Exhibit 10.55

FIRST AMENDMENT TO LEASE

THIS FIRST AMENDMENT TO LEASE (the "Amendment") is entered into as of May 21,
2004, by and between 2929 SEVENTH ST., LLC, a California limited liability
company ("Landlord") and Dynavax Technologies Corporation, a Delaware
corporation ("Tenant").

RECITALS

A. Landlord and Tenant are parties to that certain lease dated as of
January 7, 2004, which has not previously been amended (the "Lease"). Pursuant
to the Lease, Landlord has leased to Tenant premises consisting of approximately
20,251 rentable square feet as more particularly described in the Lease (the
"Premises") in the building located at 2929 Seventh Street, Berkeley, California
(the "Building").

B. Tenant has exercised its expansion option to lease Suite 100 on the 1st floor
of the Building in accordance with the terms and conditions of Section 1 of the
Addendum to Lease.

C. Tenant and Landlord mutually desire that the Lease be amended on and subject
to the following terms and conditions.

NOW, THEREFORE

, in consideration of the mutual covenants and agreements herein contained and
other good and valuable consideration, the receipt and sufficiency of which are
hereby acknowledged, Landlord and Tenant agree as follows:

Scope of Amendment and Defined Terms.

Except as expressly provided in this Amendment, the Lease shall remain in full
force and effect. Except as expressly provided in this Amendment, the term
"Lease" shall mean the Lease as modified by this Amendment. Capitalized Terms
used in this Amendment and not otherwise defined herein shall have the
respective meanings set forth in the Lease.

Expansion.

Landlord and Tenant hereby acknowledge that Tenant has exercised its expansion
option to lease Suite 100 on the 1
st
floor of the Building containing approximately 47,000 square feet of rentable
area shown on Addendum Exhibit 1 to the Lease (the "Expansion Space"). Effective
as of the Expansion Space Commencement Date (defined below), the Premises, as
defined in the Lease is increased from 20,251 rentable square feet in the
Building (i.e Suites 130 and 200) to 67,521 rentable square feet in the Building
(i.e Suites 100, 130 and 200). The Expansion Space shall be leased subject to
the terms and conditions contained in Section 1 of the Addendum to Lease except
as expressly modified herein.

Expansion Space Commencement Date.

The Expansion Space Commencement Date shall be the date Landlord has (i)
completed the Initial Expansion Space Work (defined in the Lease) and the
Additional Work as defined below and (ii) delivered possession of the Expansion
Space to Tenant. Notwithstanding anything in the Lease to the contrary,
subsequent to the Expansion Space Commencement Date, references to the "Term"
shall mean the period commencing with the Expansion Space Commencement Date and
ending with the Expansion Space Expiration Date. The Initial Expansion Space
Work and the Additional Work shall be deemed to be "complete" on the date that
the Initial Expansion Space Work and the Additional Work has been performed,
other than any details of construction, mechanical adjustment or any other
similar matter, the non-completion of which does not materially interfere with
Tenant's use of the Expansion Space. If Landlord is delayed in the performance
of the Initial Expansion Space Work and the Additional Work as a result of the
acts or omissions of Tenant or its respective contractors or vendors, including
without limitation, changes requested by Tenant to approved plans, Tenant's
failure to comply with any of its obligations under the Lease, or the
specification of any materials or equipment with long lead times (a "Tenant
Delay"), the Initial Expansion Space Work and the Additional Work shall be
deemed to be complete on the date that Landlord could reasonably have expected
to complete the Initial Expansion Space Work and the Additional Work absent any
Tenant Delay.

Monthly Base Rent

. During the Expansion Space Term (define in the Lease), in additional to
Tenant's obligations to pay Monthly Base Rent for the initial Premises, Tenant
shall pay Monthly Base Rent for the Expansion Space as follows:

PERIOD FROM / TO

MONTHLY

Months 1-12

$110,450.00

Months 13-24

$113,763.50

Months 25-36

$117,176.41

Months 37-48

$120,691.70

Months 49-60

$124,312.45

Months 61-72

$128,041.82

Months 73-84

$131,883.07

Months 85-96

$135,839.56

Months 97-108

$139,914.75

Months 109-120

$144,112.19

Monthly Base Rent attributable to the Expansion Space shall be payable in
monthly installments in accordance with the terms and conditions of Article 3 of
the Lease.

Additional Security Deposit

. As of the Expansion Space Commencement Date, the Security Deposit shall
increase by $331,350.00 (the "Security Deposit Increase"), for a total Security
Deposit under the Lease of $408,303.75; provided, however, if the sum of
Tenant's cash, cash equivalents, and marketable securities fall below $20
million for a period of 30 consecutive days or more during the Term, the amount
of the Security Deposit shall increase to $1,065,487.44. Thereafter, Tenant may
reduce the amount of the Security Deposit to $408,303.75 if: (a) projected sum
of Tenant's cash and cash equivalents will remain above $20 million for the
reminder of the Term, or (b) the sum Tenant's cash and cash equivalents actually
remains over $20 million for a period of 12 consecutive months. Tenant may
request the reduction of the Security Deposit upon written notice to Landlord
providing evidence of the existence of either condition (a) or (b) above. Tenant
shall deposit the Security Deposit Increase with Landlord on or before the
Expansion Space Commencement Date. All the terms of Article 5 of the Lease shall
apply to the Security Deposit as redefined by this Section.

Tenant's Share

. For the period commencing with the Expansion Space Commencement Date and
ending on the Expansion Space Expiration Date, Tenant's Share shall be increased
appropriately to account for the addition of the Expansion Space.

Parking

.

Effective as of the Expansion Space Commencement Date, the number of unreserved
parking spaces contained in Section 1.1(13) (Parking) of the Lease is amended
from 61 to 202.

Improvements to Expansion Space

. Landlord shall person the Subsequent Expansion Space Work in accordance with
the terms and conditions of Section 1 of the Addendum to Lease.

Expansion Space Additional Work

. Landlord shall, prior to the Expansion Space Commencement Date, complete that
work as generally described in that certain preliminary plan prepared by Folio
Architects, dated as of May 7, 2004, and delivered to Landlord on May 10, 2004,
as such preliminary plan may be modified or amended with mutual consent of
Landlord and Tenant (the "Additional Work"). The Additional Work shall be
performed at the sole cost of Tenant, provided that Landlord agrees to
contribute the sum of $350,000.00 (the "Expansion Space Additional Allowance")
toward the cost of performing the Additional Work in the Expansion Space. The
Expansion Space Additional Allowance may only be used for the cost of preparing
design and construction documents, mechanical and electrical plans for Expansion
Space, any applicable construction management fees, and for hard costs in
connection with such work.

Second Expansion Space Allowance

. In the event that Tenant has used the entire Expansion Space Additional
Allowance as provided above. Tenant shall have the right to borrow from Landlord
up to $250,000.00 (the "Second Expansion Space Allowance"), provided Tenant is
not in default under this Lease. Any Second Expansion Space Allowance borrowed
by Tenant hereunder shall be repaid to Landlord as Additional Rent in equal
monthly installments throughout the Term, plus interest fixed at eight and
one-half percent (8.5%). If (a) Tenant is in monetary default under this Lease
after the expiration of applicable cure periods, or (b) Tenant exercises its
Termination Option, the entire unpaid balance of the Second Expansion Space
Allowance borrowed by Tenant shall become immediately due and payable and,
except to the extent required by applicable law, shall not be subject to
mitigation or reduction in connection with a reletting of the Premises by
Landlord.

Brokers

. Tenant hereby represents to Landlord that Tenant has dealt with no broker in
connection with this Amendment. Tenant agrees to indemnify and hold Landlord,
its trustees, members, principals, beneficiaries, partners, officers, directors,
employees, mortgagee(s) and agents the respective principals and members of any
such agents (collectively, the Landlord Related Parties") harmless from all
claims of any brokers claiming to have represented Tenant in connection with
this Amendment. Landlord hereby represents to Tenant that Landlord has dealt
with no broker in connection with this Amendment. Landlord agrees to indemnify
and hold Tenant, its trustees, members, principals, beneficiaries, partners,
officers, directors, employees, mortgagee(s) and agents the respective
principals and members of any such agents (collectively, the Landlord Related
Parties") harmless from all claims of any brokers, claiming to have represented
Landlord in connection with this Amendment.

Waiver

. No failure of delay by a party to insist upon the strict performance of any
term, condition or covenant of this Amendment, or to exercise any right, power
or remedy hereunder shall constitute a waiver of the same of any other term of
this Amendment or preclude such party from enforcing or exercising the same or
any such other term, conditions, covenant, right, power or remedy at any later
time.

Full Force and Effect

. Excerpt as herein modified or amended, the provisions, conditions and terms of
the Lease shall remain unchanged and in full force and effect. In the case of
any inconsistency between the provisions of the Lease and this Amendment, the
provisions of this Amendment shall govern and control.

California Law

. This Amendment shall be construed and governed by the laws of the State of
California.

Authority

. This Amendment shall be binding upon and inure to the benefit of the parties,
their respective heirs, legal representatives, successors and assigns. Each
party hereto and the persons signing below warrant that the person signing below
on such party's behalf is authorized to do so and to bind such party to the
terms of this Amendment.

Attorneys' Fees and Costs

. In the event of any action of law or in equity between the parties to enforce
any of the provisions hereof, any unsuccessful party of such litigation shall
pay to the successful party all costs and expenses, including reasonable
attorneys' fees (including these costs and expenses incurred in connection with
all appeals) incurred by the successful party, and these costs, expenses and
attorneys' fees may be included in and as part of the judgment. A successful
party shall be any party who is entitled to recover its costs of suit, whether
or not the suit proceeds to final judgment.

Entire Agreement; No Amendment

. This Amendment constitutes the entire agreement and understanding between the
parties with respect to the subject of this Amendment and shall supersede all
prior written and oral agreements concerning this subject matter. This Amendment
may not be amended, modified or otherwise changed in any respect whatsoever
except by a writing duly executed by authorized representatives of Landlord and
Tenant. Each party acknowledges that it has read this Amendment, fully
understands all this Amendment's terms and conditions, and executes this
Amendment freely, voluntarily and with full knowledge of its significance. This
Amendment is entered into by the parties with and upon advice of counsel.

Severability

. If any provisions of this Amendment or the application thereof to any person
or circumstances shall be invalid or unenforceable to any extent, the remainder
of this Amendment and the application of such provisions to other persons or
circumstances, other than those to which it is held invalid, shall not be
affected and shall be enforced to the furthest extent permitted by law.

Counterparts

. This Amendment may be executed in counterparts, and such counterparts together
shall constitute but one original of the Amendment. Each counterpart shall be
equally admissible in evidence, and each original shall fully bind each party
who has executed it.

Agreement to Perform Necessary Acts

. Each party agrees that upon demand, it shall promptly perform all further acts
and execute, acknowledge and deliver all further instructions, instruments and
documents which may be reasonably necessary or useful to carry out the provision
of this Amendment.

Captions and Headings

. The titles or headings of the various paragraphs hereof are intended solely
for convenience of reference and are not intended and shall not be deemed to
modify, explain or place construction upon any of the provisions of this
Amendment.

[SIGNATURES APPEAR ON FOLLOWING PAGE]

IN WITNESS WHEREOF

, Landlord and Tenant have duly executed this Second Amendment as of the day and
year first above written.

LANDLORD

:

2929 Seventh St, LLC

,

a California limited liability company

 

By: /s/ Richard K. Robbins

Richard K. Robbins

Managing Member

 

       

TENANT

:

Dynavax Technologies Corporation

,

a Delaware corporation

 

By: /s/ Dino Dina

Name: Dino Dina

Title: President and CEO