FOURTH AMENDMENT to LICENSE AGREEMENT

Exhibit 10.42

[*] = C ERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT , MARKED BY BRACKETS , HAS

BEEN OMITTED AND FILED SEPARATELY WITH THE S ECURITIES AND E XCHANGE C OMMISSION PURSUANT TO

R ULE 24 B -2 OF THE S ECURITIES E XCHANGE A CT OF 1934, AS AMENDED .

FOURTH AMENDMENT to LICENSE AGREEMENT

UC CONTROL NUMBER 1997-04-A493, Effective March 26, 1997

between DYNAVAX TECHNOLOGIES CORPORATION

and THE REGENTS OF THE UNIVERSITY OF CALIFORNIA for

“Method, Compositions and Devices for Administration of Naked Nucleotides Which

Express Biologically Active Peptides

and

Immunostimulatory Oligonucleotide Conjugates”

This amendment (“4 ^th Amendment”) is made by and between Dynavax Technologies. Corporation, a Delaware corporation having an address at 2929 7 ^th Street, Suite 100, Berkeley, CA 94710 (“Licensee”) and The Regents of the University of California, a California corporation having its statewide administrative offices at 1111 Franklin Street, Oakland, California 94607-5200 (“The Regents”), represented by its San Diego campus having an address at University of California, San Diego, Technology Transfer Office, Mail-code 0910, 9500 Gilman Drive, La Jolla, California 92093-0910 (“UCSD”) to a certain existing license agreement between the two parties.

When signed by both parties, this 4 ^th Amendment is effective as of June 1, 2009 (“4 ^th Amendment Effective Date”).

RECITALS

Whereas , Licensee and The Regents entered into a license agreement with an Effective Date of March 26, 1997 (“License Agreement”) for UCSD Case Docket Nos. UC1992-296 (now renumbered as SD1992-C96) and titled “Method, Compositions and Devices for Administration of Naked Nucleotides Which Express Biologically Active Peptides”; and 1997-138 (now renumbered as SD1997-B38) and titled “Immunostimulatory Oligonucleotide Conjugates”;

Whereas , Licensee and The Regents have amended the License Agreement three times, on July 23, 1997; on October 2, 1998 and on September 22, 1999; and

Whereas , Licensee’s [*] is [*] with [*] specified in the amendment dated September 22, 1999 and Licensee has requested [*] to conform with [*];

1

Now Therefore , the parties agree to amend the License Agreement as set forth herein:

Licensee will pay The Regents an amendment fee of [*] in three installments as follows: the first payment of [*] shall be paid within 30 days of the 4 ^th Amendment Effective Date, the second payment of [*] shall be paid on the first anniversary of the 4 ^th Amendment Effective Date and the third payment of [*] shall be paid on the second anniversary of the 4 ^th Amendment Effective Date. However, if the License Agreement is terminated, all remaining amount of all unpaid installments will be immediately due and payable.

Background Paragraph A shall be deleted and restated as follows:

“A. Certain inventions, generally characterized in the parent applications

entitled “Method, Compositions and Devices for Administration of Naked

Nucleotides Which Express Biologically Active Peptides” UC Case No. SD1992-C96

(aka UC 92-296) and “Immunostimulatory Nucleotide Sequences”

UC Case No. SD1997-B38 (aka UC 97-138) (collectively the

“Invention”) were made in the course of research at the University of

California, San Diego by [*]

(“Inventors”) and are covered by Regents Patent Rights as defined below.”

Paragraph 1.1 shall be deleted and restated as follows :

“1.1 Regents Patent Rights” means any subject matter claimed or disclosed in any of the following:

[*]

by Inventors and assigned to The Regents; and continuation applications thereof, and divisions, substitutions, and continuations-in-part application, but only to the extent claims in any such continuation-in-part application contain subject matter included in the foregoing listed applications as originally filed in the U.S. Patent and Trademark Office (“USPTO”); any patents issuing on said applications including reissues, reexaminations and extension; and any corresponding foreign applications or patents (including inventor’s certificates).”

2

Paragraph 1.6 shall be deleted and restated as follows:

“1.6 “Attributed Income” means the following types of income received by Licensee [*] from granting rights, granting an option to certain rights or forbearing the exercise of any rights granted to LICENSEE under this Agreement: upfront licens