noted that Mr. Icahn's actions are likely to be used by IMCL (and
by future  targets  of Mr.  Icahn)  as  "evidence"  that Mr.  Icahn is not to be
trusted and is unable to work constructively with incumbents.

On Oct. 9, we spoke with Mr. Icahn to get his side of the story.

Mr. Icahn  stressed  that at the time he accepted the offer of his board seat he
had no intention of  conducting  a consent  solicitation.  He made it clear that
because it takes a  plurality  of votes to win a proxy  fight and a majority  of
outstanding  shares  to  win  a  consent   solicitation,   it  would  have  been
"ridiculous"  for him to have given up the  chance to  conduct a proxy  fight in
order to join the  board  and then  conduct  a  consent  solicitation  to remove
directors.

Mr. Icahn also stated that prior to this year's annual meeting,  IMCL approached
him to try to reach an amicable settlement of their differences.  Prior thereto,
Mr. Icahn had hired Alex Denner,  who was a director of IMCL.  IMCL then offered
to nominate  Mr.  Denner,  Mr.  Icahn and two persons  suggested by him who were
among those vetted by the company.  Mr. Icahn agreed not to nominate  others for
election at the annual meeting.

During the discussions  with IMCL, Mr. Icahn claims he made it very clear to the
company  that  he  believed  IMCL  needs  a  CEO  who  has  significant  biotech
experience.  Mr. Icahn notes that Joseph Fischer, the company's interim CEO, has
no biotech  experience.  Mr. Icahn alleges he clearly warned the company against
giving  Mr.  Fischer  a  long-term   employment   contract   during   settlement
discussions.  However, on Aug. 23, the same day IMCL and Mr. Icahn announced the
settlement  agreement,  the company also disclosed an amendment to Mr.  Fisher's
employment  agreement.  Mr. Icahn  claims he was not notified of this  amendment
before its adoption.

In addition,  Mr. Icahn says that during  discussions  he had with Mr. Kies, Mr.
Kies indicated he had no interest in continuing as chairman.  However,  on Sept.
20,  the same day as the  annual  meeting  at which Mr.  Icahn,  Denner  and two
persons  suggested  by Icahn were  elected to the board,  Mr.  Kies called for a
board vote on his own chairmanship and subsequently was re-elected chairman. Mr.
Icahn characterizes this move as a betrayal of the  representations  made to him
during settlement discussions.

In short,  Mr.  Icahn  believes  that the  company  never  seriously  considered
addressing his concerns  about the company's  chairman and CEO and that IMCL had
been  warned  that by not  taking the action  that he  suggested,  they would be
"throwing down the gauntlet."

If Mr. Icahn's version of events are accurate, it helps to explain the unusually
rapid deterioration of relations between the dissident and the target company so
soon after an announced  settlement.  We note that a day after our  conversation
with Mr. Icahn,  the company  announced the  resignation of Mr. Kies and another
director,  William  Crouse.  This  development  appears to  address  one bone of
contention  of Mr.  Icahn's;  however,  the  suitability  of the  company's  CEO
presumably remains at issue.

Unfortunately for shareholders, nearly every proxy fight becomes a "he said, she
said" exercise, a tough dynamic to analyze from the outside. One of the goals of
M&A Insight is to help interested  constituencies  to better analyze a sometimes
confusing debate.

We will  continue  to  monitor  this  situation  and market  trends,  speak with
interested  parties and, where relevant,  issue  additional M&A Insight Notes to
provide further information and guidance for clients.




Please note that this M&A Insight  research note should not be interpreted as an
indication  of how  ISS  ultimately  will  recommend  shareholders  vote  on the
proposed  transaction.  M&A Insight research notes are designed to highlight key
issues facing shareholders in selected high-profile or contentious transactions.

This issuer may have purchased  self-assessment  tools and publications from the
Corporate Service division of Institutional  Shareholder  Services Inc. ("ISS"),
or the  Corporate  Services  division  of ISS  may  have  provided  advisory  or
analytical  services to the issuer in connection  with the proxies  described in
this report.  Neither the issuer nor any corporate  services  division  employee
played a role in the  preparation of this report.  To inquire about any issuer's
use   of    Corporate    Services    products    from    ISS,    please    email
disclosure@issproxy.com

This proxy  analysis and vote  recommendation  have not been  submitted  to, nor
received approval from, the United States Securities and Exchange  Commission or
any other  regulatory  body.  While ISS  exercised  due care in  compiling  this
analysis,  we make no  warranty,  express or implied,  regarding  the  accuracy,
completeness,  or usefulness of this  information  and assume no liability  with
respect to the  consequences  of relying on this  information  for investment or
other purposes. In particular,  the research and voting recommendations provided
are not intended to constitute an offer,  solicitation  or advice to buy or sell
securities.

This  issuer  may be a client of ISS or the  parent of, or  affiliated  with,  a
client of ISS.  Neither the issuer,  nor any of its  subsidiaries or affiliates,
played any role in preparing  this report.  Some of our clients may own stock in
the issuer that is the subject of this report.

Two of ISS'  stockholders,  Warburg Pincus Private Equity VIII,  L.P. and Hermes
USA Investors  Venture,  L.L.C.,  are  institutional  investors  whose  business
activities   include   making  equity  and  debt   investments   in  public  and
privately-held  companies.  As a  result,  from time to time one or more of ISS'
stockholders  or their  affiliates (or their  representatives  who serve on ISS'
Board of Directors) may hold securities,  serve on the board of directors and/or
have the right to nominate  representatives  to the board of a company  which is
the  subject of one of ISS' proxy  analyses  and vote  recommendations.  We have
established  policies  and  procedures  to  restrict  the  involvement  of  ISS'
non-management stockholders, their affiliates and board members in the editorial
content of our analyses and vote recommendations.

Deminor Rating SA  ("Deminor/ISS  Europe") is a wholly-owned  subsidiary of ISS.
Jean-Nicolas  Caprasse,  the  managing  director  of  Deminor/ISS  Europe,  is a
non-executive partner of Deminor International SCRL ("International"), a company
which provides active  engagement and other advisory services to shareholders of
both  listed  and  non-listed  companies.  As a  result,  International  may  be
providing  engagement services to shareholders of a company which is the subject
of one of our  analyses or  recommendations  or  otherwise  working on behalf of
shareholders  with  respect to such a  company.  As a  non-executive  partner of
International, Mr. Caprasse is not involved in the engagement and other services
provided  to the  clients  of  International.  International  has no role in the
formulation of the research policies,  reports and vote recommendations prepared
by ISS or Deminor/ISS  Europe.  Mr. Caprasse will benefit  financially  from the
success of International's business in proportion to his partnership interest.

Neither   ISS'   non-management   stockholders,   their   affiliates   nor  ISS'
non-management board members are informed of the contents of any of our analyses
or recommendations prior to their publication or dissemination.

Contact:

Chris Young, JD, CFA                      Qin Tuminelli, CFA
Director & Head of M&A Research           Manager, M&A Insight
Tel. 301.556.0625                         Tel. 301.556.0415
Christopher.young@issproxy.com            Qin.tuminelli@issproxy.com









(C) 2006,  Institutional  Shareholder  Services  Inc. All Rights  Reserved.  The
information  contained  in this  ISS  Proxy  Analysis  may  not be  republished,
broadcast,  or redistributed  without the prior written consent of Institutional
Shareholder Services Inc.