<PAGE>   1
                                 UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549


                                   FORM 10-Q


(Mark One)

        [X]  QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES
             EXCHANGE ACT OF 1934 FOR QUARTER ENDED JUNE 30, 2000

                                       OR

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

                        Commission File Number: 1-12574

                        TEXAS BIOTECHNOLOGY CORPORATION
-------------------------------------------------------------------------------
             (Exact name of registrant as specified in its charter)


         Delaware                                       13-3532643
-------------------------------------------------------------------------------
(State or other jurisdiction of            (I.R.S. Employer Identification No.)
incorporation or organization)


7000 Fannin, 20th Floor, Houston, Texas                    77030
-------------------------------------------------------------------------------
(Address of principal executive office)                 (Zip code)


                                 (713) 796-8822
-------------------------------------------------------------------------------
              (Registrant's telephone number, including area code)


                                 Not Applicable
-------------------------------------------------------------------------------
              (Former name, former address and former fiscal year,
                         if changed since last report)


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

Yes  [X]    No  [ ]


Indicate the number of shares outstanding of each of the issuer's classes of
Common Stock, as of the latest practicable date.

            Class                           Outstanding at July 31, 2000
            -----                           ----------------------------

common stock, $0.005 par value                      40,860,126

<PAGE>   2

                        TEXAS BIOTECHNOLOGY CORPORATION

                               TABLE OF CONTENTS

<TABLE>
<CAPTION>
                                                                                     PAGE NO.
PART I.    FINANCIAL INFORMATION                                                     -------
<S>                                                                                  <C>
           ITEM 1:   FINANCIAL STATEMENTS

           Consolidated Balance Sheets as of June 30, 2000 and December 31, 1999        1

           Consolidated Statements of Operations for the three months ended
           June 30, 2000 and 1999 and the six months ended June 30, 2000 and 1999       2

           Consolidated Statements of Cash Flows for the six months ended
           June 30, 2000 and 1999                                                       3

           Notes to Consolidated Financial Statements                                   4

           ITEM 2:   MANAGEMENT'S DISCUSSION AND ANALYSIS OF
                     FINANCIAL CONDITION AND RESULTS OF OPERATIONS                     10

           ITEM 3:   QUANTITATIVE AND QUALITATIVE DISCLOSURES                          14
                     ABOUT MARKET RISK


PART II.   OTHER INFORMATION

           ITEM 1:  Legal Proceedings                                                  15

           ITEM 2:  Changes in Securities                                              15

           ITEM 3:  Defaults Upon Senior Securities                                    15

           ITEM 4:  Submission of Matters to a Vote of Security Holders                16

           ITEM 5:  Other Information                                                  16

           ITEM 6:  Exhibits and Reports on Form 8-K                                   17


SIGNATURES                                                                             18


INDEX TO EXHIBITS                                                                      19
</TABLE>


<PAGE>   3
                TEXAS BIOTECHNOLOGY CORPORATION AND SUBSIDIARY

                          CONSOLIDATED BALANCE SHEETS


ASSETS
------
                                                     JUNE 30,     DECEMBER 31,
                                                      2000           1999
                                                   -----------    ----------
                                                   (Unaudited)

Current assets:

   Cash and cash equivalents                       $ 24,041,853   $  2,804,270
   Short-term investments                            45,497,859     11,366,066
   Other current receivables                         11,600,448      1,067,738
   Receivable from related party under
     collaborative arrangement                        1,086,681             --
   Prepaids                                           1,238,915      1,453,090
                                                   ------------   ------------
      Total current assets                           83,465,756     16,691,164

Long-term investments                                 8,000,000      1,000,000

Equipment and leasehold improvements, at
  cost less accumulated depreciation and
  amortization                                        2,567,725      2,998,431

Investment in affiliate, at equity                   (2,498,134)            --

Other assets                                             115,096       115,096
                                                   ------------   ------------
      Total assets                                 $ 91,650,443   $ 20,804,691
                                                   ============   ============

LIABILITIES AND STOCKHOLDERS' EQUITY
------------------------------------

Current liabilities:

   Accounts payable                                $  1,051,849   $    556,664
   Accrued expenses                                   1,698,009      1,657,706
                                                   ------------   ------------
      Total current liabilities                       2,749,858      2,214,370

Commitments and contingencies                                --             --

Stockholders' equity:
   Preferred stock, par value $.005 per
     share. At June 30, 2000, 5,000,000
     shares authorized; none outstanding.
     At December 31, 1999, 5,000,000 shares
     authorized; none outstanding.                           --             --
   Common stock, par value $.005 per share.
     At June 30, 2000, 75,000,000 shares
     authorized; 40,806,822 shares issued
     and outstanding.  At December 31, 1999,
     75,000,000 shares authorized; 34,392,909
     shares issued and outstanding.                     204,034        171,964
   Additional paid-in capital                       187,585,122    118,317,599
   Accumulated deficit                              (98,888,571)   (99,899,242)
                                                   ------------   ------------
      Total stockholders' equity                     88,900,585     18,590,321
                                                   ------------   ------------
      Total liabilities and stockholders' equity   $ 91,650,443   $ 20,804,691
                                                   ============   ============


          See accompanying notes to consolidated financial statements

FORM 10                                                                 Page 1

<PAGE>   4

                TEXAS BIOTECHNOLOGY CORPORATION AND SUBSIDIARY

                     CONSOLIDATED STATEMENTS OF OPERATIONS


<TABLE>
<CAPTION>

                                                   THREE MONTHS ENDED            SIX MONTHS ENDED
                                                         JUNE 30,                    JUNE 30,
                                                   2000          1999           2000         1999
                                                -----------   -----------    -----------   -----------
                                                (unaudited)   (unaudited)    (unaudited)   (unaudited)
<S>                                             <C>           <C>            <C>           <C>
Revenues:

   Research agreement                           $    531,229      495,130       1,053,837    1,030,055
   Collaborative research and development
     from related party                              153,402           --         153,402           --
   License fee and milestone income               10,564,516           --      10,564,516           --
                                                ------------  -----------    ------------  -----------
      Total revenues                              11,249,147      495,130      11,771,755    1,030,055
                                                ------------  -----------    ------------  -----------

Expenses:
   Research and development                        3,408,450    3,056,120       7,190,399    6,214,760
   Charge for purchase of in-process
     research and development                        965,970           --         965,970           --
   General and administrative                      1,437,804    1,597,091       3,368,739    2,936,532
                                                ------------  -----------    ------------  -----------
      Total expense                                5,812,224    4,653,211      11,525,108    9,151,292
                                                ------------  -----------    ------------  -----------

      Operating income (loss)                      5,436,923   (4,158,081)        246,647   (8,121,237)

   Equity in loss of affiliate                      (566,658)          --        (566,658)          --
   Investment income                               1,127,264      302,455       1,330,682      686,774
                                                ------------  -----------    ------------  -----------

      Net income (loss)                         $  5,997,529   (3,855,626)      1,010,671   (7,434,463)
                                                ============  ===========    ============  ===========

Net income (loss) per common share:
   Basic                                        $       0.15        (0.11)           0.03        (0.22)
   Diluted                                      $       0.14        (0.11)           0.02        (0.22)

Weighted average common shares used to
  compute net income (loss) per common share:
  Basic                                           40,033,069   34,216,941      37,322,681   34,192,905
  Diluted                                         43,261,069   34,216,941      40,692,575   34,192,905
</TABLE>


          See accompanying notes to consolidated financial statements

FORM 10-Q                                                              Page 2

<PAGE>   5

                TEXAS BIOTECHNOLOGY CORPORATION AND SUBSIDIARY

                     CONSOLIDATED STATEMENTS OF CASH FLOWS


                                                      SIX MONTHS ENDED
                                                          JUNE 30,
                                                    2000           1999
                                                 -----------    -----------
                                                 (unaudited)    (unaudited)

CASH FLOWS FROM OPERATING ACTIVITIES:
   Net income (loss)                             $  1,010,671   $  (7,434,463)
   Adjustments to reconcile net income
     (loss) to net cash used in operating
     activities:
     Depreciation and amortization                    484,294         416,607
     Equity in loss of affiliate                      566,658              --
     Purchase of in-process R&D                       965,970              --
     Expenses paid with stock and warrants             14,888          11,332
     Loss on disposition of fixed assets                6,500              --
   Change in operating assets and liabilities
     (Increase) decrease in prepaids                  214,175        (982,569)
     (Increase) decrease in receivables           (10,532,710)        116,903
     Increase in receivable from related party
       under collaborative arrangement             (1,086,681)             --
     Increase (decrease) in current liabilities            --        (318,330)
                                                 ------------   -------------
        Net cash used in operating activities      (8,356,235)     (8,190,520)
                                                 ------------   -------------

CASH FLOWS FROM INVESTING ACTIVITIES:
   Purchase of equipment and leasehold
     improvements                                     (60,088)       (236,997)
   Purchase of investments                        (52,110,935)     (7,417,855)
   Maturities of investments                       11,245,034      21,232,712
   (Increase) decrease in interest receivable
     included in short-term investments              (265,892)        264,302
   Equity investment in affiliate, net              1,931,476              --
                                                 ------------   -------------
      Net cash provided by (used in)
        investing activities                      (39,260,405)     13,842,162
                                                 ------------   -------------

CASH FLOWS FROM FINANCING ACTIVITIES:
   Proceeds from sale of common stock and
     exercises of options and warrants, net        68,318,735         207,195
                                                 ------------   -------------
      Net increase in cash and cash equivalents    20,702,095       5,858,837

Cash and cash equivalents at beginning of period    2,804,270       4,176,911
                                                 ------------   -------------

Cash and cash equivalents at end of period       $ 23,506,365   $  10,035,748
                                                 ============   =============
Supplemental disclosure of noncash
  financing activities:
   Expenses and purchase of in-process of
     R&D paid with stock                         $    908,858   $      11,332
                                                 ============   =============


          See accompanying notes to consolidated financial statements

FORM 10-Q                                                               Page 3

<PAGE>   6

                 TEXAS BIOTECHNOLOGY CORPORATION AND SUBSIDIARY

                   NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

                JUNE 30, 2000 (UNAUDITED) AND DECEMBER 31, 1999


(1)    ORGANIZATION AND SIGNIFICANT ACCOUNTING POLICIES

       (a)    Organization

              Texas Biotechnology Corporation (the "Company" or "TBC") is a
              biopharmaceutical company focused on the discovery, development
              and commercialization of novel synthetic small molecule compounds
              for the treatment of a variety of vascular diseases. Since its
              formation in 1989, the Company has been engaged principally in
              research and drug discovery programs and clinical development of
              certain drug compounds. On July 25, 1994, the Company acquired
              all of the outstanding common stock of ImmunoPharmaceutics, Inc.
              ("IPI") in exchange for common stock, par value $.005 per share
              (the "Common Stock"), of the Company. On June 6, 2000 TBC and ICOS
              Corporation ("ICOS") entered into an agreement and formed
              ICOS-Texas Biotechnology, Limited Partnership, a Delaware limited
              partnership ("ICOS-TBC") to develop and globally commercialize
              endothelin-A receptor antagonists. TBC and ICOS are both 50%
              owners in ICOS-TBC.

              The Company is presently working on a number of long-term
              development projects which involve experimental and unproven
              technology, which may require many years and substantial
              expenditures to complete, and which may be unsuccessful. The
              Company anticipates the launch of its first product, argatroban,
              for the treatment of heparin induced thrombocytopenia ("HIT")
              in 2000.

       (b)    Basis of Consolidation

              The Company's consolidated financial statements include the
              accounts of the Company and its wholly owned subsidiaries, IPI
              and TBC-ET, Inc., a Delaware corporation ("TBC-ET"). All material
              intercompany transactions have been eliminated.

       (c)    Cash, Cash Equivalents, Short-Term Investments and Long-Term
              Investments

              Cash equivalents are considered to be those securities or
              instruments with original maturities, when purchased, of three
              months or less. At June 30, 2000, approximately $1,085,000 was
              invested in demand and money market accounts. Short-term
              investments are those investments which have an original maturity
              of less than one year and greater than three months at the
              purchase date. At June 30, 2000, the Company's short-term
              investments consisted of approximately $11,012,000 in Government
              Agency Discount Bonds and $34,485,000 in Corporate Commercial
              Paper and loan participations. Long-term investments consist of
              approximately $8,000,000 in Government Agency Discount Bonds with
              a remaining maturity of one year or more. Cash equivalents,
              short-term and long-term investments are stated at cost plus
              accrued interest, which approximates market value. Interest
              income is accrued as earned. The Company classifies all
              short-term investments and long-term investments as held to
              maturity.

       (d)    Equipment and Leasehold Improvements

              Equipment and leasehold improvements are stated at cost less
              accumulated depreciation and amortization. Depreciation of
              furniture and equipment is provided on the straight-line method
              over the estimated useful lives of the respective assets (3 to 10
              years). Amortization of leasehold improvements is provided on the
              straight-line method over the shorter of the useful life or the
              remaining minimum lease term.

       (e)    Investment in ICOS - TBC

              ICOS - Texas Biotechnology, Limited Partnership ("ICOS-TBC") is
              accounted for using the equity method. Accordingly, the
              investment is recorded at cost, adjusted for the Company's share
              of income or loss of the entity and amortization of revenues for
              upfront and milestone payments. See footnote 8.



       (f)    Research and Development Costs


FORM 10-Q                                                               Page 4

<PAGE>   7

              All research and development costs are expensed as incurred and
              include salaries of research and development employees, certain
              rent and related building services, research supplies and
              services, clinical trial expenses and other associated costs.
              Salaries and benefits for the three months ended June 30, 2000
              and 1999 were approximately $1,658,000 and $1,663,000,
              respectively, of which approximately $1,246,000 and $1,277,000,
              respectively, was charged to research and development. Salaries
              and benefits for the six months ended June 30, 2000 and 1999,
              were approximately $3,435,000 and $3,328,000, respectively, of
              which approximately $2,606,000 and $2,555,000, respectively, was
              charged to research and development. Payments related to the
              acquisition of in-process research and development are expensed.

       (g)    Net Income (Loss) Per Common Share

              Basic net income (loss) per common share is calculated by
              dividing the net income (loss) by the weighted average number of
              common shares outstanding during the period. For the three and
              six months ended June 30, 1999, there were no common dilutive
              shares used in the calculation of weighted average common shares
              outstanding. For the three months ended June 30, 2000 and 1999,
              the weighted average common shares used to compute basic net
              income (loss) per common share totaled 40,033,069 and 34,216,941,
              respectively. For the six months ended June 30, 2000 and 1999,
              the weighted average common shares used to compute basic net
              income (loss) per common share totaled 37,322,681 and 34,192,905,
              respectively. The exercise of stock options and warrants were not
              assumed in the calculation of diluted net loss per common share
              for the three and six months ended June 30, 1999 because the
              effect would have been antidilutive. Diluted net income per
              common share is calculated by dividing the net income by the
              weighted average number of common shares outstanding during the
              period, including dilutive securities. For the three and six
              months ended June 30, 2000, the weighted average common shares
              used to compute diluted net income per common share totaled
              43,261,069 and 40,692,575 respectively, and included the exercise
              of 1,475,575 dilutive stock options and 1,752,425 dilutive
              warrants. The following securities were not considered in the
              computation of diluted net income per share because the effect
              would have been antidilutive.

                                      THREE MONTHS ENDED    SIX MONTHS ENDED
                                         JUNE 30, 2000        JUNE 30, 2000
                                      ------------------    ----------------

                   Stock Options            358,666             230,605
                   Stock Warrants           142,858             142,858

       (h)    Reclassifications

              Certain reclassifications have been made to prior period
              financial statements to conform with the June 30, 2000
              presentation with no effect on net loss previously reported.

       (i)    Revenue Recognition

              Revenue from research agreements is recognized as the services
              are performed and/or milestones are met. Milestone payments
              related to contractual agreements are recognized as the
              milestones are achieved. Revenue from licensing fees is recorded
              when the license is granted subject to section (m) of this
              footnote (1) regarding accounting pronouncements dealing with
              revenue recognition.

       (j)    Patent Application Costs

              Costs incurred in filing for patents are expensed as incurred.

       (k)    Use of Estimates

              Management of the Company has made a number of estimates and
              assumptions relating to the reporting of assets and liabilities
              and the disclosure of contingent assets and liabilities and the
              reported amounts of revenues and expenses to prepare these
              consolidated financial statements in conformity with generally
              accepted accounting principles. Actual results could differ from
              these estimates.


FORM 10-Q                                                               Page 5

<PAGE>   8

       (l)    Interim Financial Information

              The Consolidated Balance Sheet as of June 30, 2000, and the
              related Consolidated Statement of Operations for the three and
              six months ended June 30, 2000 and 1999 and Consolidated
              Statements of Cash Flows for the six months ended June 30, 2000
              and 1999 are unaudited. In the opinion of management, all
              adjustments necessary for a fair presentation of such financial
              statements have been included. Such adjustments consisted of
              normal recurring items. Interim results are not necessarily
              indicative of results for a full year. The consolidated financial
              statements and notes are presented as permitted by Form 10-Q and
              do not contain certain information included in the Company's
              Annual Consolidated Financial Statements and Notes which should
              be read in conjunction with these consolidated financial
              statements and notes.

       (m)    New Accounting Bulletins

              In December 1999, the United States Securities and Exchange
              Commission ("SEC") issued Staff Accounting Bulletin No. 101
              ("SAB101"), Revenue Recognition in Financial Statements. SAB101
              summarizes certain of the staff's views in applying generally
              accepted accounting principles to revenue recognition in
              financial statements. The Company will be required to implement
              SAB101 in the fourth quarter of the year ended December 31, 2000.
              The Company has not yet determined the impact, if any, that
              SAB101 will have on its financial statements.

              In March 2000, the Financial Accounting Standards Board issued
              FASB Interpretation No. 44 ("FIN44"), Accounting for Certain
              Transactions involving Stock Compensation. The provisions of
              FIN44 that are applicable to the Company were effective July 1,
              2000. The Company has not yet determined the impact, if any, that
              FIN44 will have on its financial statements.

              In June 1998, the Financial Accounting Standards Board issued
              FASB Statement No. 133 ("SFAS 133"), Accounting for Derivative
              Instruments and Hedging Activities, as amended by SFAS No. 137
              and SFAS No. 138. SFAS 133 standardizes the accounting for
              derivative instruments, including certain derivative instruments
              embedded in other contracts. Under the standard, entities are
              required to carry all derivative instruments in the statement of
              financial position at fair value. We will adopt SFAS 133
              beginning in fiscal year 2001. We do not expect the adoption of
              SFAS 133 will have a material effect on our financial condition
              or results of operation because we historically have not entered
              into derivative or other financial instruments for trading or
              speculative purposes nor do we use or intend to use derivative
              financial instruments or derivative commodity instruments.

(2)    CAPITAL STOCK

       In April 2000, the Company sold 5,750,000 shares of Common Stock for
       $12.50 per share in an underwritten public offering. The net proceeds to
       the Company from this offering were approximately $65.2 million after
       deducting selling commissions and expenses of approximately $4.6 million
       related to the offering and approximately $2.1 million in proceeds
       allocable to selling shareholders.


FORM 10-Q                                                               Page 6

<PAGE>   9

(3)    STOCK OPTIONS AND WARRANTS

       The Company applies Accounting Principles Board Opinion No. 25,
       Accounting for Stock Issued to Employees and related interpretations in
       accounting for its plans and applies Financial Accounting Standards
       Board Statement No. 123, Accounting for Stock-Based Compensation and
       related interpretations in reporting for its plans.

       A summary of stock options as of June 30, 2000, follows:

<TABLE>
<CAPTION>
                            Exercise Price                                       Exercised                     Available
       Stock Option Plans      Per Share       Authorized      Outstanding       /Other       Exercisable     for Grant
       ------------------   --------------     ----------      -----------      ---------     -----------     ---------
<S>                         <C>                <C>             <C>              <C>           <C>            <C>
       1990 Plan             $1.38 - $21.59        285,715        190,495          95,220       139,496            ---

       1992 Plan             $1.41 - $21.59      1,700,000        948,601         702,832       717,071         48,567

       1995 Plan             $1.31 - $8.13       2,000,000      1,585,745         228,807     1,249,829        185,448

       1999 Plan            $20.13 - $20.13      1,000,000        181,000             ---           ---        819,000

       Director Plan         $3.50 - $4.54          71,429         34,242          37,187        34,242            ---

       1995 Director Plan    $1.38 - $11.31        500,000        259,096          36,427       175,096        204,477

                                               -----------      ---------       ---------     ---------      ---------
                    TOTALS                       5,557,144      3,199,179       1,100,473     2,315,734      1,257,492
                                               ===========      =========       =========     =========      =========
</TABLE>

       As of March 6, 2000, the Compensation and Personnel Committee of the
       Board of Directors approved an increase in the number of shares
       authorized of 200,000 shares in the Amended and Restated 1995
       Non-Employee Director Stock Option Plan which was approved by
       stockholders at the annual meeting on June 8, 2000 and are included
       above.

 (4)   INCOME TAXES

       The Company uses the asset and liability method of accounting for income
       taxes. Under the asset and liability method, deferred tax assets and
       liabilities are recognized for the future tax consequences attributable
       to differences between the financial statement carrying amounts of
       existing assets and liabilities and their respective tax bases and
       operating loss and tax credit carryforwards. Deferred tax assets and
       liabilities are measured using enacted tax rates expected to apply to
       taxable income in the years in which those temporary differences are
       expected to be recovered or settled. The effect on deferred tax assets
       and liabilities of a change in tax rates is recognized in income in the
       period that includes the enactment date.

       At June 30, 2000 the net deferred tax asset, representing primarily net
       operating loss carryforwards, totaled approximately $36,072,000. The
       Company has established a valuation allowance for the full amount of
       these deferred tax assets, as management believes that it is not more
       likely than not that the Company will recover these assets. The Company
       did not incur any tax expense in any year due to operating losses.

       At June 30, 2000 the Company had net operating loss carryforwards of
       approximately $63,255,000 for federal income tax return purposes.
       Utilization of the Company's net operating loss carryforwards is subject
       to certain limitations due to specific stock ownership changes which
       have occurred or may occur. To the extent not utilized, the
       carryforwards will expire during the years beginning 2002 through 2019.


FORM 10-Q                                                               Page 7

<PAGE>   10

(5)    EQUIPMENT AND LEASEHOLD IMPROVEMENTS

       Equipment and leasehold improvements consist of the following:


                                              June 30, 2000   December 31, 1999
                                              -------------   -----------------
       Laboratory and office equipment        $ 5,760,621       $ 5,760,113
       Leasehold improvements                   3,974,942         3,974,942
                                                ---------         ---------
                                                9,735,563         9,735,055
       Less accumulated depreciation and
        amortization                          (7,167,838)       (6,736,624)
                                              ------------      -----------
                                              $ 2,567,725       $ 2,998,431
                                              ===========       ===========

(6)    COMMON STOCK RESERVED

       The Company has reserved Common Stock for issuance as of June 30, 2000
as follows:

              Stock option plans                                  4,456,671
              Publicly traded warrants outstanding                3,882,092
              Other warrants outstanding                            634,063
                                                                  ---------
                   Total shares reserved                          8,972,826
                                                                  =========

(7)    REGULATORY FILING

       On June 30, 2000, the Company received final approval from the FDA for
       argatroban as an anticoagulant for prevention or treatment of thrombosis
       in patients with heparin-induced thrombocytopenia ("HIT").

(8)    LICENSE AGREEMENTS

       Pursuant to the terms of the limited partnership agreement for ICOS-TBC,
       TBC and ICOS will equally fund the cost of research and development of
       sitaxsentan and second-generation endothelin antagonist compounds,
       commercialize resulting products, and share equally in the profits from
       this worldwide collaboration. ICOS will make upfront and milestone
       payments to TBC that could be as much as $55.5 million for the
       development and commercialization of products resulting from the
       collaboration. The immediate focus of the ICOS-TBC partnership will be to
       initiate a Phase IIb/III pulmonary hypertension clinical trial for
       sitaxsentan, continue clinical development for sitaxsentan in chronic
       heart failure, and explore applications for second-generation endothelin
       antagonists including TBC3711.

       Pursuant to the terms of the limited partnership agreement, ICOS-TBC has
       been initially capitalized by a cash contribution from ICOS and the
       Company's contribution of intellectual property associated with
       sitaxsentan sodium. The intellectual property contributed to ICOS-TBC had
       no basis for financial reporting purposes and, accordingly, the Company
       has recorded the transfer of this technology to ICOS-TBC at zero. The
       Company received a license fee from ICOS-TBC upon transfer of this
       technology and conducts research and development activities on behalf of
       ICOS-TBC and is paid for such services based upon costs incurred. The
       Company has deferred full recognition of the license fee and has recorded
       approximately $567,000 of expenses representing its proportionate share
       of ICOS-TBC's net losses. Also, the Company recorded approximately $1.1
       million for cost reimbursements during June 2000 related to the research
       and development activities provided to ICOS-TBC of which approximately
       $153,000 was recognized as revenue. The license fee and any future
       milestones paid to the Company will be amortized over the anticipated
       development period. Pursuant to the partnership agreement, TBC assigned
       one-half of the remaining payments under the agreement with LG Chemical
       to the partnership.

       On June 30, 2000, TBC and Schering-Plough Corporation
       ("Schering-Plough") entered into a worldwide research collaboration and
       license agreement to discover, develop and commercialize VLA-4
       antagonists. VLA-4 antagonists represent a new class of compounds that
       has shown promise in multiple preclinical animal models of asthma. The
       primary focus of the collaboration will be to discover orally available
       VLA-4 antagonists as treatments for asthma.

       Under the terms of the agreement, Schering-Plough obtains the exclusive
       worldwide rights to develop, manufacture and market all compounds from
       TBC's library of VLA-4 antagonists, as well as the rights to a second
       integrin antagonist. TBC will be responsible for optimizing a lead
       compound and additional follow-on compounds. Schering-Plough will


FORM 10-Q                                                               Page 8

<PAGE>   11
       support research at TBC and will be responsible for all costs associated
       with the worldwide product development program and commercialization of
       the compound. In addition to research costs, Schering-Plough will pay an
       upfront license fee, development milestones and royalties on product
       sales resulting from the agreement. Total payments to TBC for both
       programs, excluding royalties, could reach $87.0 million.

       On June 30, 2000, TBC issued 71,429 shares of Common Stock to the former
       licensor of argatroban in conjunction with the approval of the NDA for
       argatroban in patients with HIT. The Company recorded a $965,970
       non-cash charge to in-process research and development during the second
       quarter of 2000 related to the issuance. This transaction represents the
       final amount to be paid in exchange for the license to the argatroban
       technology from the former licensee.

 (9)   COMMITMENTS AND CONTINGENCIES

       Legal Proceedings

       On November 21, 1994, a class action shareholders' suit was filed in the
       United States District Court for the Southern District of Texas, Houston
       Division seeking damages in the amount of $16.0 million. Plaintiffs were
       two individuals who purchased the Company's shares on December 16, 1993
       following the Company's initial public offering ("IPO"). In their
       complaint, plaintiffs sued the Company, certain members of the board of
       directors and certain officers alleging violations of Sections 11, 12
       and 15 of the Securities Act of 1933, as amended. A subsequently filed
       class action arising out of the IPO was dismissed in June 1996, leaving
       the first class action as the only pending litigation arising out of the
       IPO.

       In May 1999, the Company reached an agreement in principle to settle the
       pending class action. The agreement in principle achieved with
       plaintiff's counsel provides for dismissal of all claims against the
       Company and the officers and directors named as defendants. The
       settlement amount is $800,000, of which approximately $187,500 was
       expensed during 1999 and paid by the Company into escrow during January
       2000 and approximately $612,500 will be paid by the Company's insurer.

       On December 21, 1999, the Company and the plaintiffs filed a Stipulation
       of Settlement of All Claims Against Certain Defendants. On May 19, 2000,
       the Court entered an order approving the settlement and dismissing all
       claims against the Company and its officers and directors. The deadline
       for appeal of that order expired on June 18, 2000. Accordingly, all
       claims against the Company and its officers and directors are fully and
       finally dismissed.

       Lease Agreements

       On June 30, 2000, the Company extended the lease agreement for its
       facilities in Houston, Texas for a period of five years beginning
       January 1, 2001. The lease extension contains terms substantially
       similar to those contained in the original lease agreement.


FORM 10-Q                                                               Page 9

<PAGE>   12

ITEM 2.

                 TEXAS BIOTECHNOLOGY CORPORATION AND SUBSIDIARY

          MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION
                           AND RESULTS OF OPERATIONS

                JUNE 30, 2000 (UNAUDITED) AND DECEMBER 31, 1999

                                    OVERVIEW

       The following discussion of our financial condition and results of
operations should be read in conjunction with our consolidated financial
statements and the related notes to the financial statements included in Form
10-K for the year 1999 and our consolidated financial statements and the
related notes to the financial statements included this Form 10-Q.

       Since our inception in 1989, we have primarily devoted our resources to
funding drug discovery research and development. We have been unprofitable to
date and expect to incur substantial operating losses for the next several
years as we invest in product research and development, preclinical and
clinical testing and regulatory compliance. We have sustained net losses of
approximately $98.9 million from the date of our inception to June 30, 2000. We
have primarily financed our operations to date through private and public
offerings of our common and preferred stock.

       During October 1996, we signed a research and common stock purchase
agreement with LG Chemical. LG Chemical purchased 1,250,000 shares of our
common stock for $5.0 million and committed to pay us up to $10.7 million over
a five-year period to develop two compounds in clinical development. Of this
amount, $6.1 million has been paid. Currently $1.0 million is receivable from
LG Chemical. Furthermore, $1.0 million will be paid on December 31, 2000, and
$1.3 million will be paid on June 30 and December 31, 2001. In June 2000, we
assigned one-half of the remaining payments under the LG Chemical agreement to
ICOS-TBC.

       In August 1997, we entered into an agreement with SmithKline Beecham
plc, commonly known as SmithKline, whereby we granted SmithKline the exclusive
right to work with us in the development and commercialization of argatroban in
the U.S. and Canada for specified indications. Under this agreement, SmithKline
has paid an aggregate of $21 million in the form of license fees and milestone
payments for argatroban. Future milestone payments for the acute myocardial
infarction indication are subject to SmithKline's agreement to market
argatroban for the acute myocardial infarction indication. At this time,
SmithKline has no plans to conduct development work for the acute myocardial
infarction and stroke indications. We are evaluating the feasibility of
developing argatroban for ischemic stroke and possibly other indications. In
connection with the agreement, SmithKline purchased 176,922 shares of our
common stock for $1.0 million and an additional 400,000 shares of our common
stock for $2.0 million in conjunction with our public offering, which closed
during October 1997.

       On June 6, 2000, TBC and ICOS entered into the ICOS-TBC limited
partnership. The partnership will seek to develop and globally commercialize
endothelin-A receptor antagonists. ICOS-TBC will make upfront and milestone
payments to TBC that could be as much as $55.5 million for the development and
commercialization of products resulting from the collaboration. See footnote 8
to the Consolidated Financial Statements for a discussion of this transaction.

       On June 30, 2000, TBC and Schering-Plough Corporation entered into a
worldwide research collaboration and license agreement to discover, develop and
commercialize VLA-4 antagonists.


FORM 10-Q                                                               Page 10

<PAGE>   13

In addition to research costs, Schering-Plough will pay an upfront
license fee, development milestones and royalties on product sales resulting
from the agreement. Total payments to TBC for both programs, excluding
royalties, could reach $87.0 million. See footnote 8 to the Consolidated
Financial Statements for a discussion of this transaction.

       Our operating results have fluctuated significantly during each quarter,
and we anticipate that such fluctuations, which are largely attributable to
varying research and development commitments and expenditures, will continue
for the next several years.

                             RESULTS OF OPERATIONS

                THREE MONTH PERIODS ENDED JUNE 30, 2000 AND 1999

       Revenues were $495,130 and $11,249,147 during the three months ended
June 30, 1999 and 2000, respectively. Revenues were composed of amounts
recognized under license agreements and research and development agreements and
increased 2172% due to an increase in license fees received in connection with
the formation of ICOS-TBC and the research collaboration and license agreement
with Schering-Plough and the milestone payment related to final approval of
argatroban due under the license agreement with SmithKline. Interest income for
the three months ended June 30, 1999 was 273% lower than the same period of
2000 due primarily to higher investment balances in 2000.

       Research and development expenses increased 12% from $3,056,120 during
the three months ended June 30, 1999 to $3,408,450 for the same period of 2000.
The increase was due primarily to increased scaleup and manufacturing costs
related to the sitaxsentan development program for pulmonary hypertension.

       General and administrative expenses decreased 10% from $1,597,091 during
the three months ended June 30, 1999 to $1,437,804 during the same period of
2000. The decrease was due primarily to decreased patent legal fees related to
the sitaxsentan program.

       We incurred a net loss of $3,855,626 and attained net income of
$5,997,529 for the three months ended June 30, 1999 and 2000, respectively.

                             RESULTS OF OPERATIONS

                 SIX MONTH PERIODS ENDED JUNE 30, 2000 AND 1999

       Revenues were $1,030,055 and $11,771,755 during the six months ended
June 30, 1999 and 2000, respectively. Revenues were composed of amounts
recognized under license agreements and research and development agreements and
increased 1043% due to an increase in license fees received in connection with
the formation of ICOS-TBC and the research collaboration and license agreement
with Schering-Plough and the milestone payment related to final approval of
argatroban due under the license agreement with SmithKline. Interest income for
the six months ended June 30, 1999 was 94% lower than the same period of 2000
due primarily to higher investment balances in 2000.

       Research and development expenses increased 16% from $6,214,760 during
the six months ended June 30, 1999 to $7,190,399 for the same period of 2000.
The increase was due primarily to increased scaleup and manufacturing costs
related to the sitaxsentan development program for pulmonary hypertension.

       General and administrative expenses increased 15% from $2,936,532 during
the six months ended June 30, 1999 to $3,368,739 during the same period of
2000. The increase was due primarily to increases in premarketing and
consulting costs related to argatroban.

       We incurred a net loss of $7,434,463 and attained net income of
$1,010,671 for the six months ended June 30, 1999 and 2000, respectively.

       The Company had 83 employees at June 30, 1999 and 80 employees at June
30, 2000.


                        LIQUIDITY AND CAPITAL RESOURCES

       We have financed our research and development activities to date
principally through:


FORM 10-Q                                                               Page 11

<PAGE>   14

o      private and public offerings of our common and preferred stock;

o      issuances of common stock in conjunction with acquisitions, research
       and collaboration agreements and upon exercises of stock options and
       warrants;

o      milestone and research payments received in conjunction with
       research and collaborative agreements; and

o      investment income, net of interest expense.

       In April 2000, we raised approximately $65.2 million from an
underwritten public offering of our common stock. At June 30, 2000 we had cash,
cash equivalents, short-term and long-term investments of $77,540,000.
Additionally, at July 31, 2000, we had cash, cash equivalents, short-term and
long-term investments of approximately $88.0 million.

       We expect to incur substantial research and development expenditures as
we design and develop biopharmaceutical products for the prevention and
treatment of cardiovascular and other diseases. We anticipate that our
operating expenses will increase during 2000 and subsequent years because:

o      We will incur significant clinical trial costs for sitaxsentan and
       TBC1269 compounds and expect to begin to incur costs for clinical trials
       related to additional compounds. These costs include:

       o   hiring personnel to direct and carry out all operations related to
           clinical trials;

       o   hospital and procedural costs;

       o   services of a contract research organization; and

       o   purchasing and formulating large quantities of the compound to be
           used in such trials.

o      There will be additional costs in future periods related to argatroban
       in complying with ongoing FDA requirements and possible clinical trial
       expenditures for additional therapeutic indications.

Furthermore, we anticipate that the administrative costs associated with our
efforts will be significant. The amount and timing of expenditures will depend,
among other things, on our progress in ongoing research, clinical development
and commercialization efforts. On June 30, we received final approval from the
FDA for argatroban as an anticoagulant for prevention or treatment of
thrombosis in patients with HIT. As a result, we expect to begin to accrue
royalty revenues from sales of argatroban by SmithKline by year-end. Therefore,
we expect our royalty revenues to increase. However, increases in revenue, if
any, may be partially, if not fully, offset by increases in expenses related to
ICOS-TBC's development of sitaxsentan and continued research and development of
our other programs.

       We anticipate that our existing capital resources and our other revenue
sources, should be sufficient to fund our cash requirements for the foreseeable
future which is contingent upon various factors, including royalty revenues
from argatroban, the rates of patient enrollment and spending associated with
clinical trials for sitaxsentan and TBC1269 and the level of research and
development expenditures for our other compounds. We cannot assure you that
there will be market acceptance and commercial success of argatroban, which
could significantly impact our cash flow.

       We anticipate that we may need to raise substantial funds for future
operations, which may be raised through collaborative arrangements, public or
private issuance of debt and equity, or other arrangements. We expect that
additional expenditures will be required if additional product candidates enter
clinical trials, which may require additional expenditures for laboratory
space, scientific and administrative personnel, and services of contract
research organizations. We cannot assure you that we will be able to obtain
such additional financings on acceptable terms or in time to fund any necessary
or desirable expenditures. In the event such financings are not obtained, our
drug discovery or development programs may be delayed, scaled back or
eliminated; or we may be required to obtain funds through arrangements with
collaborative partners or others that may require that we relinquish rights to
certain of our technologies, product candidates or products that would not
otherwise be relinquished. Our ability to raise additional funding is
contingent upon a number of factors which include:


FORM 10-Q                                                               Page 12

<PAGE>   15

o   the market acceptance and commercial success of argatroban;

o   the ongoing cost of research and development activities;

o   the attainment of research and clinical goals of product candidates;

o   the continuance of research agreements with collaboration partners;

o   the timely approval of our product candidates by appropriate governmental
    and regulatory agencies;

o   the presence and effect of competitive products;

o   our ability to manufacture and market products commercially;

o   the retention of key personnel; and

o   conditions in the capital markets.


                 HAZARDOUS MATERIALS AND ENVIRONMENTAL MATTERS

       Our research and development processes involve the controlled use of
hazardous materials, chemicals and radioactive materials and produce waste
products. We are subject to federal, state and local laws and regulations
governing the use, manufacture, storage, handling and disposal of hazardous
materials and waste products. Although we believe that our safety procedures
for handling and disposing of hazardous materials comply with the standards
prescribed by laws and regulations, the risk of accidental contamination or
injury from these materials cannot be eliminated completely. In the event of an
accident, we could be held liable for any damages that result. This liability
could exceed our resources or not be covered by our insurance. Although we
believe that we are in compliance in all material respects with applicable
environmental laws and regulations, there can be no assurance that we will not
be required to incur significant costs to comply with environmental laws and
regulations in the future. There can also be no assurance that our operations,
business or assets will not be materially adversely affected by current or
future environmental laws or regulations.

                    IMPACT OF INFLATION AND CHANGING PRICES

       The pharmaceutical research industry is labor intensive, and wages and
related expenses increase in inflationary periods. The lease of space and
related building services for our Houston facility contains a clause that
escalates rent and related services each year based on the increase in building
operating costs and the increase in the Houston Consumer Price Index,
respectively. To date, inflation has not had a significant impact on our
operations.

              CAUTIONARY NOTE REGARDING FORWARD LOOKING STATEMENTS

       This Form 10-Q contains forward-looking statements within the meaning of
Section 27A of the Securities Act of 1933 and Section 21E of the Securities
Exchange Act of 1934. All statements other than statements of historical fact
included in and incorporated by reference into this Form 10-Q are
forward-looking statements. These forward-looking statements include, without
limitation, statements regarding our estimate of the sufficiency of our
existing capital resources and our ability to raise additional capital to fund
cash requirements for future operations, and regarding the uncertainties
involved in the drug development process and the timing of regulatory approvals
required to market these drugs. Although we believe that the expectations
reflected in these forward-looking statements are reasonable, we can not give
any assurance that such expectations reflected in these forward-looking
statements will prove to have been correct. Important factors that could cause
actual results to differ materially from our expectations are discussed in our
registration statement on Form S-3, as amended, initially filed with the
Securities and Exchange Commission on March 8, 2000.

       When used in this Form 10-Q, the words "expect," "anticipate," "intend,"
"plan," "believe," "seek," "estimate" and similar expressions are intended to
identify forward-looking statements, although not all forward-looking
statements contain these identifying words. Because these forward-looking
statements involve risks and uncertainties, actual results could differ
materially from those expressed or implied by these forward-looking statements
for a number of important reasons, including those discussed under
"Management's Discussion and Analysis of Financial Condition and Results of


FORM 10-Q                                                               Page 13

<PAGE>   16

Operations - Liquidity and Capital Resources."

       You should read these statements carefully because they discuss our
expectations about our future performance, contain projections of our future
operating results or our future financial condition, or state other
"forward-looking" information. Before you invest in our common stock, you
should be aware that the occurrence of any of the contingent factors described
under "Management's Discussion and Analysis of Financial Condition and Results
of Operations - Liquidity and Capital Resources" could substantially harm our
business, results of operations and financial condition and that upon the
occurrence of any of these events, the trading price of our common stock could
decline, and you could lose all or part of your investment.

       We cannot guarantee any future results, levels of activity, performance
or achievements. Except as required by law, we undertake no obligation to
update any of the forward-looking statements in this Form 10-Q after the date
of this Form 10-Q.

ITEM 3.  QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK

       To date, interest rate risk has not had a significant impact on the
operations of the Company.


FORM 10-Q                                                               Page 14

<PAGE>   17

PART II OTHER INFORMATION

ITEM 1.  LEGAL PROCEEDINGS

       On November 21, 1994, a class action shareholders' suit was filed in the
United States District Court for the Southern District of Texas, Houston
Division seeking damages in the amount of $16 million. Plaintiffs were two
individuals who purchased the Company's shares on December 16, 1993 following
the Company's initial public offering ("IPO"). In their complaint, plaintiffs
sued the Company, certain members of the board of directors and certain
officers alleging violations of Sections 11, 12 and 15 of the Securities Act of
1933, as amended. A subsequently filed class action arising out of the IPO was
dismissed in June 1996, leaving the first class action as the only pending
litigation arising out of the IPO.

       In May 1999, the Company reached an agreement in principle to settle the
pending class action. The agreement in principle achieved with plaintiff's
counsel provides for dismissal of all claims against the Company and the
officers and directors named as defendants. The settlement amount is $800,000,
of which approximately $187,500 was expensed during 1999 and paid by the
Company into escrow during January 2000 and approximately $612,500 will be paid
by the Company's insurer.

       On December 21, 1999, the Company and the plaintiffs filed a Stipulation
of Settlement of All Claims Against Certain Defendants. On May 19, 2000, the
Court entered an order approving the settlement and dismissing all claims
against the Company and its officers and directors. The deadline for appeal of
that order expired on June 18, 2000. Accordingly, all claims against the Company
and its officers and directors are fully and finally dismissed.

ITEM 2.  CHANGES IN SECURITIES

       In April 2000, we issued an aggregate of 48,851 shares of our common
stock to certain institutions and individuals, pursuant to the exercise of
outstanding warrants for an aggregate purchase price of $19,972 including
43,981 shares issued pursuant to a cashless exercise of privately held
warrants. In addition, we issued 71,429 shares of common stock to the former
licensor of argatroban and recorded a non-cash expense for the purchase of
in-process research and development of $965,970 in June 2000. The issuance of
common stock was exempt from registration under Section 4 (2) of the Securities
Act of 1933, as amended. The warrants and the common stock underlying the
warrants may not be sold in the United States absent registration or an
applicable exemption from registration requirements.

ITEM 3.  DEFAULTS UPON SENIOR SECURITIES

       None


FORM 10-Q                                                               Page 15

<PAGE>   18

ITEM 4.  SUBMISSIONS OF MATTERS TO A VOTE OF SECURITY HOLDERS

       On June 8, 2000, an annual meeting of our stockholders was held. The
       holders of 36,686,947 shares of common stock were present in person or
       represented by proxy at the meeting. At the meeting, the stockholders
       took the following actions:

       (a)    Election of Directors

              The stockholders elected the following persons to serve as
              directors of the Company until the next annual meeting of
              stockholders, or until their successors are duly elected and
              qualified:

                                            NUMBER OF            NUMBER OF
                       NAME                 VOTES FOR        VOTES ABSTAINING
                       ----                 ---------        ----------------
                 Ron J. Anderson            36,438,380            260,067

                 Frank C. Carlucci          36,436,610            261,837

                 Robert J. Cruikshank       36,432,755            265,692

                 Richard A. F. Dixon        36,453,450            244,997

                 David B. McWilliams        36,456,700            247,747

                 Suzanne Oparil             36,444,330            254,117

                 John M. Pietruski          36,443,375            255,072

                 James A. Thomson           36,445,950            252,497

                 James T. Willerson         34,748,944          1,949,503

       (b)    Adoption of the Amendment to the Amended and Restated 1995
              Non-Employee Director Stock Option Plan

              The stockholders approved the proposal to adopt the Amendment to
              the Amended and Restated 1995 Non-Employee Director Stock Option
              Plan. Votes were cast as follows:

                         NUMBER OF            NUMBER OF          NUMBER OF
                         VOTES FOR          VOTES AGAINST    VOTES ABSTAINING
                        ----------          -------------    ----------------
                        35,795,463             722,687            180,297

ITEM 5.  OTHER INFORMATION

None


FORM 10-Q                                                               Page 16

<PAGE>   19

ITEM 6.  EXHIBITS AND REPORTS ON FORM 8-K

       One report on Form 8-K (Item 5) was filed during the quarter ended June
30, 2000. The report was filed with the Securities and Exchange Commission
June 15, 2000 regarding the formation of ICOS-TBC.

     EXHIBIT NO.       DESCRIPTION
     -----------       -----------
        3.8            Amendment to Article II of By-laws

       99.4*           Agreement of Limited Partnership of ICOS-Texas
                       Biotechnology L.P. among ICOS-ET-LP LLC and Texas
                       Biotechnology Corporation, as Limited Partners,
                       and ICOS-ET-GP LLC and TBC-ET, Inc., as General
                       Partners dated June 6, 2000

       99.5*           Endothelin License Agreement between Texas Biotechnology
                       Corporation and ICOS-Texas Biotechnology L.P. dated
                       June 6, 2000

       99.6*           Formation and Performance Agreement between ICOS
                       Corporation and Texas Biotechnology Corporation dated
                       June 6, 2000

       99.7*           Research and Development Service Agreement among ICOS
                       Corporation, Texas Biotechnology Corporation and
                       ICOS-Texas Biotechnology L. P.

       99.8*           Research Collaboration and License Agreement between
                       Texas Biotechnology Corporation and Schering-Plough LTD.
                       dated June 30, 2000

       99.9*           Research Collaboration and License Agreement between
                       Texas Biotechnology Corporation and Schering Corporation
                       dated June 30, 2000

       27.1            Financial Data Schedule

        *              Confidential treatment requested

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


FORM 10-Q                                                               Page 17



<PAGE>   20

                        TEXAS BIOTECHNOLOGY CORPORATION

                                 JUNE 30, 2000

                                   SIGNATURES



Pursuant to the requirements of the Securities and Exchange Act of 1934, the
registrant has duly caused this report to be signed on its behalf by the
undersigned thereunto duly authorized, on the 14th day of August, 2000.




                                    TEXAS BIOTECHNOLOGY CORPORATION


                                      By:    /s/ David B. McWilliams
                                         ------------------------------
                                         David B. McWilliams
                                         President and Chief Executive Officer






                                      By:   /s/ Stephen L. Mueller
                                         -----------------------------
                                         Stephen L. Mueller
                                         Vice President, Finance and
                                         Administration Secretary and
                                         Treasurer (Principal Financial
                                         and Accounting Officer)


FORM 10-Q                                                               Page 18

<PAGE>   21

                               INDEX TO EXHIBITS


   Exhibit No.                Description of Exhibit
   -----------                ----------------------

        3.8           Amendment to Article II of By-laws

       99.4*          Agreement of Limited Partnership of ICOS-Texas
                      Biotechnology L.P. among ICOS-ET-LP LLC and Texas
                      Biotechnology Corporation, as Limited Partners, and
                      ICOS-ET-GP LLC and TBC-ET, Inc., as General Partners
                      dated June 6, 2000

       99.5*          Endothelin License Agreement between Texas Biotechnology
                      Corporation and ICOS-Texas Biotechnology L.P. dated
                      June 6, 2000

       99.6*          Formation and Performance Agreement between ICOS
                      Corporation and Texas Biotechnology Corporation dated
                      June 6, 2000

       99.7*          Research and Development Service Agreement among ICOS
                      Corporation, Texas Biotechnology Corporation and
                      ICOS-Texas Biotechnology L. P.

       99.8*          Research Collaboration and License Agreement between Texas
                      Biotechnology Corporation and Schering-Plough LTD. dated
                      June 30, 2000

       99.9*          Research Collaboration and License Agreement between Texas
                      Biotechnology Corporation and Schering Corporation dated
                      June 30, 2000

       27.1           Financial Data Schedule

        *             Confidential treatment requested

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


FORM 10-Q                                                               Page 19