Exhibit 3.1A

                            CERTIFICATE OF AMENDMENT
                                       TO
                          CERTIFICATE OF INCORPORATION
                                       OF
                          IMCLONE SYSTEMS INCORPORATED

                Under Section 242 of the General Corporation Law
                            of the State of Delaware

      The  undersigned,  being the Executive Vice  President of IMCLONE  SYSTEMS
INCORPORATED,  a Delaware corporation (the "Corporation") DOES HEREBY CERTIFY as
follows:

      FIRST:  The  Certificate  of  Incorporation  of the  Corporation is hereby
amended so that Article FOURTH (a) shall read in its entirety as follows:

            "FOURTH:  (a) The total number of shares of capital  stock which the
      Corporation   shall  have  the   authority  to  issue  is  sixty   million
      (60,000,000)  shares of Common  Stock with a par value of one tenth of one
      cent  ($.001) per share and four million  (4,000,000)  shares of Preferred
      Stock with a par value of one dollar ($1.00) per share."

      SECOND:  That such amendment was duly adopted by the Board of Directors of
the  Corporation  and by the  Stockholders of the Corporation in accordance with
Section 242 of the General Corporation Law of the State of Delaware.

      IN WITNESS  WHEREOF,  this  Certificate of Amendment to the Certificate of
Incorporation of the Corporation has been signed, and the statements made herein
affirmed as true under the penalties of perjury, this 2nd day of June 1999.


                                                     /s/Harlan W. Waksal
                                                     ------------------------
                                                     Harlan W. Waksal,
                                                     Executive Vice President


Attest:/s/ John  B. Landes
       -------------------------
       John B. Landes, Secretary