STANDARD INDUSTRIAL/COMMERCIAL MULTI-TENANT LEASE ? NET AIR COMMERCIAL REAL ESTATE ASSOCIATION

Exhibit 10.10

STANDARD INDUSTRIAL/COMMERCIAL MULTI-TENANT LEASE – NET

AIR COMMERCIAL REAL ESTATE ASSOCIATION

1. Basic Provisions ( “ Basic Provisions ” ).

1.1 Parties: This Lease (“ Lease ”), dated for reference purposes only April 20, 2004, is made by and between Portola Land Company (“ Lessor ”) and ChemoCentryx Inc., a Delaware corporation (“ Lessee ”), (collectively the “ Parties ”, or individually a “ Party ”).

1.2 (a) Premises: That certain portion of the Project (as defined below), including all improvements therein or to be provided by Lessor under the terms of this Lease, commonly known by the street address of 840—850 Maude Avenue, located in the City of Mountain View, County of Santa Clara, State of California, with zip code 94043, as outlined on Exhibit      attached hereto (“ Premises ”) and generally described as (describe briefly the nature of the Premises): Freestanding single story office/laboratory building consisting of 35,755 +/- square feet.

In addition to Lessee’s rights to use and occupy the Premises as hereinafter specified, Lessee shall have non-exclusive rights to the Common Areas (as defined in Paragraph 2.7 below) as hereinafter specified, but shall not have any rights to the roof, exterior walls or utility raceways of the building containing the Premises (“ Building ”) or to any other buildings in the Project. The Premises, the Building, the Common Areas, the land upon which they are located, along with all other buildings and improvements thereon, are herein collectively referred to as the “ Project .” (See also Paragraph 2)

1.2 (b) Parking: A pro-rata share of the unreserved vehicle parking spaces (“ Unreserved Parking Spaces ”); and N/A reserved vehicle parking spaces (“ Reserved Parking Spaces ”). (See also Paragraph 2.6)

1.3 Term: Ten (10) years and zero (0) months (“ Original Term ”) commencing May 1, 2004 (“ Commencement Date ”) and ending April 30, 2014 (“ Expiration Date ”). (See also Paragraph 3)

1.4 Early Possession: Upon fully executed Lease (“ Early Possession Date ”). (See also Paragraphs 3.2 and 3.3)

1.5 Base Rent: per month (“ Base Rent ”), payable on the see Paragraph 51—Lease Base Rent day of each month commencing                      . (See also Paragraph 4)

þ If this box is checked, there are provisions in this Lease for the Base Rent to be adjusted.

1.6 Lessee’s Share of Common Area Operating Expenses: Fifty percent (50%) (“ Lessee’s Share ”).

1.7 Base Rent and Other Monies Paid Upon Execution:

(a) Base Rent: $28,604.00 for the period May 1, 2004—May 31, 2004.

(b) Common Area Operating Expenses: $6,615.00 for the period May 1 thru. May 31, 2004.

(c) Security Deposit: $160, 000.00 (“ Security Deposit ”). (See also Paragraph 5)

(d) Other: $N/A for N/A.

(e) Total Due Upon Execution of this Lease: $195,219.00.

1.8 Agreed Use: General office, laboratory, research & development, and all other legally approved uses of the City of Mountain View. (See also Paragraph 6)

- 1 -

1.9 Insuring Party. Lessor is the “ Insuring Party ”. (See also Paragraph 8)

1.10 Real Estate Brokers: (See also Paragraph 15)

(a) Representation: The following real estate brokers (the “ Brokers ”) and brokerage relationships exist in this transaction (check applicable boxes):

¨                                                               represents Lessor exclusively (“ Lessor’s Broker ”);

¨                                                               represents Lessee exclusively (“ Lessee’s Broker ”); or

þ Cornish & Carey Commercial represents both Lessor and Lessee (“ Dual Agency ”).

(b) Payment to Brokers: Upon execution and delivery of this Lease by both Parties, Lessor shall pay to the Brokers the brokerage fee agreed to in a separate written agreement for the brokerage services rendered by the Brokers). It is understood that Randy Scott of Cornish & Carey Commercial is a minority owner of the Subject Premises.

1.11 Guarantor. The obligations of the Lessee under this Lease are to be guaranteed by N/A (“ Guarantor ”). (See also Paragraph 37)

1.12 Addenda and Exhibits. Attached hereto is an Addendum or Addenda consisting of Paragraphs 50 through 54 and Exhibits      through      , all of which constitute a part of this Lease.

2. Premises.

2.1 Letting. Lessor hereby leases to Lessee, and Lessee hereby leases from Lessor, the Premises, for the term, at the rental, and upon all of the terms, covenants and conditions set forth in this Lease. Unless otherwise provided herein, any statement of size set forth in this Lease, or that may have been used in calculating Rent, is an approximation which the Parties agree is reasonable and any payments based thereon are not subject to revision whether or not the actual size is more or less.

2.2 Condition. Lessor shall deliver that portion of the Premises contained within the Building (“ Unit ”) to Lessee broom clean and free of debris asbestos and other hazardous materials on the Commencement Date or the Early Possession Date, whichever first occurs (“ Start Date ”), and, so long as the required service contracts described in Paragraph 7.1(b) below are obtained by Lessee and in effect within thirty days following the Start Date, warrants that the existing electrical, plumbing, fire sprinkler, lighting, heating, ventilating and air conditioning systems (“ HVAC ”), loading doors, if any, and all other such elements in the Unit, other than those constructed by Lessee, shall be in good operating condition on said date and that the structural elements of the roof, bearing walls and foundation of the Unit shall be free of material defects. If a non-compliance with such warranty exists as of the Start Date, or if one of such systems or elements should malfunction or fail within the appropriate warranty period, Lessor shall, as Lessor’s sole obligation with respect to such matter, except as otherwise provided in this Lease, promptly after receipt of written notice from Lessee setting forth with specificity the nature and extent of such non-compliance, malfunction or failure, rectify same at Lessor’s expense. The warranty periods shall be as follows: (i) 6 months as to the HVAC systems, and (ii) 60 days as to the remaining systems and other elements of the Unit. If Lessee does not give Lessor the required notice within the appropriate warranty period, correction of any such non-compliance, malfunction or failure shall be the obligation of Lessee at Lessee’s sole cost and expense (except for the repairs to foundations, and/or bearing walls—see Paragraph 7). Also see Paragraph 51

2.3 Compliance. Lessor warrants that the improvements on the Premises and the Common Areas comply with the building codes that were in effect at the time that each such improvement, or portion thereof, was constructed, and also with all applicable laws, covenants or restrictions of record, regulations, and ordinances in effect on the Start Date (“ Applicable Requirements ”). Said warranty does not apply to the use to which Lessee will put the Premises or to any Alterations or Utility Installations (as defined in Paragraph 7.3(a)) made or to be made by Lessee. NOTE: Lessee is responsible for determining whether or not the Applicable Requirements, and especially

- 2 -

the zoning, are appropriate for Lessee’s intended use, and acknowledges that past uses of the Premises may no longer be allowed. If the Premises do not comply with said warranty, Lessor shall, except as otherwise provided, promptly after receipt of written notice from Lessee setting forth with specificity the nature and extent of such non-compliance, rectify the same at Lessor’s expense. If Lessee does not give Lessor written notice of a non-compliance with this warranty within 6 months following the Start Date, correction of that non-compliance shall be the obligation of Lessee at Lessee’s sole cost and expense. If the Applicable Requirements are hereafter changed so as to require during the term of this Lease the construction of an addition to or an alteration of the Unit, Premises and/or Building, the remediation of any Hazardous Substance, or the reinforcement or other physical modification of the Unit, Premises and/or Building (“ Capital Expenditure ”), Lessor and Lessee shall allocate the cost of such work as follows:

(a) Subject to Paragraph 2.3(c) below, if such Capital Expenditures are required as a result of the specific and unique use of the Premises by Lessee as compared with uses by tenants in general, Lessee shall be fully responsible for the cost thereof, provided, however that if such Capital Expenditure is required during the last 2 years of this Lease and the cost thereof exceeds 6 months’ Base Rent, Lessee may instead terminate this Lease unless Lessor notifies Lessee, in writing, within 10 days after receipt of Lessee’s termination notice that Lessor has elected to pay the difference between the actual cost thereof and the amount equal to 6 months’ Base Rent. If Lessee elects termination, Lessee shall immediately cease the use of the Premises which requires such Capital Expenditure and deliver to Lessor written notice specifying a termination date at least 90 days thereafter. Such termination date shall, however, in no event be earlier than the last day that Lessee could legally utilize the Premises without commencing such Capital Expenditure.

(b) If such Capital Expenditure is not the result of the specific and unique use of the Premises by Lessee (such as, governmentally mandated seismic modifications), then Lessor and Lessee shall allocate the obligation to pay for the portion of such costs reasonably attributable to the Premises pursuant to the formula set out in Paragraph 7.1(d); provided, however, that if such Capital Expenditure is required during the last 2 years of this Lease or if Lessor reasonably determines that it is not economically feasible to pay its share thereof, Lessor shall have the option to terminate this Lease upon 90 days prior written notice to Lessee unless Lessee notifies Lessor, in writing, within 10 days after receipt of Lessor’s termination notice that Lessee will pay for such Capital Expenditure. If Lessor does not elect to terminate, and fails to tender its share of any such Capital Expenditure, Lessee may advance such funds and deduct same, with Interest, from Rent until Lessor’s share of such costs have been fully paid. If Lessee is unable to finance Lessor’s share, or if the balance of the Rent due and payable for the remainder of this Lease is not sufficient to fully reimburse Lessee on an offset basis, Lessee shall have the right to terminate this Lease upon 30 days written notice to Lessor.

(c) Notwithstanding the above, the provisions concerning Capital Expenditures are intended to apply only to non-voluntary, unexpected, and new Applicable Requirements. If the Capital Expenditures are instead triggered by Lessee as a result of an actual or proposed change in use, change in intensity of use, or modification to the Premises then, and in that event, Lessee shall be fully responsible for the cost thereof, and Lessee shall not have any right to terminate this Lease.

2.4 Acknowledgements. Lessee acknowledges that: (a) it has been advised by Lessor and/or Brokers to satisfy itself with respect to the condition of the Premises (including but not limited to the electrical, HVAC and fire sprinkler systems, security, environmental aspects, and compliance with Applicable Requirements and the Americans with Disabilities Act), and their suitability for Lessee’s intended use, (b) Lessee has made such investigation as it deems necessary with reference to such matters and assumes all responsibility therefor as the same relate to its occupancy of the Premises, and (c) neither Lessor, Lessor’s agents, nor Brokers have made any oral or written representations or warranties with respect to said matters other than as set forth in this Lease. In addition, Lessor acknowledges that: (i) Brokers have made no representations, promises or warranties concerning Lessee’s ability to honor the Lease or suitability to occupy the Premises, and (ii) it is Lessor’s sole responsibility to investigate the financial capability and/or suitability of all proposed tenants.

2.5 Lessee as Prior Owner/Occupant. The warranties made by Lessor in Paragraph 2 shall be of no force or effect if immediately prior to the Start Date Lessee was the owner or occupant of the Premises. In such event, Lessee shall be responsible for any necessary corrective work.

- 3 -

2.6 Vehicle Parking. Lessee shall be entitled to use the number of Unreserved Parking Spaces and Reserved Parking Spaces specified in Paragraph 1.2(b) on those portions of the Common Areas designated from time to time by Lessor for parking. Lessee shall not use more parking spaces than said number. Said parking spaces shall be used for parking by vehicles no larger than full-size passenger automobiles or pick-up trucks, herein called “ Permitted Size Vehicles .” Lessor may regulate the loading and unloading of vehicles by adopting Rules and Regulations as provided in Paragraph 2.9. No vehicles other than Permitted Size Vehicles may be parked in the Common Area without the prior written permission of Lessor.

(a) Lessee shall not permit or allow any vehicles that belong to or are controlled by Lessee or Lessee’s employees, suppliers, shippers, customers, contractors or invitees to be loaded, unloaded, or parked in areas other than those designated by Lessor for such activities.

(b) Lessee shall not service or store any vehicles in the Common Areas.

(c) If Lessee permits or allows any of the prohibited activities described in this Paragraph 2.6, then Lessor shall have the right, without notice, in addition to such other rights and remedies that it may have, to remove or tow away the vehicle involved and charge the cost to Lessee, which cost shall be immediately payable upon demand by Lessor.

2.7 Common Areas—Definition. The term “ Common Areas ” is defined as all areas and facilities outside the Premises and within the exterior boundary line of the Project and interior utility raceways and installations within the Unit that are provided and designated by the Lessor from time to time for the general non-exclusive use of Lessor, Lessee and other tenants of the Project and their respective employees, suppliers, shippers, customers, contractors and invitees, including parking areas, loading and unloading areas, trash areas, roadways, walkways, driveways and landscaped areas.

2.8 Common Areas—Lessee’s Rights. Lessor grants to Lessee, for the benefit of Lessee and its employees, suppliers, shippers, contractors, customers and invitees, during the term of this Lease, the non-exclusive right to use, in common with others entitled to such use, the Common Areas as they exist from time to time, subject to any rights, powers, and privileges reserved by Lessor under the terms hereof or under the terms of any rules and regulations or restrictions governing the use of the Project. Under no circumstances shall the right herein granted to use the Common Areas be deemed to include the right to store any property, temporarily or permanently, in the Common Areas. Any such storage shall be permitted only by the prior written consent of Lessor or Lessor’s designated agent, which consent may be revoked at any time. In the event that any unauthorized storage shall occur then Lessor shall have the right, without notice, in addition to such other rights and remedies that it may have, to remove the property and charge the cost to Lessee, which cost shall be immediately payable upon demand by Lessor.

2.9 Common Areas—Rules and Regulations. Lessor or such other person(s) as Lessor may appoint shall have the exclusive control and management of the Common Areas and shall have the right, from time to time, to establish, modify, amend and enforce reasonable rules and regulations (“ Rules and Regulations ”) for the management, safety, care, and cleanliness of the grounds, the parking and unloading of vehicles and the preservation of good order, as well as for the convenience of other occupants or tenants of the Building and the Project and their invitees. Lessee agrees to abide by and conform to all such Rules and Regulations, and to cause its employees, suppliers, shippers, customers, contractors and invitees to so abide and conform. Lessor shall not be responsible to Lessee for the non-compliance with said Rules and Regulations by other tenants of the Project.

2.10 Common Areas—Changes. Lessor shall have the right, in Lessor’s sole discretion, from time to time:

(a) To make changes to the Common Areas, including, without limitation, changes in the location, size, shape and number of driveways, entrances, parking spaces, parking areas, loading and unloading areas, ingress, egress, direction of traffic, landscaped areas, walkways and utility raceways;

- 4 -

(b) To close temporarily any of the Common Areas for maintenance purposes so long as reasonable access to the Premises remains available;

(c) To designate other land outside the boundaries of the Project to be a part of the Common Areas;

(d) To add additional buildings and improvements to the Common Areas;

(e) To use the Common Areas while engaged in making additional improvements, repairs or alterations to the Project, or any portion thereof; and

(f) To do and perform such other acts and make such other changes in, to or with respect to the Common Areas and Project as Lessor may, in the exercise of sound business judgment, deem to be appropriate as long as it does not unreasonably interfere with Lessee’s work.

(g) Prior to exercising any of its rights under this paragraph that may impact Lessee’s use or occupancy of the Premises, Lessor shall give Lessee reasonable notice of the action to be taken, and shall use reasonable efforts to cooperate with Lessee to minimize the impact of such actions upon Lessee’s use and occupancy of the Premises.

3. Term.

3.1 Term. The Commencement Date, Expiration Date and Original Term of this Lease are as specified in Paragraph 1.3.

3.2 Early Possession. If Lessee totally or partially occupies the Premises prior to the Commencement Date, the obligation to pay Base Rent shall be abated for the period of such early possession. All other terms of this Lease (including but not limited to the obligations to pay Lessee’s Share of Common Area Operating Expenses, Real Property Taxes and insurance premiums and to maintain the Premises) shall, however, be in effect during such period. Any such early possession shall not affect the Expiration Date.

3.3 Delay In Possession. Lessor agrees to use its best commercially reasonable efforts to deliver possession of the Premises to Lessee by the Commencement Date. If, despite said efforts, Lessor is unable to deliver possession as agreed, Lessor shall not be subject to any liability therefor, nor shall such failure affect the validity of this Lease. Lessee shall not, however, be obligated to pay Rent or perform its other obligations until it receives possession of the Premises. If possession is not delivered within 60 days after the Commencement Date, Lessee may, at its option, by notice in writing within 10 days after the end of such 60 day period, cancel this Lease, in which event the Parties shall be discharged from all obligations hereunder. If such written notice is not received by Lessor within said 10 day period, Lessee’s right to cancel shall terminate. Except as otherwise provided, if possession is not tendered to Lessee by the Start Date and Lessee does not terminate this Lease, as aforesaid, any period of rent abatement that Lessee would otherwise have enjoyed shall run from the date of delivery of possession and continue for a period equal to what Lessee would otherwise have enjoyed under the terms hereof, but minus any days of delay caused by the acts or omissions of Lessee. If possession of the Premises is not delivered within 4 months after the Commencement Date, this Lease shall terminate unless other agreements are reached between Lessor and Lessee, in writing.

3.4 Lessee Compliance. Lessor shall not be required to tender possession of the Premises to Lessee until Lessee complies with its obligation to provide evidence of insurance (Paragraph 8.5). Pending delivery of such evidence, Lessee shall be required to perform all of its obligations under this Lease from and after the Start Date, including the payment of Rent, notwithstanding Lessor’s election to withhold possession pending receipt of such evidence of insurance. Further, if Lessee is required to perform any other conditions prior to or concurrent with the Start Date, the Start Date shall occur but Lessor may elect to withhold possession until such conditions are satisfied.

- 5 -

4. Rent.

4.1 Rent Defined. All monetary obligations of Lessee to Lessor under the terms of this Lease (except for the Security Deposit) are deemed to be rent (“ Rent ”).

4.2 Common Area Operating Expenses. Lessee shall pay to Lessor during the term hereof, in addition to the Base Rent, Lessee’s Share (as specified in Paragraph 1.6) of all Common Area Operating Expenses, as hereinafter defined, during each calendar year of the term of this Lease, in accordance with the following provisions:

(a) “ Common Area Operating Expenses ” are defined, for purposes of this Lease, as all costs incurred by Lessor relating to the ownership and operation of the Project, including, but not limited to, the following:

(i) The operation, repair and maintenance, in neat, clean, good order and condition of the following:

(aa) The Common Areas and Common Area improvements, including parking areas, loading and unloading areas, trash areas, roadways, parkways, walkways, driveways, landscaped areas, bumpers, irrigation systems, Common Area lighting facilities, fences and gates, elevators, roofs, and roof drainage systems.

(bb) Exterior signs and any tenant directories.

(cc) Any fire detection and/or sprinkler systems.

(ii) The cost of water, gas, electricity and telephone to service the Common Areas and any utilities not separately metered.

(iii) Trash disposal, pest control services, property management, security services, and the costs of any environmental inspections.

(iv) Reserves set aside for maintenance and repair of Common Areas.

(v) Real Property Taxes (as defined in Paragraph 10).

(vi) The cost of the premiums for the insurance maintained by Lessor pursuant to Paragraph 8.

(vii) Any deductible portion of an insured loss concerning the Building or the Common Areas.

(viii) The cost of any Capital Expenditure to the Building or the Project not covered under the provisions of Paragraph 2.3 provided; however, that Lessor shall allocate the cost of any such Capital Expenditure over a 12 year period and Lessee shall not be required to pay more than Lessee’s Share of 1/144th of the cost of such Capital Expenditure in any given month.

(ix) Any other services to be provided by Lessor that are stated elsewhere in this Lease to be a Common Area Operating Expense.

(b) Any Common Area Operating Expenses and Real Property Taxes that are specifically attributable to the Unit, the Building or to any other building in the Project or to the operation, repair and maintenance thereof, shall be allocated entirely to such Unit, Building, or other building. However, any Common Area Operating Expenses and Real Property Taxes that are not specifically attributable to the Building or to any other building or to the operation, repair and maintenance thereof, shall be equitably allocated by Lessor to all buildings in the Project.

- 6 -

(c) The inclusion of the improvements, facilities and services set forth in Subparagraph 4.2(a) shall not be deemed to impose an obligation upon Lessor to either have said improvements or facilities or to provide those services unless the Project already has the same, Lessor already provides the services, or Lessor has agreed elsewhere in this Lease to provide the same or some of them.

(d) Lessee’s Share of Common Area Operating Expenses shall be payable by Lessee within 10 days after a reasonably detailed statement of actual expenses is presented to Lessee. At Lessor’s option, however, an amount may be estimated by Lessor from time to time of Lessee’s Share of annual Common Area Operating Expenses and the same shall be payable monthly or quarterly, as Lessor shall designate, during each 12 month period of the Lease term, on the same day as the Base Rent is due hereunder. Lessor shall deliver to Lessee within 60 days after the expiration of each calendar year a reasonably detailed statement showing Lessee’s Share of the actual Common Area Operating Expenses incurred during the preceding year. If Lessee’s payments under this Paragraph 4.2(d) during the preceding year exceed Lessee’s Share as indicated on such statement, Lessor shall credit the amount of such over-payment against Lessee’s Share of Common Area Operating Expenses next becoming due. If Lessee’s payments under this Paragraph 4.2(d) during the preceding year were less than Lessee’s Share as indicated on such statement, Lessee shall pay to Lessor the amount of the deficiency within 10 days after delivery by Lessor to Lessee of the statement. Lessor will deliver to Lessee within 45 days of request detailed reporting and copies of invoices of Lessee’s pro-rata share of the common area expenses.

(e) Operating cost specifically attributable to buildings other than the premises described per Paragraph 1.2(a) will not be included in the common area maintenance expenses.

(f) Notwithstanding the foregoing, the following items are excluded from Common Area Operating Expenses; (i) interest payable by Lessor with respect to any debt secured by a deed of trust of mortgage on the Building and/or the Project; (ii) payments of ground rent; (iii) depreciation; (iv) leasing commissions or other brokerage commissions of any kind; (v) expenses incurred in leasing or procuring new tenants, including advertising and marketing expenses, and expenses for preparation of leases, or renovation of space(s) for new tenant; and (vi) costs incurred which are reimbursed by third parties (including insurance carriers).

4.3 Payment. Lessee shall cause payment of Rent to be received by Lessor in lawful money of the United States, without offset or deduction (except as specifically permitted in this Lease), on or before the day on which it is due. Rent for any period during the term hereof which is for less than one full calendar month shall be prorated based upon the actual number of days of said month. Payment of Rent shall be made to Lessor at its address stated herein or to such other persons or place as Lessor may from time to time designate in writing. Acceptance of a payment which is less than the amount then due shall not be a waiver of Lessor’s rights to the balance of such Rent, regardless of Lessor’s endorsement of any check so stating. In the event that any check, draft, or other instrument of payment given by Lessee to Lessor is dishonored for any reason, Lessee agrees to pay to Lessor the sum of $25 in addition to any late charges which may be due.

5. Security Deposit. Lessee shall deposit with Lessor upon execution hereof the Security Deposit as security for Lessee’s faithful performance of its obligations under this Lease. If Lessee fails to pay Rent, or otherwise Defaults under this Lease, Lessor may use, apply or retain all or any portion of said Security Deposit for the payment of any amount due Lessor or to reimburse or compensate Lessor for any liability, expense, loss or damage which Lessor may suffer or incur by reason thereof. If Lessor uses or applies all or any portion of the Security Deposit, Lessee shall within 10 days after written request therefor deposit monies with Lessor sufficient to restore said Security Deposit to the full amount required by this Lease. If the Base Rent increases during the term of this Lease, Lessee shall, upon written request from Lessor, deposit additional monies with Lessor so that the total amount of the Security Deposit shall at all times bear the same proportion to the increased Base Rent as the initial Security Deposit bore to the initial Base Rent. Should the Agreed Use be amended to accommodate a material change in the business of Lessee or to accommodate a sublessee or assignee, Lessor shall have the right to increase the Security Deposit to the extent necessary, in Lessor’s reasonable judgment, to account for any increased wear and tear that the Premises may suffer as a result thereof. If a change in control of Lessee occurs during this Lease and following such change the financial condition of Lessee is, in Lessor’s reasonable judgment, significantly reduced, Lessee shall deposit such additional monies with Lessor as shall be sufficient to cause the Security Deposit to be at a commercially reasonable level based on such change in financial condition. Lessor shall not be required to keep the Security Deposit separate from its general accounts. Within 14 days after the expiration or termination of this Lease,

- 7 -

if Lessor elects to apply the Security Deposit only to unpaid Rent, and otherwise within 30 days after the Premises have been vacated pursuant to Paragraph 7.4(c) below, Lessor shall return that portion of the Security Deposit not used or applied by Lessor. No part of the Security Deposit shall be considered to be held in trust, to bear interest or to be prepayment for any monies to be paid by Lessee under this Lease. The provisions in Paragraph 5 will not increase the security deposit.

6 . Use.

6.1 Use. Lessee shall use and occupy the Premises only for the Agreed Use, or any other legal use which is reasonably comparable thereto, and for no other purpose. Lessee shall not use or permit the use of the Premises in a manner that is unlawful, creates damage, waste or a nuisance, or that disturbs occupants of or causes damage to neighboring premises or properties. Lessor shall not unreasonably withhold or delay its consent to any written request for a modification of the Agreed Use, so long as the same will not impair the structural integrity of the improvements on the Premises or the mechanical or electrical systems therein, and/or is not significantly more burdensome to the Premises. If Lessor elects to withhold consent, Lessor shall within 7 days after such request give written notification of same, which notice shall include an explanation of Lessor’s objections to the change in the Agreed Use.

6.2 Hazardous Substances.

(a) Reportable Uses Require Consent. The term “ Hazardous Substance ” as used in this Lease shall mean any product, substance, or waste whose presence, use, manufacture, disposal, transportation, or release, either by itself or in combination with other materials expected to be on the Premises, is either: (i) potentially injurious to the public health, safety or welfare, the environment or the Premises, (ii) regulated or monitored by any governmental authority, or (iii) a basis for potential liability of Lessor to any governmental agency or third party under any applicable statute or common law theory. Hazardous Substances shall include, but not be limited to, hydrocarbons, petroleum, gasoline, and/or crude oil or any products, by-products or fractions thereof. Lessee shall not engage in any activity in or on the Premises which constitutes a Reportable Use of Hazardous Substances without the express prior written consent of Lessor and timely compliance (at Lessee’s expense) with all Applicable Requirements. “ Reportable Use ” shall mean (i) the installation or use of any above or below ground storage tank, (ii) the generation, possession, storage, use, transportation, or disposal of a Hazardous Substance that requires a permit from, or with respect to which a report, notice, registration or business plan is required to be filed with, any governmental authority, and/or (iii) the presence at the Premises of a Hazardous Substance with respect to which any Applicable Requirements requires that a notice be given to persons entering or occupying the Premises or neighboring properties. Notwithstanding the foregoing, Lessee may use any ordinary and customary materials reasonably required to be used in the normal course of the Agreed Use, so long as such use is in compliance with all Applicable Requirements, is not a Reportable Use, and does not expose the Premises or neighboring property to any meaningful risk of contamination or damage or expose Lessor to any liability therefor. In addition, Lessor may condition its consent to any Reportable Use upon receiving such additional assurances as Lessor reasonably deems necessary to protect itself, the public, the Premises and/or the environment against damage, contamination, injury and/or liability, including, but not limited to, the installation (and removal on or before Lease expiration or termination) of protective modifications (such as concrete encasements) and/or increasing the Security Deposit.

(b) Duty to Inform Lessor. If Lessee knows, or has reasonable cause to believe, that a Hazardous Substance has come to be located in, on, under or about the Premises, other than as previously consented to by Lessor, Lessee shall immediately give written notice of such fact to Lessor, and provide Lessor with a copy of any report, notice, claim or other documentation which it has concerning the presence of such Hazardous Substance.

(c) Lessee Remediation. Lessee shall not cause or permit any Hazardous Substance to be spilled or released in, on, under, or about the Premises (including through the plumbing or sanitary sewer system) and shall promptly, at Lessee’s expense, take all investigatory and/or remedial action reasonably recommended, whether or not formally ordered or required, for the cleanup of any contamination of, and for the maintenance, security and/or monitoring of the Premises or neighboring properties, that was caused or materially contributed to by Lessee, or pertaining to or involving any Hazardous Substance brought onto the Premises during the term of this Lease, by or for Lessee, or any third party.

- 8 -

(d) Lessee Indemnification. Lessee shall indemnify, defend and hold Lessor, its agents, employees, lenders and ground lessor, if any, harmless from and against any and all loss of rents and/or damages, liabilities, judgments, claims, expenses, penalties, and attorneys’ and consultants’ fees arising out of or involving any Hazardous Substance brought onto the Premises by or for Lessee, or any third party (provided, however, that Lessee shall have no liability under this Lease with respect to underground migration of any Hazardous Substance under the Premises from areas outside of the Project). Lessee’s obligations shall include, but not be limited to, the effects of any contamination or injury to person, property or the environment created or suffered by Lessee, and the cost of investigation, removal, remediation, restoration and/or abatement, and shall survive the expiration or termination of this Lease. No termination, cancellation or release agreement entered into by Lessor and Lessee shall release Lessee from its obligations under this Lease with respect to Hazardous Substances, unless specifically so agreed by Lessor in writing at the time of such agreement.

(e) Lessor Indemnification. Lessor and its successors and assigns shall indemnify, defend, reimburse and hold Lessee, its employees and lenders, harmless from and against any and all environmental damages, including the cost of remediation, which existed as a result of Hazardous Substances on the Premises prior to the Start Date or which are caused by the gross negligence or willful misconduct of Lessor, its agents or employees. Lessor’s obligations, as and when required by the Applicable Requirements, shall include, but not be limited to, the cost of investigation, removal, remediation, restoration and/or abatement, and shall survive the expiration or termination of this Lease.

(f) Investigations and Remediations. Lessor shall retain the responsibility and pay for any investigations or remediation measures required by governmental entities having jurisdiction with respect to the existence of Hazardous Substances on the Premises prior to the Start Date, unless such remediation measure is required as a result of Lessee’s use (including “Alterations”, as defined in Paragraph 7.3(a) below) of the Premises, in which event Lessee shall be responsible for such payment. Lessee shall cooperate fully in any such activities at the request of Lessor, including allowing Lessor and Lessor’s agents to have reasonable access to the Premises at reasonable times in order to carry out Lessor’s investigative and remedial responsibilities.

(g) Lessor Termination Option. If a Hazardous Substance Condition (see Paragraph 9.1(e)) occurs during the term of this Lease, unless Lessee is legally responsible therefor (in which case Lessee shall make the investigation and remediation thereof required by the Applicable Requirements and this Lease shall continue in full force and effect, but subject to Lessor’s rights under Paragraph 6.2(d) and Paragraph 13), Lessor may, at Lessor’s option, either (i) investigate and remediate such Hazardous Substance Condition, if required, as soon as reasonably possible at Lessor’s expense, in which event this Lease shall continue in full force and effect, or (ii) if the estimated cost to remediate such condition exceeds 12 times the then monthly Base Rent or $100,000, whichever is greater, give written notice to Lessee, within 30 days after receipt by Lessor of knowledge of the occurrence of such Hazardous Substance Condition, of Lessor’s desire to terminate this Lease as of the date 60 days following the date of such notice. In the event Lessor elects to give a termination notice, Lessee may, within 10 days thereafter, give written notice to Lessor of Lessee’s commitment to pay the amount by which the cost of the remediation of such Hazardous Substance Condition exceeds an amount equal to 12 times the then monthly Base Rent or $100,000, whichever is greater. Lessee shall provide Lessor with said funds or satisfactory assurance thereof within 30 days following such commitment. In such event, this Lease shall continue in full force and effect, and Lessor shall proceed to make such remediation as soon as reasonably possible after the required funds are available. If Lessee does not give such notice and provide the required funds or assurance thereof within the time provided, this Lease shall terminate as of the date specified in Lessor’s notice of termination.

6.3 Lessee’s Compliance with Applicable Requirements. Except as otherwise provided in this Lease, Lessee shall, at Lessee’s sole expense, fully, diligently and in a timely manner, materially comply with all Applicable Requirements, the requirements of any applicable fire insurance underwriter or rating bureau, and the recommendations of Lessor’s engineers and/or consultants which relate in any manner to the Premises, without regard to whether said requirements are now in effect or become effective after the Start Date. Lessee shall, within 10 days after receipt of Lessor’s written request, provide Lessor with copies of all permits and other documents, and other information evidencing Lessee’s compliance with any Applicable Requirements specified by Lessor, and shall immediately upon receipt, notify Lessor in writing (with copies of any documents involved) of any threatened or actual claim, notice, citation, warning, complaint or report pertaining to or involving the failure of Lessee or the Premises to comply with any Applicable Requirements.

- 9 -

6.4 Inspection; Compliance. Lessor and Lessor’s “ Lender ” (as defined in Paragraph 30) and consultants shall have the right to enter into Premises at any time, in the case of an emergency, and otherwise at reasonable times, for the purpose of inspecting the condition of the Premises and for verifying compliance by Lessee with this Lease. The cost of any such inspections shall be paid by Lessor, unless a violation of Applicable Requirements, or a contamination is found to exist or be imminent, or the inspection is requested or ordered by a governmental authority. In such case, Lessee shall upon request reimburse Lessor for the cost of such inspection, so long as such inspection is reasonably related to the violation or contamination. Lessor agrees to provide 48 hour notice (unless an emergency) to Lessee for inspection and/or to make repairs. Lessee agrees to be accompanied by Lessee and to comply with the safety regulations.

7 . Maintenance; Repairs, Utility Installations; Trade Fixtures and Alterations.

7.1 Lessee’s Obligations.

(a) In General. Subject to the provisions of Paragraph 2.2 (Condition), 2.3 (Compliance), 6.3 (Lessee’s Compliance with Applicable Requirements), 7.2 (Lessor’s Obligations), 9 (Damage or Destruction), and 14 (Condemnation), Lessee shall, at Lessee’s sole expense, keep the Premises, Utility Installations (intended for Lessee’s exclusive use, no matter where located), and Alterations in good order, condition and repair (whether or not the portion of the Premises requiring repairs, or the means of repairing the same, are reasonably or readily accessible to Lessee, and whether or not the need for such repairs occurs as a result of Lessee’s use, any prior use, the elements or the age of such portion of the Premises), including, but not limited to, all equipment or facilities, such as fire detection and/or sprinkler system, fume hoods, plumbing, HVAC equipment, electrical, lighting facilities, boilers, pressure vessels, fixtures, interior walls, interior surfaces of exterior walls, ceilings, floors, windows, doors, plate glass, roofs, and skylights but excluding any items which are the responsibility of Lessor pursuant to Paragraph 7.2. Lessee, in keeping the Premises in good order, condition and repair, shall exercise and perform good maintenance practices, specifically including the procurement and maintenance of the service contracts required by Paragraph 7.1(b) below. Lessee’s obligations shall include restorations, replacements or renewals when necessary to keep the Premises and all improvements thereon or a part thereof in good order, condition and state of repair.

(b) Service Contracts. Lessee shall, at Lessee’s sole expense, procure and maintain contracts, and obtain proposals for equipment repair for Lessor’s routine budgetary and monitoring of its fixed assets with copies to Lessor, in customary form and substance for, and with contractors specializing and experienced in the maintenance of the following equipment and improvements, if any, if and when installed on the Premises: (i) HVAC equipment, (ii) boiler and pressure vessels, (iii) clarifiers, and (iv) any other equipment, if reasonably required by Lessor. However, Lessor reserves the right, upon notice to Lessee, to procure and maintain any or all of such service contracts, and if Lessor so elects, Lessee shall reimburse Lessor, upon demand, for the cost thereof.

(c) Failure to Perform. If Lessee fails to perform Lessee’s obligations under this Paragraph 7.1, Lessor may enter upon the Premises after 10 days’ prior written notice to Lessee (except in the case of an emergency, in which case no notice shall be required), perform such obligations on Lessee’s behalf, and put the Premises in good order, condition and repair, and Lessee shall promptly reimburse Lessor for the cost thereof.

(d) Replacement. Subject to Lessee’s indemnification of Lessor as set forth in Paragraph 8.7 below, and without relieving Lessee of liability resulting from Lessee’s failure to exercise and perform good maintenance practices, if an item described in Paragraph 7.1(b) cannot be repaired other than at a cost which is in excess of 50% of the cost of replacing such item, then such item shall be replaced by Lessor, and the cost thereof shall be prorated between the Parties and Lessee shall only be obligated to pay, each month during the remainder of the term of this Lease, on the date on which Base Rent is due, an amount equal to the product of multiplying the cost of such replacement by a fraction, the numerator of which is one, and the denominator of which is 144 (ie. 1/144th of the cost per month). Lessee shall pay Interest on the unamortized balance at a rate that is commercially reasonable in the judgment of Lessor’s accountants. Lessee may, however, prepay its obligation at any time.

7.2 Lessor’s Obligations. Subject to the provisions of Paragraphs 2.2 (Condition), 2.3 (Compliance), 4.2 (Common Area Operating Expenses), 6 (Use), 7.1 (Lessee’s Obligations), 9 (Damage or Destruction) and 14 (Condemnation), Lessor, subject to reimbursement pursuant to Paragraph 4.2, shall keep in good order, condition and repair the foundations, exterior walls, structural condition of interior bearing walls, structural roof, fire sprinkler

- 10 -

system, Common Area fire alarm and/or smoke detection systems, fire hydrants, parking lots, walkways, parkways, driveways, landscaping, fences, signs and utility systems serving the Common Areas and all parts thereof, as well as providing the services for which there is a Common Area Operating Expense pursuant to Paragraph 4.2. Lessor shall not be obligated to paint the exterior or interior surfaces of exterior walls nor shall Lessor be obligated to maintain, repair or replace windows, doors or plate glass of the Premises. Lessee expressly waives the benefit of any statute now or hereafter in effect to the extent it is inconsistent with the terms of this Lease.

7.3 Utility Installations; Trade Fixtures; Alterations.

(a) Definitions. The term “ Utility Installations ” refers to all floor and window coverings, air lines, power panels, electrical distribution, security and fire protection systems, communication systems, lighting fixtures, HVAC equipment, plumbing, and fencing in or on the Premises. The term “ Trade Fixtures ” shall mean Lessee’s machinery and equipment that can be removed without doing material damage to the Premises. The term “ Alterations ” shall mean any modification of the improvements, other than Utility Installations or Trade Fixtures, whether by addition or deletion. “ Lessee Owned Alterations and/or Utility Installations ” are defined as Alterations and/or Utility Installations made by Lessee that are not yet owned by Lessor pursuant to Paragraph 7.4(a).

(b) Consent. Lessee shall not make any Alterations or Utility Installations to the Premises without Lessor’s prior written consent. Lessee may, however, make non-structural Utility Installations to the interior of the Premises (excluding the roof) without such consent but upon notice to Lessor, as long as they are not visible from the outside, do not involve puncturing, relocating or removing the roof or any existing walls, and the cumulative cost thereof during this Lease as extended does not exceed a sum equal to 3 month’s Base Rent in the aggregate or a sum equal to one month’s Base Rent in any one year. Notwithstanding the foregoing, Lessee shall not make or permit any roof penetrations and/or install anything on the roof without the prior written approval of Lessor. Lessor may, as a precondition to granting such approval, require Lessee to utilize a contractor chosen and/or approved by Lessor. Any Alterations or Utility Installations that Lessee shall desire to make and which require the consent of the Lessor shall be presented to Lessor in written form with detailed plans. Consent shall be deemed conditioned upon Lessee’s: (i) acquiring all applicable governmental permits, (ii) furnishing Lessor with copies of both the permits and the plans and specifications prior to commencement of the work, and (iii) compliance with all conditions of said permits and other Applicable Requirements in a prompt and expeditious manner. Any Alterations or Utility Installations shall be performed in a workmanlike manner with good and sufficient materials. Lessee shall promptly upon completion furnish Lessor with as-built plans and specifications. For work which costs an amount in excess of one month’s Base Rent. Subject to Lessee’s right to make non-structural Alterations without approval, as set forth above, Lessor shall have a period of five (5) days from receipt of the plans within which to approve or disapprove the proposed Alteration(s), after which time they shall be deemed approved by Lessor. Any Alteration made by Lessee after consent has been given, and any fixture (except trade fixtures) shall throughout the Lease, or any extension thereof, remain the property of Lessee. Lessor will advise Lessee at the time of Consent whether the proposed Alteration may remain or will need to be removed by Lessee at the end of the Lease term or the extended Lease term.

(c) Indemnification. Lessee shall pay, when due, all claims for labor or materials furnished or alleged to have been furnished to or for Lessee at or for use on the Premises, which claims are or may be secured by any mechanic’s or materialman’s lien against the Premises or any interest therein. Lessee shall give Lessor not less than 10 days notice prior to the commencement of any work in, on or about the Premises, and Lessor shall have the right to post notices of non-responsibility. If Lessee shall contest the validity of any such lien, claim or demand, then Lessee shall, at its sole expense defend and protect itself, Lessor and the Premises against the same and shall pay and satisfy any such adverse judgment that may be rendered thereon before the enforcement thereof. If Lessor shall require, Lessee shall furnish a surety bond in an amount equal to 150% of the amount of such contested lien, claim or demand, indemnifying Lessor against liability for the same. If Lessor elects to participate in any such action, Lessee shall pay Lessor’s attorneys’ fees and costs.

7.4 Ownership; Removal; Surrender; and Restoration.

(a) Ownership. Subject to Lessor’s right to require removal or elect ownership as hereinafter provided, all Alterations and Utility Installations made by Lessee shall be the property of Lessee, but considered a

- 11 -

part of the Premises. Lessor may, at any time, elect in writing to be the owner of all or any specified part of the Lessee Owned Alterations and Utility Installations. Unless otherwise instructed per paragraph 7.4(b) hereof, all Lessee Owned Alterations and Utility Installations shall, at the expiration or termination of this Lease, become the property of Lessor and be surrendered by Lessee with the Premises.

(b) Removal. By delivery to Lessee of written notice from Lessor not earlier than 90 and not later than 30 days prior to the end of the term of this Lease, Lessor may require that any or all Lessee Owned Alterations or Utility Installations be removed by the expiration or termination of this Lease. Lessor may require the removal at any time of all or any part of any Lessee Owned Alterations or Utility Installations made without the required consent.

(c) Surrender; Restoration. Lessee shall surrender the Premises by the Expiration Date or any earlier termination date, with all of the improvements, parts and surfaces thereof broom clean and free of debris, and in good operating order, condition and state of repair, ordinary wear and tear excepted. “Ordinary wear and tear” shall not include any damage or deterioration that would have been prevented by good maintenance practice. Notwithstanding the foregoing, if this Lease is for 12 months or less, then Lessee shall surrender the Premises in the same condition as delivered to Lessee on the Start Date with NO allowance for ordinary wear and tear. Lessee shall repair any damage occasioned by the installation, maintenance or removal of Trade Fixtures, Lessee owned Alterations and/or Utility Installations, furnishings, and equipment as well as the removal of any storage tank installed by or for Lessee. Lessee shall also completely remove from the Premises any and all Hazardous Substances brought onto the Premises by or for Lessee, or any third party (except Hazardous Substances which were deposited via underground migration from areas outside of the Project) even if such removal would require Lessee to perform or pay for work that exceeds statutory requirements. Trade Fixtures shall remain the property of Lessee and shall be removed by Lessee. The failure by Lessee to timely vacate the Premises pursuant to this Paragraph 7.4(c) without the express written consent of Lessor shall constitute a holdover under the provisions of Paragraph 26 below.

8. Insurance; Indemnity.

8.1 Payment of Premiums. The cost of the premiums for the insurance policies required to be carried by Lessor, pursuant to Paragraphs 8.2(b), 8.3(a) and 8.3(b), shall be a Common Area Operating Expense. Premiums for policy periods commencing prior to, or extending beyond, the term of this Lease shall be prorated to coincide with the corresponding Start Date or Expiration Date.

8.2 Liability Insurance.

(a) Carried by Lessee. Lessee shall obtain and keep in force a Commercial General Liability policy of insurance protecting Lessee and Lessor as an additional insured against claims for bodily injury, personal injury and property damage based upon or arising out of the ownership, use, occupancy or maintenance of the Premises and all areas appurtenant thereto. Such insurance shall be on an occurrence basis providing single limit coverage in an amount not less than $1,000,000 per occurrence with an annual aggregate of not less than $2,000,000, an “Additional Insured-Managers or Lessors of Premises Endorsement” and contain the “Amendment of the Pollution Exclusion Endorsement” for damage caused by heat, smoke or fumes from a hostile fire. The policy shall not contain any intra-insured exclusions as between insured persons or organizations, but shall include coverage for liability assumed under this Lease as an “ insured contract ” for the performance of Lessee’s indemnity obligations under this Lease. The limits of said insurance shall not, however, limit the liability of Lessee nor relieve Lessee of any obligation hereunder. All insurance carried by Lessee shall be primary to and not contributory with any similar insurance carried by Lessor, whose insurance shall be considered excess insurance only.

(b) Carried by Lessor. Lessor shall maintain liability insurance as described in Paragraph 8.2(a), in addition to, and not in lieu of, the insurance required to be maintained by Lessee. Lessee shall not be named as an additional insured therein.

- 12 -

8.3 Property Insurance—Building, Improvements and Rental Value.

(a) Building and Improvements. Lessor shall obtain and keep in force a policy or policies of insurance in the name of Lessor, with loss payable to Lessor, any ground-lessor, and to any Lender insuring loss or damage to the Premises. The amount of such insurance shall be equal to the full replacement cost of the Premises, as the same shall exist from time to time, or the amount required by any Lender, but in no event more than the commercially reasonable and available insurable value thereof. Lessee Owned Alterations and Utility Installations, Trade Fixtures, and Lessee’s personal property shall be insured by Lessee under Paragraph 8.4. If the coverage is available and commercially appropriate, such policy or policies shall insure against all risks of direct physical loss or damage (flood and/or earthquake), including coverage for debris removal and the enforcement of any Applicable Requirements requiring the upgrading, demolition, reconstruction or replacement of any portion of the Premises as the result of a covered loss. Said policy or policies shall also contain an agreed valuation provision in lieu of any coinsurance clause, waiver of subrogation, and inflation guard protection causing an increase in the annual property insurance coverage amount by a factor of not less than the adjusted U.S. Department of Labor Consumer Price Index for All Urban Consumers for the city nearest to where the Premises are located. If such insurance coverage has a deductible clause, the deductible amount shall not exceed $1,000 per occurrence.

(b) Rental Value. Lessor shall also obtain and keep in force a policy or policies in the name of Lessor with loss payable to Lessor and any Lender, insuring the loss of the full Rent for one year with an extended period of indemnity for an additional 180 days (“ Rental Value insurance ”). Said insurance shall contain an agreed valuation provision in lieu of any coinsurance clause, and the amount of coverage shall be adjusted annually to reflect the projected Rent otherwise payable by Lessee, for the next 12 month period.

(c) Adjacent Premises. Lessee shall pay for any increase in the premiums for the property insurance of the Building and for the Common Areas or other buildings in the Project if said increase is caused by Lessee’s acts, omissions, use or occupancy of the Premises.

(d) Lessee’s Improvements. Since Lessor is the Insuring Party, Lessor