Biopharmaceuticals

 News Release - February 27, 2006

AVANT Announces Preliminary Results of Its Phase IIb Study of TP10 in Women Undergoing Cardiac Surgery

AVANT Sets Path Forward for TP10 in Males-Only Indication

NEEDHAM, Mass.--(HSMN NewsFeed)--Feb. 27, 2006--AVANT Immunotherapeutics, Inc. (NASDAQ: AVAN ) today announced that TP10, its lead complement inhibitor, did not meet the primary endpoint in a double-blind, placebo-controlled Phase IIb study in female subjects undergoing high risk cardiac surgery utilizing cardiopulmonary bypass (CPB), thus confirming the results for female subjects in a previous TP10 trial. The objective of this female-only study was to assess the safety and ability of TP10 to reduce the incidence of death and heart attack that occurs after cardiac surgery in female patients on CPB. A previous Phase II study with TP10 in patients on CPB had demonstrated statistically significant efficacy in males but not in females, so the current study was designed to further assess the safety and efficacy of TP10 in females.

"These data confirm the results in females from our previous TP10 trial. Therefore, given the strong efficacy data in males shown in this previous study, there is a clear clinical development pathway for a males-only indication for TP10 in cardiac bypass surgery," said Una S. Ryan, Ph.D., President and Chief Executive Officer of AVANT Immunotherapeutics, Inc. "Males represent 75% of the U.S. market opportunity in cardiac bypass surgery. We believe that the TP10 program is now well positioned for a males-only cardiac bypass surgery indication and we expect to partner the TP10 program for this indication."

Announcing the results, Taha Keilani, MD, Vice President, Medical and Regulatory Affairs of AVANT said, "In both the female subjects in the previous trial and this females-only trial, there were no clinically meaningful differences in safety and efficacy between placebo and TP10 treated patients." A total of 309 female patients were screened with 297 patients randomized into the study to receive a 5 mg/kg dose of TP10 (n=150), or placebo (n=147), as a thirty-minute intravenous infusion and were followed for 28 days post surgery. The primary efficacy endpoint of the study was the comparison of TP10 treated patients versus placebo in the composite incidence of death and myocardial infarction (heart attack). TP10 was well tolerated with no apparent differences in the safety profiles of the treatment groups.

Dr. Ryan further stated, "We appreciate the enthusiasm and support of the clinical investigators, their research staffs and the patients who have participated in this study."

Dr. Ryan, Dr. Keilani and Mr. Catlin will host a conference call at 1:00 PM EST on Monday, February 27, 2006 to discuss the results of the TP10 female Phase IIb study. To access the conference call, dial 800-659-2032 (within the United States), or 617-614-2712 (if calling from outside the U.S.). The participant passcode is 94854329 An audio replay will be available immediately following the call for approximately one week and can be accessed by dialing 888-286-8010 (within the U.S.), or 617-801-6888 (if calling from outside the U.S.). The passcode for the audio replay is 35394971.

The call will also be broadcast via the Company's website: www.avantimmune.com. In order to access the webcast, your PC must have a sound card, speakers and Windows Media Player software. It is recommended that you configure your PC in advance of the webcast as the software download and installation can take several minutes.

About AVANT Immunotherapeutics, Inc.

AVANT Immunotherapeutics, Inc. discovers and develops innovative vaccines and therapeutics that harness the human immune system to prevent and treat disease. Six of AVANT's products are in clinical development, including a novel vaccine for cholesterol management. AVANT is also developing a pipeline of bacteria-fighting products for biodefense, travelers' vaccines, and global health needs based on AVANT'S rapid-protecting, single-dose, oral and temperature stable vaccine technology.

Additional information on AVANT Immunotherapeutics, Inc. can be obtained through our site on the World Wide Web: http://www.avantimmune.com.

Safe Harbor Statement Under the Private Securities Litigation Reform Act of 1995:

This release includes forward-looking statements which reflect AVANT's current views with respect to future events and financial performance. These forward-looking statements are based on management's beliefs and assumptions and information currently available. The words "believe", "expect", "anticipate", "intend", "estimate", "project" and similar expressions which do not relate solely to historical matters identify forward-looking statements. Investors should be cautious in relying on forward-looking statements because they are subject to a variety of risks, uncertainties, and other factors that could cause actual results to differ materially from those expressed in any such forward-looking statements. These factors include, but are not limited to: (1) the integration of multiple technologies and programs; (2) the ability to adapt AVANT's vectoring systems to develop new, safe and effective orally administered vaccines against anthrax and plague or other bioterrorism threats or emerging health care threats; (3) the ability to successfully complete development and commercialization of TP10, CETi-1, CholeraGarde® (Peru-15), Ty800 and other products; (4) the cost, timing, scope and results of ongoing safety and efficacy trials of TP10, CETi-1, CholeraGarde® (Peru-15), Ty800 and other preclinical and clinical testing; (5) the ability to successfully complete product research and further development, including animal, pre-clinical and clinical studies of TP10, CETi-1, CholeraGarde® (Peru-15), Ty800 and other products; (6) the ability of the Company to manage multiple late stage clinical trials for a variety of product candidates; (7) the volume and profitability of product sales of Megan®Vac 1, Megan®Egg and other future products; (8) the process of obtaining regulatory approval for the sale of ROTARIX ® in major commercial markets, as well as the timing and success of worldwide commercialization of ROTARIX ® by our partner, GlaxoSmithKline; (9) changes in existing and potential relationships with corporate collaborators; (10) the availability, cost, delivery and quality of clinical and commercial grade materials supplied by contract manufacturers; (11) the timing, cost and uncertainty of obtaining regulatory approvals to use TP10, CETi-1, CholeraGarde® (Peru-15) and Ty800, among other purposes, for adults undergoing cardiac surgery, to raise serum HDL cholesterol levels and to protect travelers and people in endemic regions from diarrhea causing diseases, respectively; (12) the ability to obtain substantial additional funding; (13) the ability to develop and commercialize products before competitors; (14) the ability to retain certain members of management; and (15) other factors detailed from time to time in filings with the Securities and Exchange Commission. We expressly disclaim any responsibility to update forward-looking statements.

Source: AVANT Immunotherapeutics

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