Document:

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                                                                    EXHIBIT 10.7

                           SECOND AMENDMENT TO LEASE

     THIS SECOND AMENDMENT TO LEASE (this "AMENDMENT") is made as for this 30th
day of September, 1998, by and between HILL MANAGEMENT SERVICES, INC., a
Maryland corporation, agent for the owner ("LANDLORD"), and Advance Paradigm
Clinical Services, Inc., a Maryland corporation ("TENANT").

                                    Recitals

     A.   WHEREAS, Landlord and Paradigm Pharmacy Management entered into a
Lease dated March 16, 1994, as amended, (collectively, the "LEASE"), for Suites
1000, 601 and 600 consisting of approximately 18,260 square feet (the "INITIAL
LEASED PREMISES"), which has an address of 11350 McCormick Rd., Hunt Valley,
Maryland 21031, and is known as Executive Plaza II (the "PROPERTY"). The
parties acknowledge and agree that Tenant has leased and occupied Suite 601
(approximately 1,055 square feet) since January 13, 1997 and that Suite 601 is
subject to all of the terms and covenants of the Lease.

     B.   WHEREAS, by separate agreement, Paradigm Pharmacy Management
transferred all of its rights, titles and interest in the Lease to Tenant.

     C.   WHEREAS, Landlord and Tenant now desire to amend certain provisions
of the Lease to provide Tenant with additional office space in the Property.

                                   Agreements

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

     Section 1. Amendment of Lease. The provisions of the Lease are amended as
follows:

     1.1. Term. Commencing November 1, 1998 the term of the Lease shall be
extended for one year and two months and the Expiration Date as set forth in
Paragraph 1.A. of the Lease, as amended, shall be October 31, 2000. The renewal
option(s) as set forth in Section 1.B. of the Lease shall remain in full force
and effect and shall apply to the extended lease term.

     1.2. Leased Premises. Commencing November 1, 1998, the Leased Premises
shall consist of approximately 20,733 square feet, and shall be comprised of the
Initial Leased Premises (Suites 1000,601 and 600) and an additional 2,473
square feet known as Suite 603 of Executive Plaza II (the "ADDITIONAL LEASED
PREMISES"). The Additional Leased Premises are more particularly depicted as
outlined in red on Exhibit A, attached hereto and made a part hereof.

     1.3. Rent. Commencing November 1, 1998, Tenant shall pay to Landlord
annual basic rent of Three Hundred Seventy-Three Thousand One Hundred
Ninety-Four and 00/100 Dollars ($373,194.00) payable in equal monthly
installments of Thirty-One Thousand Ninety Nine and 50/100 Dollars
($31,099.50). Commencing June 1, 1999, and for each twelve (12) month period
thereafter, the annual basic rent shall be increased to an amount equal to 103%
of the annual basic rent for the immediately preceding twelve (12) month period
as set forth in Section 2.C. of the Lease.

     1.4. Tenant Improvements. Landlord, at its sole cost and expense shall
construct the Additional Leased Premises using Tenant's choice of building
standard materials in accordance with the plan dated June 25, 1998 prepared by
Rubeling & Associates attached hereto and made a part hereof as Exhibit B.

     1.5. First Right of Offer. The term "First Offer Space" shall mean the
spaces on the sixth (6th) floor of the Property known as Suites 602 and 604.
Upon receipt of notice by Tenant that the First Offer Space is available for
lease, Tenant shall have the one-time Right of First Offer and shall have ten
(10) business days from receipt of the notice in which to lease the First Offer
Space, which acceptance must be made in writing and be received by the Landlord
before the expiration of said ten (10) day period. If Tenant exercises its Right
of First Offer, Landlord and Tenant shall negotiate in good faith with the
terms of the First Offer Space. If Landlord and Tenant do not, within thirty
(30) days after the 10 day period, enter into an amendment of the Lease
incorporating the terms under which the First Offer shall become null and void.
If Tenant fails to exercise the First Offer Space, then the same shall
terminate and Landlord shall be free to lease the first offer space to another
tenant.

[INITIAL STAMP]

     1.6. Underground Parking. So long as Tenant is not in default under the
Lease, Landlord shall allocate to Tenant two (2) additional reserved parking
spaces for a total of four (4) in the lower level indoor parking area of
Executive Plaza. Said spaces shall be free to charge. Except as otherwise
expressly set forth in this Section 1.6., the terms and conditions of Tenant's
use of said parking spaces shall be governed by a separate Application and
Lease for Executive Plaza Lower Lever Indoor Parking executive by Tenant and
Landlord.

     Section 2. Titles of Sections. The section titles used in this Amendment
are for convenience of reference only, and shall not constitute a part of this
Amendment nor shall they affect the meaning, construction or effect of this
Amendment or the Lease.

     Section 3. Definitions. Unless otherwise set forth in this Amendment, all
capitalized terms shall have the same meaning ascribed to them in the Lease.
<PAGE>   2

     Section 4. Interpretation. All other terms, covenants and conditions of
the Lease shall remain unchanged and continue in full force and effect except
as such terms, covenants and conditions have been amended or modified by this
Amendment, and this Amendment shall, by this reference, constitute a part of
the Lease.

     Section 5. Representations. Tenant hereby represents and warrants to
Landlord that, as of the date hereof, it (i) is the sole legal and beneficial
owner of all of the right, title and interest granted to it by the provisions
of the Lease, (ii) has not sold, transferred or encumbered any or all of such
right, title or interest, and (iii) has the full and sufficient right at law
and in equity to execute and deliver this Amendment as the owner of such right,
title, and interest, without the necessity of having any other person's consent
thereto or joinder therein.

     Section 6. Successors and Assigns. This Amendment and the terms, covenants
and conditions herein contained shall inure to the benefit of and be binding
upon Landlord and its successors and assigns, and Tenant and its permitted
successors and assigns.

     IN WITNESS WHEREOF, Landlord and Tenant have caused this Amendment to be
duly executed under seal on their behalf by their duly authorized
representative, as of the date first above written.

WITNESS/ATTEST:                         Landlord:

                                        HILL MANAGEMENT SERVICES, INC.
                                        agent for the owner

/s/ KRISTYN L. HARVEY                   By: [ILLEGIBLE]                   (SEAL)
---------------------                      ------------------------------

                                        Title: VP
                                              ---------------------------

                                        Date: 9/30/98
                                             ----------------------------

WITNESS/ATTEST:                         Tenant:

                                        ADVANCE PARADIGM CLINICAL SERVICES, INC.

/s/ JEANNE BYRNES                       By: /s/ JOE FILIPEK               (SEAL)
---------------------                      ------------------------------

                                        Printed Name: Joe Filipek
                                                     --------------------

                                        Title: President/CEO
                                              ---------------------------

                                        Date: 9/21/98
                                             ----------------------------

                                       2
<PAGE>   3
                                   EXHIBIT A

                                  [FLOOR PLAN]

                                                                [INITIAL STAMP]
<PAGE>   4

                                  [FLOOR PLAN]

                                                                [INITIAL STAMP]<PAGE>   1
                                                                    EXHIBIT 10.8

        THIS THIRD AMENDMENT TO LEASE (this "Amendment") is made as of this 1st
day of December 1999, by and between HILL MANAGEMENT SERVICES, INC., a Maryland
corporation, agent for the owner ("LANDLORD") and ADVANCE PARADIGM CLINICAL
SERVICES, INC., a Maryland corporation ("TENANT").

                                    Recitals

        A. WHEREAS, Landlord and Paradigm Pharmacy Management entered into a
Lease dated March 16, 1994, as amended by an Amendment to Lease dated October
19, 1996, and a Second Amendment to Lease dated September 30, 1999,
(collectively, the "Lease") for Suites 1000, 600, 601 and 603 consisting of
approximately 30,733 square feet (the "Initial Leased Premises"), which has an
address of 11350 McCormick Rd., Hunt Valley, Maryland 21031, and is known as
Executive Plaza II (the "PROPERTY"). The parties hereby acknowledge and agree
that Tenant commenced occupancy of payment of rent for Suite 603 as of
January 1, 1999, and that the Expiration Date pursuant to Section 1.1. Term of
the second Amendment to Lease Shall be February 28, 2001.

        B. WHEREAS, Landlord and Tenant now desire to amend certain provisions
of the Lease to provide Tenant with additional office space in the Property and
to extend the Lease Term.

                                   Agreements

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

        Section 1. Amendment of Lease. The provisions of the Lease are amended
as follows:

                Term. Commencing November 15, 1999, the term of the Lease shall
be extended for five (5) years such that the Expiration Date of the Lease shall
be February 28, 2001. The renewal option(s) as set forth in Section 1.8 of the
Lease remain in full force and effect and shall apply to the extended lease
term.

        1.2. Leased Premises. Commencing November 15, 1999, the Leased Premises
shall consists of approximately 31,363 square feet, and shall be comprised of
the Initial Leased Premises (Suites 1000, 600, 601 and 603) and an additional
10,630 square feet known as Suite 900 of Executive Plaza II (the "ADDITIONAL
LEASED PREMISES"). The Additional Leased Premises are more particularly
depicted as outlined in red on Exhibit A attached hereto and made a part hereof.

        1.3. Rent. Commencing November 15, 1999, Tenant shall pay to Landlord
annual basic rent of Five Hundred Seventy-Two Thousand Three Hundred
Seventy-Four and 75/100 Dollars ($572,374.75) payable in equal monthly
installments of Forty-Seven Thousand Six Hundred Ninety-Seven and 90/100 Dollars
($47,697.90). Commencing November 15, 2000 and each twelve (12) month period
thereafter, the annual basic rent shall be increased to an amount equal to
percent of the basic rent for the immediately preceding twelve (12) month period
as set forth in Section 2.C of the Lease.

    1.4. Tenant Improvements. Landlord, at its sole cost and expense, shall
construct the Additional Leased Premises using Tenant's choice of building
standard materials in accordance with the revised plan dated July 15, 1999 and
specifications dated February 8, 1999 prepared by Rubelling & Associates
attached hereto and made a part hereof as Exhibit ?? and Exhibit 8.1.

    1.5. Underground Parking. So long as Tenant is not in default under the
Lease, Landlord shall allocate to Tenant 21 additional reserved parking spaces
in the lower level indoor parking area of Executive Plaza. Said spaces shall be
charged at the rate of $80.00 per space per month. Except as otherwise expressly
set forth in this Section 1.5., the terms and conditions of Tenant's use of said
parking spaces shall be governed by a separate Application and Lease for
Executive Plaza II Lower Level Indoor Parking executed by Tenant and
Landlord.

    1.6. Option to Terminate. Tenant shall have the right to terminate their
occupancy of a portion of or all of the sixth ??? February 28, 2001 (the
"TERMINATION DATE"), provided Tenant has notified Landlord in writing of
Tenant's election ??? at lease one hundred twenty (120) days prior to the
Termination Date pursuant to this Section 1.6. From and ???? elected Termination
Date, the Lease as it relates to such space shall be of no further force and
effect and Landlord ??? shall have no further obligations to the other under the
Lease as it relates to such space. Notwithstanding the foregoing, Tenant shall
be responsible to pay and Additional Rent accrued through the respective
Termination Date whether or not it is billed at that time.

        1.7. Right of First Refusal. In any instance where a right of first
refusal has not been granted to another tenant in the Property, Tenant will
have the one-time right of first refusal on any space that becomes available on
the 6th, 7th or 8th floors of the Property.

        Section 2. Titles of Sections. The section titles used in this
Amendment are for convenience of reference only, and do not constitute a part
of this Amendment nor shall they affect the meaning, construction or effect of
this Amendment or ?? Lease.

        Section 3. Definitions. Unless otherwise set forth in this Amendment,
all capitalized terms shall have the same ?????????????

<PAGE>   2
     Section 5. Representations. Tenant hereby represents and warrants to
Landlord that, as of the date hereof, it (i) is the sole legal and beneficial
owner of all the right, title and interest granted to it by the provisions of
the Lease, (ii) has not sold, transferred or encumbered any or all of such
right, title or interest, and (iii) has the full and sufficient right at law
and in equity to execute and deliver this Amendment as the owner of such right,
title, and interest, without the necessity of having any other person's consent
thereto or joinder therein.

     Section 6. Successors and Assigns. This Amendment and the terms, covenants
and conditions herein contained shall inure to the benefit of and be binding
upon Landlord and its successors and assigns, and Tenant and its permitted
successors and assigns.

     IN WITNESS WHEREOF, Landlord and Tenant have caused this Amendment to be
duly executed under seal on their behalf by their duly authorized
representative, as of the date first above written.

WITNESS/ATTEST                          Landlord:

                                        HILL MANAGEMENT SERVICES, INC.
                                        agents for the owner

/s/ [Signature Illegible]               By: /s/ [Signature Illegible]     (SEAL)
----------------------------------          ------------------------------

                                        Title: VP
                                               ---------------------------------

                                        Date: 12/1/99
                                              ----------------------------------

WITNESS/ATTEST                          Tenant:

                                        ADVANCE PARADIGM CLINICAL SERVICES, INC.

/s/ SUSAN JENKINS                       By: /s/ JOE FILIPEK               (SEAL)
----------------------------------          ------------------------------

                                        Printed Name: Joe Filipek

                                        Title: President & CEO
                                               ---------------------------------

                                        Date:
                                              ----------------------------------

<PAGE>   3
9TH FLOOR:

     -    Provide all construction in accordance with the floor plan dated
          February 3, 1999 (Drawing E) prepared by Rubelling & Associates.

     -    Renovate lobby floor and walls using building standard wall
          covering, paint, and carpet finishes.

     -    Paint elevator doors.

     -    Replace/remove existing water fountain.

     -    Renovate Ladies and Men's room to include new paint and wall covering
          throughout, new flooring and countertops and wall tile.

     -    Repair or replace (as needed) building standard vertical blinds.

     -    Install uniform, building standard ceiling throughout the leased
          premises.

     -    Install building standard wall covering and a reasonable number of
          incandescent lights in the small and main conference rooms.

     -    Install building standard wall coverings, carpet and additional
          lighting in common stairwell between the 8th and 10th floors.

     -    Install insulation/sound conditioning in the small and large
          conference rooms.

10TH FLOOR:

     -    Recarpet the entire Leased Premises at Paradigm's request anytime
          during the first three (3) years of the five (5) year lease extension.

     -    Paint offices and common areas.

     -    Clean mini blinds.

     -    Shampoo existing carpet (if not replaced)

     -    Replace and clean areas around air vents.

     -    Correct signage on main floor marquee.

     -    Clean Ladies Room and Men's Room to include repainting stall doors.

     -    Repair damaged marble in lobby area (approximately 8 tiles)

     -    Provide 10th floor lounge renovations set forth on Exhibit B-1 (page
          2)

     -    Construct doorway with double doors between the existing reception
          area and conference room.

<PAGE>   4

                                  [FLOOR PLAN]

                                                                       EXHIBIT A

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