**Exhibit 10.9**

**CONFIDENTIAL****CERTAIN INFORMATION HAS BEEN REDACTED****CONFIDENTIAL TREATMENT REQUESTED**

**FOURTH AMENDMENT TO LEASE**

THIS FOURTH AMENDMENT TO LEASE (this “Fourth Amendment”)is dated as of March 31, 2004, between ARE-819/863 MITTEN ROAD, LLC, a Delawarelimited liability company (“Landlord”), and VALENTIS, INC., a Delawarecorporation  (“Tenant”).

A.            Landlordand Tenant are parties to that certain Lease (as amended, the “863 Mitten Lease”) dated as of December 21, 1993, asamended by that certain First Amendment to Lease dated March 18, 1997 (the “FirstAmendment”), that certain Second Amendment to Leases dated as of April 10, 2001(the “Second Amendment”), and that certain Third Amendment to Lease dated as ofJuly 2, 2003 (the “Third Amendment”) wherein Landlord leases to Tenant certainpremises (the “Premises”) consisting of so-called Building A and a portion ofBuilding C located at 863 Mitten Road, Burlingame, California, comprising34,673 rentable square feet, as more particularly described in the 863 MittenLease.  Initially capitalized terms notspecifically defined herein shall have the meanings set forth in the 863 MittenLease.

B.            Landlordand Tenant are also parties to that certain separate Lease, dated as of March18, 1997 (as amended, the “866 Malcolm Lease”) with respect to certain premisesconsisting of so-called Building E and Suite 120F of Building F located at 866Malcolm Road, Burlingame, California, as more particularly described in the 866Malcolm Lease.

C.            The863 Mitten Lease and the 866 Malcolm Lease do not terminate on the same date.

D.            Pursuantto Section 5 of the First Amendment, the initial term of the 863 Mitten Leasewas extended so that the 863 Mitten Lease will terminate on November 30,2004.  The 866 Malcolm Lease willterminate on October 31, 2007.

E.             Pursuantto Section 6 of the First Amendment, the Tenant was granted an option which, ifexercised by Tenant, would permit Tenant to extend the term of the 863 MittenLease so that the 863 Mitten Lease would terminate on the same date as the 866Malcolm Lease.

F.             Landlordand Tenant have agreed to permit Tenant to extend the 863 Mitten Lease for aperiod less than the period set forth in Section 6 of the First Amendment.

G.            Landlordand Tenant further desire to amend the 863 Mitten Lease as otherwise set forthin this Fourth Amendment.

NOW THEREFORE, in consideration of the foregoingrecitals, the mutual covenants and agreements contained herein, and for othergood and valuable consideration, the receipt and sufficiency of which arehereby acknowledged, Landlord and Tenant agree, and amend the 863 MittenLease  again as follows:

 

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[*] Confidential information in this Exhibit has been omitted and filedseparately with the Commission. Confidential treatment has been requested with respect to the omittedportions.

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# 1.             Premises. The definition of “Premises” as set forth in the 863 Mitten Lease is notchanged.

# 2.             Effective Date. This Fourth Amendment shall become effective as the date of fullexecution and delivery.

# 3.             Termination Date/Term:  The term of the 863 Mitten Lease shall beextended continuously for a period of 24 months, commencing on December 1, 2004(the “Fourth Amendment Commencement Date”) and expiring on November 30, 2006(the “Amended Termination Date”).  Theperiod between the Fourth Amendment Commencement Date and the AmendedTermination Date shall be called the “Extended Term”.

# 4.             Basic Rent. The definition of “Basic Rent” as set forth in the 863 Mitten Lease asamended is hereby amended so that during the Extended Term, Tenant shall paybase rent for the Premises as follows:

| **Period**          | ** ** | **base rent/sf/mo.** | ** ** | **base rent/month** | ** ** |
|---------------------|------------|----------------------|------------|---------------------|------------|
| Months 1 – 12  |       | $                    | [*]        |                | $          | [*] |   |
| Months 12 – 24 |       | $                    | [*]        |                | $          | [*] |   |

# 5.             Option to Extend. Provided that Tenant is not in default of any of the provisions of the863 Mitten Lease at the time Tenant elects to exercise the option set forth inthis Section 5 of this Fourth Amendment, then Tenant may elect to extend theterm of the 863 Mitten Lease as set forth in this Section 5 for an additionalperiod (the “Extended Option Term”).  TheExtended Option Term shall be a period commencing on the Amended TerminationDate (as defined in Section 3 above) and ending on the same date as the 866Malcolm Lease, as that lease may be extended. The option to extend the 863 Mitten Lease may be exercised by Tenant bydelivering binding written notice to Landlord of Tenant’s clear intent to do sonot less than 270 days nor more than 360 days prior to the Amended TerminationDate.  If Tenant does not timely delivernotice of its election to exercise the option, then Tenant shall be deemed tohave waived the option, and Tenant shall have no further right to extend the863 Mitten Lease.  If Tenant timelydelivers notice of its election to extend the 863 Mitten Lease for the ExtendedOption Term, the term of the 863 Mitten Lease shall be so extended.  The Extended Option Term shall be subject toall of the terms and conditions of the 863 Mitten Lease, except that Basic Rentshall be payable during the Extended Option Term at the then rate of MarketRent, as defined in the Third Amendment. This option supercedes the option set forth in Section 6 of the FirstAmendment (“First Option”), and upon execution and delivery of this FourthAmendment, the First Option shall terminate.

# 6.             [*] Equipment. The parties acknowledge that Tenant has installed various trade fixturesand built-in equipment in that portion of the Premises, which is used as a [*](the “[*] Equipment”).  Upon thetermination or earlier expiration of the 863 Mitten Lease, the [*] Equipmentshall be deemed to be the property of Landlord, and Tenant shall surrender thePremises with all of the [*] Equipment.

 

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[*] Confidential information in this Exhibit has been omitted and filedseparately with the Commission.  Confidentialtreatment has been requested with respect to the omitted portions.

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# 7.             Surrender of Premises.  Upon theexpiration of the Term or earlier termination of Tenant’s right of possession,Tenant shall surrender the Premises to Landlord in the same condition asreceived, free of Hazardous Materials (as defined in the 863 Mitten Lease)brought upon, kept, used, stored, handled, treated, created, developed,produced, generated in, or released or disposed of from the Premises by anyperson other than Landlord (collectively, “Tenant HazMat Operations”) and released of anylicense, clearance or other authorization of any kind required to enter, use orrestore the Premises issued by any governmental authority having jurisdictionover the use, storage, handling, treatment, creation, development, production,generation, release, disposal, removal or remediation of Hazardous Materialsin, on or about the Premises (collectively referred to herein as “Hazardous Materials Clearances”), broomclean, ordinary wear and tear and casualty loss and condemnation excepted.  Tenant hereby covenants to sign as theoperator of the facility any “hazardous materials generator” or similar formrequired by any governmental authority with respect to the use of HazardousMaterials on the Premises during the Term. Tenant hereby appoints Landlord as its agent in fact for the limitedpurpose of signing any “hazardous materials generator”, “hazardous wastemanifest” or similar form required by any governmental authority in connectionwith the presence, use or removal of Hazardous Materials; provided thatLandlord hereby covenants to exercise its authority as Tenant’s attorney infact only if Tenant fails or refuses to sign any such form after writtenrequest by Landlord.

Atleast 3 months prior to the Amended Termination Date (as such date may beextended), Tenant shall deliver to Landlord a narrative description of theactions proposed (or required by any governmental authority) to be taken byTenant in order to surrender the Premises at the expiration or earliertermination of the Term, free from any residual impact from the Tenant HazMatOperations and otherwise released for unrestricted use and occupancy (the “Surrender Plan”).  The Surrender Plan shall include withoutlimitation all of the items described on Exhibit A attached hereto, and shallbe reasonably satisfactory to Landlord. In connection with the review and approval of the Surrender Plan, uponthe request of Landlord, Tenant shall deliver to Landlord or its consultantsuch additional non-proprietary information concerning Tenant HazMat Operationsas Landlord shall request.  On or beforethe date of surrender, Tenant shall certify to Landlord that all action setforth in the approved Surrender Plan has been completed.  Landlord shall have the right (but not theobligation), subject to reimbursement at Tenant’s expense as set forth below,to cause Landlord’s environmental consultant to inspect the Premises andperform such additional procedures as may be deemed reasonably necessary toconfirm that the Premises are, as of the effective date of such surrender orearly termination of the 863 Mitten Lease, free from any residual impact fromTenant HazMat Operations.  Landlord’sapproval of any Surrender Plan shall not make Landlord liable in any way forthe content or, or the results of any action taken as a result of the SurrenderPlan.  Tenant shall reimburse Landlord,as Additional Rent, for the actual out-of pocket expense incurred by Landlordfor Landlord’s environmental consultant to review and approve the SurrenderPlan and to visit the Premises and verify satisfactory completion of the same,which cost shall not exceed $5,000. Landlord shall have the unrestricted right to deliver such SurrenderPlan and any report by Landlord’s environmental consultant with respect to thesurrender of the Premises to third parties.

If Tenant shall fail to prepare and submit a SurrenderPlan to Landlord, or if Tenant shall fail to complete the work described in theSurrender Plan, or if such Surrender Plan, whether or 

 

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[*] Confidential information in this Exhibit has been omitted and filedseparately with the Commission. Confidential treatment has been requested with respect to the omittedportions.

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not reviewed by Landlord’senvironmental consultant, shall fail to adequately address any residual effectof Tenant HazMat Operations in, on or about the Premises, Landlord shall havethe right, but not the obligation, to take such actions as Landlord may deemreasonable or appropriate to assure that the Premises and the Project aresurrendered free from any residual impact from Tenant HazMat Operations, thecost of which actions shall be reimbursed by Tenant as Additional Rent, withoutregard to the limitation on cost set forth in the preceding paragraph of thisSection 7 of this Fourth Amendment.

# 8.             Brokers. Landlord and Tenant each represents to the other that it has not dealtwith any broker in connection with this Fourth Amendment.  Each party (the “Indemnifying Party”) herebyagrees to indemnify, defend and hold harmless the other party from any claimfor a commission or other compensation from any broker claiming through theIndemnifying Party.

# 9.             Counterparts. This Fourth Amendment may be executed in any number of counterparts,each of which when so executed and delivered shall be deemed to be an originaland all of which counterparts taken together shall constitute but one and thesame instrument.  Signature pages may bedetached from the counterparts and attached to a single copy of this FourthAmendment to physically form one document.

# 10.           Reaffirmation of Obligations.  Landlord and Tenant hereby acknowledge andreaffirm all of the terms of the 863 Mitten Lease, as such 863 Mitten Lease hasbeen amended by this Fourth Amendment, and agrees that any reference made inany other document to the 863 Mitten Lease shall mean the 863 Mitten Leaseas amended pursuant to this Fourth Amendment. Except as expressly provided herein, the 863 Mitten Lease remainsunmodified and in full force and effect.

# 11.           Miscellaneous.   The agreements, conditions and provisionsherein contained shall apply to and bind the heirs, executors, administrators,successors and assigns of the parties hereto.  If any provisions of this Fourth Amendment or the 863 Mitten Lease shallbe determined to be illegal or unenforceable, such determination shall notaffect any other provision of the 863 Mitten Lease or this Fourth Amendment andall such other provisions shall remain in full force and effect.  If there is any inconsistency between theprovisions of this Fourth Amendment and the other provisions of the 863 MittenLease, the provisions of this Fourth Amendment shall control with respect tothe subject matter of this Fourth Amendment. This Fourth Amendment shall be construed in accordance with the laws ofthe state of California.  This FourthAmendment constitutes a part of the 863 Mitten Lease and is incorporated bythis reference.

**SIGNATURESAPPEAR ON NEXT PAGE**

 

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[*] Confidential information in this Exhibit has been omitted and filedseparately with the Commission. Confidential treatment has been requested with respect to the omittedportions.

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IN WITNESS WHEREOF, Landlord and Tenant have causedthis Fourth Amendment to be duly executed and delivered as of the date firstabove written.

“Landlord”

**ARE-819/863 MITTEN ROAD, LLC,**a Delaware limited liability company
| By:    | Alexandria Real Estate Equities, L.P.,           |
|--------|--------------------------------------------------|
|   | a Delaware limited  partnership, managing member |
|   | By:                                              | ARE-QRS CORP., |
|   |                                             | a Maryland corporation |
|   |                                             | its general partner |
|   | By:                                              | /s/ Joel S. Marcus |   |
|   | Print Name: Joel S.  Marcus                      |
|   | Print Title: President                           |
|        |                                                  |  |  |  |

 

| “Tenant”         |
|----------------------------|
| **VALENTIS,  INC.**,       |
| a Delaware corporation     |
| By                         | /s/ Joseph A. Markey |   |
| Name: Joseph A. Markey     |
| Title: Director of Finance |

 

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[*] Confidential information in this Exhibit has been omitted and filedseparately with the Commission. Confidential treatment has been requested with respect to the omittedportions.

 

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