Anesiva Announces Pivotal Phase 3 Clinical Trial of Adlea(TM) for Reducing Post-Surgical Pain Following Total Knee Replacement

SOUTH SAN FRANCISCO, Calif., April 8, 2008 /PRNewswire-FirstCall/ -- Anesiva, Inc. (Nasdaq: ANSV) today announced that a pivotal Phase 3 clinical trial evaluating Adlea(TM), its long-acting, non-opioid analgesic drug candidate, in patients following total knee replacement surgery, is underway.

In September 2007, Anesiva initiated a multicenter, randomized, double-blind, placebo-controlled Phase 2 trial to evaluate the safety and efficacy of a single 5 or 15 mg dose of Adlea or placebo administered into the surgical site in patients undergoing total knee replacement surgery. Having completed enrollment of the initially planned 80 patients, Anesiva has converted this trial into a Phase 3 trial by expanding the planned enrollment by approximately 134 patients for a total sample size of 214, increasing the number of trial sites, and focusing enrollment on the 15 mg and placebo groups.

"Total knee replacement is a commonly performed orthopedic surgery that can significantly enhance patients' quality of life," said Keith Candiotti, M.D., Associate Professor of Clinical Anesthesiology and Internal Medicine; Director of Clinical Research, Chief, Division of Perioperative Medicine, University of Miami Leonard M. Miller School of Medicine, and investigator in the Phase 3 study. "The effective management of post-surgical pain is critical since patients must begin walking and moving the knee soon after the procedure in order to begin recovery and avoid complications. Adlea may offer additive pain relief and possibly reduce the use of other pain medications such as opioids, whose systemic side effects can interfere with the recovery process."

The primary efficacy endpoint of the Phase 3 trial is a time-weighted pain score (using a standard 0 - 10 numerical rating scale of pain intensity) from four to 48 hours following knee replacement surgery. The study will also evaluate pain scores during the first two weeks following surgery, as well as opioid consumption. The safety of Adlea will be evaluated throughout the study.

"We now have two pivotal Phase 3 trials in progress for Adlea, in total knee replacement surgeries and bunionectomy surgeries, and expect to have top-line data from both by year-end," said John P. McLaughlin, chief executive officer of Anesiva. "We also are conducting a Phase 2 trial in total hip replacement surgeries and plan to initiate a Phase 2 trial in arthroscopic shoulder surgeries to support a broad label of pain management following orthopedic surgery."

Anesiva has previously completed Phase 1 and 2 trials of Adlea in total knee replacement and bunionectomy surgeries, as well as in osteoarthritis of the knee, elbow tendonitis and Morton's neuroma.

About Total Knee Replacement

Total knee replacement (also known as total knee arthroplasty) is generally performed in patients with end-stage osteoarthritis of the knee. These patients have disabling pain which imposes severe limitations on their mobility, and knee replacement is performed with the goal of relieving pain and restoring mobility and knee function. There were an estimated 565,000 total knee replacement procedures performed in the United States in 2006, and the number of replacements will continue to grow as the average age of the U.S. population increases and as these individuals conduct more active lives. The American Academy of Orthopedic Surgeons projects that approximately 3.5 million of these procedures will be done each year by 2030.

How Adlea May Address the Need for Long-Duration, Well-Tolerated Pain Relief

Adlea is a long-acting, non-opioid drug with the potential to provide pain relief for weeks to months after a single localized treatment. Its novel mechanism of action results in site-specific efficacy intended to avoid the unwanted side effects associated with systemically administered analgesic drugs such as opioids and NSAIDs.

Adlea is a highly purified form of capsaicin (derived from chili peppers) that acts primarily on C-fiber neurons, which transmit long-term pain, by binding to and desensitizing the TRPV1 pain receptors. This leads to a prolonged, reversible and localized desensitization of the pain fibers. The drug generally has a short half-life of 1 to 2 hours, and is undetectable in the blood after 24 hours.

Adlea's short duration of systemic exposure relative to the longer duration of analgesia may offer a safe, additive treatment option in the management of post-surgical orthopedic pain. In clinical trials to date, adverse events have been similar in patients receiving Adlea or placebo. Adlea is also in clinical development for the treatment of pain associated with moderate to severe osteoarthritis.

About Anesiva and its Diverse Pipeline of Pain Products

Anesiva, Inc. is a late-stage biopharmaceutical company that seeks to be the leader in the development and commercialization of novel pharmaceutical products for pain management. The company has one FDA-approved product, Zingo(TM), for the reduction of pain associated with peripheral venous access procedures in children ages three to 18. In clinical trials, the most common adverse reactions to Zingo were redness (erythema), red dots (petechiae) and swelling (edema). The second product in Anesiva's pipeline, Adlea(TM), reduces pain after only a single administration for weeks to months based on mid-stage clinical trials for site-specific, acute and chronic, moderate-to-severe pain. Anesiva is based in South San Francisco, CA. For more information about Anesiva's leadership in the development of products for pain management, and an overview of the clinical challenges being addressed by its product candidates, go to http://www.anesiva.com.

Forward Looking Statements

This press release includes "forward-looking statements" within the meaning of the safe harbor provisions of the United States Private Securities Litigation Reform Act of 1995. Words such as "expect," "estimate," "project," "budget," "forecast," "anticipate," "intend," "plan," "may," "will," "could," "should," "believes," "predicts," "potential," "continue," and similar expressions are intended to identify such forward-looking statements. Forward-looking statements in this press release include matters that involve known and unknown risks, uncertainties and other factors that may cause actual results, levels of activity, performance or achievements to differ materially from results expressed or implied by this press release. Such risk factors include, among others: the timing and results of our clinical trials, and our regulatory approval strategy for Adlea. Actual results may differ materially from those contained in the forward-looking statements in this press release. Additional information concerning these and other risk factors is contained in Anesiva's annual report on Form 10-K for the year ended December 31, 2007.

Anesiva undertakes no obligation and does not intend to update these forward-looking statements to reflect events or circumstances occurring after this press release. You are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date of this press release. All forward-looking statements are qualified in their entirety by this cautionary statement.

SOURCE Anesiva, Inc.