On November 9, 2009, Dynavax and Holdings entered into a series of related agreements pursuant to which the parties agreed to amend the terms of the Purchase Option and Program Option, as set forth in an amended and restated purchase option agreement (the "Amended Purchase Option Agreement"). In connection with such amendments, Dynavax and Holdings also entered into a warrant purchase agreement (the "Warrant Purchase Agreement"), an amended and restated registration rights agreement (the "Amended Registration Rights Agreement"), and a promissory note (the "Note") with Holdings (such agreements, together with the Amended Purchase Option Agreement, are collectively referred to as the "Transaction Documents").

Concurrently with the execution of the Transaction Documents, Dynavax notified Holdings of its exercise of the Purchase Option, pursuant to the Amended Purchase Option Agreement.

The Amended Purchase Option Agreement provides that, upon the closing of the Purchase Option, Dynavax will:

(i)        issue to Holdings 13,000,000 shares of its common stock (the "Shares") in exchange for the cash held by SDI of $20.4 million, which represents a share price of $1.57 per share;

(ii)        issue to Holdings five-year warrants to purchase 2,000,000 shares of its common stock (the "Warrant"), at an exercise price of $1.94 per share, which represents a 25% premium over Dynavax's preceding 30 trading-day volume weighted-average price per share of $1.55 through November 9, 2009, pursuant to the Warrant Purchase Agreement. The warrants issued initially to Holdings on April 18, 2006 will be cancelled concurrently with the issuance of the Warrant. Dynavax has agreed to provide certain registration rights under the Securities Act of 1933, as amended, with respect to the Shares and the shares of Dynavax's common stock issuable upon exercise of the Warrant pursuant to the Amended Registration Rights Agreement;

(iv)        enter into the Note with Holdings to defer the $15 million Program Option obligation due to Symphony by 20 months (until December 31, 2012) and convert the obligation previously payable solely in cash, to payable in stock and/or cash at Dynavax's election.

In connection with the closing of the Purchase Option, Dynavax will also expand its Board of Directors to include one director designated by Holdings and one independent director acceptable to both Holdings and Dynavax, as long as Holdings' ownership exceeds more than 10% of the total Dynavax common stock outstanding. Holdings also agreed to certain limitations on its ability acquire additional securities of Dynavax, vote its shares or take certain actions intended to influence control of Dynavax.

It is a condition to the effectiveness of the Transaction Documents and related closing of the Purchase Option that Dynavax receive the approval of its stockholders for the issuance of the Shares and the shares of Dynavax's common stock issuable upon exercise of the Warrants and payment of the Note. Dynavax has agreed to use commercially reasonable efforts to obtain such stockholder approval.

Except as described herein, the transaction agreements among Dynavax, Symphony Capital, Holdings and SDI entered into on April 18, 2006 remain unchanged and in full force and effect.

On November 10, 2009, Dynavax issued a press release describing the transactions described herein. A copy of the press release is attached as Exhibit 99.1 to this Current Report on Form 8-K and incorporated herein by reference.