Company: DVAX
Filing Date: 2025-04-29
Form Type: DEFA14A
Source: 0000930413-25-001558
Chunk: 4

Company: DYNAVAX TECHNOLOGIES CORP
Filing Date: 2025-04-29
Form: DEFA14A
Chunk 4
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 at least $400 million; |

| · | Enter into an expensive                   
 royalty financing leveraging HEPLISAV-B®; |

| · | Abandon internal development efforts and business development efforts; and |

| · | Focus solely on HEPLISAV-B® 
 commercialization.          |

Moreover, aside from demanding these short-sighted
initiatives, Deep Track has yet to provide any actionable ideas on how to grow HEPLISAV-B, a core pillar of its
own plan, which our Board and management team are already doing with great success.

<div align='center'>YOUR VOTE IS IMPORTANT – HELP ENSURE DYNAVAX’S CONTINUED MOMENTUM</div>

We do not believe the changes to the Board proposed
by Deep Track are warranted or in the best interests of all stockholders. The current Dynavax Board is best equipped to guide the Company’s strategy, with the expertise necessary to successfully drive enhanced stockholder value.

Thank you for your support,

The Dynavax Board of Directors

Advisors

Goldman Sachs & Co. LLC is serving as financial advisor
to Dynavax and Cooley LLP is serving as legal counsel.

About Dynavax

Dynavax is a commercial-stage biopharmaceutical company developing
and commercializing innovative vaccines to help protect the world against infectious diseases. The Company has two commercial
products, HEPLISAV-B vaccine (Hepatitis B Vaccine (Recombinant), Adjuvanted), which is approved in the U.S., the
European Union and the United Kingdom for the prevention of infection caused by all known subtypes of hepatitis B virus in adults
18 years of age and older, and CpG 1018 adjuvant, currently used in HEPLISAV-B and multiple adjuvanted COVID-19
vaccines. For more information about our marketed products and development pipeline, visit www.dynavax.com.

Forward-Looking Statements

This communication contains “forward-looking” statements
within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of
1934, as

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amended, which are subject to a number of risks and uncertainties. All statements that are not historical facts are forward-looking
statements. Forward-looking statements can generally be identified by the use of words such as “anticipate,” “believe,”
“continue,” “expect,” “will,” “may