- Creates New Company Focused on Targeted Pain Therapeutics that Address Large Markets With Unmet Needs -

- Conference Call Scheduled for Wednesday, August 5, 2009 at 8:30 AM EDT -

SOUTH SAN FRANCISCO, Calif., and BALTIMORE, Aug. 5 /PRNewswire-FirstCall/ -- Anesiva, Inc. (Nasdaq: ANSV) and Arcion Therapeutics, Inc., a privately held company, announced today the signing of a definitive merger agreement. The merger will result in a public company with a portfolio of late-stage targeted pain therapeutics. The merger transaction, approved by both companies' Boards of Directors, will combine the companies under the name of Arcion Therapeutics, and is expected to close in the third quarter of 2009. Upon closing of the merger, Arcion and Anesiva shareholders will own approximately 64% and 36%, respectively, of the outstanding shares of the combined company. Closing of the merger is contingent upon, among other conditions, a vote of approval by Anesiva's current shareholders.

The proposed merger of Anesiva and Arcion creates a highly synergistic company with a pipeline comprised of late-stage programs that address large markets with unmet needs, such as neuropathic pain, moderate-to-severe osteoarthritis and post-operative pain. Anesiva's Adlea(TM) (capsaicin) for post-operative pain completed two Phase 3 trials last year, and Arcion's ARC-4558 (0.1% topical clonidine gel) is currently in Phase 2b for painful diabetic neuropathy (PDN). Other development programs include Arcion's ARC-2022, a topical drug for post-herpetic neuralgia, which is currently in late-stage preclinical development.

"This merger and the synergies that it offers present an exciting new opportunity for Anesiva investors. The combined company will have the financial resources, pipeline of products and the management team to maximize shareholder value going forward," said Michael Kranda, Chief Executive Officer of Anesiva. "Because of the focus of our product portfolio and the strength of the combined team of executives and advisors, we believe that we can operate under a virtual, cost-efficient business model that will create many value-driving milestones."

"There is a tremendous need to create drugs that treat pain where the pain signal originates and we believe that our targeted treatments will address the shortcomings of current therapies, including addiction, systemic side-effects, insufficient efficacy, and frequent or inconvenient dosing," said James Campbell, M.D., Chief Executive Officer of Arcion. "Merging with Anesiva creates a portfolio of late-stage product candidates with extensive safety and efficacy databases that could fulfill many unmet needs in the U.S. prescription pain market. "

Details on the Proposed Transaction

Upon closing of the merger, Anesiva will issue shares of Anesiva common stock to Arcion stockholders such that Arcion stockholders will own approximately 64% of the outstanding shares of the combined company and Anesiva stockholders will own approximately 36% of the outstanding shares of the combined company. The transaction contemplates a reverse stock split ranging from one-for-30 to one-for-50, subject to approval from Anesiva's shareholders. The transaction also contemplates that Anesiva will repay holders (the "January 2009 Holders") approximately $6.3 million of principal amount outstanding of its securities issued pursuant to a securities purchase agreement, dated January 20, 2009, at 100% of the principal plus interest.