June 7, 2010 Ms. Michelle Burris TRUBION PHARMACEUTICALS, INC.

Exhibit 10.16

June 7, 2010

Xx. Xxxxxxxx Xxxxxx

TRUBION PHARMACEUTICALS, INC.

0000 Xxxxxx Xxxxxx, Xxxxx 0000

Xxxxxxx, Xxxxxxxxxx 00000

Dear Xxxxxxxx:

Please refer to the Fourth and Battery Office Lease dated April 28, 2003 and all addenda and amendments thereto (the “Office Lease” or “Lease”) for the space Trubion Pharmaceuticals (hereinafter referred to as “Trubion” or “Lessee”) occupies within the Fourth and Battery building. This letter (this “Amendment”) shall constitute an amendment to the Lease. Capitalized terms used but not otherwise defined herein shall have the meanings ascribed to such terms in the Lease.

PARKING

Effective July 1, 2010 Lessee shall have the right but not the obligation to lease seven (7) additional parking spaces at the surface lot adjacent to the Fourth and Battery Building to the west. The cost of such parking shall be consistent with market rates for comparable parking at the market rate.

MISCELLANEOUS

This Amendment (together with the Lease) constitutes the entire agreement between Lessor and Lessee regarding the Expansion Space and the subject matter contained herein and supersedes any and all prior and/or contemporaneous oral or written negotiations, agreements or understandings. This Amendment shall be binding upon and inure to the benefit of Lessor and Lessee and their respective heirs, legal representatives, successors and assigns. No subsequent change or addition to this Amendment shall be binding unless in writing and duly executed by both Lessor and Lessee. Except as specifically amended hereby, all of the terms and conditions of the Lease are and shall remain in full force and effect and are hereby ratified and confirmed.

Please consider this document, when fully executed, as our agreement for the amendment of your Office Lease. If you are in agreement with the above, please sign below where indicated and return all four copies to me for Xxxxxx Xxxxx’x signature. Upon full execution, I will return two copies for your own files.

0000 XXXXXX XXXXXX

XXXXX 0000

XXXXXXX, XXXXXXXXXX 00000-0000

(000) 000-0000

FAX (000) 000-0000

Xx. Xxxxxxxx Xxxxxx

TRUBION PHARMACEUTICALS, INC.

June 7, 2010

Page 2

Thank you Xxxxxxxx, for this lease of additional space. We appreciate your tenancy with us and look forward to continuing to satisfy your office and lab space needs.

Very truly yours,

/s/ Xxxxxxx Xxxxxx

Xxxxxxx Xxxxxx

TRUBION0528.10

AGREED AND ACCEPTED:

XXXXX REAL ESTATE HOLDINGS EIGHT, L.L.C.						TRUBION PHARMACEUTICALS, INC.
		/s/ Xxxxxx Xxxxx						/s/ Xxxxxxxx Xxxxxx
By:		Xxxxxx Xxxxx				By:		Xxxxxxxx Xxxxxx
Its:		Managing Member				Its:		COO
Dated:		June 15, 2010				Dated:		14 June 0000

XXXXX XX XXXXXXXXXX		)
		)		ss.
COUNTY OF KING		)

On this 15^th day of June, 2010, before me, a Notary Public in and for the State of Washington, personally appeared XXXXXX XXXXX, to me known to be the Managing Member, respectively, of Xxxxx Real Estate Holdings Eight, LLC the entity that executed the foregoing instrument and acknowledged said instrument to be the free and voluntary act and deed of said entity, for the uses and purposes therein mentioned, and on oath stated that he/she/they is/are authorized to execute said instrument on behalf of the entity.

/s/ Xxxx X. Xxxxxx

Notary Public in and for the State of Washington

Residing at: Sammamish

My commission expires: 11.8.12

STATE OF		)
		)		ss.
COUNTY OF		)

On this 14^th day of June, 2010, before me, a Notary Public in and for the State of Washington, personally appeared Xxxxxxxx Xxxxxx, to me known to be the Chief Operating Officer, respectively, of Trubion Pharmaceuticals, Inc., the corporation that executed the within and foregoing instrument, and acknowledged said instrument to be the free and voluntary act and deed of said corporation, for the uses and purposes therein mentioned, and on oath stated that he/she/they is/are authorized to execute said instrument and that the seal affixed thereto is the corporate seal of said corporation.

IN WITNESS WHEREOF, I have hereunto set my hand and affixed by official seal, the day and year first above written.

notary.amendments.version2

/s/ Xxxxx X. Xxxxxxxxx Notary Public in and for the State of Washington Residing at: Seattle My commission expires: April 19, 2013