<PAGE>   1

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

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

                                   ----------



                                   FORM 10-Q/A



(MARK ONE)
       X        QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d)
                     OF THE SECURITIES EXCHANGE ACT OF 1934
                  For the quarterly period ended March 31, 2001
                                       OR
                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 0-22147

                               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.)


                4545 HORIZON HILL BLVD.
                  SAN ANTONIO, TEXAS                         78229
       (ADDRESS OF PRINCIPAL EXECUTIVE OFFICES)           (ZIP CODE)

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



                                   ----------


         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 7, 2001 IS 26,349,097.


<PAGE>   2



                                      INDEX



<TABLE>
<S>      <C>                                                                                           <C>
PART I. FINANCIAL INFORMATION

     ITEM 1.  FINANCIAL STATEMENTS
         Consolidated Balance Sheets - March 31, 2001 and December 31, 2000                              3

         Consolidated Statements of Operations - Three Month Period Ended March 31, 2001 and 2000        5

         Consolidated Statements of Cash Flows - Three Month Period Ended March 31, 2001 and 2000        6

         Notes to Consolidated Financial Statements                                                      7

     ITEM 2.  MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS     14


PART II. OTHER INFORMATION

     ITEM 6.  EXHIBITS AND REPORTS ON FORM 8-K                                                          20

SIGNATURES                                                                                              21
</TABLE>





                                       2
<PAGE>   3



PART I.  FINANCIAL INFORMATION

ITEM 1.  FINANCIAL STATEMENTS

                           CONSOLIDATED BALANCE SHEETS
               (In Thousands, Except Shares and Per Share Amounts)

<TABLE>
<CAPTION>

                                                                           March 31,     December 31,
                                                                             2001            2000
                                                                         ------------    ------------
                                                                          (Unaudited)
<S>                                                                      <C>             <C>
                                             ASSETS
                                             ------

CURRENT ASSETS:
   Cash and cash equivalents                                             $     32,992    $     18,099
   Investments in marketable securities                                       123,329         136,913
   Restricted investments                                                       6,635           1,635
   Accounts receivable, net of allowance for doubtful accounts of
     $344 in 2001 and 2000, respectively
       Billed                                                                   7,185           6,155
       Unbilled                                                                 2,298           2,186
       Employee                                                                    18             154
       Other                                                                      126             126
   Interest receivable                                                          3,332           4,368
   Prepaid expenses and other                                                   1,769             975
                                                                         ------------    ------------

                           Total current assets                               177,684         170,611
                                                                         ------------    ------------



NONCURRENT ASSETS:
   Investments in marketable securities                                        15,020          42,960
   Restricted investments                                                       3,165           3,165
   Investments in and advances to joint venture                                (4,274)         (7,104)
   Intangible asset                                                               300              --
   Other assets                                                                   240             248
                                                                         ------------    ------------
                           Total noncurrent assets                             14,451          39,269
                                                                         ------------    ------------

PROPERTY AND EQUIPMENT, at cost, net of accumulated
   depreciation of $4,207 and $3,763 in 2001 and 2000, respectively             6,631           6,476
                                                                         ------------    ------------

                           Total assets                                  $    198,766    $    216,356
                                                                         ============    ============
Z
</TABLE>




       The accompanying notes are an integral part of these consolidated
                              financial statements.


                                       3
<PAGE>   4

                           CONSOLIDATED BALANCE SHEETS
               (In Thousands, Except Shares and Per Share Amounts)

<TABLE>
<CAPTION>
                                                                           March 31,      December 31,
                                                                             2001            2000
                                                                         ------------    ------------
                                                                         (Unaudited)
<S>                                                                      <C>             <C>

                                LIABILITIES AND STOCKHOLDERS' EQUITY

CURRENT LIABILITIES:
   Accounts payable-
     Related parties                                                     $        240    $         30
     Other                                                                      4,052           6,706
   Accrued subcontractor costs-
     Related parties                                                              380             678
     Other                                                                      2,222           2,181
   Accrued liabilities                                                          3,211           3,671
   Deferred revenue                                                             5,853           5,725
                                                                         ------------    ------------

               Total current liabilities                                       15,958          18,991
                                                                         ------------    ------------

DEFERRED INCOME TAXES                                                              73              --
LONG-TERM LIABILITIES                                                             904           1,360
                                                                         ------------    ------------

                                                                               16,935          20,351
                                                                         ------------    ------------

COMMITMENTS AND CONTINGENCIES

STOCKHOLDERS' EQUITY:
   Preferred stock, $0.01 par value; 20,000,000 shares authorized;
     no shares issued or outstanding                                               --              --
   Common stock, $0.01 par value; 100,000,000 shares authorized;
     26,381,563 and 25,815,243 shares issued; 26,342,563 and
     25,776,243 shares outstanding in 2001 and 2000, respectively                 264             258
   Additional paid-in capital                                                 327,001         312,687
   Accumulated deficit                                                       (144,770)       (116,320)
   Accumulated other comprehensive loss                                          (147)           (103)
   Less - Treasury stock at cost; 39,000 shares in 2001 and 2000                 (517)           (517)
                                                                         ------------    ------------

               Total stockholders' equity                                     181,831         196,005
                                                                         ------------    ------------

               Total liabilities and stockholders' equity                $    198,766    $    216,356
                                                                         ============    ============
</TABLE>





        The accompanying notes are an integral part of these consolidated
                             financial statements.



                                       4
<PAGE>   5


                      CONSOLIDATED STATEMENTS OF OPERATIONS
                    (In Thousands, Except Per Share Amounts)
                                   (Unaudited)

<TABLE>
<CAPTION>
                                                                          Three Months Ended
                                                                              March 31,
                                                                         2001            2000
                                                                     ------------    ------------
<S>                                                                  <C>             <C>

REVENUE:
   Product development                                               $        680    $      1,038
   Contract research services                                               5,628           5,576
                                                                     ------------    ------------

                      Total revenue                                         6,308           6,614
                                                                     ------------    ------------

OPERATING EXPENSES:
   Research and development costs                                           7,421           5,314
   Licensing costs                                                          1,286              25
   Direct cost of research services                                         4,668           5,105
   General and administrative                                               2,330             939
   In-process research and development                                     21,112              --
                                                                     ------------    ------------

                      Total operating expenses                             36,817          11,383
                                                                     ------------    ------------

OPERATING LOSS                                                            (30,509)         (4,769)

OTHER INCOME (EXPENSE):
   Equity in (losses) income of joint venture                              (1,161)             39
   Interest income, net                                                     3,220           1,516
   Minority interest in consolidated subsidiary                                --             (75)
                                                                     ------------    ------------

LOSS BEFORE INCOME TAXES                                                  (28,450)         (3,289)

   Provision for foreign income taxes                                          --              95
                                                                     ------------    ------------

NET LOSS                                                             $    (28,450)   $     (3,384)
                                                                     ============    ============

BASIC AND DILUTED NET LOSS PER SHARE                                 $      (1.09)   $      (0.15)
                                                                     ============    ============

WEIGHTED AVERAGE NUMBER OF SHARES OF COMMON STOCK OUTSTANDING
                                                                           26,084          22,039
                                                                     ============    ============
</TABLE>




        The accompanying notes are an integral part of these consolidated
                             financial statements.



                                       5
<PAGE>   6


                      CONSOLIDATED STATEMENTS OF CASH FLOWS
                                 (In Thousands)
                                   (Unaudited)

<TABLE>
<CAPTION>
                                                                                   Three Months Ended
                                                                                       March 31,
                                                                                  2001           2000
                                                                             ------------    ------------
<S>                                                                          <C>             <C>

CASH FLOWS FROM OPERATING ACTIVITIES:
    Net loss                                                                 $    (28,450)   $     (3,384)
    Adjustments to reconcile net loss to net cash used
     in operating activities:
       Depreciation and amortization                                                  590             525
       In-process research and development                                         21,112              --
       Net activity of joint venture                                                  539          (1,076)
       Minority interest                                                               --              75
       Deferred compensation expense for consultants' options                          --             976
       Loss on disposal of equipment                                                   68              --
       Changes in operating assets and liabilities:
           Decrease (increase) in receivables, net                                     30          (2,247)
           Increase in prepaid expenses and other                                    (521)           (338)
           Decrease in other noncurrent assets                                          8              --
           Decrease in accounts payable and accrued liabilities                    (3,299)           (763)
           (Decrease) increase in accrued subcontractor costs                        (257)             13
           Increase in deferred revenue                                               128           4,409
           Decrease in other long-term liabilities                                   (435)             (8)
                                                                             ------------    ------------

                   Net cash used in operating activities                          (10,487)         (1,818)
                                                                             ------------    ------------

CASH FLOWS FROM INVESTING ACTIVITIES:
   Net activity of marketable securities' transactions                             41,524         (31,778)
   Net activity in restricted investments                                          (5,000)            425
   Purchase of property and equipment                                                (601)           (715)
   Proceeds from sale of property and equipment                                         3              --
   Advances to joint venture                                                       (3,369)             --
   Acquisitions, net of cash acquired                                              (7,529)           (136)
                                                                             ------------    ------------

                   Net cash provided by (used in) investing activities             25,028         (32,204)
                                                                             ------------    ------------

CASH FLOWS FROM FINANCING ACTIVITIES:
   Issuance of common stock for cash, net of issuance costs                            --         127,272
   Exercise of stock options and warrants                                             413           1,072
   Principal payments for capital lease obligations                                   (17)             --
                                                                             ------------    ------------

                   Net cash provided by financing activities                          396         128,344
                                                                             ------------    ------------

Effect of Exchange Rate Changes on Cash and Cash Equivalents                          (44)            (25)

NET INCREASE IN CASH AND CASH EQUIVALENTS                                    $     14,893    $     94,297

CASH AND CASH EQUIVALENTS, beginning of period                                     18,099          43,477
                                                                             ------------    ------------

CASH AND CASH EQUIVALENTS, end of period                                     $     32,992    $    137,774
                                                                             ============    ============
</TABLE>



        The accompanying notes are an integral part of these consolidated
                             financial statements.


                                       6
<PAGE>   7


NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
(Amounts in Thousands, Except Share Information, Per Share Information or As
Otherwise Indicated) (Unaudited)

1. PRINCIPLES OF CONSOLIDATION AND BASIS OF PRESENTATION

The accompanying interim Consolidated Financial Statements presented herein
include the accounts of ILEX Oncology, Inc. and its subsidiaries ("the Company"
or "ILEX"). All significant intercompany transactions and accounts have been
eliminated in consolidation. These interim consolidated financial statements
have been prepared by the Company, without audit, pursuant to the rules and
regulations of the Securities and Exchange Commission. Certain information and
footnote disclosures normally included in financial statements prepared in
accordance with generally accepted accounting principles have been condensed or
omitted pursuant to such rules and regulations. In management's opinion, all
adjustments that are necessary for a fair presentation of financial position and
results of operations have been made.

It is recommended that these interim consolidated financial statements are read
in conjunction with the financial statements and notes thereto included in the
Company's Annual Report on Form 10-K for the year ended December 31, 2000. The
results of operations for any interim period are not necessarily indicative of
the results of operations for the entire year. Certain prior period amounts have
been reclassified to conform to the current period presentation.

2. MERGERS AND ACQUISITIONS


On February 13, 2001, the Company acquired Symphar S.A., now ILEX
Research-Europe, S.A., a drug discovery firm located in Geneva, Switzerland that
combines a targeted medicinal chemistry platform with expertise in the biology
of nuclear receptors important in controlling such cellular functions as
apoptosis, cholesterol synthesis and calcium metabolism. The acquisition has
been accounted for using the purchase method of accounting. Under the terms of
the agreement, ILEX acquired Symphar for approximately $29 million, including
$15 million in cash, of which $5 million is contingently issuable, and 521,121
shares of the Company's common stock. The issued shares are restricted and will
be made available for trading as follows: 30 percent after 90 days after
closing, 40 percent after 180 days after closing, and 30 percent after 270 days
after closing. The value of the common stock issued in connection with this
merger was calculated using a fair value of $ 26.6875 per share. This per share
fair value represents the closing price of the Company's stock on the day the
merger terms were agreed to and announced. The purchase price was allocated to
the assets purchased, liabilities assumed, intangible assets and in-process
research and development expense based upon their respective fair values. The
purchase price was allocated as follows:



<TABLE>
<S>                                         <C>
Current assets                                 $  2,744
Property                                            215
Assembled workforce                                 300
Current liabilities                                (464)
In-process research and development              21,112
                                               --------
Total purchase price                           $ 23,907
                                               ========
</TABLE>



The cash portion of the purchase price came from the Company's working capital.
The amount paid by the Company was arrived at through negotiations between the
Company and the shareholders of Symphar and was based on a variety of factors,
including, but not limited to, the prospect for commercializing certain of the
assets of Symphar and the nature of the research-based pharmaceutical industry.
The new entity operates under the name ILEX Research-Europe, S.A., and is
comprised of former employees of Symphar. The Company has granted certain
registration rights for the shares issued in connection with the acquisition.
Concurrent with the acquisition, ILEX Research-Europe entered into a three-year
employment agreement with one of the founders of Symphar. The agreement
specifies a compensation level. The founder was granted an option to purchase a
total of 30,000 shares of the Company's common stock under terms of the 2000
Employee Stock Compensation Plan.



Additionally, of the $15 million cash payment, the Company placed $4.5 million
in escrow as a reserve for possible indemnification against certain future
claims. This amount was included in the purchase price allocation, and will be
released in equal installments of $1.5 million every six months following
closing for a period of 18 months provided no claims arise. In addition, $5.0
million of the purchase price is in escrow to be released in the event a
commitment is reached with a third party within one year of closing to provide
funding of at least $5.0 million for a period of at least one year for
non-oncology indications. Upon the execution of an agreement with a third party,
the Company would recognize additional in-process research and development
expense for the $5 million held in escrow. The $5.0 million escrow balance is
included in restricted investments as a current asset.



The Company acquired certain intangible assets including intellectual property
in the area of targeted medicinal phosphonate chemistry. Additionally, the
Company has recorded an intangible asset in the amount of $300 related to
assembled workforce that will be amortized over three years. In accordance with
purchase accounting, the Company has included the results of operations for
Symphar from the date of acquisition.



In connection with the purchase price allocation, $21.1 million was expensed as
a charge for the purchase of in-process research and development. The Company
allocated values to the in-process research and development based on an in depth
assessment of the research and development projects. The value assigned to these
assets was limited to significant research projects for which technological
feasibility had not been established, including development, testing, and
regulatory activities associated with the introduction of Symphar's projected
product launches. The value assigned to purchased in-process technology was
determined by estimating the costs to develop the purchased in-process
technology into commercially viable products, estimating the resulting net cash
flows from the projects and discounting the net cash flows to their present
value. Due to the complexity of the acquired research and development, the
technologies under development, could, once completed, only be economically used
for their specific and intended purposes in the targeted disease segments. If
the Company were to fail in its efforts to commercialize its developmental drug
candidates, no alternative economic value is envisioned at this time. Given the
very specific nature of the development, it was determined that there were no
alternative economic uses for the acquired research and development outside of
those originally envisioned by the Company. The assembled workforce was valued
using the cost approach. Under this approach, the workforce is valued by
calculating the savings realized by the Company through obtaining a
pre-existing, trained and fully efficient engineering, operations,
administrative and sales team rather than incurring the costs to assemble and
train an equivalent workforce.


                                       7
<PAGE>   8



The income approach was the primary technique utilized in valuing the purchased
research and development projects. The value assigned to these projects was
limited because technological feasibility had not been established, including
development, testing and regulatory activities associated with the introduction
of projected product launches. The value assigned to purchased in-process
technology was determined by estimating the costs to develop the purchased
in-process technology into commercially viable products, estimating the
resulting net cash flows from the projects and discounting the net cash flows to
their present value. The independent appraisal also considered the fact that the
existing know-how diminishes in value over time as new technologies are
developed and changes in market conditions render current products and
methodologies obsolete. The assumptions underlying the cash flow projections
used were derived primarily from investment banking reports, historical results,
company records and discussions with management.



The revenue projection used to value the in-process research and development was
based on estimates of relevant market sizes and growth factors, expected trends
in technology and the nature and expected timing of new product introductions by
the Company, its partners, and its competitors. Future royalty revenue estimates
were aggregated for the Apomine cancer indications and Lp(a) inhibitor based on
management's estimate of the following: i) addressable number of patients in the
US market, ii) market penetration, iii) average sales price, iv) estimate of
remaining worldwide market, and v) the Company's projected royalty rate received
from its partner. The discount rate selected for the in-process technology was
30 percent for both Apomine and Lp(a). Due to the aggressive nature of
management's forecast and the high level of risk associated with the Company
achieving the projected cash flows, the discount rate was calculated using
venture capital-type rates of return. The rate was determined based on analysis
of three venture capital studies utilizing rates appropriate to start-up type
companies.



For the purposes of the independent appraisal, only the economics related to
Symphar's lead drug candidates, Apomine and Lp(a) were considered. It was
determined that forecasting cash flows for Symphar's other developmental
projects was not feasible at the time of acquisition due to their early stage of
development. At the time of acquisition, management estimated that approximately
$14 to $15 million had been spent on Apomine and Lp(a) to date, and an
additional $17 to $20 million is expected to still be incurred to complete
clinical testing and gain marketing approval.



Apomine, targeted at several cancer indications, as well as bone repair and
osteoporosis, represented approximately 45% of the in-process research and
development value. As of the date of the acquisition, the project was expected
to be completed and commercially available in the US in 2007 for its first
cancer indication, with an estimated cost to complete of approximately $12 to
$14 million. Management believes that the Company may be able to license its
product to a major pharmaceutical company or marketing partner and begin
receiving upfront licensing, milestone and collaborative research revenue
resulting in net cash inflows beginning in 2004. Product launches for
additional cancer indications are anticipated between 2008 and 2011.
Additionally, the Company is estimating royalty revenue upon the
commercialization of the product of approximately 8% starting with product
launch. As of March 2001, the Company had not abandoned nor had any plans to
abandon Apomine.



Lp(a), an inhibitor that may lead to a reduction in coronary heart disease,
represented approximately 55% of the in-process research and development value.
As of the date of the acquisition, the Lp(a) project was expected to be
completed and commercially available in the US in 2007, with an estimated cost
to complete of approximately $5 to $6 million. Management believes that the
Company may be able to license its product to a major pharmaceutical company or
marketing partner and begin receiving upfront licensing, milestone and
collaborative research revenue resulting in net cash inflows beginning in 2005.
Additionally, the Company is estimating royalty revenue upon the
commercialization of the product of approximately 8% starting with product
launch. As of March 2001, the Company had not abandoned nor had any plans to
abandon Lp(a).



The Company believes that the foregoing assumptions used in the purchase price
allocation were reasonable at the time of the acquisition. No assurance can be
given, however, that the underlying assumptions used to estimate revenue,
development costs or profitability or the events associated with such projects
will transpire as estimated. For these reasons, actual results may vary from
projected results. The most significant and uncertain assumptions relating to
the in-process projects relate to the projected timing of completion and
revenues attributable to each project.



The following table reflects unaudited pro forma combined results of operations
of ILEX and Symphar as if the acquisition had occurred on January 1, 2001 and
2000. Included in pro forma results is amortization of assembled workforce in
the amount of $25 for the three-month periods ended March 31, 2001 and 2000.
Also included in the pro forma results is $21.1 million recorded as in-process
research and development for the three-month period ended March 31, 2001. Such
pro forma information is presented for informational purposes only and is not
necessarily indicative of the consolidated results that would have been achieved
had the acquisition actually been consummated at January 1, 2001 and 2000.



<TABLE>
<CAPTION>
                                                  March 31,
                                          ------------------------
                                             2001          2000
                                          ----------    ----------
<S>                                       <C>           <C>
Total revenue                             $    6,691    $    7,382
Net loss                                  $ (28,475)    $   (3,361)
Basic and diluted net loss per share      $   (1.08)    $     (0.15)
</TABLE>


                                       8
<PAGE>   9


3. STOCKHOLDERS' EQUITY

On March 30, 2001, the Board of Directors of the Company declared a dividend of
one Preferred Share purchase right (a "Right") for each outstanding share of
common stock, par value $.01 per share (the "Common Shares"), of the Company and
authorized the issuance of one Right for each Common Share which shall become
outstanding between the Record Date and the earlier of the Distribution Date (as
hereinafter defined) or the final expiration date of the Rights. The dividend is
payable on April 20, 2001 (the "Record Date") to the stockholders of record on
that date. Each Right entitles the registered holder to purchase from the
Company one one-thousandth interest in one share of Series I Preferred Stock,
par value $.01 per share (the "Preferred Shares"), of the Company at a price of
$120.00 per one one-thousandth interest in a Preferred Share (the "Purchase
Price"), subject to adjustment. The Rights will become exercisable ten days
after (i) an Acquiring Party accumulates beneficial ownership of 20 percent or
more of the Company's common stock or (ii) following the commencement of, or
announcement of an intention to make, a tender offer or exchange offer the
consummation of which would result in an Acquiring Party accumulating 20 percent
or more of the common stock. In the event the Company is, in effect, acquired in
a merger or other business combination transaction or 50 percent or more of its
consolidated assets or earning power is sold, proper provision will be made so
that each holder of a Right will thereafter generally have the right to receive,
upon the exercise thereof at the then current exercise price of the Right, that
number of shares of common stock of the acquiring company which at the time of
such transaction will have a market value of two times the then current Purchase
Price of the Right.

The description and terms of the Rights are set forth in a Rights Agreement (the
"Rights Agreement") between the Company and American Stock Transfer & Trust Co.,
as Rights Agent (the "Rights Agent"). The plan was not adopted in response to
any unsolicited offer or takeover attempt. A copy of the Rights Agreement was
filed with the Securities and Exchange Commission as an exhibit to a Current
Report on Form 8-K dated April 11, 2001.

4. LOSS PER SHARE

Diluted net loss per share is equal to basic net loss per share, as the effect
of all common stock equivalents is antidilutive.

5. STATEMENTS OF CASH FLOWS:

Non-cash financing and investing activities for the three months ended March 31,
2001 and 2000, include the following:

<TABLE>
<CAPTION>
                                                   2001         2000
                                                ----------   ----------
<S>                                             <C>          <C>
Issuance of common stock for acquisition        $   13,907   $       --
Assets acquired in acquisition                         788           --
Liabilities acquired in acquisition                    464           --
Cashless exercise of warrants                           --            2
</TABLE>

6. COMPREHENSIVE INCOME

Comprehensive income is defined as the change in equity during a period from
transactions and other events and circumstances from non-owner sources. The
following table presents the components of the Company's comprehensive loss:

<TABLE>
<CAPTION>
                                                        Three Months Ended
                                                             March 30,
                                                       2001            2000
                                                   ------------    ------------
<S>                                                <C>             <C>
Net loss                                           $    (28,450)   $     (3,384)
Other comprehensive loss:
  Foreign currency translation adjustments                  (44)            (25)
                                                   ------------    ------------

Comprehensive loss                                 $    (28,494)   $     (3,409)
                                                   ============    ============
</TABLE>


                                       9
<PAGE>   10


7. LICENSING AGREEMENTS

In March 2001, ILEX paid $1.1 million to Bioenvision, Inc. and entered into a
definitive agreement to co-develop clofarabine, a nucleoside analog. In clinical
studies, clofarabine has shown promise as a potential new treatment for patients
with hematological malignancies, including acute lymphocytic leukemia (ALL) and
acute myelogenous leukemia (AML), and in preclinical studies, for solid tumors.
ILEX will take the lead role in developing clofarabine in the United States and
Canada, where it will have exclusive manufacturing and marketing rights in
exchange for an in-licensing fee, milestone payments and royalties. Bioenvision
will retain the lead role in developing the compound in Europe and elsewhere,
where it will have exclusive manufacturing and marketing rights and the Company
will have rights to royalties. The Company may be required to make future
license maintenance payments in cash in accordance with the agreement if certain
drug development milestones are met.




                                       10
<PAGE>   11
8. INVESTMENTS IN AND ADVANCES TO JOINT VENTURES

In May 1997, the Company entered into an agreement with LeukoSite, Inc., now
Millennium Pharmaceuticals, Inc. ("Millennium"), for an equally owned joint
venture, Millennium & ILEX Partners, L.P. ("M&I Partners") to develop
Campath(R). The Company accounts for its investment in M&I Partners using the
equity method of accounting. In August 1999, M&I Partners entered into an
agreement which grants Schering AG ("Schering") exclusive marketing and
distribution rights to Campath in the U.S., Europe and the rest of the world
except Japan and East Asia, where ILEX and Millennium have retained rights. The
agreement provides that Schering will advance up to $30 million to M&I Partners
for the rights to Campath and for the achievement of certain regulatory
milestones. Profits from the sale of Campath in the U.S. will be shared equally
among ILEX, Millennium and Schering's U.S. affiliate, Berlex Laboratories, Inc.
For sales made outside the U.S., Schering will make royalty payments
approximately equivalent to the rate of profit sharing in the U.S.

The agreement provides for interest bearing (prime rate plus one percent)
advances to the partnership of up to $30 million in up-front and milestone
payments. M&I Partners has received a total of $20 million of these payments.
The revenues recorded by M&I Partners are based upon the research and
development expenses they incurred which, pursuant to the distribution
agreement, offset the advance balances due Schering. The advance balance is
reduced and revenue is recognized at an amount equal to 110% of the amount of
services rendered by Millennium and ILEX in connection with the development of
Campath for the CLL indication. The Company has recorded product development
revenue related to the research and development fees in the amount of $0.6
million and $1.0 million for the three month periods ended March 31, 2001 and
2000, respectively. In February 2001, ILEX made a capital contribution to M&I
Partners of $3.4 million in cash and development expenses of $1.6 million was
settled as additional capital contributions. The following is summarized
financial information for M&I Partners:

                    Summarized Income Statement Information
                    ---------------------------------------

<TABLE>
<CAPTION>
                                       Three Months Ended
                                           March 31,
                                     2001            2000
                                 ------------    ------------
<S>                              <C>             <C>
Revenue                          $      1,952    $      2,163
Operating expenses                      4,163           1,967
Operating income (loss)                (2,211)            196
Net income (loss)                      (2,322)             79
</TABLE>

                      Summarized Balance Sheet Information
                      ------------------------------------

<TABLE>
<CAPTION>
                                     March 31,     December 31,
                                       2001            2000
                                   ------------    ------------
<S>                                <C>             <C>

Assets                             $      8,710    $      4,755
Liabilities                              18,232          21,855
                                   ------------    ------------
Partners' equity                   $     (9,522)   $    (17,100)
                                   ============    ============
</TABLE>

9. COMMITMENTS AND CONTINGENCIES

On August 16, 2000, Cytokine Pharmasciences Inc. ("CPI"), successor-in-interest
to Cytokine Networks, Inc. ("CNI"), filed a lawsuit against Convergence
Pharmaceuticals, Inc. ("Convergence"), a Delaware corporation and wholly owned
indirect subsidiary of ILEX Oncology, Inc., and Glenn Rice, Ph.D. ("Dr. Rice")
in the Superior Court Department of Trial Court of the Commonwealth of
Massachusetts. The suit alleges that Convergence's predecessor which was merged
into Convergence, through Dr. Rice, used intellectual property of CNI and
requests unspecified damages and a permanent injunction against Dr. Rice and
Convergence from using or disclosing any intellectual property developed in
whole or in part by Dr. Rice while he was employed by CNI. The Company believes
there are meritorious defenses to the claims and intends to defend against the
lawsuit vigorously. In addition, the Company believes that the Company and
Convergence are entitled to indemnification for damages from certain
stockholders of Convergence, costs and expenses arising out of this lawsuit up
to $10.0 million under the agreement relating to the acquisition of Convergence.
This case is still in the pre-trial discovery stage.




                                       11
<PAGE>   12


10. SEGMENT REPORTING

The Company has two reportable segments: ILEX Products, Inc. ("ILEX Products")
and ILEX Oncology Services, Inc. ("ILEX Services"). ILEX Products develops
proprietary compounds for the treatment and prevention of cancer. ILEX Services
provides contract research services for the development, manufacturing, and
regulatory approval of oncology compounds. The Company's reportable segments are
strategic business units that are managed separately, as each business requires
different technology and marketing strategies. The Company evaluates performance
based on the profit or loss from operations before income taxes.

                          Selected Segment Information
                          ----------------------------

<TABLE>
<CAPTION>
                                                  Three Months Ended March 31, 2001
                                             --------------------------------------------
                                               Services        Products         Total
                                             ------------    ------------    ------------
<S>                                          <C>             <C>             <C>
Revenue from external customers              $      5,628    $        680    $      6,308
Intersegment revenue                                  406              --             406
                                             ------------    ------------    ------------

    Total revenue                                   6,034             680           6,714

Direct costs                                        4,971           7,524          12,495
Licensing costs                                        --           1,286           1,286

In-process research and development                    --          21,112          21,112
                                             ------------    ------------    ------------


Segment operating income (loss)                     1,063         (29,242)        (28,179)

Equity in losses of joint venture                      --          (1,161)         (1,161)
                                             ------------    ------------    ------------


Segment net income (loss)                    $      1,063    $    (30,403)   $    (29,340)
                                             ============    ============    ============

Segment assets                               $     12,520    $      5,229    $     17,749
Corporate assets                                                                  315,646
Elimination of intersegment balances                                             (134,629)
                                                                             ------------
Consolidated total assets                                                    $    198,766
                                                                             ============

<CAPTION>

                                                  Three Months Ended March 31, 2001
                                             --------------------------------------------
                                               Services        Products         Total
                                             ------------    ------------    ------------
<S>                                          <C>             <C>             <C>
Revenue from external customers              $      5,576    $      1,038    $      6,614
Intersegment revenue                                2,413              --           2,413
                                             ------------    ------------    ------------

    Total revenue                                   7,989           1,038           9,027

Direct costs                                        6,275           6,557          12,832
Licensing costs                                        --              25              25
                                             ------------    ------------    ------------


Segment operating income (loss)                     1,714          (5,544)         (3,830)

Equity in income of joint venture                      --              39              39
                                             ------------    ------------    ------------

Segment net income (loss)                    $      1,714    $     (5,505)   $     (3,791)
                                             ============    ============    ============

Segment assets                               $     20,307    $        822    $     21,129
Corporate assets                                                                  273,650
Elimination of intersegment balances                                              (64,788)
                                                                             ------------
Consolidated total assets                                                    $    229,991
                                                                             ============
</TABLE>



                                       12
<PAGE>   13


          Reconciliation of Segment Information to Consolidated Totals
          ------------------------------------------------------------

<TABLE>
<CAPTION>
                                                         Three Months Ended
                                                              March 31,
                                                     ----------------------------
                                                         2001            2000
                                                     ------------    ------------
<S>                                                  <C>             <C>

Research and development costs:
   Reportable products segment direct costs          $      7,524    $      6,557
   Elimination of intersegment gross profit                  (103)         (1,243)
                                                     ------------    ------------
Consolidated research and development costs          $      7,421    $      5,314
                                                     ============    ============

Direct costs of research services:
   Reportable services segment direct costs          $      4,971    $      6,275
   Elimination of intersegment expenses                      (303)         (1,170)
                                                     ------------    ------------
Consolidated direct costs of research services       $      4,668    $      5,105
                                                     ============    ============

<CAPTION>

                                                         Three Months Ended
                                                              March 31,
                                                     ----------------------------
                                                         2001            2000
                                                     ------------    ------------
<S>                                                  <C>             <C>

Operating net loss:
   Reportable segment operating loss                 $    (28,179)   $     (3,830)
   Corporate general and administrative                    (2,330)           (939)
                                                     ------------    ------------
Consolidated operating loss                          $    (30,509)   $     (4,769)
                                                     ============    ============

Net loss:
   Reportable segment net loss                       $    (29,340)   $     (3,791)
   Corporate general and administrative                    (2,330)           (939)
   Interest income, net                                     3,220           1,516
   Minority interest in consolidated subsidiary                --             (75)
   Provision for foreign income taxes                         (95)
                                                     ------------    ------------

Consolidated net loss                                $    (28,450)   $     (3,384)
                                                     ============    ============
</TABLE>

11. SUBSEQUENT EVENTS

On May 7, 2001, the U.S. Food and Drug Administration ("FDA") cleared Campath
(alemtuzumab) humanized monoclonal antibody for marketing as a treatment for
patients with B-cell chronic lymphocytic leukemia (B-CLL) who have been treated
with alkylating agents and have failed fludarabine therapy. With this decision,
Berlex Laboratories, Inc., the marketing and distribution partner for M&I
Partners, will provide patients with refractory B-CLL a new treatment option.
Campath therapy for B-CLL was developed by M&I Partners, an equally owned joint
venture of Millennium and ILEX.




                                       13
<PAGE>   14


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

         The following discussion is included to describe the Company's
financial position and results of operations for the three month period ended
March 31, 2001. The Consolidated Financial Statements and notes thereto contain
detailed information that should be referred to in conjunction with this
discussion.

GENERAL

         ILEX Oncology, Inc. (the "Company" or "ILEX") is building a leading
oncology-focused pharmaceutical company by assembling and developing a portfolio
of novel treatments both for advanced stage cancers and for early stage cancers
and premalignant conditions. We have a portfolio of eight anticancer product
candidates in clinical development and several preclinical stage product
candidates. We built this portfolio primarily through in-licensing and
acquisition. In addition to our clinical development programs, ILEX is
conducting drug discovery research, translational research, and preclinical
studies in the fields of angiogenesis inhibition and targeted medicinal
phosphonate chemistry, laying the groundwork for bringing proprietary product
candidates into our pipeline.

         We have historically operated through two subsidiaries: ILEX Products,
Inc., through which we develop our own portfolio of anticancer compounds, and
ILEX Oncology Services, Inc. ("ILEX Services"), which is our full service
contract research organization ("CRO"). We operated ILEX Services to build our
expertise in the area of managing preclinical research and clinical trials. In
February 2001, we announced our intent to focus our in-house drug development
capabilities on our own proprietary products, including those being jointly
developed with strategic partners. As we progress into an oncology-focused
pharmaceutical company, we will use the ILEX Services development organization
solely for our own product candidates. In the meantime, ILEX will continue to
recognize revenue from current client projects.

         We have incurred losses since inception and had an accumulated deficit
through March 31, 2001 of $144.8 million. Our losses have resulted primarily
from product development activities, including in-licensing of products for
which we incur in-process research and development fees, and related
administrative expenses. We expect to continue to incur operating losses for at
least the next year. To date we have not generated any revenue from the sale of
our drug candidates. Our revenue for the foreseeable future will be limited to
product development funding under our collaborative relationships, interest
income, and other miscellaneous income. Our portion of the profit or loss
generated by the sale of Campath(R) will be reflected in our consolidated
statements of operations as equity in income (losses) of joint venture.

         We are developing Campath in partnership with Millennium
Pharmaceuticals, Inc. ("Millennium") through our equally owned joint venture,
Millennium & ILEX Partners, L.P. ("M&I Partners"). In August 1999, M&I Partners
entered into an agreement, which grants Schering AG exclusive marketing and
distribution rights to Campath in the U.S., Europe and the rest of the world
except Japan and East Asia, where ILEX and Millennium have retained rights.
Profits from the sale of Campath in the U.S. will be shared equally among ILEX,
Millennium and Berlex Laboratories, Inc. ("Berlex"), the U.S. affiliate of
Schering. For sales made outside the U.S., Schering will make royalty payments
approximately equivalent to the rate of profit sharing in the U.S. Drug product
sales, net of related expenses, for Campath will be recorded as revenue by M&I
Partners. We have historically accounted for Campath development activities as
follows:

o   our operating revenue includes product development revenue we receive from
    M&I Partners;

o   our research and development expenses include all of the development costs
    for Campath, which are largely offset by M&I Partners' revenue we receive;
    and

o   our actual share of Campath development costs is reported as equity in
    income (losses) of joint venture.

         On May 7, 2001, we received notification from the U.S. Food and Drug
Administration ("FDA") clearing Campath (alemtuzumab) as a treatment for
patients with B-cell chronic lymphocytic leukemia ("B-CLL") who have been
treated with alkylating agents and have failed fludarabine therapy. With this
decision, Berlex will market and distribute Campath in the U.S. and provide
patients with refractory B-CLL a new treatment option.

         Additionally, the European Agency for the Evaluation of Medicinal
Products ("EMEA") Committee on Proprietary Medicinal Products ("CPMP") issued a
positive opinion in March 2001 to recommend approval under


                                       14
<PAGE>   15


exceptional circumstances of MabCampath(TM), the trademark for Campath in
Europe. The Marketing Authorization Application for Campath was accepted for
review in April 2000 by the EMEA. The application, which was submitted in late
March of 2000, was reviewed under the EMEA's centralized procedure, required for
biotechnology products. We anticipate that the European Commission will ratify
the opinion and will issue a Marketing Authorization in mid-2001. Under this
authorization, M&I Partners would be granted a single license for marketing
MabCampath in the 15 member states of the European Union and would receive
national licenses in two additional countries, Iceland and Norway.

         In March 2001, ILEX entered a definitive agreement to co-develop
clofarabine, a nucleoside analog, with Bioenvision Inc. We paid $1.1 million
upon execution of the agreement and may be required to make future payments in
accordance with the agreement if certain drug development milestones are met. In
clinical studies, clofarabine has shown promise as a potential new treatment for
patients with hematological malignancies, including acute lymphocytic leukemia
(ALL) and acute myelogenous leukemia (AML), and in preclinical studies, for
solid tumors. ILEX will take the lead role in developing clofarabine in the U.S.
and Canada, and will have exclusive manufacturing and marketing rights in
exchange for an in-licensing fee, milestone payments and royalties. Bioenvision
will retain the lead role in developing the compound in Europe and elsewhere,
and will have exclusive manufacturing and marketing rights and ILEX will have
rights to royalties.


         In February 2001, the Company acquired Symphar S.A., whose research
platform in targeted medicinal chemistry and nuclear receptor biology has led to
drug candidates in several therapeutic fields, including bone disease, an
important complement to our oncology pipeline. The Symphar acquisition, combined
with our preclinical angiogenesis inhibition program in Boston, gives the
Company the strong capability to translate early-stage research leads into
clinical drug development programs. Under the terms of the agreement, we
acquired Symphar for approximately $29 million, including $15 million in cash
and 521,121 shares of our common stock. Symphar owns certain intangible assets
including intellectual property in the area of targeted medicinal phosphonate
chemistry. In connection with the purchase price allocation, $21.1 million was
expensed as a charge for the purchase of in-process research and development. Of
the $15 million paid in cash, the Company has placed in escrow $4.5 million to
provide indemnification against future claims. This amount will be released in
equal installments of $1.5 million every six months following closing for a
period of 18 months provided no claims have arisen. The Company has also placed
in escrow $5.0 million of the purchase price to be released in the event a
commitment is reached with a third party within one year of closing to provide
funding for a period of at least one year for non-oncology indications. Upon the
execution of the agreement with a third party, the Company would recognize
in-process research and development expense. The $5.0 million escrow balance is
included in restricted investments as a current asset. Additionally, the Company
has recorded an intangible asset in the amount of $300,000 related to workforce
that will be amortized over three years.


         Our CRO business generates revenue by performing services for companies
within the pharmaceutical and biotechnology industries. The terms of our
contracts vary, ranging from several months to five years, or completion of the
project, and generally may be terminated upon notice of 60 to 90 days by our
customers. We recognize revenue with respect to our services either on a
percentage-of-completion or fee-for-service basis as work is performed. The CRO
business performs all of the development services for ILEX Products; however,
our consolidated CRO revenue does not include any amounts related to the
services provided to ILEX Products.


RESULTS OF OPERATIONS - THREE MONTHS ENDED MARCH 31, 2001 AND 2000

OPERATING REVENUES

         Total revenue decreased to $6.3 million in the first quarter of 2001,
from $6.6 million in the first quarter of 2000. The decrease of $0.3 million, or
4.5%, was due to a decrease in product development revenues related to work
performed for the Campath joint venture. CRO revenue of $5.6 million for the
first quarter of 2001 remained relatively unchanged compared with the same
quarter in 2000.

OPERATING EXPENSES

         Total Operating Expenses. Total operating expenses increased to $15.7
million in the first quarter of 2001, excluding in-process research and
development expenses totaling $21.1 million, from $11.4 million in 2000. This
increase of $4.3 million, or 38%, is primarily due to an increase in research
and development costs and licensing



                                       15
<PAGE>   16


costs, largely due to the $1.1 million paid to Bioenvision for the right to
co-develop clofarabine, as well as additional resources being directed toward
the development of our proprietary product candidates. ILEX believes that
research and development costs will continue to increase in future periods as
the Company evaluates in-licensing opportunities, and expands its preclinical
research and clinical trials associated with developing existing compounds.








                                       16
<PAGE>   17


         Research and Development Costs. Research and development costs
increased to $7.4 million in the first quarter of 2001, from $5.3 million in
2000. This increase of $2.1 million, or 40%, was due to increased development
spending on the Company's product pipeline, particularly for DFMO, Elinafide and
OXYPRIMTM. Additionally, research and development expense increased due to the
acquisition of Symphar and the addition of our drug discovery research offices
in Geneva, Switzerland.

         Licensing Costs. Licensing costs increased to $1.3 million in the first
quarter of 2001, from $25,000 in 2000. This increase of $1.3 million was due an
agreement to co-develop clofarabine, a nucleoside analog, with Bioenvision Inc.
We paid $1.1 million upon execution of the agreement and may be required to make
future payments in accordance with the agreement if certain drug development
milestones are met.

         Direct Cost of Research Services. Direct cost of research services
expense decreased to $4.7 million during the first quarter of 2001, from $5.1
million in 2000. This decrease of $0.4 million, or 8%, is attributable to the
Company's transition out of the fee-for service business. We are no longer
incurring business development expenses related to the CRO business, with those
internal resources allocated to the development of our own product candidates.
As such, our CRO operating margin has increased to 16 percent in the first
quarter of 2001, as compared to nine percent for the same quarter a year ago.

         General and Administrative Costs. General and administrative costs
increased to $2.3 million for the first quarter of 2001, compared to $0.9
million for the same quarter in 2000. This increase of $1.4 million, or 156%, as
previously mentioned is due in part to the transition out of the CRO business,
and the corresponding transition of existing internal resources to focus on new
business opportunities, build strategic relationships and develop our
proprietary products. The costs associated with these management and business
development activities were previously included in direct costs of research
services and are now reflected in general and administrative expense.

OPERATING LOSS

         Excluding in-process research and development expense of $21.1 million
incurred in the prior year, loss from operations increased to $9.4 million in
the first quarter of 2001, from $4.8 million in 2000. This increase of $4.6
million, or 96%, is due to an increase in research and development costs and
licensing costs, as well as an increase in general and administrative expense,
partially offset by the improved profitability of the Company's CRO business.

EQUITY IN LOSSES OF JOINT VENTURE

         Equity in losses of joint venture was $1.2 million for the first
quarter of 2001, compared to approximately break even in 2000, an increase of
$1.2 million, or 100%. The loss for the first quarter of 2001 is primarily
attributable to pre-commercialization marketing and selling expenses incurred by
the Campath joint venture. Break even results for the first quarter of 2000 was
attributable to advances made to the partnership from Schering, which were
partially offset by development expenses, as required by a distribution and
development agreement.

NET INTEREST INCOME

         Net interest income increased to $3.2 million for the quarter ended
March 31, 2001, from $1.5 million for the same period a year ago. This increase
of $1.7 million, or 113%, is attributable to an increase in average cash and
investment balances during the first quarter of 2001, compared to the same
period a year ago, primarily as a result of proceeds received from a private
placement in late March 2000.

NET LOSS

         Net loss increased $25.1 million in the first quarter of 2001, or 738%,
to $28.5 million, from $3.4 million in 2000. Net loss per share increased $0.94
per share to $1.09 per share in 2001, from $0.15 per share in 2000. Excluding
in-process research and development expense, net loss increased $4.0 million, or
118%, to $7.4 million in the first quarter of 2001, from $3.4 million for the
same period in 2000, and net loss per share increased $0.13 per share to $0.28
per share, from $0.15 per share in 2000.



                                       17
<PAGE>   18


LIQUIDITY AND CAPITAL RESOURCES

         ILEX has historically financed its operations primarily through the
sale of its capital stock, through development and licensing fee revenues
provided by its collaborative partners and through fee-for-service or
participatory revenues pursuant to contracts with its CRO clients.

         At March 31, 2001, we had cash, cash equivalents, restricted
investments and investments in marketable securities of $181.1 million and
working capital of $161.7 million. Cash, cash equivalents, restricted
investments and investments in marketable securities decreased $21.7 million
compared to December 31, 2000, primarily due to acquisition costs, drug
licensing costs, and a capital contribution to the Campath joint venture
primarily, as well as general operating requirements, including capital
purchases. Our cash requirements are expected to continue to increase each year
as we expand our activities and operations.


         In February 2001, we acquired Symphar for approximately $29 million,
including $15 million in cash and 521,121 shares of our common stock. The
acquisition agreement specifies that, subject to the viability of performance,
we agree to fund a minimum operating and capital budget between $4 to $5 million
annually for each of the next three years. Of the $15 million paid in cash, the
Company has placed in escrow $4.5 million to provide indemnification against
future claims. This amount will be released in equal installments of $1.5
million every six months following closing for a period of 18 months provided no
claims have arisen. The Company has also placed in escrow $5.0 million of the
purchase price to be released in the event a commitment is reached with a third
party within one year of closing to provide funding for a period of at least one
year for non-oncology indications. Upon the execution of the agreement with a
third party, the Company would recognize in-process research and development
expense. The $5.0 million escrow balance is included in restricted investments
as a current asset.


         Our cash requirements are expected to continue to increase each year as
we expand our activities and operations. We may never generate significant
product revenue or achieve or sustain profitability. We expect our current funds
will be adequate to cover all of our obligations for at least the next year.
Until our business can generate sufficient levels of cash from product sales, we
expect to continue to finance our operations through existing cash, revenue from
collaborative relationships, and proceeds from the sale of equity securities.

         In connection with research and development efforts, the Company has
entered into agreements with certain development partners, which generally
expire over several years. The terms of these agreements require the Company to
make payments in either cash or stock if certain drug development or time based
milestones are met. Total future commitments under these agreements are
approximately $20.4 million through the year 2005.

         We plan to continue our policy of investing available funds in
government securities and investment-grade, interest-bearing securities,
primarily with maturities of one year or less. We do not invest in derivative
financial instruments, as defined by Statement of Financial Accounting Standards
No. 119.

         ILEX's future expenditures and capital requirements will depend on
numerous factors, including but not limited to, the progress of its research and
development programs, the progress of its preclinical and clinical testing, the
magnitude and scope of these activities, the time and costs involved in
obtaining regulatory approvals, the cost of filing, prosecuting, defending and
enforcing any patent claims and other intellectual property rights, competing
technological and market developments, changes in or termination of existing
collaborative arrangements, the ability of the Company to establish, maintain
and avoid termination of collaborative arrangements and the purchase of capital
equipment and acquisitions of compounds, technologies or businesses. As of March
31, 2001, the Company did not have any material commitments for capital
expenditures. The Company may never be able to generate product revenue or
achieve or sustain profitability. The Company expects its cash, cash
equivalents, and marketable securities will be adequate to cover all of its
obligations for the next year.

FORWARD-LOOKING STATEMENTS - CAUTIONARY STATEMENTS

         This Quarterly Report on Form 10-Q contains certain forward-looking
statements as such term is defined in the Private Securities Litigation Reform
Act of 1995 and information relating to the Company and its subsidiaries that
are based on the beliefs of the Company's management as well as assumptions made
by and information currently available to the Company's management. When used in
this report, the words anticipate, believe, estimate, expect and intend and
words or phrases of similar import, as they relate to the Company or its
subsidiaries or Company management, are intended to identify forward-looking
statements. Such statements reflect the current risks, uncertainties and
assumptions related to certain factors including, without limitations, risks
associated with preclinical and clinical developments in the biopharmaceutical
industry in general and in ILEX's compounds under development in particular; the
potential failure of the Company's compounds under development to prove safe and
effective for treatment of disease; uncertainties inherent in the early stage of
the Company's compounds under development; market acceptance of Campath; failure
to successfully implement or complete clinical trials; failure to



                                       18
<PAGE>   19


receive marketing clearance from regulatory agencies for our compounds under
development; management's ability to implement strategic initiatives; the
ability of the Company to predict its future expenses and capital needs; risks
related to the outcome of litigation filed against the Company; the development
of competing products; the ability of the Company to combine its disparate
research capabilities and translate them into clinical drug development
programs; uncertainties related to the Company's dependence on and relationships
with third parties and partners; unanticipated decrease in the demand for the
Company's fee-for-service contract research business; general economic and
market conditions; risks inherent in the biopharmaceutical industry; stock price
volatility; variability of license, royalty and other revenue; market acceptance
of Campath; risks related to the outcome of litigation filed against us;
uncertainties related to protection of our intellectual property; rapid
technological change could render our technologies obsolete; one-time events and
those risks described herein, in the Company's Form S-3 filed March 8, 2000
(Commission file #333-32000) and in other filings made by the Company with the
SEC. Based upon changing conditions, should any one or more of these risks or
uncertainties materialize, or should any underlying assumptions prove incorrect,
actual results may vary materially from those described herein as anticipated,
believed, estimated, expected or intended. The Company does not intend to update
these forward-looking statements.





                                       19
<PAGE>   20


PART II. OTHER INFORMATION



ITEM 6. EXHIBITS AND REPORTS ON FORM 8-K

         (a)  Exhibits

              Exhibit
              Number
              3.1*         Amended and Restated Certificate of Incorporation of
                           the Company

              4.1          Rights Agreement dated April 10, 2001 by and between
                           ILEX Oncology, Inc. and American Stock Transfer &
                           Trust Co. which includes as Exhibit A the Form of
                           Certificate of Designations of Series I Preferred
                           Stock, as Exhibit B the Form of Rights Certificate
                           and as Exhibit C the Summary of Rights to Purchase
                           Common Stock. (Incorporated herein by reference to
                           Exhibit 4.1 to the Company's Form 8-K filed April 11,
                           2001)

              10.1+        Supply Agreement dated as of June 4, 1999 between
                           Millennium & ILEX Partners, L.P. (formerly L&I
                           Partners, L.P.) and Boehringer Ingelheim Pharma KG.
                           (Incorporated herein by reference to Exhibit 10.25 to
                           the Millennium Pharmaceuticals, Inc. 10-K for the
                           fiscal year ending December 31, 1999)

              10.2+        License Agreement, dated May 2, 1997, between
                           Millennium & ILEX Partners, L.P. (formerly L&I
                           Partners, L.P.) and Millennium Pharmaceuticals, Inc
                           (as successor to LeukoSite, Inc.). Incorporated by
                           reference to Exhibit 10.17(b) to LeukoSite, Inc.'s
                           Registration Statement on Form S-1 (No. 333-30213)
                           filed June 27, 1997)

              10.3         First Amended and Restated Agreement of Limited
                           Partnership of Millennium & ILEX Partners L.P.
                           (formerly L&I Partners, L.P.) (Incorporated herein by
                           reference to Exhibit 10.26 to the Millennium
                           Pharmaceuticals, Inc. 10-K for the fiscal year ending
                           December 31, 2000).

              11.1*        Computation of Net Loss Per Share

         (b)  Reports on Form 8-K:
              The Company has recently filed the following Form 8-K's:

                           Dated April 27, 2001, to disclose that the pro forma
                           financial information of Symphar S.A. is not required
                           based on the level of significance.

                           Dated April 11, 2001, to disclose the adoption of a
                           shareholder rights plan.

                           Dated February 28, 2001, to disclose the acquisition
                           of Symphar, S.A., a drug discovery firm located in
                           Geneva, Switzerland.

                           Dated February 14, 2001, to file a press release
                           announcing its 2000 fourth quarter and year end
                           results of operations.

                           Dated February 13, 2001, to file a press release
                           announcing its acquisition of Symphar S.A.


*        Previously filed.


+        Confidential treatment has been granted with respect to certain
         portions of this exhibit. Omitted portions have been filed separately
         with the Securities and Exchange Commission.





                                       20
<PAGE>   21



                                   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 June 27, 2001.


                                     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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