1
                                                                   EXHIBIT 10.77

                      AMENDMENT TO OFFICE LEASE AGREEMENT


     THIS AMENDMENT TO OFFICE LEASE AGREEMENT ("Amendment") is to be effective
for all purposes as of January 1, 2001, by and between the Board of Regents of
The University of Texas System ("Landlord"), and Texas Biotechnology
Corporation, a Delaware Corporation ("Tenant").

                                    RECITALS

     A. Landlord and Tenant entered into an Office Lease Agreement ("Lease")
dated February 24, 1995, and subsequent Amendment dated April 1, 1999 and
renewal option exercised June 30, 2000 covering approximately 37,500 square feet
of net rentable area in the building located at 7000 Fannin ("Building") in
Houston, Harris County, Texas.

     B. Tenant has requested that Landlord amend the Lease to include additional
storage space.

     C. Landlord is willing to amend the Lease on the terms and conditions
stated below.

                                   PROVISIONS

     NOW, THEREFORE, in consideration of the mutual covenants contained herein,
and for other good and valuable consideration, the receipt and legal sufficiency
of which are hereby acknowledged by the parties, Landlord and Tenant hereby
agree as follows:

     1. Defined Terms. Capitalized terms that are not otherwise defined in this
Amendment have the respective meanings assigned to them in the Lease.

     2. Additional Space. The Lease shall include approximately 450 additional
square feet of storage space (Unite P2-8) ("Additional Space") for the period
from January 1, 2001 through December 31, 2002. Additional space shall be used
and occupied only for the purpose of storage of goods in accordance with the
terms and conditions listed in Exhibit A attached hereto and incorporated
herein.

     3. Payment of Rental. The Rental during the Extended Term shall be $531.00
per month, payable in advance as provided in the Lease.


                                       1
   2
     4. Performance of and Compliance With the Terms and Conditions of the
Lease. Landlord and Tenant each promise and agree to perform and comply with the
terms, provisions, and conditions of and the agreements in the Lease, as
modified by this Amendment.

     5. Ratification and Reaffirmation of Lease. Landlord and Tenant each hearby
ratify, affirm, and agree that the Lease, as herein modified, represents the
valid, binding and enforceable obligations of Landlord and Tenant, respectively.

     6. Continuation of Lease. Except as expressly stated in this Amendment, the
terms of the Lease shall remain unchanged and in full force and effect as
originally provided.

     7. Applicable Law. Landlord and Tenant hereby agree that this Amendment and
the Lease shall be governed and construed according to the laws of the State of
Texas from time to time in effect.

     8. Inurement. This Amendment shall be binding on and inure to the benefit
of Landlord and Tenant and their respective heirs, executors, administrators,
legal representatives, successors and assigns.

     9. No Commission. Landlord and Tenant each warrant and represent to the
other that no commission of fee is due or will be paid in connection with this
Amendment.

    10. Entirety and Amendments. The Lease, as expressly modified by this
Amendment, constitutes the sole and only agreement of the parties to the Lease
and supersedes any prior understandings or written or oral agreements between
the parties concerning the lease of the Premises. The Lease may be amended or
supplemented only by an instrument in writing executed by the party against whom
enforcement is sought.

     11. Construction. Each party acknowledges that it and its counsel have
reviewed this Amendment and that the normal rule of construction shall not be
applicable and there shall be no presumption that any ambiguities will be
resolved against the drafting party in interpretation of this Amendment.

12. Authority. Tenant warrants and represents that (a) Tenant has the full
right, power and authority to enter into this Amendment, (b) all requisite
action to authorize Tenant to enter into this Amendment and to carry out
Tenant's obligations hereunder has



                                       2
   3
     13.  Paragraph Headings. The paragraph headings used herein are intended
for reference purposes only and shall not be considered in the interpretation
of the terms and conditions hereof.

     14.  Counterparts. This Amendment may be executed in any number of
counterparts, all of which taken together shall constitute one and the same
agreement, and any of the parties to this Amendment may execute the Amendment
by signing any of the counterparts.

     In witness whereof, this Amendment is executed to be effective as of the
date first set forth above.

                                           LANDLORD:

                                           BOARD OF REGENTS OF THE
                                           UNIVERSITY OF TEXAS SYSTEM


                                           By: /s/ JAMES S. WILSON
                                              ---------------------------------
                                                   James S. Wilson
                                              Executive Director of Real Estate
                                              The University of Texas System



                                           TENANT:

                                           TEXAS BIOTECHNOLOGY
                                           CORPORATION


                                           By: /s/ DAVID B. McWILLIAMS
                                              ----------------------------------
                                           Name:   David B. McWilliams
                                                --------------------------------
                                           Title:  President & CEO
                                                 -------------------------------




                                       3
   4

                                   EXHIBIT A

Tenant warrants and represents to Landlord that the Leased Premises shall be
used and occupied only for the purpose of STORAGE OF GOODS.

Tenant shall occupy the Leased Premises, conduct its business, and control its
agents and employees in such a way as is lawful, reputable, and will not create
any nuisance or otherwise interfere with, annoy, or disturb any other tenant in
its normal business operations.

Tenant shall not commit, or suffer to be committed, any waste on the Leased
Premises, nor shall Tenant permit the Leased Premises to be used in any way
which would, in the opinion of the Landlord, create a hazardous or unsightly
environment.

Tenant is responsible for placing any waste items that are not equipment or
non-goods that can be recycled in a recycling bin provided by building
management and removing from the premises items that are waste and not
considered items for recycling.