AVANT IMMUNOTHERAPEUTICS INC

NEEDHAM, Mass., Sep 23, 2003 (BUSINESS WIRE) -- AVANT Immunotherapeutics, Inc. (AVAN) announced, prior to a presentation today at the UBS Global Life Sciences Conference in New York, that the company has reinstated development plans for its novel complement inhibitor, TP10. AVANT plans to conduct a Phase II double-blind, placebo-controlled trial of that product in approximately 200 women undergoing cardiopulmonary by-pass surgery. The trial is currently being planned to begin by year-end.

Una S. Ryan, AVANT president and chief executive officer, also reported continued advancement in AVANT's biodefense vaccine program. She said that the company had already been awarded $4 million of a potential $8 million in biodefense contracts funding the development of oral vaccines with combined protection against anthrax and plague. She also noted that the company's recently announced pilot manufacturing plant in Fall River, MA would be used for the production of these biodefense vaccines as well as the company's other bacterial vaccines.

Recommitment to TP10

"Full, detailed analysis of the data from our Phase II adult cardiac surgery study completed in February 2002 resulted in the finding of significant treatment benefits in the male participants. The benefits seen in the male population were directly related to mortality and the benefit seen was very impressive. This made it clear to AVANT's board of directors that TP10 remains an exciting product opportunity deserving further investigation by AVANT," said Una S. Ryan, AVANT president and chief executive officer. "While we continue to be open to partnering TP10, we are now convinced of this molecule's continued promise, and AVANT is very pleased to recommit to its development internally."

AVANT announced in February 2002 that preliminary analysis of clinical data from a Phase II adult cardiac surgery study of TP10 had not achieved a significant reduction in the primary endpoint of death, myocardial infarction (MI), prolonged intubation or prolonged intra-aortic balloon pumping in the prospectively defined intent to treatment population of 564 patients. The company subsequently reported in April 2003 that further data analysis showed that the male population experienced a statistically significant 36% (p=0.01) reduction in the primary endpoint, as well as a significant 43% (p=0.02) reduction in the combined endpoint of death or MI. Investigators did not see a similar effect in the female population, who comprised approximately 28% of the treated patients. TP10 was well tolerated in the overall patient population. Adverse events reported following TP10 treatment were generally similar to those seen in placebo-treated patients and were events that are routinely observed following cardiopulmonary bypass.

The proposed double-blind, placebo-controlled Phase II trial will examine the effect of 5 mg/kg TP10 versus placebo in approximately 200 women undergoing cardiac surgery, with approximately equal numbers of patients receiving placebo as receive TP10. The study, planned to begin around year-end 2003 and conclude around year-end 2004, will be conducted at approximately 10 sites throughout the United States.

"Women participating in the previous Phase II trial did not appear to benefit significantly from treatment with TP10, however we would not have expected to see benefits in such small numbers," said Dr. Ryan. "The goals of the trial are to clarify the effect that TP10 has for women undergoing cardiac surgery, as well as augment the safety data for that patient population to allow for the design of a subsequent registration-directed trial."

Dr. Ryan noted that principal clinical investigators for the adult Phase II trial of TP10 would present the full results of that study at two major upcoming scientific meetings, the American Society of Anesthesiology on October 15 and the American Heart Association on November 11.

AVANT Immunotherapeutics, Inc. is engaged in the discovery, development and commercialization of products that harness the human immune system to prevent and treat disease. The company is developing a broad portfolio of vaccines addressing a wide range of applications including bacterial and viral diseases, chronic human disease, biodefense and food safety. These include single-dose, oral vaccines that protect against important disease-causing agents and a novel, proprietary vaccine candidate for cholesterol management. AVANT's goal is to demonstrate proof-of-concept for its products before leveraging their value through partnerships. Current collaborations encompass the development of an oral human rotavirus vaccine, vaccines to combat threats of biological warfare, and vaccines addressed to human food safety and animal health.

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