<PAGE>
                                                                   EXHIBIT 10.13

                             SUB-SUBLEASE AGREEMENT

         THIS SUB-SUBLEASE AGREEMENT (the "Sub-Sublease"), made as of this 3rd
day of July, 2001, by and between Parson Group, LLC, having an office at 190
South LaSalle Street, Chicago, Illinois ("Sub-Sublessor") and Endeavor
Pharmaceuticals,Inc., a Delaware corporation having an office at 127 Racine
Drive, Wilmington, North Carolina ("Sub-Sublessee").

                                 WITNESSETH:

         WHEREAS, Sub-Sublessor as "Sublessee" entered into a sublease with The
Ayco Company, L.P., dated April 10, 2000 (the "Sublease"); and

         WHEREAS, The Ayco Company, L.P., as "Tenant," (herein "Tenant"
or "Sublessor") had entered into a lease with Mack-Cali Campus Realty, LLC,
(the "Prime Landlord"), as "Landlord", dated September 30, 1998 which lease
was amended two (2) times, with the most-recent amendment dated April 4, 2000,
(the lease and all amendments thereto are collectively referred to as the
"Prime Lease") leasing certain space on the 3rd floor of that certain building
located at 8 Campus Drive, Parsippany, New Jersey (the "Building"). Said Prime
Lease to which reference is made above is incorporated herein by reference; and,

         WHEREAS, Sub-Sublessor and Sub-Sublessee have agreed that
Sub-Sublessor shall sublet approximately 4,258 rentable square feet of such
space as rented under the Prime Lease and the Sublease to Sub-Sublessee, as
such space is shown on Exhibit "A" attached hereto and by this reference
incorporated herein upon the terms and conditions as herein described.

         NOW, THEREFORE, in consideration of the mutual covenants and
agreements hereinafter contained, the parties hereto hereby covenant and agree
as follows:

         1.                PREMISES, RENT AND TERM. (a) Sub-Sublessor hereby
                  leases to Sub-Sublessee approximately 4,258 rentable square
                  feet, more or less, of space on the 3rd floor of the Building,
                  shown on Exhibit "A" (the "Sublease Premises") commencing
                  on June 25, 2001, (the "Commencement Date") and ending on
                  March 31, 2004 (the "Term").

                  (b) The base rent for such Sublease Premises shall be
                  $10,112.75 calendar month during the Term. The base rent shall
                  be paid beginning August 1, 2001 (the "Rent Commencement
                  Date").

                  (c) Sub-Sublessee shall pay the base rent and Additional Rent
                  as defined in Section 3 below (collectively the "Rent")
                  provided for hereunder in advance on the first day of every
                  month during the Term. If Rent is not received within ten
                  (10) days after the due date, Sub-Sublessee agrees to pay a
                  late payment to Sub-Sublessor equal to 10% of the installment
                  of the Rent.
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                  (d) Notwithstanding anything to the contrary contained
                  herein, Sub-Sublessee shall pay the Rent directly to the
                  Sub-Sublessor, Sublessor, or Prime Landlord, as
                  Sublessor shall direct.

                  (e) Sub-Sublessee shall have the use of Sub-Sublessor's
                  parking under the Sublease.

         2.                ASSIGNMENT.  Sub-Sublessee shall not have the
                  right to assign this Sub-Sublease or further sublet the
                  Sublease Premises, in whole or in part, nor shall Sub-
                  Sublessee permit Sub-Sublessee's interest in this Sub-
                  Sublease to be vested in any third-party by operation
                  of law or otherwise, without the prior written approval
                  from Sub-Sublessor, Sublessor, and the Prime Landlord.

         3.                OTHER CHARGES.  Sub-Sublessee shall be liable for
                  100% of electricity charges relating to the Sublease Premises.
                  Sub-Sublessee shall pay, on the first of every month during
                  the Term beginning August 1, 2001, one-twelfth (1/12) of
                  annual estimated electricity charges of $1.50 a square foot of
                  the Sublease Premises. At the end of each calendar year during
                  the Term hereof, Sub-Sublessor shall prorate the actual
                  electricity charges allocable to the Sublease Premises based
                  upon the electricity charges presented to Sub-Sublessor by
                  Sublessor, or by the Prime Landlord. In the event the
                  estimated electricity charges paid by Sub-Sublessee do not
                  equal or exceed the prorated actual electricity charges,
                  Sub-Sublessee shall immediately pay the difference to
                  Sub-Sublessor. In the event Sub-Sublessee is entitled to a
                  credit, it shall be applied to the next installment of Rent.
                  If Sub-Sublessee shall procure any additional services from
                  the Building, such as after-hour HVAC, Sub-Sublessee shall
                  pay for same at the rates charged therefore by the Prime
                  Landlord and shall make such payment to the Sub-Sublessor,
                  Sublessor, or Prime Landlord, as Sublessor shall direct. Any
                  Rent or other sums payable by Sub-Sublessee under this
                  Paragraph 3 shall be Additional Rent and collectible by
                  Sub-Sublessor as such. If Sub-Sublessor shall receive any
                  refund from Prime Landlord, or Sublessor, Sub-Sublessee shall
                  be entitled to the return of so much thereof as shall be
                  attributable to prior payments by Sub-Sublessee.

         4.                SUBORDINATE TO PRIME LEASE AND SUBLEASE.  This Sub-
                  Sublease is subject and subordinate in all instances and under
                  all circumstances to the Prime Lease and the Sublease. In case
                  of any breach hereof by Sub-Sublessee, Sub-Sublessor shall
                  have all the rights against Sub-Sublessee as would be
                  available to Prime Landlord against "Tenant" under the Prime
                  Lease.

         5.                USE. Sub-Sublessee shall use the Sublease Premises in
                  accordance with and subject to the Prime Lease, and in a
                  manner which does not interfere with Tenant or Sub-Sublessor,
                  or create any disturbance or nuisance to any other party.


<PAGE>

         6.                SERVICES. Not withstanding anything to the contrary
                  contained herein, the only services or rights to which Sub-
                  Sublessee is entitled hereunder are those to which
                  Sub-Sublessor is entitled to as a Sublessee under the Sublease
                  and that for all such services and rights Sub-Sublessee will
                  look to Prime Landlord under the Prime Lease. In the event
                  Sub-Sublessor is in default as Sublessee under the Sublease,
                  Sub-Sublessee shall have the right to cure Sub-Sublessor's
                  default and pay any Rent payable hereunder directly to the
                  Prime Landlord or Sublessor.

         7.                NO ACTS; INDEMNITY. (a) Sub-Sublessee shall neither
                  do nor permit anything to be done which would cause the Prime
                  Lease or Sublease to be terminated or forfeited or any claims
                  to accrue to the benefit of the Prime Landlord by reason of
                  any right of termination or forfeiture reserved or vested
                  in Prime Landlord under the Prime Lease, or any rights to
                  damages accruing to or for the benefit of Prime Landlord
                  under the Prime Lease.

                  (b) Sub-Sublessee hereby indemnifies and holds Sub-Sublessor
                  and Sublessor harmless from and against all loss, cost, damage
                  or expense, including, but not limited to, attorneys' fees and
                  court costs, incurred by Sub-Sublessor or Sublessor by reason
                  of any default on the part of Sub-Sublessee by reason of which
                  the Prime Lease or Sublease may be terminated or forfeited, or
                  any claims shall accrue to the benefit of or for Prime
                  Landlord under the Prime Lease, and against any and all other
                  loss, cost, damage or expense incurred or suffered by
                  Sub-Sublessor or Sublessor as a result of or arising out of
                  the negligence of Sub-Sublessee or the failure of
                  Sub-Sublessee to act in accordance with this Sub-Sublease.

         8.                PAYMENTS TO SUB-SUBLESSOR BY SUB-SUBLESSEE.
                  Sub-Sublessee shall pay Sub-Sublessor, upon the execution
                  and delivery of this Sub-Sublease, the sum of Ten Thousand
                  One Hundred Twelve Dollars and Twenty-Five Cents ($10,112.75)
                  as a security deposit. Such security deposit shall be returned
                  to Sub-Sublessee within ten days of the end of the
                  Sub-Sublease Term unless Sub-Sublessor notifies Sub-Sublessee
                  within such ten-day period of a default or breach that
                  justifies not returning any such security deposit. If security
                  deposit is not returned in a timely manner Sub-Sublessor shall
                  pay Sub-Sublessee interest on any portion not returned at a
                  rate of one and one-half percent (1-1/2%) per month.


         9.                SUBLEASE PREMISES; REVIEW BY SUB-SUBLESSEE:
                  (a) Sub-Sublessee shall take the Sublease Premises
                  "as is, where is", and Sub-Sublessor makes and has made no
                  representations or warranties whatsoever with respect to
                  the Sublease Premises or the fitness thereof for
                  Sub-Sublessee's intended purpose.

                  (b) Sub-Sublessee hereby acknowledges and agrees that
                  Sub-Sublessee has had the opportunity to and has reviewed the
                  Prime Lease and the Sublease. Sub-Sublessor makes no
                  representations or warranties about said Prime Lease and
                  Sublease.
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                  (c) Sub-Sublessee shall not alter the Sublease Premises in
                  any manner without the prior written consent of Sub-Sublessor,
                  Sublessor and Prime Landlord.

         10.               BROKERAGE. Sub-Sublessor and Sublessee (individually
                  hereafter, "Indemnitor") each represent and warrant to the
                  other party ("Indemnitee") that neither it nor its officers
                  or agents nor anyone acting on its behalf has death with any
                  real estate broker other than Newmark JGT of New Jersey, LLC,
                  and Peter Elliott, New Jersey, LLC, and Indemnitor agrees to
                  indemnify and hold Indemnitee, its agents, employees,
                  partners, directors, shareholders and independent contractors
                  harmless from all liabilities, costs, demands,judgments,
                  settlements, claims, and losses, including reasonable
                  attorneys fees and costs, incurred by Indemnitee in
                  conjunction with any such claim or claims of any broker or
                  brokers claiming to have interested Sub-Sublessee in the
                  Building or Sublease Premises on behalf of Indemnitor or
                  claiming to have cause Sub-Sublessee to enter into this
                  Sub-Sublease on behalf of Indemnitor. Sub-Sublessor shall pay
                  the fees of Newmark JGT of New Jersey, LLC, and Peter Elliott,
                  New Jersey, LLC.

         11.               INSURANCE. Sub-Sublessee shall obtain and maintain
                  continuously during the Term of this Sub-Sublease all
                  insurance identified on Exhibit B, attached hereto.

         12.               CONSENT OF PRIME LANDLORD AND SUBLESSOR. This
                  Sub-Sublease is contingent upon the written consent of the
                  Prime Landlord and Sublessor to the same. If such consent is
                  not granted within thirty (30) days of the date hereof, this
                  Sublease shall automatically terminate, Rent shall be
                  prorated to the date of termination and neither party shall
                  have any liability to the other as a result of such
                  termination.

         13.               FURNITURE: WIRING. Sub-Sublessor shall transfer to
                  Sub-Sublessee all of its right, title and interest in the
                  furniture located at the Sublease Premises, listed on
                  Exhibit C, attached hereto, and in the data/communications
                  wiring and "rack" located at the Sublease Premises, at no
                  additional cost. Sub-Sublessee accepts all such furniture,
                  wiring and "rack" "as is" and "where is".

         14.               NO OTHER AGREEMENTS. All prior understandings and
                  agreements between Sub-Sublessor and Sub-Sublessee are
                  merged within this Sub-Sublease, which alone fully and
                  completely sets forth the understanding of the parties hereto.
                  This Sub-Sublease may not be changed or terminated in any
                  manner other than by an agreement in writing, executed by
                  the party against whom enforcement of the change or
                  termination is sought.



<PAGE>
         15.      NOTICE. Any notice of demand which either party may or must
              give to the other hereunder shall be in writing and delivered
              personally or sent by certified mail, return receipt requested,
              addressed as follows:

              If to Sublease:       Endeavor Pharmaceuticals, Inc.
                                    8 Campus Drive
                                    Parsippany, NJ 07054
                                    ATTN: Kathleen M. Milligan

              With a copy to:       Endeavor Pharmaceuticals, Inc.
                                    127 Racine Drive, Suite 202
                                    Wilmington, NC 28403
                                    ATTN: Stephen F. Rizzo

              If to Sublessor:      Parson Group, LLC
                                    190 South LaSalle Street
                                    Fifth Floor
                                    Chicago, Illinois 60606
                                    ATTN: Dan Weinfurter

              With a copy to:       Charles J. Corrigan
                                    The Collins Law Firm, P.C.
                                    1770 North Park Street
                                    Suite 200
                                    Naperville, Illinois 60563

              Either party may, by notice in writing, direct that future notices
              or demands be sent to a different address.

         16.      BINDING. The covenants and agreements herein contained shall
              bind and inure to the benefit of Sub-Sublessor, Sub-lessee, and
              their respective executors, administrators, successors and
              assigns.

<PAGE>
         IN WITNESS WHEREOF, the undersigned have caused this Sub-Sublease to be
executed on the day and year first above-written.



"SUB-SUBLESSOR"

Parson Group, LLC

By: /s/
   ------------------------------


"SUB-SUBLESSEE"

Endeavor Pharmaceuticals, Inc.

By: Steven F. Rizzo
   ------------------------------
    Steven F. Rizzo
    Vice President



<PAGE>
                                   EXHIBIT A
                                   ---------


                                  [FLOOR PLAN]


<PAGE>
                                   EXHIBIT B
                                   ---------

         Sub-Sublessee shall be required to maintain the following insurance
coverage during the Term of the Sub-Sublease:

         1.       Commercial General Liability Insurance with respect to the
                  Sublease Premises and the business of the Sub-Sublessee, under
                  limits of liability of not less than Two Million Dollars
                  ($2,000,000.00) combined single limit per occurrence for
                  bodily or personal injury (including death) and property
                  damage. Such insurance may be carried: (a) under a blanket
                  policy covering the Sublease Premises and other locations of
                  Sub-Sublessee; or (b) under a primary liability policy of not
                  less than One Million Dollars ($1,000,000.00) and the balance
                  under an umbrella policy.

         2.       Fire and Extended Coverage in an amount adequate to cover the
                  cost of replacement of all personal property, trade fixtures,
                  furnishings, equipment and all contents in the Sublease
                  Premises.

         3.       Workers' Compensation Insurance in the minimum statutory
                  amount covering all persons employed by Sub-Sublessee.

         All insurance shall name the Prime Landlord, Sublessor, and
Sub-Sublessor as additional named insureds.



<PAGE>


                                   EXHIBIT C

                              FURNITURE INVENTORY

Reception Area Desk

4 tables, long narrow

3 file cabinets - 4 drawer

2 desks

3 round tables

1 large table

Refrigerator (small)

Microwave

Cabinet

19 Maroon Deskside Chairs

17 Black Desk Chairs

2 easels

1 whiteboard