FIFTH LEASE AMENDMENT TO LEASE AGREEMENT

Exhibit 10.249

FIFTH LEASE AMENDMENT TO LEASE AGREEMENT

THIS FIFTH LEASE AMENDMENT TO LEASE AGREEMENT (hereinafter referred to as the “Amendment”) is made as of the 7 day of July 2005, by and between DUKE REALTY LIMITED PARTNERSHIP, an Indiana limited partnership doing business in North Carolina as Duke Realty of Indiana Limited Partnership, successor by merger to Weeks Realty, L.P. (hereinafter referred to as “Landlord”) and PPD DEVELOPMENT LP, a Texas limited partnership and successor in interest to PPD Development, Inc. (hereinafter referred to as “Tenant”).

WITNESSETH:

WHEREAS, pursuant to a Lease Agreement dated June 26, 1998 by and between Landlord and Tenant, as amended by that certain First Lease Amendment to Lease Agreement dated October 28, 1998, and as amended by that certain Second Amendment to Lease Agreement dated October 1, 2002, and as mended by that certain Third Lease Amendment to Lease Agreement dated September 22, 2003 and as further amended by that certain Fourth Lease Amendment to Lease Agreement dated March 31, 2005 (the Lease Agreement, and all amendments thereto shall be referred to herein collectively as the “Lease”), Landlord leased to Tenant certain premises consisting of approximately 83,719 rentable square feet (the “Original Premises”) in a building located on certain land (the “Land”) which had been provided the address of 4023 Paramount Parkway, but is now known as 3900 South Paramount Parkway, Morrisville, Wake County, North Carolina 27560, all as more particularly described in the Lease; and

WHEREAS, the parties hereto desire to correct the date on which the Base Rent and Operating Expenses for the entire Premises will be adjusted as set forth in that certain Second Amendment to Lease Agreement, Third Amendment to Lease Agreement and Fourth Amendment to Lease Agreement (collectively “the Amendments”); and

WHEREAS, the parties hereto desire to amend the Lease, among other things, to expand the Premises by approximately 3,730 rentable square feet in Suite 225 (the “Suite 225 Space”) and approximately 8,696 square feet of space in Suite 250 (the “Suite 250 Space”) of the Building (the Suite 225 Space and the Suite 250 Space shall hereinafter collectively be referred to as the “Additional Space”) and provide for an additional tenant improvement allowance ; and

NOW, THEREFORE, for and in consideration of Ten Dollars ($10.00) paid by Landlord and Tenant to one another, and for other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged by Landlord and Tenant, Landlord and Tenant amend the Agreement as follows:

1. Premises and Term.

(a) Premises. Subparagraph (a) of Article 1 of the Lease is hereby amended to provide that Tenant shall lease the Original Premises and the Suite 225 Space effective June 15, 2005 (the “Suite 225 Expansion Date”). Subparagraph (a) of Article 1 of the Lease is hereby further amended to provide that Tenant shall lease the Original Premises and the Suite 250 Space effective September 1, 2005 (the Suite 250 Expansion Date”). Together the Original Premises, the Suite 225 Space and the Suite 250 Space shall consist of approximately 96,145 rentable square feet of space and shall hereinafter collectively be referred to as the “Premises”.

(b) Term. Subparagraph (a) of Article 1 of the Lease is hereby modified to reflect that the term of the Suite 225 Space shall commence on the Suite 225 Expansion Date and the term of the Suite 250 Space shall commence on the Suite 250 Expansion Date, and shall each expire on November 8, 2013 (the “Expansion Term”) and shall be coterminous with the existing Lease Term of the Original Premises.

2. Base Rent, Operating Expenses and Security Deposit.

(a) Base Rent. The first paragraph of paragraph 2 (a) of the Lease is amended by adding the following:

The Lease is hereby further amended wherever applicable to reflect that the date on which the Base Rent and Operating Expenses for the entire Premises will be adjusted should have been November 9, 2008 rather than November 8, 2008 as was incorrectly stated in the Amendments.

Rent Adjustment. On November 9, 2008 (the “Rent Adjustment Date”), Tenant’s Base Rent for the entire Premises shall be adjusted to the then current Market Rent (as hereinafter defined) and taking into account the readjustment of the operating expenses as set out in Paragraph 2(b) of the Second Amendment; provided, however, that in no event shall the Base Rent per square foot, as adjusted, be less than Tenant’s then current rent.”

Market Rent. For purposes of this Lease, “Market Rent” shall mean the rental rate and other economic terms then in effect for buildings in the Research Triangle Park, North Carolina area of similar size, age, construction, with similar amenities and landscaping, and similar occupancy levels to the

Building. The monthly rental installments shall be an amount equal to one-twelfth (1/12) of the Base Rent for the remainder of the Term and shall be paid at the same time and in the same manner provided herein.

Arbitration. If Tenant disagrees with Landlord’s determination of Market Rent, Tenant shall deliver to Landlord a written objection to Landlord’s calculation of the Market Rent within fifteen (15) business days after Tenant’s receipt of Landlord’s determination of the Market Rent. If the parties cannot agree on the Market Rent within ten (10) days after Tenant’s written objection, Tenant may choose arbitration to determine the Market Rent. If Tenant chooses arbitration, Tenant shall give Landlord written notice of its desire to seek arbitration within three (3) days after expiration of such ten (10) day period (“Arbitration Notice”). Within ten (10) days after Tenant provides Landlord with its Arbitration Notice, the parties shall each appoint an appraiser to determine the Market Rent for the Premises. Each appraiser so selected shall be either an MAI appraiser or a licensed real estate broker, each having at least ten (10) years prior experience in the appraisal or leasing of comparable space in the Research Triangle Park area and with a working knowledge of current rental rates and practices. If the two appraisers cannot agree upon the Market Rent for the Premises within twenty (20) days after their appointment, then, within ten (10) days after the expiration of such twenty (20) day period, the two appraisers shall select a third appraiser meeting the above criteria. Once the third appraiser has been selected as provided for above, then such third appraiser shall within ten (10) days after appointment make its determination of the Market Rent. The average of the two closest determinations of the Market Rent shall be used as the Base Rent and shall be binding on both Landlord and Tenant. Landlord and Tenant shall each bear the cost of its appraiser and shall share the cost of the third. If Tenant fails to provide the Arbitration Notice as provided above, then Landlord’s original determination of Market Rent shall be deemed to be the Market Rent.”

(b) Operating Expenses. Effective on the Suite 225 Expansion Date, Tenant’s proportionate share of Taxes (as defined in Article 2(b) of the Lease, hereinafter “Taxes”) and Operating Expenses for the Premises shall be 73.38% and effective on the Suite 250 Expansion Date, Tenant’s proportionate share of taxes and Operating Expenses for the Premises shall be 80.68% and shall be calculated consistently with the provision of paragraph 2(b)(ii) of the Lease. Notwithstanding the foregoing, Tenant shall not be charged Operating Expenses on (i) the Suite 225 Space for the period beginning June 15, 2005 through and including November 15, 2005, and (ii) the Suite 250 Space for the period beginning September 1, 2005 through and including January 8, 2006; provided, however, that if any such expenses were incurred solely as a result of Tenant’s occupancy, then Tenant shall be responsible for such particular Operating Expenses.

3. Additional Space Improvements.

(a) Landlord shall provide Tenant with a tenant improvement allowance for the construction of the tenant improvements to the Additional Space in the amount of Twelve and 00/100 Dollars ($12.00) per rentable square foot of the Additional Space (the “Additional Space Improvement Allowance”). The Additional Space Improvement Allowance shall be applied toward construction, engineering, professional, telecommunication, design, project management, plan review, permits, architecture, voice and data cabling and other costs and expenses associated with the Additional Space Improvements (as hereinafter defined) to the Additional

Space and shall be paid by Landlord upon the receipt of proper documentation from Tenant that such work has been done. Landlord shall be responsible for the payment of all costs and expense associated with improvements to the Additional Space up to the Additional Space Improvement Allowance. Any cost or expense incurred by Landlord and approved by Tenant in connection with the Additional Space Improvements to the Additional Space in excess of the Additional Space Improvement Allowance (the “Excess”) shall be borne by Tenant and shall be paid by Tenant to Landlord within thirty (30) days of Tenant’s receipt of an invoice from Landlord providing sufficient detail and documentation for such costs and expenses. Failure by Tenant to pay any portion of the Excess as aforesaid is an event of default hereunder. If the tenant has not used the Additional Space Improvement Allowance within the first year of the Effective Date or the Additional Space Improvement Allowance exceeds the Cost Statement (as hereinafter defined) (taking into account any increases or decreases resulting from any Change Orders), such savings shall be the property of Tenant.

(b) Following the date of this Amendment, Tenant will work with a space planner to develop a space plan for the Additional Space that is reasonably acceptable to Landlord (the “Space Plan”). Within thirty (30) days after Landlord’s receipt of the Space Plan, Tenant shall prepare and submit to Landlord a set of plans and specifications and/or construction drawings (the “Plans and Specifications”) prepared by an architect reasonably acceptable to Landlord covering all work to be performed by