Document:

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                                                                   Exhibit 10.22
                                 LEASE AGREEMENT

                                 OFFICE BUILDING

      This Lease Agreement is made and entered into as of the 20th day of
February, 2002 between FRM WEST LOOP ASSOCIATES #6, LTD., a Texas limited
partnership, hereinafter referred to as "Lessor" and TEXAS BIOTECHNOLOGY
CORPORATION, a Delaware corporation, hereinafter referred to as "Lessee":

                                   WITNESSETH:

SEC. 1 LEASED PREMISES: In consideration of the mutual covenants as set forth
herein, Lessor and Lessee hereby agree as follows:

      A. Lessor hereby leases to Lessee and Lessee hereby leases from Lessor for
the rental and on the terms and conditions hereinafter set forth approximately
Fifteen Thousand Two Hundred Five (15,205) square feet of rentable area on the
fourth (4th) floor as indicated on the plan attached hereto as Exhibit "A" and
known as Suite 400 (the "Leased Premises") in the office building located at
6700 West Loop South (the "Building"), Bellaire, Harris County, Texas.
Facilities and areas of the Building that are intended and designated by Lessor
from time to time for the common, general and nonexclusive use of all tenants of
the Building are defined as the "Common Areas". Lessor has the exclusive control
over and right to manage the Common Areas. Lessor shall have the exclusive use
and control over all other areas of the Building and the property including, but
not limited to, risers, horizontal and vertical shafts and telephone closets.

      B. Lessor also leases to Lessee eight (8) reserved parking spaces and up
to fifty-two (52) unreserved parking spaces in the garage as provided in Exhibit
"B" attached hereto.

SEC. 2 TERM: Subject to and upon the conditions set forth herein, or any exhibit
or addendum hereto, the Term of this Lease Agreement shall be for a period of
forty (40) months, beginning April 1, 2002 ("Commencement Date") and shall end
at midnight on July 31, 2005; provided, however, that Lessee shall have the
right to extend the Term of this Lease Agreement under the same terms and
conditions contained herein to December 31, 2005 by giving Lessor ninety (90)
days prior written notice.

SEC. 3 USE: The Leased Premises shall be used and occupied by Lessee solely as
general office use and for no other purpose.

SEC. 4 SECURITY DEPOSIT: INTENTIONALLY DELETED.

SEC. 5 BASE RENT: As part of the consideration for the execution of this Lease
Agreement, Lessee covenants and agrees and promises to pay as Base Rent an
annual sum of Two Hundred Eighty-One Thousand Two Hundred Ninety-Two and 48/100
Dollars ($281,292.48) payable at the Building management office or to a location
designated by Lessor in monthly installments of Twenty-Three Thousand Four
Hundred Forty-one and 04/100 Dollars ($23,441.04) in legal tender of the United
States of America, in advance, without demand and without deduction, on the
first day of each calendar month during the term hereof. Lessee shall not have
to pay Base Rent for the first four (4) months of the Term hereof, and Lessee
shall be allowed to occupy the Leased Premises free of any Base Rent for said
four (4) month period. Such Base Rent shall be subject to adjustments as
hereinafter provided.

      In addition to the foregoing rent, Lessee agrees to pay to Lessor as
additional rent all charges for any services, goods or materials furnished by
Lessor at Lessee's request which are not required to be furnished by Lessor
under this Lease Agreement, as well as other sums payable by Lessee hereunder,
within ten (10) days after Lessor renders a statement therefor to Lessee. All
past due installments shall bear interest at the rate of eighteen percent (18%)
per annum or the highest lawful rate, whichever is less, from date due until
paid.

SEC. 6 ADJUSTMENT OF BASE RENT: The Base Rent provided for herein includes a
component applicable to Basic Cost (as hereinafter defined) equal, on a per
annum basis to Base Year 2002 per square foot of rentable area of office space
in the Building, such amount being hereinafter referred to as "Base Operating
Expense".

      A. "Basic Cost" as said term is used herein shall consist of the operating
expenses of the Building, which shall be computed on the accrual basis. For the
purpose of calculating the Basic Cost for the Base Year, Lessor shall increase
Basic Cost to the amount which would have been incurred had the Building been
occupied to the extent of ninety-five percent (95%) of rentable area thereof and
building standard services had been provided through the entire Building. All
operating expenses shall be determined in accordance with generally accepted
accounting principles, consistently applied in accordance with the accounting
practices of a majority of the other comparable office buildings in the West
Loop/Galleria market area. Subject to Section 6.C below, the term "Operating
Expenses" as used herein shall mean all expenses, costs and disbursements (but
not replacement of capital investment items nor general office expense nor
specific costs especially billed to and paid by specific tenants) in connection
with the ownership and operation of the Building and parking facility
appurtenant thereto, including but not limited to the following:
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            (1)   Wages, salaries and fees of any management company engaged to
                  manage the Building and parking facility and all employees in
                  operation and maintenance of the Building and parking
                  facility, including taxes, insurance and benefits relating
                  thereto. Notwithstanding the foregoing, Lessor shall not
                  assign in excess of 21.381% of the Operating Cost associated
                  with the parking facility to the Building.

            (2)   All supplies and materials used in operation and maintenance
                  of the Building and parking facility.

            (3)   Cost of water and power, heating, lighting, air conditioning
                  and ventilating the Building and parking facility.

            (4)   Cost of all janitorial service, maintenance and service
                  agreements on equipment, including alarm service, Musak,
                  window cleaning and elevator maintenance.

            (5)   Cost of casualty and liability insurance applicable to the
                  Building and parking facility and Lessor's personal property
                  used in connection therewith.

            (6)   All taxes and assessments and other governmental charges
                  whether Federal, State, county or municipal and whether they
                  be by taxing districts or authorities presently taxing the
                  Leased Premises or by others subsequently created or
                  otherwise, and any other taxes and improvements assessments
                  attributable to the Building and parking facility or its
                  operation excluding, however, Federal and State taxes on
                  income. It is agreed that Lessee will be responsible for ad
                  valorem taxes on its personal property and on the value of
                  leasehold improvements to the extent that the same exceed
                  standard building allowance.

            (7)   Cost of repairs and general maintenance.

      B. In the event that Basic Cost of Lessor's operation of the Building
during any calendar year of the term of this Lease Agreement shall exceed the
Base Operating Expense set out in Section 6.A above, Lessee shall pay to Lessor
as additional rent its pro rata share of the increase in such Basic Cost for
such year over the Base Operating Expense. Lessee's pro rata share shall be a
fraction of the total of such increase, the numerator of which shall be the
rentable area contained in the Leased Premises then leased by Lessee in the
Building and the denominator of which shall be 70,416 square feet which is
ninety-five percent (95%) of the total rentable area contained in the Building.

            All amounts which may be due under this paragraph shall be due
within ten (10) days after Lessor submits to Lessee a bill or invoice therefor.
Lessor shall monitor Basic Cost for the Building throughout the term hereof and
prepare projections of the anticipated Basic Cost for the Building for each
calendar year during the term hereof. At any time that such projection shall
indicate that Basic Cost shall exceed Base Operating Expense, Lessor may
commence monthly billings for the collection of the amount of the anticipated
excess. Lessor may submit to Lessee a bill or invoice each month for one-twelfth
(1/12) of the amount of the excess of projected or actual Basic Cost over Base
Operating Expense for the calendar year in question, as same may be ascertained
by Lessor to be due by Lessee under this paragraph. The amount of the first such
bill or invoice shall be determined by multiplying the monthly amount due by the
number of calendar months of the calendar year in question which have commenced
as of the date of the bill or invoice. In the event of such billing or invoicing
procedure by Lessor, then Lessee shall be bound and obligated to pay such
indicated amount contemporaneously with required payment of rent hereunder on
the first day of each calendar month, monthly in advance, for each month in the
Term of this Lease Agreement, in lawful money of the United States.
Notwithstanding any other provision herein to the contrary, it is agreed that in
the event the Building is not fully occupied during any year of the Term, an
adjustment shall be made in computing the Operating Expenses for such year as
though the Building had been 95% occupied during such year.

            Once each calendar year, Lessor shall perform such computations as
are necessary to determine the amount properly payable by Lessee under this
Section 6.B for the preceding calendar year, whereupon if Lessee shall have
overpaid, Lessor shall refund to Lessee the amount of the excess; but if Lessee
shall have underpaid, Lessor shall invoice Lessee for the amount of the
underpayment and such underpayment shall be due within thirty (30) days after
delivery of such invoice to Lessee.

      C.    The following shall be excluded from the definition of Operating
            Expenses as set forth in Section 6.1 above:

            (1)   Depreciation and amortization.

            (2)   Financing and refinancing costs, interest on debt or
                  amortization payment on any mortgage or mortgages, and rental
                  under any ground or underlying leases or lease together with
                  all costs incidental to the items mentioned in this
                  subparagraph.

            (3)   Any costs required by or incurred in connection with any
                  federal, state or local law enacted before the date of this
                  Lease Agreement, including, without limitation, the American's
                  with Disabilities Act, other laws relating to accessibility or
                  life safety, and the Clean Air Act and any other laws relating
                  to the removal of chlorofluorocarbons (freon) from the
                  Building's HVAC systems.

            (4)   Any costs relating to the presence of asbestos-containing
                  materials located in the Building prior to the date of this
                  Lease Agreement, including, without limitation, costs of any
                  encapsulation or removal thereof required by any laws or
                  regulations, whether currently existing or hereafter enacted.
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            (5)   Costs of correcting material defects in the original design or
                  any subsequent construction of the Building or the material
                  used in the construction of the Building (including latent
                  defects in the original or any subsequent construction of the
                  Building or defects in the design of the Building) or in the
                  Building equipment or appurtenances thereto.

            (6)   The cost of any repair to remedy damage caused by or resulting
                  from the negligence of any other tenant(s) in the Building,
                  including their agents, servants, employees or invitees,
                  together with the costs and expenses incurred by Lessor in
                  attempting to recover such costs.

            (7)   Legal and other fees, leasing commissions, advertising or
                  marketing expenses and other similar costs incurred in
                  connection with the leasing of the Building.

            (8)   Costs incurred in renovating or otherwise improving or
                  decorating or redecorating space for new tenants or other
                  existing tenants or occupants in the Building or vacant space
                  in the Building or costs related thereto (including
                  architectural and engineering fees); and costs incurred by
                  Lessor that are specifically reimbursed to Lessor by other
                  tenants (other than as part of Operating Expenses) in
                  connection with maintenance or repair of above building
                  standard condition improvements.

            (9)   Any items not otherwise excluded to the extent Lessor is
                  specifically reimbursed by insurance or otherwise compensated
                  (other than as part of Operating Expenses), including direct
                  reimbursement by any tenant.

            (10)  A bad debt loss, rent loss or reserves for bad debts or rent
                  loss.

            (11)  The cost (or any amortization thereof) of any alteration,
                  addition, change, replacement, improvement, repair or other
                  item which is properly capitalized under generally accepted
                  accounting principles other than cost saving capital
                  improvements (which will be amortized over the useful life of
                  such improvements, but only to the extent of the savings
                  achieved). Upon Lessee's request, Lessor will provide Lessee a
                  cost justification of any such capital improvements.

            (12)  Any item of cost which is includable in Operating Expenses,
                  but which represents an amount paid to an affiliate of Lessor
                  or an affiliate of any partner or shareholder of Lessor, or to
                  the property management company or an affiliate of the
                  property management company, to the extent the same is in
                  excess of the reasonable cost of said item or service in an
                  arms-length transaction.

            (13)  Any interest or penalties incurred as a result of Lessor's
                  failure to pay any financial obligation when due or within any
                  applicable grace period.

            (14)  An amount equal to any costs which represent any payments
                  received by Lessor or the Building manager, or the employees
                  or officers of either, from suppliers of goods or services as
                  kick-backs, finders' fees, expediting fees or other similar
                  dishonest fees.

            (15)  Any and all costs associated with the operation of the
                  business of the entity which constitutes Lessor: excluded
                  items shall specifically include, but shall not be limited to,
                  formation of the entity; internal accounting and legal
                  matters, including but not limited to, preparation of tax
                  returns and financial statements and gathering of data
                  therefor; costs of defending any lawsuits with any mortgagee
                  (except as the actions of a tenant may be in issue); costs of
                  selling, syndication, financing, mortgaging or hypothecating
                  any of Lessor's interest in the Building; costs of any
                  disputes between Lessor and its employees (if any) not engaged
                  in the operation of the Building; disputes between Lessor and
                  the property management company managing the Building; and,
                  Lessor's headquarters office costs and general overhead.

            (16)  Any cost or expense for services or amenities that are
                  specifically for the benefit of a particular tenant and that
                  are of a nature not generally provided to all tenants in the
                  Building or for services or amenities generally provided to
                  all tenants in the Building but which are provided to any
                  particular tenant without additional charge or at a reduced
                  charge (on a net effective basis) than the charge imposed upon
                  other tenants.

            (17)  Lessor's cost of electricity, incremental air conditioning and
                  other services provided to other tenants at times or in
                  amounts for which Lessee would be billed under this Lease
                  Agreement as an additional charge.

            (18)  Any expense incurred as a direct result of the negligence of
                  Lessor, its agents, servants or employees or arising out of
                  Lessor's negligent failure to manage the Building consistently
                  with the standard required by this Lease Agreement to the
                  extent that such expense would not have been incurred in the
                  absence of such negligence.

            (19)  Costs incurred for the production and distribution of any
                  tenant newsletters, tenant perception surveys or the creation
                  and implementation of tenant retention programs.

            (20)  Charitable donations.

            (21)  Costs that would duplicate costs theretofore included in
                  Operating Expenses.

      D. Lessor agrees that it will maintain complete and accurate records of
all costs, expenses and disbursements which are incurred by Lessor, its
employees, agents and/or contractors, with respect to Operating Expenses and the
constituent components thereof. Lessee and/or its employees or a nationally
recognized certified public accounting firm, at Lessee's sole cost and expense,
shall have the right to inspect and/or audit not more often than once per
calendar year Lessor's books and records relating to this Lease Agreement for
any year or years during the Term hereof. Any such inspection and/or audit shall
be conducted at Lessor's office during normal business hours. Lessee must give
Lessor advance written notice of Lessee's intent to audit within two (2) years
after Lessee has received a statement setting forth the prior lease year's
Operating Expenses chargeable to Lessee, and if such notice is not sent by
Lessee within such two (2) year period, then Lessee waives its right to an audit
for that lease year. Such audit will be at Lessee's sole cost and expense,
provided that Lessor agrees to reimburse Lessee for the reasonable professional
or accounting costs and expenses incurred by Lessee in connection with any
inspection and/or audit that results in a determination that Operating Expenses
were overstated by five percent (5%) or more for the subject lease year. The
right of Lessee to audit and any audit by Lessee of Lessor's books and records
shall not affect the obligation of Lessee to pay, in accordance with the terms
hereof, Base Rent, additional rent or estimated additional rent subject,
however, to Lessor's reimbursement and/or reconciliation obligations set forth
herein. Lessor's and Lessee's obligations to reconcile estimated additional rent
with additional rent shall survive the expiration or termination of this Lease
Agreement by one (1) year.

      E. Notwithstanding anything contained in the Lease Agreement to the
contrary, Lessor shall limit increases in controllable expenses to six percent
(6%) per year, compounded annually. Controllable expenses shall include all
Operating Expenses except taxes, insurance, utilities and governmentally
mandated changes (ie, minimum wage).

SEC. 7 SERVICE AND UTILITIES: Lessor will provide water at those common points
of supply provided for drinking, toilet and lavatory purposes and with
electricity for ordinary office uses (not to include, however, data processing
machines other than personal computers and related equipment that consumes less
than .25 kilowatts per hour at rated capacity or requires a voltage of 120 volts
single phase, including air conditioning costs therefor, large business machines
and similar equipment of high electrical consumption characteristics); ballast
and lamp replacement for the Building's standard fluorescent lighting fixtures
located in the Leased Premises; elevator service; janitorial service on a five
(5) day per week basis, in the manner and to the extent deemed standard by
Lessor during the periods and hours as such services are normally furnished to
all tenants. Lessee will pay all telephone charges. Lessor agrees to furnish
Lessee with refrigerated water at those points of supply provided for general
use of other tenants in the Building; heated and refrigerated air conditioning
in season to be provided during the hours of 7:00 a.m. to 6:00 p.m. on weekdays
and 8:00 a.m. to 1:00 p.m. on Saturday, at temperatures and in amounts which
Lessor considers standard. Lessor shall not be liable in damages or otherwise
for failure, stoppage or interruption of any such service, nor shall the same be
construed as an eviction of Lessee, work an abatement of rent, or relieve Lessee
from the operation of any covenant or agreement; but in the event of any
failure, stoppage or interruption thereof, Lessor shall use reasonable diligence
to restore service promptly. The work

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of the building janitor shall not be hindered by Lessee. In the event Lessee
desires heating and air conditioning at times other than herein specified,
Lessee agrees to pay the entire cost thereof.

SEC. 8 MAINTENANCE, REPAIRS AND USE: Lessor shall provide for the cleaning and
maintenance of the public portions of the Building including painting and
landscaping surrounding the Building. Unless otherwise expressly stipulated
herein, Lessor shall not be required to make any improvements or repairs of any
kind or character on the Leased Premises during the Term of this Lease
Agreement, except such repairs as may be required by normal maintenance
operations which shall include repairs to the exterior walls, corridors,
windows, roof and other structural elements and equipment of the Building, and
such additional maintenance as may be necessary because of damages by persons
other than Lessee, its agents, employees, invitees or visitors. Lessor shall
have sole control over the parking of automobiles and other vehicles and shall
designate parking areas and building service areas.

      Lessor, its officers, agents and representatives, subject to any security
regulations imposed by any governmental authority, after reasonable notice to
Lessee, shall have the right to enter all parts of the Leased Premises at all
reasonable hours to inspect, clean, make repairs, alterations and additions to
the Building or Leased Premises which it may deem necessary or desirable, or to
provide any service which it is obligated to furnish to Lessee, and Lessee shall
not be entitled to any abatement or reduction of rent by reason thereof.

      Lessor may, at its option and at the cost and expense of Lessee, repair or
replace any damage or injury done to the Building or any part thereof, caused by
Lessee, Lessee's agents, employees, licensees, invitees or visitors; Lessee
shall pay the cost thereof to Lessor on demand. Lessee further agrees to
maintain and keep the interior of the Leased Premises in good repair and
condition at Lessee's expense. Lessee agrees not to commit or allow any waste or
damage to be committed on any portion of the Leased Premises, and at the
termination of this Lease Agreement, by lapse of time or otherwise, to deliver
up the Leased Premises to Lessor in as good condition as on date of possession
by Lessee, ordinary wear and tear alone excepted, and upon such termination of
this Lease, Lessor shall have the right to re-enter and resume possession of the
Leased Premises.

      Lessee will not use, occupy or permit the use or occupancy of the Leased
Premises for any purpose which is directly or indirectly forbidden by law,
ordinance or governmental or municipal regulation or order, or which may be
dangerous to life, limb or property; or permit the maintenance of any public or
private nuisance; or do or permit any other thing which may disturb the quiet
enjoyment of any other tenant of the Building; or keep any substance or carry on
or permit any operation which might emit offensive odors or conditions into
other portions of the Building; or use any apparatus which might make undue
noise or set up vibrations in the Building; or permit anything to be done which
would increase the fire and extended coverage insurance rate on the Building or
contents and if there is any increase in such rates by reason of acts of Lessee,
then Lessee agrees to pay such increase promptly upon demand therefor by Lessor.

SEC. 9 QUIET ENJOYMENT: Lessee, on paying the said rent and performing the
covenants herein agreed to be by it performed, shall and may peaceably and
quietly have, hold and enjoy the Leased Premises for the said term.

SEC. 10 ALTERATIONS: Lessee covenants and agrees to keep the Leased Premises
free of all liens for improvements or otherwise and that it will make no
structural change or major alteration without Lessor's written consent in
advance, and without first furnishing Lessor fifteen (15) days advance written
notice outlining in detail the proposed changes or alterations.

SEC. 11 FURNITURE, FIXTURES AND PERSONAL PROPERTY: Lessee may remove its trade
fixtures, office supplies and movable office furniture and equipment not
attached to the Building provided: (a) such removal is made prior to the
termination of the term of this Lease Agreement; (b) Lessee is not in default of
any obligation or covenant under this Lease Agreement at the time of such
removal; and (c) Lessee promptly repairs all damage caused by such removal. All
other property at the Leased Premises and any alterations or additions to the
Leased Premises (including wall-to-wall carpeting, paneling or other wall
covering) and any other article attached or affixed to the floor, wall or
ceiling of the Leased Premises shall become the property of Lessor and shall
remain upon and be surrendered with the Leased Premises as a part thereof at the
termination of the Lease Agreement by lapse of time or otherwise, Lessee hereby
waiving all rights to any payment or compensation therefor.

SEC. 12 SUBLETTING AND ASSIGNMENT:

      A. In the event Lessee should desire to assign this Lease Agreement or
sublet the Leased Premises or any part thereof or allow same to be used or
occupied by others, Lessee shall give Lessor written notice (which shall specify
the duration of said desired sublease or assignment, the date same is to occur,
the exact location of the space affected thereby, the proposed rentals on a
square foot basis chargeable thereunder and sufficient information of the
proposed sublessee or assignee regarding its financial condition and business
operations) of such desire at least ninety (90) days in advance of the date on
which Lessee desires to make such assignment or sublease or allow such a use or
occupancy. Lessor shall then have a period of sixty (60) days following receipt
of such notice within which to notify Lessee in writing that Lessor elects:

            (1)   IN THE EVENT SUCH ASSIGNEE OR SUBLESSEE FAILS TO MEET THE
                  CONDITIONS SET FORTH IN SUBPARAGRAPH (III) BELOW, to refuse to
                  permit Lessee to assign this Lease Agreement or sublet such
                  space, and in such case this Lease Agreement shall continue in
                  full force and effect in accordance with the terms and
                  conditions hereof; or

            (2)   To terminate this Lease Agreement as to the space so affected
                  as of the date so specified by Lessee in which event Lessee
                  shall be relieved of all obligations hereunder as to such
                  space arising from and after such date; or

            (3)   To permit Lessee to assign this Lease Agreement or sublet such
                  space for the duration specified in such notice, subject to
                  Lessor's subsequent written approval of the proposed assignee
                  or sublessee, which approval shall not be unreasonably
                  withheld or delayed if (a) the nature and character of the
                  proposed assignee or sublessee, its business and activities
                  and intended use of the Leased Premises are in Lessor's
                  reasonable judgment consistent with the current standards of
                  the Building and the floor or floors on which the Leased
                  Premises are located, (b) neither the proposed assignee or
                  sublessee (nor any party which, directly or indirectly,
                  controls or is controlled by or is under common control with
                  the proposed assignee or sublessee) is a department,
                  representative or agency of any governmental body or currently
                  an occupant of any part of the Building or a party with whom
                  Lessor is then negotiating to lease space in the Building or
                  in any adjacent Building owned by Lessor, (c) the form and
                  substance of the proposed sublease or instrument of assignment
                  is acceptable to Lessor (which acceptance by Lessor shall not
                  be unreasonably withheld) and is expressly subject to all of
                  the terms and provisions of this Lease Agreement and to any
                  matters to which this Lease Agreement is subject, (d) the
                  proposed occupancy would not (1) increase the office cleaning
                  requirements, (2) impose an extra burden upon the services to
                  be supplied by Lessor to Lessee hereunder, (3) violate the
                  current rules and regulations of the Building, (4) violate the
                  provisions of any other leases of tenants in the Building or
                  (5) cause alterations or additions to be made to the Building
                  (excluding the Leased Premises), (e) Lessee enters into a
                  written agreement with Lessor whereby it is agreed that fifty
                  percent (50%) of any profit realized by

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                  Lessee as a result of said sublease or assignment and any and
                  all sums and other considerations of whatsoever nature paid to
                  Lessee by the assignee or sublessee for or by reason of such
                  assignment or sublease, including, but not limited to, sums
                  paid for the sale of Lessee's fixtures, leasehold
                  improvements, equipment, furniture, furnishings or other
                  personal property (that is, after deducting and giving Lessee
                  credit for Lessee's reasonable costs directly associated
                  therewith, including reasonable brokerage fees and the
                  reasonable cost of remodeling or otherwise improving the
                  Leased Premises for said assignee or sublessee but excluding
                  any free rentals or the like offered to any such sublessee or
                  assignee) shall be payable to Lessor as it accrues as
                  additional rent hereunder, and (f) the granting of such
                  consent will not constitute a default under any other
                  agreement to which Lessor is a party or by which Lessor is
                  bound.

      B. No assignment or subletting by Lessee shall be effective unless Lessee
shall execute, have acknowledged and deliver to Lessor, and cause each sublessee
or assignee to execute, have acknowledged and deliver to Lessor, an instrument
in form and substance acceptable to Lessor in which (i) such sublessee or
assignee adopts this Lease Agreement and assumes and agrees to perform jointly
and severally with Lessee, all of the obligations of Lessee under this Lease
Agreement, as to the space transferred to it, (ii) Lessee and such sublessee or
assignee agree to provide to Lessor, at their expense, direct access from a
public corridor in the Building to the transferred space, (iii) such sublessee
or assignee agrees to use and occupy the transferred space solely for the
purpose specified in Section 3 and otherwise in strict accordance with this
Lease Agreement and (iv) Lessee acknowledges and agrees that, notwithstanding
such subletting or assignment, Lessee remains directly and primarily liable for
the performance of all the obligations of Lessee hereunder (including, without
limitation, the obligation to pay rent), and Lessor shall be permitted to
enforce this Lease Agreement against Lessee or such sublessee or assignee, or
both, without prior demand upon or proceeding in any way against any other
persons.

      C. Any consent by Lessor to a particular assignment or sublease shall not
constitute Lessor's consent to any other or subsequent assignment or sublease,
and any proposed sublease or assignment by any assignee or sublessee shall be
subject to the provisions of this Section 12 as if it were a proposed sublease
or assignment by Lessee. The prohibition against an assignment or sublease
described in this Section 12 shall be deemed to include a prohibition against
Lessee's mortgaging or otherwise encumbering its leasehold estate, as well as
against an assignment or sublease which may occur by operation of law, each of
which shall be ineffective and void and shall constitute an event of default
under this Lease Agreement unless consented to by Lessor in writing in advance.

SEC. 13 FIRE AND CASUALTY: The parties hereto mutually agree that if the Leased
Premises are partially or totally destroyed by fire or other casualty covered by
the fire and extended coverage insurance carried by Lessor, then Lessor may
after thirty (30) days written notice to Lessee, at Lessor's option, repair and
restore the Leased Premises as soon as it is reasonably practicable, to
substantially the same condition in which the Leased Premises were before such
damage, or Lessor may terminate the Lease Agreement, provided, however, that in
the event the Leased Premises are completely destroyed or so badly damaged that
repairs cannot be commenced within thirty (30) days and completed within six (6)
months thereafter, then this Lease Agreement shall be terminable as of the date
of the occurrence of the damage or destruction, by either party hereto by
serving written notice to the other; and provided further, that, in any event,
if repairs have not been commenced within thirty (30) days from the date of said
damage and thereafter completed within a reasonable time, in no case to exceed
six (6) months, this Lease Agreement may be immediately terminated by Lessee as
of the date of occurrence of the damage or destruction, by serving written
notice upon Lessor.

      In the event the Leased Premises are completely destroyed or so badly
damaged by fire or other casualty covered by the fire and extended coverage
insurance to be carried by Lessor that it cannot reasonably be used by Lessee
for the purposes herein provided and this Lease Agreement is not terminated as
above provided, then there shall be a total abatement of rent until the Leased
Premises are made usable. In the event the Leased Premises are partially
destroyed or damaged by fire or other hazard so that the Leased Premises can be
only partially used by Lessee for the purpose herein provided, then there shall
be a partial abatement in the rent corresponding to the time and extent which
the Leased Premises cannot be used by Lessee.

      If the Leased Premises are damaged by fire or other casualty resulting
from the fault or negligence of Lessee, or the agents, employees, licensees or
invitees of Lessee, such damage shall be repaired by and at the expense of
Lessee under the direction and supervision of Lessor, and rent shall continue
without abatement.

SEC. 14 CONDEMNATION: In the event the Building, Leased Premises or any portion
thereof shall be taken or condemned in whole or in part for public purposes,
then the term of this Lease Agreement shall, at the option of Lessor, forthwith
cease and terminate, and Lessor shall receive the entire award for land and
buildings. Lessee shall have the right to recover from such condemning
authority, but not from Lessor, any compensation as may be awarded to Lessee on
account of the difference between the actual rental rate of the Leased Premises
and the fair market value thereof, to the extent the fair market value exceeds
such actual rental, moving and relocation expenses, and depreciation to and
removal of Lessee's personal property. In the event Lessor does not terminate as
herein provided, there shall be a proportionate reduction in rent.

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<PAGE>

SEC. 15 DEFAULT BY LESSEE: If Lessee should default in any covenant or agreement
to be performed by it or abandon or vacate the Leased Premises and, if after
written notice is given by Lessor to Lessee (except for a default caused by the
nonpayment of rent as set forth in Section 5 hereof, for which no notice is
required), such default shall continue for a period of ten (10) days or if the
leasehold interest of Lessee shall be taken on execution or other process of
law, then and in any of said cases, Lessor may immediately or at any time
thereafter, without further notice or demand, enter upon and into the Leased
Premises or any part thereof and take absolute possession of the same fully and
absolutely without such re-entry automatically working a forfeiture of the rents
to be paid and the covenants to be performed by Lessee for the full term of this
Lease Agreement and at Lessor's election, Lessor may either lease or sublet the
Leased Premises or any part thereof on such terms and conditions and for such
rents and for such times as Lessor may reasonably elect and after crediting the
proceeds of any rent collected by Lessor from such reletting on the rentals
stipulated to be paid under this Lease Agreement by Lessee, collect from Lessee
any balance remaining due on the rent reserved under this Lease Agreement, or
Lessor may declare this Lease Agreement forfeited and may take full and absolute
possession of the Leased Premises free from any subsequent rights or obligations
of Lessee or at the option of Lessor, the present value of the entire rent for
the balance of the Term, computed using a discount rate of eight percent (8%),
but allowing for a reasonable period fo vacancy as determined by the market
conditions at that time (during which reasonable period of vacancy no discount
rate shall be applied) shall at once become due and payable, as if by the terms
of this Lease Agreement it were all payable in advance. In the event of such
default and reletting by Lessor, Lessee agrees to pay all costs of refurbishing
and all costs of reletting the Leased Premises.

      All remedies herein given Lessor, including all those not set forth but
provided by law, shall be cumulative, and the exercise of one or more of such
remedies by Lessor shall not exclude the exercise of any other consistent
remedy, nor shall any waiver by Lessor, express or implied, or any breach of any
term, covenant or condition hereof be deemed a waiver of such term, condition or
covenant, or of any subsequent breach of the same or any other term, covenant or
condition hereof. Acceptance of rent by Lessor from Lessee or any assignee,
sublessee or other successor in interest to Lessee, with or without notice,
shall never be construed as a waiver of any breach of any term, condition or
covenant of this Lease Agreement. Failure of Lessor to declare any default upon
occurrence thereof, or delay in taking action with respect thereto, shall not
waive such default, but Lessor shall have the right to declare such default at
any time and take such action as may be authorized hereunder, in law or equity,
or otherwise.

      In addition to the payment of the rents and the late payment charge as
provided herein, Lessee agrees to reimburse Lessor for all expenses incurred by
Lessor in effecting enforcement of these Lease Agreement provisions, lease
termination, right of re-entry and in securing possession of the Leased
Premises, including attorneys' fees, (whether suit is filed or not) and court
costs. In the event of a money judgment, attorneys' fees shall be reasonable.

SEC. 16 HOLD HARMLESS: Lessee will indemnify Lessor for, and hold Lessor
harmless from and against all fines, suits, claims, demands, liabilities, and
actions (including costs and expenses of defending against such claims)
resulting or alleged to result from any breach, violation or non-performance of
any covenant or condition hereof or from the use or occupancy of the Leased
Premises, by Lessee or Lessee's agents, employees, licensees or invitees. Lessor
shall not be liable to Lessee or Lessee's agents for any damage to person or
property resulting from any act or omission or negligence of any co-tenant,
visitor or other occupant of the Building.

SEC. 17 LIEN WAIVER: Lessor expressly waives any and all liens, express or
implied, statutory or contractual, that would otherwise serve to secure Lessee's
obligation hereunder.

SEC. 18 NON-WAIVER: Neither acceptance of rent by Lessor nor failure by Lessor
to exercise available rights and remedies, whether singular or repetitive, shall
constitute a waiver of any of Lessor's rights hereunder. Waiver by Lessor of any
right for any default of Lessee shall not constitute a waiver of any right for
either a subsequent default of the same obligation or any other default. No act
or thing done by Lessor or its agent shall be deemed to be an acceptance or
surrender of the Leased Premises and no agreement to accept a surrender of the
Leased Premises shall be valid unless it is in writing and signed by a duly
authorized officer or agent of Lessor.

SEC. 19 RULES AND REGULATIONS: Such reasonable rules and regulations applying to
all tenants in the Building as may be hereafter adopted by Lessor for the
safety, care and cleanliness of the premises and the preservation of good order
thereon, are hereby made a part hereof and Lessee agrees to comply with all such
rules and regulations. Lessor shall have the right at all times to change such
rules and regulations or to amend them in any reasonable manner as may be deemed
advisable by Lessor, all of which changes and amendments will be sent by Lessor
to Lessee in writing and shall be thereafter carried out and observed by Lessee.
(See Exhibit "C" attached.)

SEC. 20 ASSIGNMENT BY LESSOR: Lessor shall have the right to assign or transfer,
in whole or in part, every feature of its rights and obligations hereunder and
in the Building and Leased Premises. Such assignments or transfers may be made
to a corporation, trust, trust company, individual or group of individuals, and
howsoever made shall be in all things respected and recognized by Lessee. Lessee
specifically agrees to look solely to Lessor's interest in the Building for the
recovery of any judgment from Lessor, it being agreed that Lessor shall never be
personally liable for any such judgment.

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<PAGE>

SEC. 21 SEVERABILITY: This Lease Agreement shall be construed in accordance with
the laws of the State of Texas. If any clause or provision of this Lease
Agreement is illegal, invalid or unenforceable, under present or future laws
effective during the term hereof, then it is the intention of the parties hereto
that the remainder of this Lease Agreement shall not be affected thereby, and it
is also the intention of both parties that in lieu of each clause or provision
that is illegal, invalid or unenforceable, there be added as part of this Lease
Agreement a clause or provision as similar in terms to such illegal, invalid or
unenforceable clause or provision as may be possible and be legal, valid and
enforceable.

SEC. 22 SIGNS: No signs of any kind or nature, symbol or identifying mark shall
be put on the Building, in the halls, elevators, staircases, entrances, parking
areas or upon the doors or walls, whether plate glass or otherwise, of the
Leased Premises or within the Leased Premises so as to be visible from the
public areas or exterior of the Building without prior written approval of
Lessor. All signs or lettering shall conform in all respects to the sign and/or
lettering criteria established by Lessor.

SEC. 23 SUCCESSORS AND ASSIGNS: Lessor and Lessee agree that all provisions
hereof are to be construed as covenants and agreements as though the words
imparting such covenants were used in each separate paragraph hereof, and that,
except as restricted by the provisions of the section entitled "Subletting and
Assigning" hereof, this Lease Agreement and all the covenants herein contained
shall be binding upon the parties hereto, their respective heirs, legal
representatives, successors and assigns.

SEC. 24 SUBORDINATION: Lessor shall obtain and deliver to Lessee within thirty
(30) days after the date of this Lease Agreement a Subordination,
Non-Disturbance and Attornment Agreement (the "SNDA") from Lessor's mortgagee
providing, as a condition to Lessee's subordination or attornment to such
mortgagee, that Lessee shall not be disturbed in its possession of the Leased
Premises during the Term hereof, nor will Lessee's rights under this Lease
Agreement be terminated, so long as Lessee is not under default under this Lease
Agreement beyond any applicable cure period. In the event Lessor does not
deliver the SNDA within such thirty (30) day period, Lessee shall have the right
to terminate this Lease Agreement. Lessee shall, in the event of any proceedings
brought for the foreclosure of, or in the event of the exercise of the power of
sale under, any mortgage or deed of trust covering the Leased Premises, attorn
to and recognize such purchaser or assignee or mortgagee as Lessor under this
Lease Agreement.

SEC. 25 ACCESS BY LESSOR: After reasonable notice to Lessee, except in the case
of an emergency, Lessor, its agents and employees shall have access to and the
right to enter upon the Leased Premises at any reasonable time to examine the
condition thereof, to make any repairs or alterations required to be made by
Lessor hereunder, to show the Leased Premises to prospective purchasers or
tenants and for any other purpose deemed reasonable by Lessor.

SEC. 26 DELAY IN POSSESSION: In the event the Leased Premises should not be
ready for occupancy by the Commencement Date stated in Section 2 hereinabove by
reason of acts of God, strikes, walkouts or other industrial disturbance,
explosions, unavailability of materials, acts of governments or for any reason
whatsoever, Lessor shall not be liable or responsible for any claims, damages or
liabilities in connection therewith or by reason thereof, and the term of this
Lease Agreement shall commence at the time the Leased Premises are ready for
occupancy by Lessee. Should the term of this Lease Agreement commence on a date
other than that specified in Section 2 hereinabove for any reason, Lessor and
Lessee will, at the request of either, execute a revised commencement date and
the stated term in this Lease Agreement shall thereupon commence and the
expiration date shall be extended so as to give effect to the full stated term.

SEC. 27 HOLDING OVER: In the event of holding over by Lessee after the
expiration or termination of the Lease Agreement, such hold over shall be as a
tenant at will and all of the terms and provisions of this Lease Agreement shall
be applicable during such period, except that Lessee shall pay Lessor as rental
for the period of such hold over an amount equal to one hundred fifty percent
(150%) the rent payable by Lessee for the month immediately preceding the
holdover period, and Lessee will vacate the Leased Premises and deliver the same
to Lessor upon Lessee's receipt of notice from Lessor to vacate the Leased
Premises. The rental payable during such hold over period shall be payable to
Lessor on demand. No holding over by Lessee, whether with or without consent of
Lessor, shall operate to extend this Lease Agreement except as herein provided.

SEC. 28 INDEPENDENT OBLIGATION TO PAY RENT: It is the intention of the parties
hereto that the obligations of Lessor and Lessee hereunder shall be separate and
independent covenants and agreements, that the rent and all other sums payable
by Lessee hereunder shall continue to be payable in all events and that the
obligations of Lessee hereunder shall continue unaffected, unless the
requirement to pay or perform the same shall have been terminated pursuant to an
express provision of this Lease Agreement.

      Lessee agrees that it will remain obligated under this Lease Agreement in
accordance with its terms, and that it will not take any action to terminate,
rescind or void this Lease Agreement, notwithstanding (a) the bankruptcy,
insolvency, reorganization, composition, readjustment, liquidation, dissolution,
winding up or other proceeding affecting Lessor or any assignee of Lessor in any
such proceeding and (b) any action with respect to this Lease Agreement which
may be taken by any trustee or receiver of Lessor or of any assignee of Lessor
in any such proceeding or by any court in any such proceeding.

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<PAGE>

      Except as otherwise expressly provided herein, Lessee waives the right (a)
to quit, terminate or surrender this Lease Agreement or the Leased Premises or
any part thereof, or (b) to any abatement, suspension, deferment or reduction of
the rent or any other sums payable under this Lease Agreement.

SEC. 29 INDEMNITY OF LESSOR-INSURANCE:

      A. Except for Lessor's gross negligence or willful misconduct not waived
by Lessee, Lessee covenants that Lessor shall not be liable for any damage or
liability of any kind or for any injury to or death of persons or damage to
property of Lessee or any other person, including consequential loss or damage
from any cause whatsoever by reason of the construction, use, occupancy or
enjoyment of the Leased Premises by Lessee or any person therein or holding
under Lessee or by or through the acts or omissions of other tenants of the
Building. Lessee hereby agrees, as part of the material consideration for this
Lease Agreement, to indemnify and save Lessor harmless from all claims, action,
demands, costs and expenses and liability whatsoever, including reasonable
attorneys' fees, on account of any such real or claimed damage or liability, and
from all liens, claims and demands occurring in, on or at any portion of the
Leased Premises and its facilities, or any repairs or alterations which Lessee
may make upon the Leased Premises.

      B. Lessee shall carry insurance during the entire Term insuring Lessee and
Lessor, as their interests may appear, with provisions, coverages and in
companies reasonably acceptable to Lessor, and with such increases in limits as
Lessor may from time to time request; initially, Lessee shall maintain coverages
as follows:

            (1)   LIABILITY COVERAGE. In case of personal injury to or death of
                  any person, $1,000,000 for each occurrence and, in case of
                  property damage, not less than $500,000 for any one
                  occurrence.

            (2)   FIRE AND EXTENDED COVERAGE. In case of fire, sprinkler
                  leakage, malicious mischief, vandalism and other extended
                  coverage perils, for the full insurable replacement value of
                  all additions, and of all office furniture, office equipment,
                  merchandise and all other items of Lessee's property in the
                  Leased Premises.

            (3)   WORKER'S COMPENSATION COVERAGE. Throughout the Term of this
                  Lease Agreement, Lessee shall maintain in full force and
                  effect a policy or policies of statutory worker's compensation
                  insurance, in the amount required by law, issued by an
                  insurance company acceptable to Lessor.

            (4)   CERTIFICATE OF INSURANCE. Upon the earlier of fifteen (15)
                  days after the execution hereof or fifteen (15) days prior to
                  the Commencement Date, Lessee shall furnish to Lessor policies
                  or certificates evidencing such coverage, which certificates
                  shall state that such insurance coverage may not be changed or
                  cancelled without at least thirty (30) days prior written
                  notice to Lessor and Lessee. In the event Lessee shall fail to
                  procure such insurance, Lessor may, at its option, procure the
                  same for the account of Lessee and the cost thereof shall be
                  paid to Lessor as additional rent upon receipt by Lessee of
                  bills therefor.

      C. Lessor shall at all times during this Term of this Lease Agreement
maintain in effect a policy or policies of insurance covering the Building
(excluding property required to be insured by Lessee) in an amount equal to one
hundred percent (100%) of replacement cost for the Building providing protection
against perils included within the standard Texas form of fire and extended
coverage insurance policy, together with insurance against sprinkler damage,
vandalism and malicious mischief, and such other risks as Lessor may from time
to time determine. Lessor shall at all times during the Term hereof maintain in
effect a policy of commercial general liability insurance with limits of at
least One Million and 00/100 Dollars ($1,000,000.00) per occurrence and Two
Million and 00/100 Dollars ($2,000,000.00) in the aggregate.

SEC. 30 WAIVER OF SUBROGATION: Lessor and Lessee hereby waive any rights each
may have against the other, on account of any loss or damage occasioned to
Lessor or Lessee, as the case may be, their respective property, the Leased
Premises, its contents or to the other portion of the property arising from any
risk covered by valid and enforceable fire and extended coverage insurance, to
the extent of such coverage. Lessor and Lessee each agree to cause an
endorsement to be furnished to their respective insurance policies recognizing
this waiver of subrogation.

SEC. 31 ENTIRE AGREEMENT: This instrument and any attached addenda or exhibits
signed by the parties constitute the entire agreement between Lessor and Lessee;
no prior written or prior or contemporaneous oral promises or representations
shall be binding. This Lease Agreement shall not be amended, changed or extended
except by written instrument signed by both parties hereto. Paragraph captions
herein are for Lessor's and Lessee's convenience only, and neither limit nor
amplify the provisions of this instrument. Lessee agrees, at Lessor's request,
to execute a recordable Memorandum of this Lease Agreement.

SEC. 32 NOTICES: Whenever in this Lease Agreement it shall be required or
permitted that notice or demand be given or served by either party to this Lease
Agreement to or on the other, such notice or demand shall be given or served and
shall not be

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<PAGE>

deemed to have been given or served unless in writing and delivered personally
or forwarded by Certified or Registered Mail, postage prepaid or other reputable
common carrier guaranteeing next-day delivery, addressed as follows:

         To the Lessor: FRM West Loop Associates #6, Ltd.
                        1021 Main, Suite 1400
                        Houston, TX 77002

         To the Lessee: At the Address noted for Lessee on the signature page
                        hereof until the Commencement Date, at which time it
                        shall become the Address of the Leased Premises.

Such addresses may be changed from time to time by either party by serving
notice as above provided.

SEC. 33 COMMENCEMENT DATE: As of date hereof, Lessor and Lessee acknowledge that
the Leased Premises has not been completed. Lessor shall use its best efforts to
accomplish the completion of the Leased Premises in accordance with the
construction agreement attached hereto as Exhibit "F" and deliver possession
thereof to Lessee by April 1, 2002. Any delay in delivering possession of the
Leased Premises shall result in a change in the Commencement Date unless the
delay is caused solely by Lessee. In the event that said Leased Premises have
not in fact then been completed as aforesaid, Lessee shall notify Lessor in
writing of its objections. Lessor shall have a reasonable time after delivery of
such notice in which to take such corrective action as may be necessary, and
shall notify Lessee in writing as soon as it deems such corrective action has
been taken and the Leased Premises are completed and ready for occupancy by
Lessee. Taking of possession by Lessee shall be conclusively deemed to establish
that said Leased Premises are in good and satisfactory condition as of the date
possession was so taken by Lessee, except for latent defects, if any. Lessee
shall, if requested by Lessor, execute and deliver to Lessor an Acceptance of
Premises Memorandum of the Leased Premises, which shall be attached as Exhibit
"D" hereto. The date the Leased Premises have been completed in accordance
herewith shall be the first day of the term hereof and said Acceptance of
Premises Memorandum, if requested by Lessor, shall bear such date, and the rent
herein imposed shall accrue from and after such date which is hereby designated
"Commencement Date". In the event that the Commencement Date is a date after the
first day of the Term as stated in Section 2 of this Lease Agreement, then the
expiration date shall be extended by the same number of days. In the event that
the Commencement Date is a date prior to the first day of the Term as stated in
Section 2 of this Lease Agreement, then the expiration date shall not change.

SEC. 34 RELOCATION OF LESSEE: INTENTIONALLY DELETED.

SEC. 35 BROKERS: Lessee warrants that it has had no dealings with any real
estate broker or agent in connection with the negotiation of this Lease
Agreement, excepting only the broker(s) named on the signature page of this
Lease Agreement and that it knows of no other real estate broker(s) or agent(s)
who is(are) or might be entitled to a commission in connection with this Lease
Agreement. Lessor shall agree to pay all real estate commissions due in
connection with this Lease Agreement only to the broker(s) named herein and
Lessee agrees to indemnify and hold harmless Lessor from and against any
liability from all other claims for commission arising from the negotiation of
this Lease Agreement.

SEC. 36 ESTOPPEL CERTIFICATES: From time to time after Lessee accepts the Leased
Premises, within ten (10) days after request in writing therefor from Lessor,
Lessee agrees to execute and deliver to Lessor, or to such other addressee or
addresses as Lessor may designate (and Lessor and any such addressee may rely
thereon), a statement in writing in the form of Exhibit "E" or in such other
form and substance reasonably satisfactory to Lessor (herein called "Lessee's
Estoppel Certificate"), certifying to all or any part of the information
provided for in Exhibit "E" as is requested by Lessor.

      In the event that Lessee fails to provide Lessee's Estoppel Certificate
within ten (10) days after Lessor's written request therefor, Lessee does hereby
irrevocably appoint Lessor as attorney-in-fact of Lessee, coupled with an
interest, in Lessee's name, place and stead to sign and deliver Lessee's
Estoppel Certificate as if the same had been signed and delivered by Lessee.

SEC. 37 EXHIBITS: Exhibits A through F are attached hereto and made a part of
this Lease Agreement.

      IN WITNESS WHEREOF, Lessor and Lessee, acting herein by duly authorized
individuals, have caused these presents to be executed in multiple counterparts,
each of which shall have the force and effect of an original on this 20th day of
February, 2002.

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<PAGE>

                                  LESSOR:
                                  FRM WEST LOOP ASSOCIATES #6, LTD.,
                                  a Texas limited partnership
                                  By: FRM 1603, Inc., General Partner

                                  By: /s/ Frederick R. McCord
                                      -----------------------
                                      Frederick R. McCord, President

                                  LESSEE:

                                  TEXAS BIOTECHNOLOGY CORPORATION,
                                  a Delaware corporation

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

                                  7000 Fannin, 20th Floor
                                  Houston, TX 77030

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<PAGE>

                                    EXHIBIT B

                                PARKING AGREEMENT

Building:  6700 West Loop South                   Suite No.:      400

Lessor:    FRM West Loop Associates #6, Ltd.

Lessee:    Texas Biotechnology Corporation,       Date of Lease: 2/20/02
           a Delaware corporation

So long as the Lease Agreement of which this agreement is a part shall remain in
effect, Lessee or persons designated by Lessee shall rent on a non-exclusive
basis up to eight (8) reserved parking spaces and up to fifty-two (52)
unreserved parking spaces on Level 2 or above of the garage.

Lessee shall pay as rent for each parking space, at the same times and in the
same manner as Base Rent is due under the Lease Agreement; the rate for such
parking spaces from time to time designated by Lessor as standard for the
Building.

Lessee shall pay initially for each space rented a sum of Sixty and 00/100
Dollars ($60.00) per space, per month (plus applicable sales tax) for reserved
parking spaces and Forty-Five and 00/100 Dollars ($45.00) per space, per month
(plus applicable sales tax) for unreserved parking spaces; provided, however,
that Lessee shall pay only for those spaces actually being utilized by Lessee up
to eight (8) reserved and twenty-six (26) unreserved parking spaces. Lessee
shall have the right to use the balance of up to twenty-six (26) unreserved
parking spaces at no cost throughout the Term hereof.

Lessor shall provide Lessee at least sixty (60) days notice of any change in the
standard parking rates and the giving of such notice shall be deemed an
amendment to this Agreement and Lessee shall thereafter pay the adjusted rent.

Lessee may validate visitor parking by such method or methods as Lessor may
approve, at the validation rate from time to time generally applicable to
visitor parking. Lessor expressly reserves the right to designate and
redesignate parking areas for Lessee and/or Lessee's visitors, and to modify the
parking structure for other uses or to any extent.

A condition of any parking shall be compliance by the parker with garage rules
and regulations, including any sticker or other identification system
established by Lessor. The following rules and regulations are in effect until
notice is given to Lessee of any change. Lessor reserves the right to modify
and/or adopt such other reasonable and non-discriminatory rules and regulations
for the garage as it deems necessary for the operation of the garage. Lessor may
refuse to permit any person who violates the rules to park in the garage, and
any violation of the rules shall subject the car to removal.

                          PARKING RULES AND REGULATIONS

1.    Cars must be parked entirely within the stall lines painted on the floor.

2.    All directional signs and arrows must be observed.

3.    The speed limit shall be five (5) miles per hour.

4.    Parking prohibited:

      (a)   in areas not striped for parking

      (b)   in aisles

      (c)   where "no parking" signs are posted

      (d)   on ramps

      (e)   in cross-hatched areas

      (f)   in spaces reserved for exclusive use by designated tenants

      (g)   in such other areas as may be designated by Lessor or Lessor's
            agent(s).

5.    Parking stickers or any other device or form of identification supplied by
      Lessor shall remain the property of Lessor and shall not be transferable.
      There will be a replacement charge payable by Lessee equal to the amount
      posted from time to time by Lessor for loss of any magnetic parking card
      or parking sticker.

6.    Garage managers or attendants are not authorized to make or allow any
      exceptions to these Rules and Regulations.

7.    Every parker is required to park and lock his own car. All responsibility
      for damage to cars or persons is assumed by the parker.

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<PAGE>

8.    Lessee is required to give Lessor, on a quarterly basis, a list of
      employees parking in the garage which shall include year, make and model
      of car and license number.

Failure to promptly pay the rent required hereunder or persistent failure on the
part of Lessee or Lessee's designated parkers to observe the Rules and
Regulations above shall give Lessor the right to terminate Lessee's right to use
the parking structure. No such termination shall create any liability on Lessor
or be deemed to interfere with Lessee's right to quiet possession of its
Premises.

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<PAGE>

                                    EXHIBIT C

                              RULES AND REGULATIONS

The following standards shall be observed by Lessee for the mutual safety,
cleanliness and convenience of all occupants of the Building. These rules are
subject to change from time to time, as specified in the Lease Agreement.

1.    All tenants will refer all contractors' representatives and installation
      technicians who are to perform any work within the Building to Lessor for
      Lessor's supervision, approval and control before the performance of any
      such work. This provision shall apply to all work performed in the
      Building including, but not limited to, installations of telephones,
      computer equipment, electrical devices and attachments, and any and all
      installations of every nature affecting floors, walls, woodwork, trim,
      windows, ceilings, equipment and any other physical portion of the
      Building. Lessee shall not mark, paint, drill into, or in any way deface
      any part of the Building or the Leased Premises, except with the prior
      written consent of the Lessor, and as the Lessor may direct.

2.    The work of the janitorial or cleaning personnel shall not be hindered by
      Lessee after 5:30 p.m., and such work may be done at any time when the
      offices are vacant. The windows, doors and fixtures may be cleaned at any
      time. Lessee shall provide adequate waste and rubbish receptacles,
      cabinets, book cases, map cases, etc., necessary to prevent unreasonable
      hardship to Lessor in discharging its obligations regarding cleaning
      service.

3.    Movement of furniture or office equipment in or out of the Building, or
      dispatch or receipt by Lessee of any heavy equipment, bulky material or
      merchandise which requires use of elevators or stairways, or movement
      through the Building's service dock or lobby entrance shall be restricted
      to such hours as Lessor shall designate. All such movement shall be in a
      manner to be agreed upon between Lessee and Lessor in advance. Such prior
      arrangements shall be initiated by Lessee. The time, method and routing of
      movement and limitations for safety or other concern which may prohibit
      any article, equipment or other item from being brought into the Building
      shall be subject to Lessor's discretion and control. Any hand trucks,
      carryalls or similar appliances used for the delivery or receipt of
      merchandise or equipment shall be equipped with rubber tires, side guards
      and such other safeguards as the Building shall require. Although Lessor
      or its personnel may participate in or assist in the supervision of such
      movement, Lessee assumes final responsibility for all risks as to damage
      to articles moved and injury to persons or property engaged in such
      movement, including equipment, property and personnel of Lessor if damaged
      or injured as a result of acts in connection with carrying out this
      service for Lessee, from the time of entering the property to completion
      of work. Lessor shall not be liable for the acts of any person engaged in,
      or any damage or loss to any of said property or persons resulting from
      any act in connection with such service performed for Lessee.

4.    No sign, advertisement or notice shall be displayed, painted or affixed by
      Lessee, its agents, servants or employees, in or on any part of the
      outside or inside of the Building or Leased Premises without prior written
      consent of Lessor, and then only of such color, size, character, style and
      material and in such places as shall be approved and designated by Lessor.
      Signs on doors and entrances to the Leased Premises shall be placed
      thereon by Lessor.

5.    Lessee shall not place, install or operate on the Leased Premises or in
      any part of the Building any engine, refrigerating, heating or air
      conditioning apparatus, stove or machinery, or conduct mechanical
      operations, or place or use in or about the Leased Premises any
      inflammable, explosive, hazardous or odorous solvents or materials without
      the prior written consent of Lessor. No portion of the Leased Premises
      shall at any time be used for cooking, sleeping or lodging quarters.
      Lessee may use coffee pots, refrigerators or microwaves in Leased
      Premises.

6.    Lessee shall not make or permit any loud or improper noises in the
      Building or otherwise interfere in any way with other tenants.

7.    Lessor will not be responsible for any lost or stolen personal property or
      equipment from the Leased Premises or public areas, regardless of whether
      such loss occurs when the area is locked against entry or not.

8.    Lessee, or the employees, agents, servants, visitors or licensees of
      Lessee, shall not, at any time or place, leave or discard rubbish, paper,
      articles or objects of any kind whatsoever outside the doors of the Leased
      Premises or in the corridors or passageways of the Building or attached
      garage. No animals, bicycles or vehicles of any description shall be
      brought into or kept in or about the Building.

9.    No additional lock or locks shall be placed by Lessee on any door in the
      Building unless written consent of Lessor shall have first been obtained.
      Two (2) keys will be furnished by Lessor for the Leased Premises, and any
      additional key required must be obtained from Lessor. A charge will be
      made for each additional key furnished. All keys shall be surrendered to
      Lessor upon termination of tenancy.

10.   None of the entries, passages, doors, hallways or stairways in the
      Building shall be blocked or obstructed.

13
<PAGE>

11.   Lessor shall have the right to determine and prescribe the weight and
      proper position of any unusually heavy equipment, including computers,
      safes, large files, etc., that are to be placed in the Building, and only
      those which in the exclusive judgement of the Lessor will not do damage to
      the floors, structure and/or elevators may be moved into the Building. Any
      damage caused by installing, moving or removing such aforementioned
      articles in the Building shall be paid for by Lessee.

12.   All Christmas and other decorations must be constructed of flame retardant
      materials. Live Christmas trees are not permitted in the Leased Premises.

13.   Lessee shall provide Lessor with a list of all personnel authorized to
      enter the Building after hours (6:00 p.m. to 7:00 a.m. Monday through
      Friday, 1:00 p.m. to 12:00 midnight Saturdays, and 24 hours a day on
      Sundays and holidays).

14.   After hours air conditioning/heating (6:00 p.m. to 7:00 a.m. Monday
      through Friday; 1:00 p.m. to 12:00 midnight Saturday; and 24 hours a day
      Sunday and holidays) must be requested in writing by noon of a regular
      work day prior to the day for which additional air conditioning is
      requested. Lessee shall be charged the prevailing hourly rate.

15.   The following dates shall constitute "holidays" as said term is used in
      this Lease Agreement: New Year's Day, Memorial Day, Independence Day,
      Labor Day, Thanksgiving and the Friday following Thanksgiving Day,
      Christmas and any other holiday recognized and taken by tenants
      cumulatively occupying at least one-half of the net rentable area of
      office space of the Building.

16.   Lessee shall notify Lessor of furniture or equipment to be removed from
      the Building after hours. Description and serial numbers shall be provided
      if requested by Lessor.

17.   Lessor shall designate one elevator to be the freight elevator to be used
      to handle packages and shipments of all kinds. The freight elevator shall
      be available to handle such deliveries from 9:00 a.m. to 11:00 a.m. and
      2:00 p.m. to 3:30 p.m. weekdays. Parcel Post, express, freight or
      merchants' deliveries can be made anytime within these hours. No furniture
      or freight shall be handled outside the above hours, except by previous
      arrangement.

18.   Names to be placed on or removed from the directory board in the lobby of
      the Building should be furnished to the Building Manager in writing on
      Lessee's letterhead. Lessee is allocated one (1) directory strip. At
      Lessor's option, additional strips may be provided to Lessee at Lessor's
      cost plus fifteen percent (15%).

19.   Any additional services as are routinely provided to tenants, not required
      by the Lease Agreement to be performed by Lessor, which Lessee requests
      Lessor to perform, and which are performed by Lessor, shall be billed to
      Lessee at Lessor's cost plus fifteen percent (15%).

20.   All doors leading from public corridors to the Leased Premises are to be
      kept closed when not in use.

21.   Canvassing, soliciting or peddling in the Building is prohibited and
      Lessee shall cooperate to prevent same.

22.   Lessee shall give immediate notice to the Building Manager in case of
      accidents in the Leased Premises or in the Building or of defects therein
      or in any fixtures or equipment, or of any known emergency in the
      Building.

23.   Lessee shall not use the Leased Premises or permit the Leased Premises to
      be used for photographic, multilith or multigraph reproductions, except in
      connection with its own business.

24.   The requirements of Lessee will be attended to only upon application to
      the Building Manager. Employees of Lessor shall not perform any work or do
      anything outside of their regular duties, unless under special
      instructions from the Building Manager.

25.   Lessee shall place or have placed solid pads under all rolling chairs such
      as may be used at desks or tables. Any damages caused to carpet by not
      having same shall be repaired or replaced at the expense of Lessee.

26.   Lessee, or the employees, agents, servants, visitors or licensees of
      Lessee shall abide by the rules and regulations for the garage included in
      the Parking Agreement attached hereto as Exhibit B.

27.   Lessor reserves the right to rescind any of these Rules and Regulations of
      the Building, and to make such other and further rules and regulations as
      in its judgement shall from time to time be needful for the safety,
      protection, care and cleanliness of the Building, the Leased Premises and
      the attached garage, the operation thereof, the preservation of good order
      therein and the protection and comfort of the other tenants in the
      Building and their agents, employees and invitees, which rules and
      regulations, when made and written notice thereof is given to Lessee,
      shall be binding upon Lessee in like manner as if originally herein
      prescribed.

14
<PAGE>

28.   Lessor will provide sixty (60) cardkeys to Lessee. All others will be
      furnished to Lessee at a cost of Ten and 00/100 Dollars ($10.00) per card.
      Any future increase in the cost of cardkeys will be passed on to Lessee
      for any additional cardkeys required.

29.   Lessee, or its employees, agents, servants, visitors, invitees or
      licensees of Lessee, shall not smoke or permit to be smoked cigarettes,
      cigars or pipes within the Leased Premises or Building. Smoking shall be
      confined to area(s) designated by Lessor. Lessor shall have no obligation
      to Lessee for failure of another tenant, its employees, agents, servants,
      visitors, invitees or licensees to comply with this paragraph.

15
<PAGE>

                                    EXHIBIT D

                        ACCEPTANCE OF PREMISES MEMORANDUM

This Memorandum is an amendment to the Lease Agreement for space in 6700 West
Loop South, Bellaire, Harris County, Texas, executed on the _______________ day
of _________________________, 20_____ between FRM WEST LOOP ASSOCIATES #6, LTD.
as Lessor and TEXAS BIOTECHNOLOGY CORPORATION, a Delaware corporation as Lessee.
Lessor and Lessee hereby agree that:

1.    Except for those items shown on the attached "punch list", if any, which
      Lessor will remedy within ___________ days hereof, Lessor has fully
      completed the construction work required under the terms of the Lease
      Agreement.

2.    The Leased Premises are tenantable, the Lessor has no further obligation
      for construction (except as specified above), and Lessee acknowledges that
      both the Building and the Leased Premises are satisfactory in all
      respects.

3.    The Commencement Date of the Lease Agreement is hereby agreed to be the
      ________________________ day of _____________________________, 20_____.

4.    The Expiration Date of the Lease Agreement is hereby agreed to be the
      ______________________ day of __________________________, 20______.

All other terms and conditions of the Lease Agreement are hereby ratified and
acknowledged to be unchanged.

Agreed and Executed this _______________ day of _________________________,
20__________.

Lessor:

FRM WEST LOOP ASSOCIATES #6, LTD., a Texas limited partnership

By: FRM 1603, Inc., General Partner

By: ________________________________________
    Frederick R. McCord, President

Lessee:

TEXAS BIOTECHNOLOGY CORPORATION,
a Delaware corporation

By:        ________________________________________

Name:      ________________________________________

Title:     ________________________________________

16
<PAGE>

                                    EXHIBIT E

                          LESSEE'S ESTOPPEL CERTIFICATE

(Addressee)

RE: 6700 West Loop South - Bellaire, Texas

Gentlemen:

The undersigned ("Lessee") has executed and entered into that certain lease
agreement ("Lease Agreement") attached hereto as Exhibit A and made a part
hereof for all purposes with respect to those certain premises ("Leased
Premises") which are located in the above-referenced project ("Project") and are
more fully described in the Lease Agreement. Lessee understands that the entity
to whom this letter is addressed ("Addressee") has committed to loan or invest a
substantial sum of money in reliance upon this certification by the undersigned,
which certification is a condition precedent to making such loan or investment,
or that Addressee intends to take some other action in reliance upon this
certification.

With respect to the Lease Agreement, Lessee certifies to you the following, with
the intention that you may rely fully thereon:

1.    A true and correct copy of the Lease Agreement, including any and all
      amendments and modifications thereto, is attached hereto as Exhibit A;

2.    The original Lease Agreement is dated ______________________________,
      20_____, and has been assigned, modified, supplemented or amended only in
      the following respects:

      (Please write "None" above or, on a separate sheet of paper, state the
      effective date of and describe any oral or written modifications,
      supplements or amendments to the Lease Agreement and attach a copy of such
      modifications, supplements or amendments, with the Lease Agreement as
      Exhibit A);

3.    Lessee is in actual occupancy of the Leased Premises under the Lease
      Agreement; the Leased Premises are known as Suite _________, of the
      Project; and the Leased Premises contain approximately ______________
      square feet;

4.    The initial term of the Lease Agreement commenced on
      ______________________________, 20____, and ends at midnight on
      __________________________________, 20_____, at a monthly base rent of
      $_______________________________, and no rentals or other payments in
      advance of the current calendar month have been paid by Lessee, except as
      follows:

      (Please write "None" above or describe such payments on a separate sheet
      of paper);

5.    Base Rent with respect to the Lease Agreement has been paid by Lessee
      through ______________, 20______; all additional rents and other charges
      have been paid for the current periods;

6.    There are no unpaid concessions, bonuses, free months' rent, rebates or
      other matters affecting the rent for Lessee, except as follows:

      (Please write "None" above or describe such matters on a separate sheet of
      paper);

7.    No security or other deposit has been paid by Lessee with respect to the
      Lease Agreement, except as follows:

      (Please write "None" above or describe such deposits on a separate sheet
      of paper);

8.    The Lease Agreement is in full force and effect and there are no events or
      conditions existing which, with notice or the lapse of time or both, could
      constitute a monetary or other default of the Lessor under the Lease
      Agreement, or entitle Lessee to any offset or defense against the prompt
      current payment of rent or constitute a default by Lessee under the Lease
      Agreement, except as follows:

      (Please write "None" above or describe such default on a separate sheet of
      paper);

9.    All improvements required to be made by Lessor under the terms of the
      Lease Agreement have been satisfactorily completed and accepted by Lessee
      as being in conformity with the Lease Agreement, except as follows:

      (Please write "None" above or describe such improvements on a separate
      sheet of paper);

17
<PAGE>

Lessee's Estoppel Certificate
Page 2

10.   Lessee has no option to expand or rent additional space within the Project
      or any right of first refusal with regard to any additional space within
      the Project, other than the Leased Premises, except as follows:

      (Please write "None" above or describe such right or option on a separate
      sheet of paper);

11.   Lessee has no right or option to renew the Lease Agreement for any period
      of time after the expiration of the initial term of the Lease Agreement,
      except as follows:

      (Please write "None" above or describe such right on a separate sheet of
      paper);

12.   To the best of Lessee's knowledge, any and all broker's leasing and other
      commissions relating to and/or resulting from Lessee's execution of the
      Lease Agreement and occupancy of the Leased Premises have been paid in
      full and no broker's leasing or other commissions will be or become due or
      payable in connection with or as a result of either Lessee's execution of
      a new Lease Agreement covering all or any portion of the Leased Premises
      or any other space within the Project or Lessee's renewal of the Lease
      Agreement, except as follows:

      (Please write "None" above or describe such right on a separate sheet of
      paper);

13.   To the best of Lessee's knowledge, the use, maintenance or operation of
      the Leased Premises complies with, and will at all times comply with, all
      applicable federal, state, county or local statutes, laws, rules and
      regulations of any governmental authorities relating to environmental,
      health or safety matters (being hereinafter collectively referred to as
      the Environmental Laws);

14.   The Leased Premises have not been used and Lessee does not plan to use the
      Leased Premises for any activities which, directly or indirectly, involve
      the use, generation, treatment, storage, transportation or disposal of any
      petroleum product or any toxic or hazardous chemical, material, substance,
      pollutant or waste;

15.   Lessee has not received any notices, written or oral, of violation of any
      Environmental Law or of any allegation which, if true, would contradict
      anything contained herein and there are not writs, injunctions, decrees,
      orders or judgments outstanding, no lawsuits, claims, proceedings or
      investigations pending or threatened, relating to the use, maintenance or
      operation of the Leased Premises, nor is Lessee aware of a basis for any
      such proceeding;

16.   There are no actions, whether voluntary or otherwise, pending against
      Lessee under the bankruptcy or insolvency laws of the United States or of
      any state.

17.   Lessee understands that the Lease Agreement may be assigned to Addressee
      and Lessee agrees to attorn to Addressee in all respects in accordance
      with the Lease Agreement.

Dated:     ____________________________________, 20__________.

Very truly yours,

TEXAS BIOTECHNOLOGY CORPORATION,
a Delaware corporation

By:        ____________________________________

Name:      ____________________________________

Title:     ____________________________________

18
<PAGE>

                                    EXHIBIT F

                               TENANT IMPROVEMENTS

Building:  6700 West Loop South                      Suite No.:       400

Lessor:    FRM West Loop Associates #6, Ltd.

Lessee:    Texas Biotechnology Corporation,          Date of Lease: 2/20/02
           a Delaware corporation

      Cost of Tenant Improvements. Lessor shall provide a construction allowance
not to exceed Seventy-Six Thousand Twenty-Five and 00/100 Dollars ($76,025.00)
for improvements within the Leased Premises (the "Construction Allowance").
Lessee shall reimburse Lessor for any such costs and expenses in excess of the
Construction Allowance within thirty (30) days following delivery to Lessee of
an itemized statement thereof. The foregoing notwithstanding, Lessee shall have
the right to utilize any unused portion of the Construction Allowance to help
offset costs incurred with Lessee's relocation to the Leased Premises.

      Work by Lessor. Subject to Lessee's approval, Lessor shall cause to be
constructed and/or installed in the Leased Premises the permanent Tenant
Improvements and tenant finish desired by Lessee and approved by Lessor as shown
on the attached Exhibit F-1 which supercedes the original Exhibit F-1 of the
Lease Agreement (the "TENANT IMPROVEMENTS").

      Planning and Construction. Lessor and Lessee shall cooperate in good faith
in the planning and construction of the Tenant Improvements, and Lessee shall
respond promptly to any request from Lessor or Lessor's architect or contractor
for Lessee's approval of any particular aspect thereof, it being agreed and
understood that it is the intent and desire of the parties that the Leased
Premises be ready for Lessee's occupancy on or before the first (1st) day of
April, 2002 (the "ESTIMATED LEASED PREMISES DELIVERY DATE").

      Completion of Construction. The "TENANT IMPROVEMENTS COMPLETION DATE"
shall mean the date upon which the Tenant Improvements are substantially
complete. The phrase "substantially complete" shall mean that the Leased
Premises may reasonably be used and occupied for the purposes intended under
this Lease Agreement, and the progress of the construction of the Tenant
Improvements to date is such that final completion of the Tenant Improvements
can occur within a reasonable period of time and without undue interference to
the Lessee's use of the Leased Premises. If the Leased Premises are not ready
for occupancy by the Estimated Leased Premises Delivery Date for any reason,
Lessor shall not be liable or responsible for any claims, damages or liabilities
in connection therewith or by reason thereof.

      Disclaimer of Warranty. LESSEE ACKNOWLEDGES THAT THE CONSTRUCTION AND
INSTALLATION OF THE TENANT IMPROVEMENTS WILL BE PERFORMED BY AN UNAFFILIATED
CONTRACTOR OR CONTRACTORS AND THAT ACCORDINGLY LESSOR HAS MADE AND WILL MAKE NO
WARRANTIES TO LESSEE WITH RESPECT TO THE QUALITY OF CONSTRUCTION THEREOF OR AS
TO THE CONDITION OF THE LEASED PREMISES, EITHER EXPRESS OR IMPLIED, AND THAT
LESSOR EXPRESSLY DISCLAIMS ANY IMPLIED WARRANTY THAT THE LEASED PREMISES ARE OR
WILL BE SUITABLE FOR LESSEE'S INTENDED COMMERCIAL PURPOSE. LESSEE'S OBLIGATION
TO PAY BASE AND ADDITIONAL RENTAL HEREUNDER IS NOT DEPENDENT UPON THE CONDITION
OF THE LEASED PREMISES OR THE BUILDING OR THE PERFORMANCE BY LESSOR OF ITS
OBLIGATIONS HEREUNDER, AND LESSEE SHALL CONTINUE TO PAY THE BASE AND ADDITIONAL
RENTAL WITHOUT ABATEMENT, SETOFF OR DEDUCTION, NOTWITHSTANDING ANY BREACH BY
LESSOR OF ITS DUTIES OR OBLIGATIONS HEREUNDER, WHETHER EXPRESS OR IMPLIED.
However, Lessor agrees that in the event that any defect in the construction of
the Tenant Improvements is discovered, Lessor will diligently pursue and seek to
enforce any warranties of the contractor(s) and/or the manufacturer of any
defective materials incorporated therein.

19<PAGE>
                                                                   Exhibit 10.28

                              AMENDED AND RESTATED

                 LICENSE AND RESEARCH AND DEVELOPMENT AGREEMENT

                                     BETWEEN

      REVOTAR BIOPHARMACEUTICALS AG, registered in the commercial register of
      the local court of Neuruppin HRB 5951 represented by its CEO, Dr. Gunter
      Rosskamp

                                                    - referred to as "Revotar" -

and

      TEXAS BIOTECHNOLOGY CORPORATION, represented by its President and C.E.O.
      Dr. Bruce D. Given, 7000 Fannin, USA TX 77030 Houston,

                                                          referred to as "TBC" -
<PAGE>

                                TABLE OF CONTENTS

<TABLE>
<CAPTION>
                                                                                                   PAGE
                                                                                                   ----
<S>                                                                                                <C>
1.       DEFINITIONS ..........................................................................       1
         1.1      "AFFILIATE" .................................................................       1
         1.2      "CASH EQUIVALENTS" ..........................................................       2
         1.3      "COMPOUND" ..................................................................       2
         1.4      "CONFIDENTIAL INFORMATION" ..................................................       2
         1.5      "COPD" ......................................................................       2
         1.6      "COST OF GOODS SOLD" OR "COGS" ..............................................       2
         1.7      "DEVELOPMENT COSTS" .........................................................       2
         1.8      "DEVELOPMENT PROGRAM" .......................................................       3
         1.9      "DISTRIBUTION COSTS" ........................................................       3
         1.10     "EFFECTIVE DATE" ............................................................       3
         1.11     "EUROPEAN MARKET" ...........................................................       4
         1.12     "FDA" .......................................................................       4
         1.13     "FIELD OF USE" ..............................................................       4
         1.14     "FIRST COMMERCIAL SALE" .....................................................       4
         1.15     "GROSS RECEIPTS" ............................................................       4
         1.16     "IND" .......................................................................       4
         1.17     "IMPROVEMENTS" ..............................................................       4
         1.18     "LICENSING TRANSACTION" .....................................................       4
         1.19     "MANUFACTURING COSTS" .......................................................       5
         1.20     "NDA ........................................................................       5
         1.21     "NET INCOME .................................................................       6
         1.22     "NET SALES" .................................................................       6
         1.23     "NEW INDICATIONS" ...........................................................       6
         1.24     "NORTH AMERICA ..............................................................       6
         1.25     "PRA" .......................................................................       6
         1.26     "PARTICIPATION AGREEMENT" ...................................................       6
         1.27     "PATENTS" ...................................................................       6
         1.28     "PHASE I CLINICAL TRIALS" ...................................................       7
         1.29     "PHASE II CLINICAL TRIALS" ..................................................       7
         1.30     "PHASE III CLINICAL TRIALS" .................................................       7
         1.31     "PRODUCT" ...................................................................       7
         1.32     "PRODUCT EBITDA" ............................................................       7
         1.33     "PROJECT REPRESENTATIVE" ....................................................       7
         1.34     "SUBJECT TECHNOLOGY" ........................................................       8
         1.35     "TBC1269 PROGRAM" ...........................................................       8
         1.36     "TECHNOLOGY" ................................................................       8
         1.37     "TERRITORY" .................................................................       8
         1.38     "THIRD PARTY" ...............................................................       8
         1.39     "WORK PLAN" .................................................................       8
         1.40     "WORLDWIDE LICENSE" .........................................................       9

2.       LICENSE TO REVOTAR ...................................................................       9
</TABLE>

                                       i
<PAGE>

<TABLE>
<CAPTION>
                                                                                                   PAGE
                                                                                                   ----
<S>                                                                                                <C>
         2.1      EXCLUSIVE LICENSE FOR THE TERRITORY .........................................       9
         2.2      RIGHT OF REVOTAR AND TBC TO GRANT SUBLICENSES ...............................       9
         2.4      RIGHTS AND DUTIES IN CONNECTION WITH A LICENSING TRANSACTION TO A THIRD PARTY      10

3.       DEVELOPMENT PROGRAM ..................................................................      10
         3.1      GOALS .......................................................................      10
         3.2      PROGRAM ADMINISTRATION ......................................................      13
         3.3      PERFORMANCE OF SERVICES .....................................................      16
         3.4      RECORDS AND DATA ............................................................      16
         3.5      VISIT OF FACILITIES .........................................................      17

4.       PAYMENTS AND REPORTS .................................................................      17
         4.1      Development Funding .........................................................      17
         4.2      ROYALTIES ...................................................................      18
         4.3      AUDIT RIGHTS ................................................................      21
         4.4      PAYMENT CURRENCY ............................................................      22
         4.5      PAYMENT MECHANICS ...........................................................      23

5.       COMMERCIALIZATION ....................................................................      24
         5.1      TBC TO MANUFACTURE ..........................................................      24
         5.2      REVOTAR AND TBC TO SELL IN TERRITORY AND NORTH AMERICA, RESPECTIVELY ........      24
         5.3      SUBLICENSING ................................................................      25

6.       TBC REPRESENTATIONS AND WARRANTIES ...................................................      25
         6.1      NO THIRD PARTY AGREEMENTS ...................................................      25
         6.2      NO THIRD PARTY RIGHTS .......................................................      25

7.       PROPRIETARY RIGHTS ...................................................................      27
         7.1      IMPROVEMENTS ................................................................      27
         7.2      PATENT PROSECUTION AND MAINTENANCE ..........................................      27
         7.3      THIRD PARTY CLAIM OF INFRINGEMENT ...........................................      29
         7.4      INFRINGEMENT BY THIRD PARTIES ...............................................      30

8.       CONFIDENTIALITY ......................................................................      31
         8.1      GENERAL .....................................................................      31
         8.2      DISCLOSURE OF AGREEMENT .....................................................      32

9.       INDEMNIFICATION ......................................................................      33
         9.1      MUTUAL RIGHT TO INDEMNIFICATION .............................................      33
         9.2      PROCEDURE ...................................................................      34
         9.3      PRODUCT LIABILITY INSURANCE .................................................      35

10.      TERM AND TERMINATION .................................................................      35
         10.1     LICENSE TERM ................................................................      35
         10.2     TERMINATION FOR BREACH ......................................................      36
         10.3     TERMINATION FOR FAILURE TO PROCEED ..........................................      36
         10.4     SURVIVAL OF OBLIGATIONS .....................................................      38
</TABLE>

                                       ii
<PAGE>

<TABLE>
<CAPTION>
                                                                                                   PAGE
<S>                                                                                                <C>
11.      MISCELLANEOUS ........................................................................      38
         11.1     FORCE MAJEURE ...............................................................      38
         11.2     RELATIONSHIP OF THE PARTIES .................................................      39
         11.3     NOTICES.: ...................................................................      39
         11.4     SUCCESSORS AND ASSIGNS ......................................................      39
         11.5     AMENDMENTS AND WAIVERS ......................................................      40
         11.6     GOVERNING LAW ...............................................................      40
         11.7     DISPUTE RESOLUTION ..........................................................      40
         11.8     SEVERABILITY ................................................................      42
         11.9     HEADINGS ....................................................................      42
         11.10    EXECUTION IN COUNTERPARTS ...................................................      42
         11.11    ENTIRE AGREEMENT ............................................................      42
</TABLE>

                                      iii
<PAGE>

                              AMENDED AND RESTATED
                 LICENSE AND RESEARCH AND DEVELOPMENT AGREEMENT

This Amended and Restated License and Research and Development Agreement is
entered into on this day of January 24, 2003, between Texas Biotechnology
Corporation, a Delaware corporation ("TBC"), and Revotar Biopharmaceuticals AG,
a German stock company.

                                 R E C I T A L S

A.    TBC and Revotar entered into a License and Research and Development
      Agreement dated July 21, 2000 (the "License Agreement").

B.    TBC and Revotar wish to amend and restate the License Agreement pursuant
      to this Amended and Restated License and Research and Development
      Agreement (the "Agreement").

In consideration of the foregoing and the mutual promises and covenants
contained in this Agreement, the parties hereto agree to amend and restate the
License Agreement in its entirety effective as of the date hereof as follows:

1. DEFINITIONS.

The following capitalized terms used herein shall have the respective meanings
set forth below. The accounting terms used but not defined herein shall have the
meanings ascribed to them under U.S. Generally Accepted Accounting Principles.
Certain other capitalized terms are defined elsewhere in this Agreement.

      1.1   "AFFILIATE" means a person or entity that directly or indirectly
            controls, is controlled by or is under common control with, a party
            to this Agreement. "Control" (and, with correlative meanings, the
            terms "controlled by" and "under common control with") means, in the
            case of a corporation, the ownership of more than 50% of the
            outstanding voting securities thereof or the right to acquire
<PAGE>

            such securities within 60 days and, in the case of any other type of
            entity (including without limitation joint ventures), an interest
            that results in the ability to direct or have a significant impact
            on the direction of the management and policies of such entity or a
            significant ownership position of no less than 25%.

      1.2   "CASH EQUIVALENTS" means cash or other instrument which is
            convertible into cash including equity in a Third Party valued as
            follows: the value of securities that are freely tradable in an
            established market will be determined by taking the average of the
            closing market price for the 10 trading days prior to the execution
            of an agreement, and the value of securities that are not freely
            tradable shall be the fair market value thereof as determined by
            Revotar and TBC.

      1.3   "COMPOUND" means the compound owned by TBC and known as TBC1269, and
            any salt forms thereof, and any Improvements thereon.

      1.4   "CONFIDENTIAL INFORMATION" means all proprietary information
            communicated to, learned of, developed or otherwise acquired by
            either party separately or jointly under this Agreement.

      1.5   "COPD" means chronic obstructive pulmonary disease.

      1.6   "COST OF GOODS SOLD" OR "COGS" means TBC's total Manufacturing Costs
            plus 10% of the Manufacturing Costs.

      1.7   "DEVELOPMENT COSTS" means (a) the direct costs, fees and
            out-of-pocket or other expenses incurred in the course of performing
            the work under the Development Program (b) overhead allocable to
            development and (c) the amount paid to Third Parties to acquire
            goods and services for the development work, whether or not
            completed. Overhead allocated to development shall be limited to (i)
            a reasonable

                                       2
<PAGE>

            allocation of the cost of employees who have a direct relationship
            with the Development Program, but who are not classified as direct
            labor, which allocation shall be based on each such employee's time
            spent in the Development Program as compared to time spent on all
            such employee's work, and (ii) a reasonable allocation of
            facilities' costs allocable to development works. Development Costs
            shall be determined on a reasonable and typical basis consistent
            with the developing party's internal cost accounting system or on
            actual charges from Third Parties.

      1.8   "DEVELOPMENT PROGRAM" means development and other work conducted by
            the parties hereunder on a Product or Compound for use in the Field
            of Use, including clinical testing, regulatory submissions and
            ongoing Product and Compound development.

      1.9   "DISTRIBUTION COSTS" means all freight and other transportation
            costs actually incurred by a party hereto in delivering a Product to
            its final distribution point before delivery to an invoiced
            customer, including transportation costs to a storage facility,
            storage charges, Third Party handling fees, insurance during
            transport and taxes payable for such transportation or storage
            services. Distribution Costs shall exclude any transportation or
            other charges deducted in calculating Net Sales. Distribution Costs
            incurred by a party hereto shall be determined on a reasonable basis
            consistent with such party's internal cost accounting system.

      1.10  "EFFECTIVE DATE" means the day of the signing of this Agreement.

                                       3
<PAGE>

      1.11  "EUROPEAN MARKET" means countries which are party of the European
            Patent Treaty ("Europaisches Patentrechtsubereinkommen").

      1.12  "FDA" means the United States Food and Drug Administration.

      1.13  "FIELD OF USE" means the development, manufacture, use or sale of
            the Compound, Products or Subject Technology for any indication
            except: a) organ transplantation, b) organ reperfusion injury, or c)
            immunologic tissue rejection.

      1.14  "FIRST COMMERCIAL SALE" means the first arms-length sale in the
            Territory pursuant to this Agreement to one or more Third Parties of
            any Product following receipt of approval to commence manufacturing
            and selling such Product from any one PRA.

      1.15  "GROSS RECEIPTS" means all cash or Cash Equivalents received by
            Revotar or TBC from a Third Party pursuant to a Licensing
            Transaction, including without limitation, up front payments,
            royalties, milestones, and profit or cash flow payments.

      1.16  "IND" means an investigational new drug application filed with the
            FDA, or the similar filing made with any PRA, prior to beginning
            clinical trials in humans.

      1.17  "IMPROVEMENTS" means any Technology that is discovered, developed or
            otherwise acquired in the course of the Development Program
            hereunder that may be applied to the discovery, development,
            manufacture, sale or use of the Compound or Products, excluding any
            new chemical entities that are developed by Revotar under this
            Agreement using the Subject Technology.

      1.18  "LICENSING TRANSACTION" means any agreement or arrangement of any
            type pursuant to which Revotar licenses or transfers to a Third
            Party any interest or

                                       4
<PAGE>

            rights of any kind to any Subject Technology, Compound or Product
            which is the subject of this Agreement including without limitation
            the rights to use and sell any Compound or Product in the Field of
            Use.

      1.19  "MANUFACTURING COSTS" means (a) the direct material and labor costs
            associated with manufacturing the Products, (b) overhead allocable
            to manufacture of the Products and (c) the amount paid to Third
            Parties to acquire manufactured Products, whether or not completed,
            and (d) Distribution Costs. Direct material costs include the costs
            of purchasing raw materials and packaging components. Direct labor
            includes the costs of employees directly employed in Product
            manufacturing, quality control or packaging. Overhead allocated to
            manufacture of the Products shall be limited to (i) a reasonable
            allocation of the cost of employees who have a direct relationship
            with Product manufacturing, quality control or packaging, but who
            are not classified as direct labor, which allocation shall be based
            on each such employee's time spent in Product manufacturing, quality
            control or packaging as compared to time spent on all such
            employee's work, and (ii) a reasonable allocation of facilities'
            costs allocable to Product manufacturing, quality control and
            packaging. Manufacturing Costs shall be determined on a reasonable
            and typical basis consistent with the manufacturing party's internal
            cost accounting system or on actual charges from Third Parties.

      1.20  "NDA" means a new drug application filed with the FDA, or a similar
            application filed with any PRA to obtain marketing approval for a
            Product.

                                       5
<PAGE>

      1.21  "NET INCOME" means Gross Receipts and Net Sales minus Cost of Goods
            Sold, promotional and selling expenses, payments to Third Parties,
            general and administrative overhead expenses that can all be
            attributed to the sales of Product.

      1.22  "NET SALES" means the gross amount billed for Products sold pursuant
            to this Agreement to a Third Party, less discounts, rebates,
            returns, credits, allowances, uncollectible sales, shipping,
            distribution and insurance charges, sales taxes, and other
            governmental charges measured by the amount billed.

      1.23  "NEW INDICATIONS" means any topical indication for the Compound,
            Products or Subject Technology being proposed for addition to the
            Work Plan.

      1.24  "NORTH AMERICA": countries and regions which are subject to the
            patent legislation of the USA and Canada.

      1.25  "PRA" means any applicable regulatory authority in any jurisdiction
            included within the Territory which regulates the development,
            approval and marketing of pharmaceuticals.

      1.26  "PARTICIPATION AGREEMENT" means that certain agreement entered into
            on July 21, 2000 by and between TBC and Revotar and certain German
            venture capital investors known as bmp Life Science AG Venture
            Capital, bmp Venture Tech and Mediport Venture Fonds GmbH.

      1.27  "PATENTS" means (a) the patent applications listed on APPENDIX 1
            attached hereto and all patent applications hereafter filed in the
            Territory that are owned by or licensed to or otherwise acquired by
            TBC in the Territory and which have one or more claims covering the
            Compound, Subject Technology or Improvements, (b) any patent
            application in the Territory constituting an equivalent, reissue,

                                       6
<PAGE>

            extension, continuation-in-part or a division of any of the
            foregoing, and (c) any patents issued upon any of the foregoing
            applications or any other patents acquired by TBC relating to the
            Compound, Subject Technology or Improvements.

      1.28  "PHASE I CLINICAL TRIALS" means the first phase of human clinical
            trials of a Compound required by the FDA or a PRA in which the
            Compound is tested to determine early safety profile, drug
            distribution patterns, and metabolism.

      1.29  "PHASE II CLINICAL TRIALS" means the second phase of human clinical
            trials of a Compound required by the FDA or a PRA in which the
            Compound is tested in patients afflicted with a particular disease
            in order to gain preliminary evidence of efficacy, optimal dosage
            and expanded evidence of safety.

      1.30  "PHASE III CLINICAL TRIALS" means the third phase of human clinical
            trials of a Compound required by the FDA or a PRA in which the
            Compound is tested in patients afflicted with a particular disease
            in order to gain statistical proof of efficacy and safety.

      1.31  "PRODUCT" means any pharmaceutical composition incorporating the
            Compound which is to be used in the Field of Use.

      1.32  "PRODUCT EBITDA" means the Net Income before interest expense,
            taxes, depreciation expense and amortization expense that can be
            attributed to the development and commercialization of a Product.

      1.33  "PROJECT REPRESENTATIVE" means an individual designated by a party
            pursuant to Section 3.2(a). A Project Representative of a party may
            be changed at any time by written notice to the other party.

                                       7
<PAGE>

      1.34  "SUBJECT TECHNOLOGY" means (i) all Technology owned or controlled by
            TBC as of the date hereof or owned or controlled by TBC hereafter
            during the term of this Agreement, but only to the extent that such
            Technology relates to the use, manufacture or sale of the Compound
            or Products. Technology "owned or controlled" includes Technology as
            to which TBC has the right to grant or cause to be granted
            sublicenses and/or immunity from suit.

      1.35  "TBC1269 PROGRAM" means the development of TBC1269 pursuant to this
            Agreement for the development of Products for use in the Field of
            Use.

      1.36  "TECHNOLOGY" means all ideas, methods, formulations, inventions,
            techniques, processes, know-how, trade secrets and other
            information.

      1.37  "TERRITORY" shall mean all countries of the World excluding the use
            and sale of the Compound, Products or Subject Technology for topical
            indications in North America.

      1.38  "THIRD PARTY" means any entity other than TBC, Revotar or their
            Affiliates.

      1.39  "WORK PLAN" means a written summary of the tasks to be undertaken by
            each party during a particular calendar year in connection with the
            development of the Compound or Products in the Territory only for
            topical indications, together with a budget of the anticipated
            Development Costs associated therewith, adopted by the parties. Each
            Work Plan will include reasonably detailed descriptions of the tasks
            and work to be performed, the resources required to accomplish the
            work, the costs associated with the planned work, the party that
            will be responsible for accomplishing each task, and the
            reimbursement or payment of costs by Revotar incurred by each party.

                                       8
<PAGE>

      1.40  "WORLDWIDE LICENSE" means a Licensing Transaction, which may include
            multiple agreements with the same Third Party or Third Party
            Affiliate(s), in at least - but not necessarily only - all countries
            within North America and the European Market.

2. LICENSE TO REVOTAR.

      2.1   EXCLUSIVE LICENSE FOR THE TERRITORY. Subject to the terms and
            conditions of this Agreement, TBC hereby grants to Revotar an
            exclusive right and license in the Territory, including the
            exclusive right to grant sublicenses in the Territory, to develop,
            use and sell the Compound, Products or Subject Technology in the
            Field of Use.

                  TBC retains the exclusive rights to develop, make, have made,
            use and sell the Compound or Products for a) topical indications in
            North America, and b) all indications excluded from Field of Use.

                  The right of manufacturing remains with TBC pursuant to
            section 5.1 hereof unless (a) Revotar grants a sublicense to a Third
            Party which includes the manufacturing rights within the scope of
            the sublicense agreement, (b) Revotar is able to produce the goods
            at lesser Manufacturing Costs than TBC or (c) TBC determines that it
            does not want to commence manufacturing of the Compound or any
            Products, or with one year's notice to Revotar, determines that it
            will cease its manufacturing of the Compound or any Products.

      2.2   RIGHT OF REVOTAR AND TBC TO GRANT SUBLICENSES. TBC hereby grants to
            Revotar an exclusive right and license to enter into a sublicense
            agreement in the Territory of the same scope as defined in sec. 2.1
            above in the Field of Use . TBC

                                       9
<PAGE>

            has the right to enter into a sublicense agreement for topical
            indications in North America and a worldwide right for a) organ
            transplantation, b) organ reperfusion injury, or c) immunologic
            tissue rejection.

            Revotar and TBC shall be obligated to perform in full all of the
            obligations and agreements of any sublicenses, including payment of
            royalties.

      2.3

      2.4   RIGHTS AND DUTIES IN CONNECTION WITH A LICENSING TRANSACTION TO A
            THIRD PARTY. Revotar will inform TBC if it enters into negotiations
            with a Third Party concerning any Licensing Transaction. Revotar
            will furthermore inform TBC about the course of such negotiations
            and provide TBC the opportunity for review and comment under the
            terms contained in 4.2.3(f) prior to the conclusion of a License
            Transaction with a Third Party.

3. DEVELOPMENT PROGRAM.

      3.1   GOALS.

            3.1.1 WORK PLANS FOR TOPICAL INDICATIONS. TBC and Revotar agree that
            they will conduct the development on the Compound and it's Products
            according to the Work Plans, with the goal of developing
            commercially marketable Products for topical indications in the
            shortest feasible period of time. The parties also agree that
            Revotar shall be responsible under the Work Plans for the
            development program defined therein, conduct any non-clinical work
            necessary for development of topical applications of the Compound,
            conduct the clinical trials regarding the Compound and it's Products
            in the Territory, and Patent filing,

                                       10
<PAGE>

            maintenance and prosecution regarding the Products in the Territory.
            The obligations of the Work Plans for topical indications are
            considered to be completed when the conditions described in
            paragraph 3.2.2 (ii) or (iii) apply.

            3.1.2 DEVELOPMENT PROGRAM FOR OTHER INDICATIONS. Revotar will be
            responsible for conducting all the Development Programs regarding
            the Compound and the Products for all indications in the Field of
            Use other than the topical indications, and will be responsible for
            all costs associated therewith. TBC will have no responsibilities
            under and bear none of the expense for such efforts.

            3.1.3 PARTICIPATION BY TBC IN DEVELOPMENT PROGRAMS. Except where TBC
            and Revotar agree that it is necessary for obtaining regulatory
            approval, TBC does not intend to develop the Compound or it's
            Products in the Territory and in the Field of Use pursuant to the
            Development Program or the Work Plans. TBC, at its own expense, may
            undertake development work on the Compound or it's Products for use
            in topical indications in North America, or organ transplantation,
            organ reperfusion injury or immunologic tissue rejection throughout
            the world.

            3.1.4 LIMITATION ON CLINICAL TRIAL SPENDING BY REVOTAR.
            Notwithstanding the foregoing to the contrary, the parties
            contemplate that Revotar will not be required under the Development
            Program and the Work Plans to conduct and pay for any Phase III
            Clinical Trials involving the Compound or it's Products. The parties
            instead contemplate that Revotar will enter into a Licensing
            Transaction whereby a Third Party will conduct such trials.

            3.1.5 SHARING OF INFORMATION. Any safety data or information
            generated by TBC or Revotar (the "Parties") regarding the Compound
            will be shared with the

                                       11
<PAGE>

            other party in English without cost for use as safety data and for
            the maintenance of the worldwide safety database. Any non-safety
            information generated by Revotar in topical indications will be
            shared with TBC in English without cost. Any information which is
            relevant for registration purposes generated by the Parties for
            non-topical indications will be shared in English upon reimbursement
            of 50% of the Development Costs associated with such work. Once
            information is paid for by a Party, its uses will be limited in the
            following manner; (i) for internal evaluation, (ii) non-confidential
            summary information may be shared with Third Parties without prior
            consent from either Party, (iii) detailed data can be used by the
            Parties or their licensees for registration or regulatory purposes
            necessary to obtain approvals from governmental agencies, (iv)
            detailed data may also be shared with a Third Party pursuant to a
            separate confidentiality agreement subject to the limitations
            contained in paragraph 8.2 and (v) any publication or public
            presentation of information will require prior approval of the
            originating party; such approval not to be unreasonably withheld.
            Revotar and TBC will endeavor to oblige any of its sublicensees, at
            their option, to pass on information concerning the Compound and
            Products relating to non-topical indications and to assent to
            passing on such information to Revotar and TBC on the same basis as
            provided above. Regarding topical indications, Revotar and TBC will
            endeavor to oblige any sublicensee to provide information regarding
            Compound or it's Products to Revotar or TBC in English without cost.
            TBC and Revotar will treat information in a manner consistent with
            (i) through (v) above.

                                       12
<PAGE>

            3.1.6 BEST EFFORTS. While the parties agree to use best efforts to
            achieve the goals of the Development Program, neither TBC nor
            Revotar warrants or guarantees that their efforts will result in a
            marketable or approvable Product or that the goals specified in the
            Work Plan will be achieved within the periods set forth therein.

      3.2   PROGRAM ADMINISTRATION.

            3.2.1 PROJECT REPRESENTATIVE. The parties have each designated one
            Project Representative to facilitate liaison between it and the
            other party, oversee and review the progress of the Work Plans. In
            addition, the Project Representatives will agree on the Work Plans,
            will select which topical indications to pursue, determine the
            development program of the Work Plans for topical indications,
            develop clinical trial protocols, manage the clinical/regulatory
            process and discuss potential competition and other relevant matters
            to assure rapid development and commercialization of the Compound
            and the Products for topical indications within the Work Plans.

            3.2.2 DISAGREEMENTS. All decisions made hereunder relating to the
            Work Plans for topical indications shall require the approval of the
            Project Representatives. The Project Representatives shall attempt
            in good faith to reach consensus on all matters regarding such Work
            Plans. As long as (i) at least 30% of clinical spending in any
            calendar year by Revotar is related to topical indications, or as
            long as (ii) the Phase II clinical development for psoriasis and/or
            atopic dermatitis is completed, or as long as (iii) Revotar
            completes a Licensing Transaction for psoriasis and/or atopic
            dermatitis involving the European Union, then the final

                                       13
<PAGE>

            decision making regarding any disagreements with the Work Plan will
            reside with the CEO of Revotar. In any year where none of (i)
            through (iii) above do occur, then the Project Representatives shall
            promptly present the disagreement to the chief executive officers of
            the Parties or their designees, who shall attempt resolution of the
            matter. If the chief executives or designees cannot promptly resolve
            such disagreement within thirty (30) days, then the dispute shall be
            resolved under the arbitration provisions of Section 11.7.

            3.2.3 WORK PLANS. The parties hereto will agree on the initial Work
            Plan for 2003 within 90 days of the Effective Date. If the Project
            Representatives agree to pursue New Indications, then a new Work
            Plan for those indications will be developed. The Work Plan for
            topical indications shall be the plan and budget as approved by both
            parties in writing. Prior to November 1 of each year, the Project
            Representatives shall prepare and recommend to each party a proposed
            Work Plan for the next calendar year. Each Work Plan adopted shall
            be agreed upon and signed by an officer of both parties no later
            than January 10 of the year covered by the Work Plan. The Project
            Representatives shall actively consult with one another throughout
            the term of the Development Program so as to adjust the specific
            work performed under each Work Plan to conform to evolving
            developments in technology and the results of the development work
            performed. While minor adjustments to a Work Plan may be made from
            time to time upon approval by the Project Representatives,
            significant changes to the scope or direction of the work in a Work
            Plan shall be agreed to in writing by each party,

                                       14
<PAGE>

            in the absence of which the most recently approved Work Plan shall
            remain in effect.

            3.2.4 TOPICAL WORK OUTSIDE OF WORK PLAN BY TBC. TBC may conduct
            development work with the Product in topical indications outside of
            the Work Plan at TBC's expense. Revotar or its sublicensee will gain
            access to this information by reimbursing TBC 100% of its costs to
            generate such information and use of this information is limited to
            the terms of 3.1.5 (i) through 3.1.5 (v).

            3.2.5 PROGRESS REPORTS. Within 10 business days following the end of
            each six-month period, (a) the Project Representatives shall jointly
            produce a summary written report which shall describe the work
            performed by the respective party during the six month period on the
            Work Plans for topical indications and if appropriate, recommend any
            revisions to such Work Plan that would improve the progress of such
            Development Program, and (b) Revotar will provide TBC via the
            Revotar Supervisory Board with a progress report of the development
            program for all indications.

            3.2.6 MEETINGS. The Project Representatives and other employees or
            consultants of the parties responsible for management of the Work
            Plans for topical indications shall consult each other and meet as
            needed during the term of the Work Plans for review. Such meetings
            shall be at such times as may be agreed to by the Project
            Representatives, and may be conducted telephonically or in person as
            necessary at a time and location to be agreed upon by the Project
            Representatives. Revotar shall be responsible for the organization
            of such meetings, including payment for transportation and hotel
            accommodations. The

                                       15
<PAGE>

            Project Representatives shall jointly produce minutes summarizing
            the matters reviewed and any actions taken at such meetings within
            10 business days following each meeting. Each party may invite
            additional colleagues to participate at meetings as appropriate and
            acceptable to the other party. Revotar shall be responsible for the
            preparation and communication to TBC of the specific agenda of each
            meeting in advance of each meeting and either party may place items
            for consideration on the agenda.

      3.3   PERFORMANCE OF SERVICES. Each party shall perform the work assigned
            to it in a prudent and skillful manner in accordance, in all
            material respects, with the Work Plan then in effect and applicable
            laws. Revotar shall reimburse TBC its Development Costs, and its out
            of pocket costs, including travel, lodging, salaries and benefits
            for all labor, supervision, facilities, supplies and materials
            necessary to perform the work assigned to TBC in accordance with the
            Work Plan. All cost allocations for developmental work to be
            performed by either party will be defined in detail in the Work Plan
            and are binding to both parties. Revotar and TBC agree that all
            development activities performed by either party will be conducted
            according to accepted guidelines of the International Conference on
            Harmonisation.

      3.4   RECORDS AND DATA. Each party shall maintain records in sufficient
            detail and in good scientific manner appropriate for patent and
            regulatory purposes and so as to properly reflect all work done by
            TBC and Revotar, and results achieved in the performance of the Work
            Plans. Such records shall include books, records, reports, research
            notes, charts, graphs, comments, computations, analyses,

                                       16
<PAGE>

            recordings, photographs, computer programs and documentation
            thereof, computer information storage means, samples of materials
            and other graphic or written data generated in connection with the
            Work Plans, including any data required to be maintained pursuant to
            applicable governmental regulations. Each party shall provide the
            other the right to inspect all such records, and shall provide
            copies in the English language of all such requested records.

      3.5   VISIT OF FACILITIES. Representatives of each party may, upon
            reasonable notice and at times reasonably acceptable to the other
            party, (a) visit the facilities at their own expense where the Work
            Plans are being conducted and/or the facilities where the other
            party manufactures any Product or Compound contained therein (or has
            a Product or such a Compound manufactured by a Third Party), (b)
            consult informally, during such visits and by telephone, with
            personnel of the other party performing work on the Work Plans and
            (c) with the other party's prior approval, which approval shall not
            be unreasonably withheld, visit the sites of any clinical trials or
            other experiments being conducted by such other party in connection
            with the Work Plans, but only to the extent in each case as such
            trials or other experiments relate to the Work Plans.

4. PAYMENTS AND REPORTS.

      4.1   Development Funding. All Development Costs relating to the Compound
            and Products in the Field of Use in the Territory, whether incurred
            before or after marketing approval of any Product, shall be borne by
            Revotar. Except as provided in Section 3.1.5 and 3.2.4 above, TBC
            will bear its Development Costs regarding the Compound and Products
            for use in topical indications in North

                                       17
<PAGE>

            America and for organ transplantation, organ reperfusion injury and
            immunologic tissue rejection.

      4.2   ROYALTIES.

            4.2.1 PAYMENTS TO TBC WHEN NO LICENSING TRANSACTION. In the event
            that Revotar commences sales of Products without having entered into
            any Licensing Transaction, Revotar or its Affiliates shall pay TBC
            the following amounts:

                  (a) [*] of Net Sales relating to sales of Products in the
            Territory for use in topical indications, asthma or COPD.

                  (b) [*] of Product EBITDA relating to sales of Products in the
            Territory for use in all indications other than asthma, topical
            indications or COPD.

            4.2.2 PAYMENTS BY TBC TO REVOTAR. In the event that TBC or its
            licensees commences sales of any products incorporating a Compound
            relating to any organ transplantation, organ reperfusion injury or
            immunologic tissue rejection, TBC or its Affiliates shall pay
            Revotar [*] of TBC's Product EBITDA for sales of such products by
            TBC, its licensees and its Affiliates. In the event TBC, its
            licensees and its Affiliates commence sales of Products for topical
            indications in North America, TBC or its Affiliates shall pay
            Revotar [*] of TBC's Product EBITDA for such Product sales by TBC,
            its licensees and its Affiliates; provided, that if Revotar is
            successful in obligating a licensee to share data with TBC as
            desired in 3.1.5, then TBC or its Affiliates shall pay Revotar [*]
            (instead of [*]) of TBC's Product EBITDA for such Product sales by
            TBC, its licensees and its Affiliates.

            4.2.3 ROYALTY RATES PAID TO TBC AFTER LICENSING TRANSACTION BY
            REVOTAR.

----------
[*]   This information has been omitted in reliance on Rule 24B-2 under the
      Securities Exchange Act of 1934, and has been filed separately with the
      Securities and Exchange Commission.

                                       18
<PAGE>

                  (a) If Revotar enters into a Worldwide License pursuant to
            Sec. 2.4 with a Third Party covering the asthma indication alone or
            covering the asthma indication and COPD, then all royalties, license
            fees, milestone payments and other payments or revenues of any kind
            received by Revotar and its Affiliates pursuant to such Worldwide
            License relating to the asthma indication and COPD shall be shared
            equally with TBC. For purposes of this Section 4.2.3(a), in the
            event that Revotar enters into any Worldwide License with a Third
            Party covering Products for the treatment of asthma and then enters
            into a Licensing Transaction with the same Third Party covering COPD
            within nine (9) months before or after the Worldwide License
            involving asthma, then Revotar shall be considered for purposes of
            this Section 4.2.3 to have entered into a Worldwide License covered
            by the provisions of this subparagraph (a) as to asthma and COPD.

                  (b) In the event Revotar enters into any Licensing Transaction
            involving Products covering (i) any topical indication, or (ii) the
            asthma indication alone or the asthma and COPD indications together
            (which will include the series of Licensing Transactions described
            in the second sentence of Section 4.2.3(a)), that includes only
            countries within the European Market, and TBC is not required to
            fund a Phase III Clinical Trial to obtain FDA approval regarding the
            Product, then Revotar shall pay to TBC [*] of Revotar's royalty
            revenues relating to such Products by Revotar and its Affiliates.
            This applies to Revotar only to the royalty revenues generated out
            of the European Market as defined above .

----------
[*]   This information has been omitted in reliance on Rule 24B-2 under the
      Securities Exchange Act of 1934, and has been filed separately with the
      Securities and Exchange Commission.

                                       19
<PAGE>

                  (c) In the event Revotar enters into any Licensing Transaction
            involving Products covering topical indications that includes only
            countries within the European Market, and TBC is required to fund a
            Phase III Clinical Trial to obtain FDA approval regarding the
            Product, then Revotar shall pay to TBC [*] of Revotar's royalty
            revenues relating to such Products by Revotar and its Affiliates.
            This applies to Revotar only to the royalty revenues generated out
            of the European Market as defined above.

                  (d) In the event Revotar enters into any Licensing Transaction
            involving Products covering (i) topical indications, or (ii) the
            asthma indication alone or the asthma and COPD indications together
            (which will include the series of License Transactions described in
            the second sentence of Section 4.2.3(a)), which includes the
            European Market and any other countries in the Territory (i) all
            royalties and other revenues received by Revotar for sales generated
            outside the European Market which are in excess of Development Costs
            incurred by Revotar in the development of the Product in question
            shall be shared equally by Revotar and TBC, and (ii) Revotar shall
            make payments to TBC according to subparagraphs (b) or (c) above for
            Product sales within the European Market.

                  (e) In the event Revotar enters into any Licensing Transaction
            (including a Worldwide License) not covered or described in Sections
            4.2.3(a) through (d) above, then Revotar will pay TBC [*] of
            Revotar's Product EBITDA for sales of such Products by Revotar and
            its Affiliates.

----------
[*]   This information has been omitted in reliance on Rule 24B-2 under the
      Securities Exchange Act of 1934, and has been filed separately with the
      Securities and Exchange Commission.

                                       20
<PAGE>

                  (f) TBC is entitled to review and provide comments to, for a
            period not to exceed 14 days prior to execution by Revotar, any
            Licensing Transaction entered into by Revotar and a Third Party.
            Revotar may not enter into any Licensing Transaction, the terms of
            which cause TBC to incur liabilities or obligations with a Third
            Party, or agreements to indemnify or hold harmless a Third Party, of
            any type.

                  (g) Revotar and TBC shall impose on their third party
            licensees the duty to report on their Net Sales classified to the
            regions defined for TBC and Revotar.

            4.2.4 [NOT USED]

            4.2.5 REPORTS AND PAYMENT. Each party shall keep, and shall require
            all Affiliates and sublicensees to keep, accurate records in
            sufficient detail to enable the amounts due to the other party to be
            determined. Each party shall deliver to the other party within 60
            days after the end of each calendar quarter a written accounting in
            the English language, including quantities and monetary amounts of
            sales of each Product by such party and its Affiliates and
            sublicensees, on a country-by-country basis, and the amount of the
            payments, if any, due to the other party for such quarter. Each
            party or its Affiliates, simultaneously with the delivery of each
            such accounting, shall tender payment of all amounts due hereunder.
            In the event the Parties are being compensated by securities, the
            Parties may choose to compensate each other either by cash or
            securities.

      4.3   AUDIT RIGHTS. Each party shall permit the other party or its
            representatives to have access, at its own expense, no more than
            once in each calendar year during

                                       21
<PAGE>

            the term of this Agreement and twice during the three (3) calendar
            years following the termination hereof, during regular business
            hours and upon reasonable notice, to its records and books for the
            sole purpose of determining the appropriateness of all amounts
            payable hereunder or verifying the royalties and profit sharing
            amounts payable hereunder. If such examination reveals that such
            amounts have been overstated or such royalties have been understated
            for any calendar year, such overpayment shall be promptly refunded
            or in the case of any underpayment, such party shall promptly pay
            the amount of any underpayment; provided that if such examination
            was not conducted by an independent accountant, the party whose
            records were examined shall have the right to engage an independent
            accountant reasonably acceptable to examining party to verify the
            results of such examination. Any sublicense granted by Revotar
            hereunder shall contain audit provisions as set forth in this
            Section 4.4, mutatis mutandis.

      4.4   PAYMENT CURRENCY. All payments to be made under this Agreement shall
            be made (a) if to TBC, in United States dollars and (b) if to
            Revotar, in Euros. In the case of sales in foreign currencies, the
            rate of exchange to be used in computing the amount of currency
            equivalent in United States dollars due to TBC for the calendar
            quarter just ended shall be made at the rate of exchange prevailing
            on the last day of such calendar quarter published by a New York
            money center bank designated by Revotar which Revotar uses for
            currency conversion in the preparation of Revotar financial reports.

                                       22
<PAGE>

      4.5   PAYMENT MECHANICS. All payments under this Agreement shall be made
            by wire transfer of immediately available funds to such account as
            the receiving party shall specify or by other payment method
            acceptable to the parties.

                                       23
<PAGE>

5. COMMERCIALIZATION.

      5.1   TBC TO MANUFACTURE. TBC has the right, but not the obligation,
            subject to the provisions of Section 2.1 above, to manufacture all
            Revotar's requirements for the Compound and/or Products, subject to
            customary forecast and order procedures. If TBC or its subcontractor
            is manufacturing the Compound and/or Products, TBC's (or its
            subcontractor's) responsibilities shall include all aspects of the
            manufacturing process, including maintenance of manufacturing
            inventory, quality control and shipment of Compound and/or Products
            in accordance with orders placed by Revotar. TBC and Revotar will
            also agree to negotiate in good faith a manufacturing agreement
            which will include provisions on forecasts, delivery time, quality
            control, quality assurance, delivery location, insurance, packaging,
            inventories, term and time of payment and such other provisions as
            are customarily included in agreements of this type. As compensation
            for such manufacturing services, TBC shall be entitled to receive
            payment of its COGS. Revotar shall have the right to audit at its
            expense the manufacturer or submanufacturer of the Compound or
            Products.

      5.2   REVOTAR AND TBC TO SELL IN TERRITORY AND NORTH AMERICA,
            RESPECTIVELY. Following regulatory approval in any country in the
            Territory or in North America, Revotar and TBC shall use
            commercially reasonable efforts to market and sell the Products in
            such country. Revotar and TBC will use all resources in such
            marketing and sales efforts that it would use regarding any of its
            other products with similar commercial potential. All terms of sale,
            including pricing policies, credit terms, cash discounts and returns
            and allowances, shall be set by

                                       24
<PAGE>

            Revotar or TBC in their respective regions. Revotar and TBC shall be
            responsible for invoicing the customers in their respective regions
            for Products and collecting payment therefore. The Parties will
            consult each other regarding the selection of the trademarks to be
            used for the sale of Products in the Territory, which selection will
            take into account the desirability for worldwide trademarks. Such
            trademarks regarding sales of Products in the Territory will be
            owned by Revotar. In the event TBC is marketing and selling
            Products, TBC will have the right to use such trademarks outside the
            Territory at no cost to TBC.

      5.3   SUBLICENSING. If Revotar or TBC will grant a sublicense to Third
            Parties then Revotar and TBC will impose to the sublicensee to
            assume the obligations entered into by Revotar and TBC in section
            5.2, sentences 1 and 2.

6. TBC REPRESENTATIONS AND WARRANTIES.

            TBC represents and warrants to Revotar as follows:

      6.1   NO THIRD PARTY AGREEMENTS. Except for the Participation Agreement
            and the Side Letter to the Participation Agreement dated July 21,
            2000, there are no agreements with third parties relating to the
            Products.

      6.2   NO THIRD PARTY RIGHTS. TBC owns or possesses adequate licenses or
            other rights to use all patents, patent rights, inventions and
            know-how necessary for the manufacture, use and sale of the Compound
            and Products and to grant the licenses granted herein. To the best
            knowledge of TBC, the manufacture, use or sale of the Products and
            Compound pursuant to this Agreement will not infringe or conflict
            with any Third Party right or patent and TBC is not aware of any
            pending patent

                                       25
<PAGE>

            application that if issued would be infringed by the manufacture,
            use or sale of the Products pursuant to this Agreement. TBC has not
            received any notice from a third party that any manufacture, use or
            sale of the Products and Compound pursuant to this Agreement
            infringes or conflicts with any Third party right or patent.

                                       26
<PAGE>

7. PROPRIETARY RIGHTS.

      7.1   IMPROVEMENTS. Improvements conceived or made solely by the employees
            of either party during the term of this Agreement shall be the sole
            property of such party. Improvements made jointly by employees of
            both parties during the term of this Agreement shall be owned by
            Revotar. All Improvements no matter if conceived solely by one party
            to this Agreement or jointly shall be automatically included in the
            license granted to Revotar under Section 2; provided, that the
            parties agree to negotiate in good faith appropriate modifications
            to the terms of this Agreement which reflect the fact that an
            Improvement has been jointly developed or developed only by TBC.
            Each party shall promptly disclose to the other any Improvements
            developed by its employees or agents acting on its behalf. Each
            party agrees that all employees and other persons acting on its
            behalf under this Agreement shall be obligated under a binding
            written agreement to assign (or exclusively license in the case of
            academics) to such party or as such party shall direct all
            Improvements made or conceived by such employee or other person.

            New Chemical Entities, including Compound follow-up molecules
            discovered by Revotar will be the exclusive intellectual property of
            Revotar. TBC agrees to waive patent infringement litigation against
            Revotar related to such discoveries.

      7.2   PATENT PROSECUTION AND MAINTENANCE. The parties agree that they will
            coordinate with each other in all reasonable respects the worldwide
            prosecution of the Patents, subject to the provisions of this
            Section 7. TBC shall be responsible,

                                       27
<PAGE>

            at its expense, for prosecuting and maintaining any patents and
            patent applications relating to the Patents in existence on the date
            of the License Agreement. Revotar shall be responsible, at its
            expense, for filing, prosecuting and maintaining the Patents to the
            extent they are not in existence on the date of the License
            Agreement (including Improvements owned by Revotar or jointly
            developed by Revotar and TBC, but excluding Improvements owned
            exclusively by TBC). Each party shall furnish the other party with
            copies of any patent application concerning Subject Technology or
            Improvements sufficiently in advance of the anticipated filing date
            (but in no event less than 5 working days before filing) so as to
            give the other party a reasonable opportunity to review and comment.
            Each party shall also furnish copies to the other party of all
            communications to and from United States and foreign patent offices
            regarding patents or patent applications relating to this Agreement
            within a reasonable time prior to filing such communication or
            promptly following the receipt thereof. Each party shall reasonably
            consider any comments the other party may have related to such
            patent applications or communications. Each party shall have the
            right at its expense to file, prosecute and maintain patents in the
            United States and all foreign countries on Improvements owned solely
            by it. Notwithstanding the foregoing, beyond best efforts, neither
            party assumes liability to the other for the successful prosecution
            of any patent application. However, if either party shall fail to
            pay an annuity, tax or other maintenance fee with respect to a
            Patent or Patent application or otherwise decide not to pursue a
            Patent relating to Improvements owned solely by

                                       28
<PAGE>

            it, it shall give the other party timely notice and the opportunity
            to take such action and assume all ownership rights to such Patent
            or Patent application.

      7.3   THIRD PARTY CLAIM OF INFRINGEMENT. Each party shall give the other
            prompt notice of each claim or allegation that the exercise of
            rights hereunder constitutes an infringement of one or more patents
            or other rights of a Third Party. Revotar shall use all commercially
            reasonable efforts to defend the parties against any such claim or
            allegation with counsel of its own choice reasonably acceptable to
            Revotar. The costs of such defense and any costs of settling or
            otherwise satisfying such claim (including damage awards, if any)
            shall be borne as follows:

            7.3.1 TBC COSTS. TBC shall bear all costs associated with claims
            based on any patent issued or patent application published as of the
            date of the License Agreement. If Revotar continues to sell the
            Products following notice of such claim against explicit requests to
            the contrary by TBC, then Revotar shall have the obligation to
            satisfy all claims in connection with such continued sales activity.
            At all times, Revotar shall have the right to defend itself at its
            cost against this with counsel of its own choice reasonably
            acceptable to TBC.

            7.3.2 REVOTAR COSTS. Revotar shall bear all costs associated with
            claims based on any patent or patent application that was not issued
            or published as of the date of the License Agreement.

            7.3.3 COOPERATION. Each party agrees to cooperate with the other in
            the defense of any such claim or allegation, including, to the
            extent able, furnishing testimony by its employees and providing
            technical support and information as requested. Neither party shall
            settle or discontinue defense of any such case without the

                                       29
<PAGE>

            other's prior written consent, which shall not be unreasonably
            withheld. In the case of any proposed settlement involving a
            cross-license with a Third Party, neither party may unreasonably
            refuse to enter into such a cross-license. The provisions of this
            Section 7.3 shall also apply to actions for declaratory relief which
            raise or are in response to an issue of infringement of a Third
            Party patent.

      7.4   INFRINGEMENT BY THIRD PARTIES. Each party shall give the other party
            prompt written notice of any incident of infringement of Patents
            that comes to its attention. The parties shall thereupon confer as
            to what steps are to be taken to stop or prevent such infringement.
            Revotar agrees to use reasonable efforts to stop any such
            infringement, but shall not be obligated to commence proceedings
            against the infringer. If Revotar decides to commence proceedings,
            however, Revotar shall be responsible for any legal costs incurred
            and will be entitled to retain any settlement or damage award
            received, and TBC agrees to cooperate with Revotar in such
            proceeding. TBC shall have the right at its expense to engage its
            own counsel in connection with such proceedings. Should Revotar
            decide not to commence proceedings, and should the infringement
            represent a substantial threat to the commercial value of any
            Products, TBC shall be entitled (but not obligated) to do so in its
            own name and/or in Revotar's name against the infringer, in which
            event TBC shall be responsible for all legal costs incurred, and
            will be entitled to retain any settlement or damage award received,
            and Revotar agrees to cooperate with TBC in such proceedings and
            Revotar shall have the right at its expense to engage its own
            counsel in connection with such proceedings.

                                       30
<PAGE>

8. CONFIDENTIALITY.

      8.1   GENERAL. Any party receiving Confidential Information pursuant to
            this Agreement shall maintain the confidential and proprietary
            status of such Confidential Information, keep such Confidential
            Information and each part thereof within its possession or under its
            control sufficient to prevent any activity with respect to the
            Confidential Information that is not specifically authorized by this
            Agreement and prevent the disclosure of any Confidential Information
            to any Third Party using the same degree of care it would use with
            respect to its own information of like importance; provided,
            however, that such restrictions shall not apply to any Confidential
            Information that is (a) independently developed outside the scope of
            this Agreement by employees of the receiving party having no access
            to or knowledge of the Confidential Information disclosed hereunder,
            (b) in the public domain at the time of its receipt or thereafter
            becomes part of the public domain through no fault of the receiving
            party, (c) lawfully received without an obligation of
            confidentiality from a Third Party having the right to disclose such
            information, (d) released from the restrictions of this Section 8 by
            the express written consent of the disclosing party, (e) disclosed
            to any permitted assignee, sublicensee or subcontractor or customer
            of Revotar or TBC, provided that such assignee, sublicensee,
            subcontractor or customer is subject to the provisions of this
            Section 8 or substantially similar provisions or (f) required by
            law, statute, rule or court order to be disclosed, including
            requirements of the Securities and Exchange Commission, the FDA, any
            PRA, and other regulatory authorities, provided that the disclosing
            party uses commercially reasonable efforts to obtain

                                       31
<PAGE>

            confidential treatment of any such disclosure. Without limiting the
            generality of the foregoing, Revotar and TBC each shall use all
            commercially reasonable efforts to obtain, if not already in place,
            confidentiality agreements from its respective relevant employees
            and agents, to protect the Confidential Information as herein
            provided.

      8.2   DISCLOSURE OF AGREEMENT. Neither party shall make a public
            announcement or otherwise disclose the terms of this Agreement to
            any Third Party without the prior written consent of the other
            except that the parties may without such consent disclose (a) the
            existence of this Agreement, (b) the identity of the other party and
            (c) the general subject matter of this Agreement. Notwithstanding
            the foregoing statement, both parties may disclose details of this
            agreement to third parties, pursuant to a confidentiality agreement,
            for the purpose of business negotiations with potential licensees,
            financial investors, financial advisors, patent attorneys and
            governmental agencies.

            Each party shall also be permitted to make such disclosure of the
            terms of this Agreement as its counsel reasonably determines is
            necessary to comply with law, provided that such party shall use
            commercially reasonable efforts to obtain confidential treatment of
            any such disclosure.

                                       32
<PAGE>

9. INDEMNIFICATION.

      9.1   MUTUAL RIGHT TO INDEMNIFICATION. Each party shall defend, indemnify
            and hold harmless the other and its directors, officers, employees
            and agents from and against any and all claims, liabilities, losses
            and expenses, including attorneys' fees, incurred by or asserted
            against it or any of the foregoing arising out of the development,
            testing, manufacture, handling or storage of any Product by such
            party, including without limitation (i) any actual or alleged bodily
            injury, death or property damage resulting from the use of any
            Product manufactured by such party, (ii) any actual or alleged
            violation of law applicable to the development, testing,
            manufacture, handling or storage of the Products by such party and
            (iii) any Product recall of Product manufactured by such party that
            is ordered by a governmental agency or required by a confirmed
            Product failure as reasonably determined by the parties, except as
            otherwise provided herein and except to the extent that such
            liabilities, losses and expenses result from the negligence or
            willful misconduct of a party, in which case the party who engaged
            in such negligence or willful misconduct shall indemnify and hold
            harmless the other party and its directors, officers, employees and
            agents. Each party shall defend, indemnify and hold harmless the
            other party and its directors, officers, employees and agents from
            and against any and all claims, liabilities, losses and expenses,
            including attorneys' fees, incurred by or asserted against the other
            party or any of the foregoing arising out of a misrepresentation
            regarding any sales of Products by such party, it Affiliates or
            sublicensees which is not in accordance with

                                       33
<PAGE>

            approved Product claims.

      9.2   PROCEDURE. Any person that intends to claim indemnification under
            this Section 9 (an "Indemnitee") shall promptly notify the other
            party (the "Indemnitor") of any claim, in respect of which the
            Indemnitee intends to claim such indemnification, and the Indemnitor
            shall assume the defense thereof with counsel mutually satisfactory
            to the parties; provided, however, that an Indemnitee shall have the
            right to retain its own counsel, with the fees and expenses to be
            paid by the Indemnitor, if representation of such Indemnitee by the
            counsel retained by the Indemnitor would be inappropriate due to
            actual or potential differing interests between such Indemnitee and
            any other party represented by such counsel in such proceedings. The
            indemnity agreement in this Section 9 shall not apply to amounts
            paid in settlement of any loss, claim, liability or action if such
            settlement is effected without the consent of the Indemnitor, which
            consent shall not be withheld unreasonably. The failure to deliver
            notice to the Indemnitor within a reasonable time after the
            commencement of any such action, if prejudicial to its ability to
            defend such action, shall relieve such Indemnitor of any liability
            to the Indemnitee under this Section 9, but not any liability that
            it may have to any Indemnitee otherwise than under this Section 9.
            The Indemnitee and its employees and agents shall cooperate fully
            with the Indemnitor and its legal representatives in the
            investigation of any action, claim or liability covered by this
            indemnification. In the event that each party claims indemnity from
            the other and one party is finally held liable to indemnify the
            other, the Indemnitor shall additionally be liable to pay the
            reasonable legal costs

                                       34
<PAGE>

            and attorneys' fees incurred by the Indemnitee in establishing its
            claim for indemnity.

      9.3   PRODUCT LIABILITY INSURANCE. Each party shall use all commercially
            reasonable efforts to maintain product liability insurance with
            respect to its manufacture and sale of the Products hereunder. Such
            insurance shall be in such amounts and subject to such deductibles
            as the parties may agree based upon standards prevailing in the
            industry at the time such manufacturing commences. At such time as a
            Product is being launched by a party for commercial sale, the
            parties shall attempt to maximize the product liability insurance
            coverage for both parties. TBC shall maintain such insurance for so
            long as Revotar continues to sell any Product manufactured by TBC,
            and thereafter for so long as TBC maintains insurance for itself
            covering such manufacture or sales. Revotar shall maintain such
            insurance for as long as Revotar continues to sell any Product
            pursuant to this Agreement manufactured by it, and thereafter for so
            long as Revotar maintains insurance for itself covering such
            manufacture or sales.

10. TERM AND TERMINATION.

      10.1  LICENSE TERM. The obligations of Revotar under the license granted
            in section 2 shall terminate on a country by country and Product
            formulation by Product formulation basis upon the legal sale by a
            Third Party of a generic version of TBC1269 for that particular
            formulation in that particular country. Thereafter, Revotar shall
            have a license to and perpetual rights in such Patents and Subject
            Technology in such country as to the Product or Compound in
            question.

                                       35
<PAGE>

      10.2  TERMINATION FOR BREACH. Either party may terminate this Agreement by
            written notice to the other in the event that (i) the other party
            fails to perform any material obligation hereunder and such failure
            is not cured within 60 days following prompt notice thereof from the
            non-defaulting party, or (ii) any bankruptcy, receivership,
            insolvency or bankruptcy reorganization proceedings are instituted
            by the other party or any such proceedings are instituted against
            the other party and not dismissed within 120 days. The bankruptcy of
            a party shall not give rise to the right of the bankrupt party to
            terminate any license granted herein.

      10.3  TERMINATION FOR FAILURE TO PROCEED.

            Regarding the asthma indication, if more than 18 months lapse
            between the last patient completing treatment in a clinical trial
            for asthma conducted by Revotar and (i) enrollment of the next
            patient in a new clinical trial for asthma conducted by Revotar, or
            (ii) the submission of a marketing application for asthma to the
            EMEA or any country within the European Union by Revotar or (iii)
            entering into a license(s) agreement(s) between Revotar and a Third
            Party covering the asthma indication in at least the European
            Market, Japan and/or North America market, then the license will
            terminate for asthma. In the event that Revotar has entered into a
            license agreement for Japan, an additional 6 months will be added to
            the 18 month lapse period. Revotar must assure that adequate due
            diligence provisions obligate its licensee(s) to timely conduct
            clinical development and regulatory submissions. In case of breach
            of contract by the licensee(s), the license will revert to Revotar
            and Revotar will reassume the obligations as the licensee of TBC as
            stated in this Agreement.

                                       36
<PAGE>

            Regarding the topical indications, if more than 18 months lapse
            between the last patient completing treatment in a clinical trial
            for a topical indication conducted by Revotar and (i) enrollment of
            the next patient in a new clinical trial for a topical indication
            conducted by Revotar, or (ii) the submission of a marketing
            application for a topical indication to the EMEA or any country
            within the European Union by Revotar or (iii) entering into a
            license(s) agreement(s) between Revotar and a Third Party covering
            the topical indications in at least the European Market and/or
            Japan, then the license will terminate for the topical indications.
            Revotar must assure that adequate due diligence provisions obligate
            its licensee(s) to timely conduct clinical development and
            regulatory submissions. In case of breach of contract by the
            licensee(s), the license will revert to Revotar and Revotar will
            reassume the obligations as the licensee of TBC as stated in this
            Agreement

            Regarding TBC's obligations for developing the topical indications,
            following provision by Revotar to TBC of a Phase II package, as
            defined in APPENDIX 2, TBC's rights in North America with respect to
            the topical indications shall revert to Revotar upon the occurrence
            of any of the following: (i) more than 36 months lapses between the
            receipt of the Phase II package and the initiation of a Phase III
            clinical trial for a topical indication in North America by TBC and
            TBC has not entered into a license(s) covering a topical indication
            within North America within 36 months of receipt of the Phase II
            package, or (ii) more than 36 months lapses between the last patient
            completing treatment in a clinical trial for a topical

                                       37
<PAGE>

            indication conducted by TBC and the enrollment of the next patient
            in a new clinical trial for a topical indication (except where TBC
            has submitted a regulatory approval dossier in any country within
            North America) and TBC has not entered into a license(s) covering a
            topical indication within North America. TBC must assure that
            adequate due diligence provisions obligate its licensee(s) to timely
            conduct clinical development and regulatory submissions.

      10.4  SURVIVAL OF OBLIGATIONS. No termination of this Agreement shall
            eliminate any rights and obligations accrued prior to such
            termination. Promptly following any termination of this Agreement,
            each party shall return all written materials containing
            Confidential Information, except one copy that may be retained by
            counsel for each of the parties for record keeping purposes only.
            The provisions of Sections 7.3, 9, 10.4, 11.6 and 11.7 shall survive
            any termination of this Agreement. The provisions of Section 8 shall
            survive until five years after the expiration of the license as to
            all of the Products.

11. MISCELLANEOUS.

      11.1  FORCE MAJEURE. Each Party shall be excused for any failure or delay
            in performing any of its obligations under this Agreement, if such
            failure or delay is caused by Force Majeure. For purposes of this
            Agreement, "Force Majeure" shall mean any act of God, accident,
            explosion, fire, storm, earthquake, flood, drought, riot, embargo,
            civil commotion, war, act of war or any other circumstances or event
            beyond the reasonable control of the party relying upon such
            circumstance or event.

                                       38
<PAGE>

      11.2  RELATIONSHIP OF THE PARTIES. The parties agree that each is acting
            as an independent contractor with respect to the other and nothing
            contained in this Agreement is intended, or is to be construed, to
            constitute Revotar and TBC as partners or joint venturers or TBC an
            agent of Revotar. Neither party hereto shall have any express or
            implied right or authority to assume or create any obligations on
            behalf of or in the name of the other party or to bind the other
            party to any contract, agreement or undertaking.

      11.3  NOTICES. Any notice or other communication hereunder shall be in
            writing and shall be deemed given when so delivered in person, by
            overnight courier (with receipt confirmed) or by facsimile
            transmission (with receipt confirmed by telephone or by automatic
            transmission report) or on the tenth business day after being sent
            by registered or certified mail (postage prepaid, return receipt
            requested), as follows (or to such other person's address as may be
            specified in writing to the other party hereto):

            Texas Biotechnology Corporation
            7000 Fannin, 20th Floor
            Houston, Texas 77030
            Attention: President
            Facsimile: (713) 796-8232

            Revotar Biopharmaceuticals AG
            Attention: President
            Neuendorfstrasse 24a
            16761 Hennigsdorf
            Germany
            Facsimile: +49 3302 202 5011

      11.4  SUCCESSORS AND ASSIGNS. The terms and provisions of this Agreement
            shall inure to the benefit of, and be binding upon, Revotar, TBC,
            and their respective

                                       39
<PAGE>

            successors (including a successor pursuant to a merger of a party
            hereto) and assigns. This Agreement, or any of the rights granted
            hereunder, may be assigned by Revotar or TBC to any of their
            respective Affiliates; provided, that such assignment expressly
            provides that the assignor remains liable for its obligations
            hereunder and the performance of its Affiliate under this Agreement.

      11.5  AMENDMENTS AND WAIVERS. No amendment, modification, waiver,
            termination or discharge of any provision of this Agreement, nor
            consent to any departure by Revotar or TBC therefrom, shall in any
            event be effective unless the same shall be in writing specifically
            identifying this Agreement and the provision intended to be amended,
            modified, waived, terminated or discharged and signed by the party
            against whom enforcement of such amendment is sought, and each
            amendment, modification, waiver, termination or discharge shall be
            effective only in the specific instance and for the specific purpose
            for which given. No provision of this Agreement shall be varied,
            contradicted or explained by any oral agreement, course of dealing
            or performance or any other matter not set forth in an agreement in
            writing and signed by the party against whom enforcement of such
            variance, contradiction or explanation is sought.

      11.6  GOVERNING LAW. This Agreement shall be governed by and construed in
            accordance with the laws of the Federal Republic of Germany.

      11.7  DISPUTE RESOLUTION

            11.7.1 The parties agree to effect all reasonable efforts to resolve
            any and all disputes between them in connection with this Agreement
            in an amicable manner. The parties agree that any dispute that
            arises in connection with this Agreement

                                       40
<PAGE>

            and which cannot be amicably resolved by the parties shall be
            resolved by binding Alternative Dispute Resolution (ADR) in the
            manner set forth in the following Section 11.7.2

            11.7.2 All disputes arising in connection with this Agreement or its
            validity which cannot be amicably resolved by the parties shall be
            finally settled in accordance with the Arbitration Rules of the
            German Institution of Arbitration e.V. (DIS) without recourse to the
            ordinary courts of law if not agreed otherwise in this section
            11.7.2.

                  The place of arbitration shall be Berlin. The language of the
            arbitral proceedings shall be English.

                  The arbitral tribunal shall consist of a single neutral
            individual selected according to the following subsection.

                  If a party intends to begin ADR to resolve a dispute, such
            party shall provide written notice to the other party informing the
            other party of such intention and the issues to be resolved. Within
            ten (10) business days after its receipt of such notice, the other
            party may, by written notice to the party initiating ADR, add
            additional issues to be resolved. If the parties cannot agree upon
            the selection of a neutral within twenty (20) business days
            following receipt of the original ADR notice, a neutral shall be
            selected by the then President ("Vorstandsvorsitzender") of the
            German Institution of Arbitration (D.I.S.), Bonn. The neutral shall
            be a single individual having relevant experience in the
            pharmaceutical industry. The neutral selected shall not be an
            employee, director or shareholder of either party or of an
            Affiliate. Each party shall have ten (10)

                                       41
<PAGE>

            business days from the date the neutral is selected to object in
            good faith to the selection of that person. If either party makes
            such an objection, the then President of the DIS shall, as soon as
            possible thereafter, select another neutral under the same
            conditions as set forth above.

      11.8  SEVERABILITY. If any provision hereof should be held invalid,
            illegal or unenforceable in any respect in any jurisdiction, then,
            to the fullest extent permitted by law, (a) all other provisions
            hereof shall remain in full force and effect in such jurisdiction
            and shall be liberally construed in order to carry out the
            intentions of the parties hereto as nearly as may be possible and
            (b) such invalidity, illegality or unenforceability shall not affect
            the validity, legality or enforceability of such provision in any
            other jurisdiction.

      11.9  HEADINGS. Headings used herein are for convenience only and shall
            not in any way affect the construction of, or be taken into
            consideration in interpreting, this Agreement.

      11.10 EXECUTION IN COUNTERPARTS. This Agreement may be executed in any
            number of counterparts, each of which counterparts, when so executed
            and delivered, shall be deemed to be an original, and all of which
            counterparts, taken together, shall constitute one and the same
            instrument.

      11.11 ENTIRE AGREEMENT. This Agreement and the Research Agreement, as
            amended and attached hereto, contains the entire agreement and
            understanding of the parties hereto, and supersedes any prior
            agreements or understandings between the parties with respect to the
            subject matter hereof.

                                       42
<PAGE>

      IN WITNESS HEREOF, the parties hereto have caused this Agreement to be
duly executed on this 24th day of January, 2003.

                             TEXAS BIOTECHNOLOGY CORPORATION

                             By: /s/ Dr. Bruce D. Given
                                ------------------------------------------------

                             Title: President and CEO
                                   ---------------------------------------------

                             REVOTAR BIOPHARMACEUTICALS AG

                             By: /s/ Dr. Gunter Rosskamp
                                ------------------------------------------------

                             Title: CEO
                                   ---------------------------------------------

                                       43

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