Rotarix® Receives Favorable Recommendation from FDA Advisory Committee

Business Wire, Feb 21, 2008

NEEDHAM, Mass. -- AVANT Immunotherapeutics, Inc. (Nasdaq: AVAN) today announced that Rotarix([R]), an oral, two-dose rotavirus candidate vaccine to prevent rotavirus gastroenteritis in infants, received a favorable recommendation from the U.S. Food and Drug Administration's (FDA) Vaccines and Related Biological Products Advisory Committee (VRBPAC). AVANT licensed the technology for Rotarix([R]) to GlaxoSmithKline in 1997 for worldwide commercialization. Severe, dehydrating gastroenteritis occurs primarily among children aged three to 35 months. The committee's favorable recommendation, although not binding, will be considered by the FDA in its review of the Biologics License Application (BLA) for the candidate vaccine, which is currently underway.

If approved by the FDA, GSK's candidate vaccine would allow for completion of the rotavirus vaccination series by four months of age and could be integrated into the current vaccine schedule at the two and four month immunization visits. Severe rotavirus diarrhea and dehydration can occur as young as three months of age. Of children under five years of age in the U.S. hospitalized with rotavirus, approximately one in five are younger than six months of age. Rotavirus infects virtually every child in the US by age five and is the leading cause of severe gastroenteritis in infants and young children worldwide.

"We are delighted that Rotarix([R]) has received a favorable recommendation by the Advisory Committee," said Una S. Ryan, Ph.D., President and Chief Executive Officer of AVANT Immunotherapeutics. "The FDA review marks a significant milestone towards the global commercialization of Rotarix([R]), which has already been approved for commercial use in over 100 countries worldwide, including the European Union."

About Rotarix([R])

Rotarix([R]) is an oral, two-dose, live attenuated vaccine against rotavirus disease in infants. AVANT licensed the technology for Rotarix([R]) to GSK in 1997 for worldwide commercialization. The vaccine was originally developed at Cincinnati Children's Hospital Medical Center. Rotarix([R]) is the first human rotavirus vaccine derived from a human virus strain available in the market. The vaccine was developed to prevent rotavirus gastroenteritis by mimicking the protective effects of natural human rotavirus infection. Naturally occurring human rotavirus infection provides significant protection against subsequent moderate to severe rotavirus gastroenteritis regardless of the infecting serotype(s). Five Phase 3 clinical trials were conducted worldwide to assess the safety and efficacy of GSK's Rotarix([R]) vaccine in support of U.S. licensure. The BLA for the GSK rotavirus candidate vaccine is based on one of the largest clinical development plans undertaken by a vaccine manufacturer and includes data from nearly 75,000 infants. The clinical trials conducted in support of U.S. licensure demonstrated efficacy against rotavirus gastroenteritis of any severity due to the five most common currently circulating rotavirus types. The most common solicited adverse reactions in clinical trials were fussiness/irritability, cough/runny nose, fever, loss of appetite, and vomiting.

About GlaxoSmithKline

GlaxoSmithKline, with U.S. operations in Philadelphia, PA, and Research Triangle Park, NC, is one of the world's leading research-based pharmaceutical and healthcare companies and is committed to improving the quality of human life by enabling people to do more, feel better and live longer. GSK Biologicals (GSK Bio), one of the world's leading vaccine manufacturers, is headquartered in Rixensart, Belgium, where the majority of GlaxoSmithKline's activities in the field of vaccine research, development and production are conducted. GSK Bio employs more than 1,500 scientists, who are devoted to discovering new vaccines and developing more cost-effective and convenient combination products to prevent infections that cause serious medical problems worldwide. In 2006, GSK Bio distributed more than 1.1 billion doses of vaccines to 169 countries in both the developed and the developing world - an average of 3 million doses a day. Of those vaccine doses, approximately 136 million were doses of combination pediatric vaccines which protect the world's children from up to six diseases in one vaccine.

About AVANT Immunotherapeutics, Inc.

AVANT Immunotherapeutics, Inc. is a Massachusetts-based NASDAQ-listed company discovering and developing innovative vaccines and therapeutics that harness the human immune system to prevent and treat disease. AVANT's innovative bacterial vector delivery technologies with unique manufacturing and preservation processes offer the potential for a new generation of vaccines. AVANT has three commercialized products, including Rotarix([R]) for the treatment of rotavirus and two human food safety vaccines for reducing salmonella infection in chickens and eggs. AVANT also has four product candidates in its development pipeline, an anti-inflammatory agent, TP10, and three candidates based on its oral, rapidly-protecting, single-dose and temperature-stable vaccine technology, including combination vaccines for travelers, the military and global health needs.