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                UNITED STATES SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

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                                   FORM 10-Q/A


     (MARK ONE) QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d)
          X      OF THE SECURITIES EXCHANGE ACT OF 1934 For the
                      quarterly period ended March 31, 2000
                                       OR
                TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d)
                     OF THE SECURITIES EXCHANGE ACT OF 1934
                        For the transition period from          to
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                         Commission file number 0-22147

                               ILEX ONCOLOGY, INC.
             (EXACT NAME OF REGISTRANT AS SPECIFIED IN ITS CHARTER)


                DELAWARE                                       74-2699185
     (STATE OR OTHER JURISDICTION OF                         (I.R.S. EMPLOYER
     INCORPORATION OR ORGANIZATION)                         IDENTIFICATION NO.)


      11550 I.H. 10 WEST, SUITE 100
           SAN ANTONIO, TEXAS                                      78230
(ADDRESS OF PRINCIPAL EXECUTIVE OFFICES)                         (ZIP CODE)

       REGISTRANT'S TELEPHONE NUMBER, INCLUDING AREA CODE: (210) 949-8200




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         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  X   NO   .
                                              ---    ---

         THE NUMBER OF SHARES OUTSTANDING OF THE REGISTRANT'S COMMON STOCK AS OF
MAY 5, 2000 IS 24,857,873.


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ILEX ONCOLOGY, INC.
MARCH 31, 2000 - QUARTERLY REPORT ON FORM 10-Q/A
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PORTIONS AMENDED

The Company hereby amends the cover page to the Company's Quarterly Report on
Form 10-Q for the quarterly period ended March 31, 2000 to change the number of
shares of the Company's common stock reported outstanding as of May 5, 2000 from
25,857,873 to 24,857,873. No other changes are made to the Company's Quarterly
Report on Form 10-Q for the quarterly period ended March 31, 2000.



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ILEX ONCOLOGY, INC.
MARCH 31, 2000 - QUARTERLY REPORT ON FORM 10-Q/A
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                                   SIGNATURES

Pursuant to the requirements of Section 13 or 15(d) of the Securities Act of
1934, the Registrant has duly caused this report to be signed on its behalf by
the undersigned, thereunto duly authorized, in the city of San Antonio, Texas,
on May 26, 2000.

                                            ILEX ONCOLOGY, INC.

                                      By:   /s/ RICHARD L. LOVE
                                         ------------------------------
                                            Richard L. Love
                                            President and Chief
                                            Executive Officer
                                            (Principal Executive
                                            Officer)

                                      By:   /s/ GREGORY L. WEAVER
                                         -----------------------------
                                            Gregory L. Weaver
                                            Vice President and Chief
                                            Financial Officer
                                            (Chief Financial and
                                            Accounting Officer)



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