Document:

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                                                                   EXHIBIT 10.31

CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY
ASTERISKS, HAS BEEN OMITTED AND FILED SEPARATELY WITH THE SECURITIES AND
EXCHANGE COMMISSION PURSUANT TO RULE 406 UNDER THE SECURITIES ACT OF 1933, AS
AMENDED.

[NABI LOGO]

                 FIRST AMENDMENT TO PRODUCTION AGREEMENT BETWEEN
                            NABI AND INHIBITEX, INC.
                             DATED DECEMBER 5, 2001

The parties to this First Amendment to the Production Agreement dated December
5, 2001 are Nabi Biopharmaceuticals, formerly Nabi, a Delaware corporation
("Nabi"), and Inhibitex, Inc., a Delaware corporation ("Inhibitex").

Background:

         WHEREAS, Nabi and Inhibitex entered into a Production Agreement having
an Effective Date of December 5, 2001 (the "Agreement"), pursuant to which Nabi
has agreed to manufacture Product for Inhibitex (capitalized terms used herein
shall have the meanings defined in the Agreement unless otherwise defined
herein); and

         WHEREAS, Nabi and Inhibitex desire to amend the Agreement as
hereinafter provided to define the structure for profit sharing in connection
with the sale of a By-Product, Fraction V, in accordance with Section 10 of the
Agreement, and acknowledge that no previous amendments to the Agreement have
been made; and

         WHEREAS, the parties hereby agree and confirm that the Agreement is
currently in full force and effect as between them, and further agree that all
terms and conditions as they previously applied shall continue to apply to the
Agreement, except as hereby amended.

         NOW, THEREFORE, in consideration of the mutual premises contained
herein and other valuable consideration, the receipt and sufficiency of which
are hereby acknowledged, and intending to be legally bound hereby, the parties
hereto agree as follows:

Amendments:

         1.       Each of Sections 1.26, 2.5(b), 2.5(e), 2.5(f), 2.5(h) and 9.2
is hereby amended by inserting the phrase "and any By-Product" immediately after
each reference to "Product" contained therein. Each of Sections 2.5(d), 2.5(m),
2.5(n), 2.5(p), 2.5(q), 2.5(r), 3.3 and 17.5 is hereby amended by inserting the
phrase "or any By-Product" immediately after each reference to "Product"
contained therein.

         2.       Section 2.5 is hereby amended by adding new subsection (z) to
read in its entirety as follows:

         "(z)     have sole responsibility for the manufacture, testing,
filling, labeling, storage and shipping of any By-Product."

         3.       Section 10 is hereby amended by numbering the existing
paragraph "10.1" and adding new subsection 10.2 to read in its entirety as
follows:

"10.2    Terms of Sale for Fraction V By-Product:

         Nabi shall have the exclusive right to sell Fraction V By-Product
throughout the term of the Agreement on behalf of Inhibitex pursuant to the
following terms:

                                                                  [NABI ADDRESS]

<PAGE>

         (a)               For purposes of this Section 10.2, "Profits" shall be
                  defined as the amount remaining after (i) direct costs
                  incurred by Nabi (calculated in accordance with Nabi's cost
                  accounting practices for other manufactured products) for
                  labor, raw materials and supplies used specifically in the
                  process of producing Fraction V from Fraction II + III
                  centrifugate and (ii) reasonable deductions for cash or other
                  discounts or uncollected accounts on the sale of Fraction V
                  are subtracted from (iii) Nabi's gross receipts from the sale
                  of Fraction V. No other overheads or non-direct cost
                  allocations are to be deducted from gross receipts from the
                  sale of Fraction V in the calculation of Profits.

         (b)               Inhibitex and Nabi shall share the Profits from the
                  sale of Fraction V as follows:

                  [ *** ] to Nabi
                  [ *** ] to Inhibitex

         (c)               Nabi shall be responsible for negotiating all sales
                  terms and conditions with customers, and shall have the right
                  to enter into contracts for the sale of Fraction V without the
                  prior approval of Inhibitex.

         (d)               Nabi will remit payment of monies owed to Inhibitex
                  on the sale of Fraction V within fifteen (15) days of receipt
                  of payment from Nabi's customer. Nabi will certify, if
                  requested, that the gross receipts used to calculate Profits
                  include all amounts remitted to Nabi in consideration of the
                  sale of Fraction V to the customer and that Nabi will not be
                  receiving any other remuneration from the customer or any
                  other party in consideration of such sale (such as free goods,
                  add-on values, etc.).

         (e)               At the beginning of each calendar year, Nabi shall
                  provide Inhibitex with a goof faith estimate of its direct
                  costs and the selling price it expects to be used in the
                  calculation of Profits for the next year. With each payment of
                  monies made by Nabi to Inhibitex pursuant to 10.2 (d) Nabi
                  will provide an accounting statement that reflects the actual
                  calculation of Profits, including the actual direct costs and
                  selling price obtained in those particular sales of Fraction
                  V. and an explanation of any material variances from its good
                  faith estimate. Inhibitex shall have the right to make
                  enquiries and ask for reasonable support relative to any
                  material variances in the calculation of Profits included in
                  the accounting statement. In the event that Inhibitex and Nabi
                  cannot reach agreement as to the reasonableness or accuracy of
                  the calculation of Profits as it relates to a payment or
                  payments, the parties agree to retain an independent public
                  accountant, satisfactory to both parties, to resolve the
                  dispute. The parties agree to accept the decision of the
                  independent public accountants as final. The fees and expenses
                  of the independent account will be borne by the parties in
                  proportion to the differences between the respective estimates
                  of Profits and Profits as finally determined by the
                  independent public accountant.

         4.       Section 17.3 is hereby amended by adding new subsection (d) to
read in its entirety as follows:

         "(d)     any claim brought by a third party arising out of or in
                  connection with the use or sale of any By-Product."

Miscellaneous:

Each Party represents and warrants that each of its representations and
warranties set forth in the Agreement is true and correct as of the date hereof
as though made on the date hereof.

<PAGE>

Except as expressly provided herein, all terms and conditions set forth in the
Agreement remain unchanged and continue in full force and effect.

The Parties agree that they and their employees shall execute all documents and
do all other things necessary to carry out the intent to implement the
provisions of this First Amendment.

This First Amendment to the Agreement is effective the 6th day of May, 2002.

IN WITNESS WHEREOF, the parties hereby have caused this First Amendment to the
Agreement to be executed and the persons signing the same warrant that they are
duly authorized to sign for and on behalf of the respective parties.

Nabi Biopharmaceuticals                           Inhibitex, Inc.

By: /s/ Thomas H. McLain                          By: /s/Robert Schweiger
    --------------------                              --------------------------
                                                      R. Schweiger
Title: Exec VP and COO                            Title: VP Business Development<PAGE>

                                                                   Exhibit 10.32

                               [ATHEROGENICS LOGO]

                    SUBLEASE AGREEMENT - Amended and Restated

1.       Parties. This sublease agreement (the "Sublease"), entered into this
         1st day of January, 2001 is made by and between ATHEROGENICS, INC., a
         Corporation formed under the laws of the State of Georgia (hereinafter
         called "Sublessor"), and INHIBITEX, INC., a Corporation formed under
         the laws of the State of Delaware (hereinafter referred to as
         "Sublessee").

2.       Subleased Premises. Sublessor hereby subleases to Sublessee and
         Sublessee hereby subleases from Sublessor for the Term (hereinafter
         defined), at the Rental, and upon all of the terms and conditions set
         forth in this Sublease, that certain office space containing
         approximately 12,414 rentable square feet (including approximately
         1,464 of rentable feet designated as the "ACF") more particularly
         described on Exhibit A (herein defined as the "Subleased Premises"),
         together with all other rights, benefits and privileges of a Sublessor
         as tenant under the Prime Lease including, without limitation, the
         right of use and enjoyment in common with others, of the common areas
         and facilities appurtenant to and serving the Subleased Premises, and
         no other furniture, fixtures, machinery, equipment or other furnishings
         of Sublessor. The Subleased Premises comprise portions of the Science
         and Administration Facility (and its related parking area) (hereinafter
         referred to as the "Leased Property"), having a street address of 8995
         Westside Parkway, Alpharetta, Georgia, 30004. Sublessor is the tenant
         of the Leased Property by virtue of a certain Prime Lease dated June
         19, 1998 ("Prime Lease"), with Cousins Properties, Inc. ("Prime
         Landlord"), which is attached hereto as Exhibit B and incorporated
         herein by reference in its entirety. Sublessee agrees that it will
         occupy the Subleased Premises in accordance with the terms of the Prime
         Lease and will not suffer to be done or omit to do, any action which
         may result in a violation of or a default under any of the terms an
         conditions of the Prime Lease, or render the Sublessor liable for any
         damage, charge or expense thereunder. This Sublease is and shall be at
         all times subject and subordinate to each and every one of the terms
         and conditions of the Prime Lease, except for those provisions of the
         Prime Lease which are directly contradicted by or inapplicable to the
         Sublease, in which event the terms of this Sublease shall control over
         the Prime Lease and the Sublessee shall comply with the applicable
         terms and provisions of the Prime Lease (e.g., the Rental amount is
         governed by paragraph 4 below)) which is incorporated herein by
         reference as though fully set forth. Sublessee's rights under this
         Sublease shall be contingent upon Sublessor's rights under the Prime
         Lease, and in the event the Prime Lease is terminated for any reason,
         then the Sublease shall be terminated and Sublessor shall have no
         liability to Sublessee as a result of said termination. Sublessor
         covenants that it has the right, power and authority to enter into and
         fulfill the obligations of this Sublease. Provided that Inhibitex is
         not in default hereunder, Sublessor shall take all reasonable actions
         and pay all monies due under the Prime Lease, in order to keep the
         Prime Lease in full force and effect. Nothing herein shall be construed
         in any way to affect the rights and obligations of the Prime Landlord,
         and no contractual relationship is intended hereby directly between
         Sublessee and Prime Landlord. Sublessor shall reasonably assist
         Sublessee in obtaining any consents or approvals of the

<PAGE>

         Prime Landlord regarding Sublessee's signage or alterations to the
         Subleased Premises, if required under the Prime Lease.

3.       Sublease Term. The term of this Sublease (the "Sublease Term") shall be
         the period commencing on the date this Sublease is executed and
         continuing through December 31, 2005. The Sublease Term shall end at
         midnight December 31, 2005, unless sooner terminated pursuant to any
         provision hereof. Sublessee acknowledges and agrees that Sublessee has
         no right or option to extend or renew the Sublease Term beyond December
         31, 2005.

4.       Rental. From and after the date that rental payments of Sublessee shall
         commence (the "Rent Commencement Date"), Sublessee shall pay to
         Sublessor base annual rent for the Subleased Premises during the
         Sublease Term in the amount of ONE HUNCRED EIGHTY-ONE THOUSAND SIX
         HUNDRED AND SEVENTEEN DOLLARS ($181,617), per annum, said base annual
         rent to be paid in equal monthly installments in the amount of FIFTEEN
         THOUSAND ONE HUNDRED AND THIRTY-FOUR DOLLARS AND 75/100 ($15,134.75)
         (the foregoing being hereinafter sometimes referred to as the "Base
         Rental"). In the event of partial month occupancy, the Base Rental will
         be pro rated based on the actual number of days. The Base Rent due
         hereunder shall increase annual as of each anniversary of the
         Commencement Date according to the adjustment mechanisms set forth in
         Section 3.02 of the Prime Lease.

5.       Other Charges. Sublessor covenants and agrees to pay, from time to time
         as provided in the Prime Lease, all other amounts and the sums with
         respect to the Subleased Premises exclusive of the Base Rental, which
         Sublessor assumed and agreed to pay under the terms of the prime Lease.
         In addition to Base Rental Sublessee agrees to reimburse to Sublessor
         its prorata share of such other amounts and sums, including taxes,
         attributable to the Subleased Premises ("The Sublessee Reimbursement")
         which Sublessor is required to pay under the Prime Lease. Such sums
         shall be prorated based on the relative square footage of the Subleased
         Premises (12,414) in relation to the total space leased by Sublessor
         (50,821) under the Prime Lease. Sublessee shall make such Sublessee
         Reimbursement within thirty (30) days after receipt from Sublessor of
         an invoice.

6.       Required Licenses and Compliance with the Law. Sublessee shall, at its
         own cost and expense, obtain or cause to be obtainable any operating
         licenses necessary for its use of the Subleased Premises which may
         include, but is not limited to, licenses for (i) the housing of
         animals; (ii) the use and disposal of isotopes; and (iii) the use and
         disposal of biologically active agents. Sublessee shall comply with all
         laws, ordinances and regulations in obtaining and maintaining such
         licenses. Sublessee shall, at Sublessee's expense, comply promptly with
         all applicable statues, ordinances, rules, regulations, codes, orders,
         restrictions of records, and requirements in effect during the Term or
         any part of the Term hereof regulating the use of the Subleased
         Premises. Sublessee shall not use or permit the use of the Subleased
         Premises in any manner that will tend to create waste, odors, noise,
         heat, cold, vibration or a nuisance, or which shall tend to
         unreasonably disturb Sublessor or other subtenants of the Leased
         Premises, if any.

                                       2

<PAGE>

7.       Sublessor's Insurance. Sublessor is not responsible for, or obligated
         to, provide any insurance on the Subleased Premises for the benefit of
         the Sublessee. Sublessee shall provide its own liability, business
         interruption or any other insurance it may desire.

8.       Assignment and Subletting. Sublessee shall have the right to assign
         this Sublease and sublease the Subleased Premises (but only in its
         entirety, except for the area designated as the ACF as described above
         in paragraph 2) in the same manner and only to the extent that
         Sublessor has a corresponding right to make such assignment or sublease
         under the terms of Article XIII of the Prim Lease. Any proposed
         assignment or sublease by Sublessee shall be made only in accordance
         with all f the terms of Article XIII of the Prime Lease, and notice or
         request for approval of such proposed assignment or sublease, if
         required under the Prime Lease, shall be given to the Prime Landlord
         and to Sublessor. In the event that during the Sublease Term, the
         Sublessee subleases the Subleased Premises except for the ACF (the
         "Sublease"), the Sublease Term for the ACF shall automatically be
         adjusted to the shorter of (i) the original Sublease Term or, (ii) the
         period ending one year from the date on which the Sublease is executed.
         Sublessor shall not unreasonable withhold, condition or delay its
         consent to a proposed assignment or sublease which is made in
         accordance with Article XIII of the prime Lease, and Sublessor will use
         its reasonable efforts to assist Sublessee in obtaining any required
         consent of the Prime Landlord to any such proposed assignment or
         sublease.

9.       Consent of Prime Lessor. Notwithstanding Sections 8.02 and 12.01 of the
         Prime Lease, Sublessor hereby reserves the right to approve any
         Sublessee modifications to the Subleased Premises, which approval shall
         not be unreasonably withheld, conditioned or delayed.

         The forgoing notwithstanding, Sublessor shall have the right to
         withhold its consent to an assignment pending its receipt of the
         proposed assignee's financial statements as is required of any proposed
         assignee under the Prime Lease and Sublessor's reasonable determination
         concerning whether proposed assignee is capable of meeting all of its
         financial obligations under the Sublease. If those conditions are found
         to exist and Sublessor expressly consents to the proposed assignment
         and, only with respect to assignments that do note require consent
         under the Prime Lease, Sublessee shall be relieved of liability under
         this Sublease immediately upon execution of any such assignment.

10.      Notices. Any notice by either party to the other required, permitted or
         provided for herein shall only be valid if (a) delivered personally, or
         (b) sent by means of Federal Express, UPS Next Day Air or another
         reputable express mail delivery service guaranteeing next day delivery,
         or (c) sent by United States certified or registered mail, return
         receipt requested, postage pre-paid addressed (I) if to Sublessor, at
         the following addresses:

AtheroGenics, Incorporated
8995 Westside Parkway
Alpharetta, Georgia 300004

                                       3

<PAGE>

Attention: Mark Colonnese, Chief Financial Officer

Plus a copy to:
Dennis A. Davison, Esquire
Mark R. Heilbrun, Esquire
Long Aldridge & Norman, Suite 600
701 Pennsylvania Avenue, N.W.
Washington, D.C. 20004

And (ii) if to the Sublessee, at the following addresses:

Inhibitex, Inc.
8995 Westside Parkway
Alpharetta, Georgia 30004
Attention: William Johnston, Chief Executive Officer

With a copy to:

King & Spalding
191 Peachtree Street
Atlanta, Georgia 30303
Attention: Lynn Scott, Esquire

Or at such other address for either party as that party may designate by notice
to the other. A notice given as set forth above shall be deemed effective, if
delivered personally, upon hand delivery thereof, if sent via express mail, upon
hand delivery, and if mailed by United States certified or registered mail, five
(5) days following such mailing in accordance with this Section.

11.      Quiet Enjoyment. If Sublessee shall pay the rent, and perform all of
         the covenants, terms, conditions and agreements of this Sublease on the
         part of the Sublessee to be performed, Sublessee shall, during the Term
         hereof, freely, peaceably and quietly occupy and enjoy the Subleased
         Premises without molestation or hindrance by Sublessor or any party
         claiming by, through or under Sublessor, subject to the terms and
         conditions of this Sublease and the Prime Lease.

12.      Indemnity. Sublessee hereby agrees to indemnify and hold Sublessor
         harmless from and against any cost, damage, claim, liability or
         expense, including attorneys' fees, incurred by Sublessor arising from
         any breach of Sublessee hereof or from Sublessee's failure to perform
         or observe any of the terms and conditions of the prime Lease which it
         is obligated under this Sublease to perform or observe, or otherwise
         resulting form Sublessee's use or occupancy of the Subleased Premises,
         except if and to the extend any such cost, damage, claim, liability or
         expense occasioned by the negligence or willful misconduct of
         Sublessor. Sublessor hereby agrees to indemnify and hold Sublessee
         harmless from and against any cost, damage, claim, liability or
         expense, including attorney's fees, incurred by Sublessee if

                                       4

<PAGE>

         and to the extent arising from the negligence and willful misconduct of
         Sublessor or any breach of Sublessor's obligations, or default by
         Sublessor, under the Prime Lease or this Sublease.

13.      Sublessor's Default under Prime Lease. In the event that there is an
         Event of Default by Sublessor under the Prime Lease, and such default
         is not caused by Sublessee, and Sublessor does not cure the Event of
         Default within five (5) days after written notice by Prime Landlord to
         Sublessor in the event of monetary default and fifteen (15) days after
         such notice in the event of non-monetary default, Sublessor shall
         immediately notify Sublessee in writing of such Event of Default.
         Sublessee shall have the right to cure such Event of Default on
         Sublessor's behalf and Sublessor shall promptly reimburse Sublessee for
         all reasonable, out-of-pocket expenses incurred by Sublessee in
         connection with such curative action. In the event that Sublessor does
         not reimburse Sublessee within fifteen (15) days after written notice
         to Sublessor, Sublessee shall have the right to deduct any such sums
         due to Sublessee from the rent due under this Sublease plus interest
         calculated at a rate of eighteen percent (18%) per annum thereon from
         the date incurred by Sublessee until offset by Sublessee.

14.      Sublessor's Representation and Warranty. Sublessor hereby represents,
         warrants and certifies to Sublessee as follows:

(a)          A true, complete, and accurate copy of the Prime Lease is attached
             hereto as Exhibit "B" and except as attached hereto, the Prime
             Lease has not been modified or amended.

(b)          The prime Lease is in full force and effect and there has occurred
             no Event of Default by Sublessor thereunder.

15.      Interruption of Utility Service. Except in the event any interruption
         in utility services is caused by Sublessee's negligence or misconduct,
         if Sublessee cannot reasonably use the Subleased Premises for
         Sublessee's intended business operations by reason of any interruption
         in utility services to be provided by Sublessor (and Sublessee does not
         in fact use the Subleased Premises) and such condition exists for three
         (3) consecutive business days, then Sublessee's rent shall be equitably
         abated for that portion of the Subleased Premises that Sublessee is
         unable to use the Sublessee's intended business operations for the
         period commencing after the end of the three-day period above to and
         until such service is restored to the Premises. If such condition
         exists for thirty (30) consecutive days, then Sublessee may terminate
         this Sublease.

16.      Sublessor's Default Under Sublease. In the event that Sublessor
         defaults under it obligations under this Sublease, Sublessee shall
         promptly notify Sublessor in writing of such default and Sublessor
         shall have thirty (30) days within which to cure such default (or if
         such default is not capable of being cured within such time, Sublessor
         shall diligently proceed to cure such default). In the event that
         Sublessor does not cure the default within such thirty (30) day period
         or does not diligently proceed to cure such default if such default is
         not capable of being cured within such thirty (30) day period,
         Sublessee shall

                                       5

<PAGE>

         have the right to cure such default on Sublessor's behalf and Sublessor
         shall promptly reimburse Sublessee for all reasonable, out-of-pocket
         expenses incurred by Sublessee in connection with such cure.

17.      Repairs by Sublessor. Sublessor shall make all reasonably necessary
         repairs, alterations or additions that affect the Building's structural
         components and all mechanical, electrical and plumbing systems and
         other building systems servicing the Subleased Premises.

18.      Fire or Other Casualty Damage. If any portion of the Subleased Premises
         shall be destroyed or damaged by fire or any other casualty or any
         other portion of the building such that Sublessee may not reasonably
         use the Subleased Premises, then Sublessee shall be entitled to an
         equitable abatement of the rent hereunder until such time as the
         damaged portion of the Subleased Premises are required or restored by
         Sublessor, and the Sublessee shall have the right to terminate this
         Sublease if such damage cannot be repaired or restored within 180 days
         after the date of such casualty.

19.      Acceptance of Subleased Premises. Sublessee accepts the Subleased
         Premises in their existing condition, without representation or
         warranty, express or implied, in fact or by law, and no representation,
         statement or warranty, express or implied, has been made by or on
         behalf of Sublessor as to such condition, or as to the use that may be
         made of said Sublease Premises."

20.      Defined Terms. All capitalized terms not otherwise defined herein shall
         have the meaning ascribed hereto as set forth in the Prime Lease.

                  IN WITNESS WHEREOF, the parties hereto hereby execute this
Sublease as of the day and year first above written.

SUBLESSEE:                                     SUBLESSOR:

INHIBITEX, INC.                                ATHEROGENICS, INC.

By: /s/ William D. Johnston                    By: /s/ Mark P. Colonnese
    ----------------------------                   --------------------------
    William Johnston                               Mark P. Colonnese
    Chief Executive Officer                        Chief Financial Officer

                                       6

<PAGE>

Exhibit A - [Layout of Office Space]

                                       7

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