FIRST AMENDMENT TO LEASE

Exhibit 10.4

FIRST AMENDMENT TO LEASE

THIS FIRST AMENDMENT TO LEASE (this “Amendment”) is entered into as of this 30^th day of August, 2011, by and between BMR-3450 MONTE VILLA PARKWAY LLC, a Delaware limited liability company (“Landlord”), and AVI BIOPHARMA, INC., an Oregon corporation (“Tenant”).

RECITALS

A. WHEREAS, Landlord and Tenant entered into that certain Lease dated as of July 27, 2009, as amended by that certain Acknowledgement of Term Commencement Date and Term Expiration Date dated as of October 7, 2009 (collectively, and as the same may have been further amended, supplemented or modified from time to time, the “Lease”), whereby Tenant leases certain premises (the “Premises”) from Landlord at 3450 Monte Villa Parkway in Bothell, Washington (the “Building”);

B. WHEREAS, Tenant wants to extend the dates for effectiveness of the Termination Option and the Termination Notice due date; and

C. WHEREAS, Landlord and Tenant desire to modify and amend the Lease only in the respects and on the conditions hereinafter stated.

AGREEMENT

NOW, THEREFORE, Landlord and Tenant, in consideration of the mutual promises contained herein and for other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, and intending to be legally bound, agree as follows:

1. Definitions. For purposes of this Amendment, capitalized terms shall have the meanings ascribed to them in the Lease unless otherwise defined herein.

2. Amendment to Section 3.2. The first sentence of Section 3.2 of the Lease shall be amended and restated in its entirety to read as follows:

“Tenant shall have the one-time option to terminate this Lease (the “Termination Option”) effective on March 1, 2013 (the “Permitted Early Termination Date”) (except for those provisions that expressly survive the expiration or earlier termination of this Lease) upon delivery of written notice to Landlord no later than March 1, 2012 (the “Termination Notice”); provided that Tenant pay to Landlord at the time Tenant delivers to Landlord the Termination Notice a termination fee equal to Two Hundred Ten Thousand Five Hundred Fifty and 12/100 Dollars ($210,550.12), which Landlord and Tenant agree equals the sum of (a) any unamortized TI Allowance, (b) any unamortized broker fees or commissions and (c) one month of Base Rent at the rate in effect at the time of Tenant’s exercise of the Termination Option (collectively, the “Termination Fee”).”

3. Broker. Tenant represents and warrants that it has not dealt with any broker or agent in the negotiation for or the obtaining of this Amendment other than EDG Commercial Real Estate and agrees to indemnify, defend and hold Landlord harmless from any and all cost or liability for compensation claimed by any other broker or agent employed or engaged by it.

4. No Default. Tenant represents, warrants and covenants that, to Tenant’s actual knowledge, without inquiry, Landlord and Tenant are not in default of any of their respective obligations under the Lease and no event has occurred that, with the passage of time or the giving of notice (or both) would constitute a default by either Landlord or Tenant thereunder.

5. Effect of Amendment. Except as modified by this Amendment, the Lease and all the covenants, agreements, terms, provisions and conditions thereof shall remain in full force and effect and are hereby ratified and affirmed. The covenants, agreements, terms, provisions and conditions contained in this Amendment shall bind and inure to the benefit of the parties hereto and their respective successors and, except as otherwise provided in the Lease, their respective assigns. In the event of any conflict between the terms contained in this Amendment and the Lease, the terms herein contained shall supersede and control the obligations and liabilities of the parties. From and after the date hereof, the term “Lease” as used in the Lease shall mean the Lease, as modified by this Amendment.

6. Mortgagee Consent. Landlord represents that there is currently no mortgagee with respect to the Property.

7. Miscellaneous. This Amendment becomes effective only upon execution and delivery hereof by Landlord and Tenant. The captions of the paragraphs and subparagraphs in this Amendment are inserted and included solely for convenience and shall not be considered or given any effect in construing the provisions hereof. All exhibits hereto are incorporated herein by reference. Submission of this instrument for examination or signature by Tenant does not constitute a reservation of or option for a lease, and shall not be effective as a lease, lease amendment or otherwise until execution by and delivery to both Landlord and Tenant.

8. Counterparts. This Amendment may be executed in one or more counterparts, each of which, when taken together, shall constitute one and the same document.

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IN WITNESS WHEREOF, Landlord and Tenant have hereunto set their hands as of the date and year first above written, and acknowledge that they possess the requisite authority to enter into this transaction and to execute this Amendment.

LANDLORD:

TENANT:

STATE OF WASHINGTON )

                                                   : ss.

COUNTY OF SNOHOMISH )

I certify that I know or have satisfactory evidence that Christopher Garabedian is the person who appeared before me, and he acknowledged that he signed this instrument, on oath stated that he was authorized to execute the instrument and acknowledged it as the Chief Executive Officer of AVI BioPharma, Inc., a corporation, to be the free and voluntary act of such corporation for the uses and purposes mentioned in the instrument.

Dated this 31 day of August, 2011.

On August 30, 2011, before me, Nicole L. Smith, a Notary Public in and for said County and State, personally appeared John Bonanno,

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