PRESS RELEASE: FDA Approves ACAM2000 Vaccine for Protection Against Smallpox

FDA Approves ACAM2000 Vaccine for Protection Against Smallpox

CAMBRIDGE, England and CAMBRIDGE, Massachusetts, September 3 /PRNewswire-FirstCall/ -- Acambis plc (Acambis) , a leading vaccine company, announced today that the US Food and Drug Administration (FDA) has approved its ACAM2000 (Smallpox (Vaccinia) Vaccine, Live) vaccine for protection against smallpox. The vaccine is intended for active immunization against smallpox disease for persons determined to be at high risk for smallpox infection. ACAM2000 is the first biodefense vaccine to be approved as part of the US response to the 2001 bioterrorism attacks.

Acambis developed ACAM2000 under contracts with the US Centers for Disease Control and Prevention (CDC). To date, Acambis has supplied 192.5 million doses of ACAM2000 to the CDC for the US Strategic National Stockpile (SNS), which was established to provide medicines to the American public in the event of a public health emergency, such as a terrorist attack.

Having produced a stockpile of ACAM2000 doses for the SNS, Acambis and the CDC are now in advanced discussions on a "warm-base manufacturing" contract for Acambis to provide ACAM2000 production and license maintenance activities for the long term.

Ian Garland, Acambis Chief Executive Officer, said: "The licensure of ACAM2000 is a significant milestone not only for Acambis but also for the US Government in its efforts to ensure a state of preparedness against the threat of smallpox. This has been a highly successful collaboration between Acambis and the CDC, and Acambis is very proud to have played a role in providing this countermeasure against a significant bioterrorism threat. We look forward to finalizing an agreement with the CDC that will ensure that a US-based capability to manufacture ACAM2000 remains at the ready."

ACAM2000 was developed to be a modern smallpox vaccine with a safety and efficacy profile comparable to the previous US vaccine but manufactured using advanced production capabilities. Until the development of ACAM2000, smallpox vaccines were last manufactured in the US in 1982 and were produced from calf lymph.

ACAM2000, which is a single-dose vaccine, is the primary smallpox vaccine for use in an emergency and forms the majority of the US Government's smallpox vaccine stockpile.

The clinical trials data generated on ACAM2000 were reviewed by the FDA Vaccines and Related Biological Products Advisory Committee in May 2007, which voted unanimously (11-0) in favor of the vaccine's safety and efficacy. In addition to being stockpiled for emergency use, ACAM2000 will be used by the US Department of Defense for protection of military personnel.

Important safety information

ACAM2000 may not protect all persons exposed to smallpox. ACAM2000 is contraindicated for individuals with severe immunodeficiency who are not expected to benefit from the vaccine. These individuals may include persons who are undergoing bone marrow transplantation or persons with primary or acquired immunodeficiency states who require isolation.

- The most serious adverse events associated with smallpox vaccination are myocarditis, pericarditis, encephalitis, encephalomyelitis, encephalopathy, progressive vaccinia, generalized vaccinia, severe vaccinial skin infections, and erythema multiforme major (including STEVENS-JOHNSON SYNDROME) and eczema vaccinatum resulting in permanent sequelae or death, ocular complications, blindness, and fetal death have occurred following either primary vaccination or revaccination with smallpox vaccines.

- The most common side effects following smallpox vaccination include itching, swollen lymph nodes, sore arm, fever, headache, body ache, mild rash, and fatigue.

Full prescribing information may be obtained by calling Acambis at +1-866-440-9440 (toll free) or +1-617-866-4500.

About smallpox

Smallpox is a highly contagious disease caused by the variola virus, a member of the Orthopox virus family. It is one of the most devastating diseases known to humanity, with a mortality rate as high as 30%. In 1967, the World Health Organization embarked upon an intensified vaccination campaign to eliminate smallpox, which culminated in the successful eradication of the disease globally by 1980.(1)

By the mid-1980s, there were only two known repositories of variola virus: the Institute of Virus Preparations in Russia, and the US CDC. The events in the US in September and October 2001 highlighted the risk that the variola virus might be used as an agent of bioterrorism.(2) Governments around the world are taking precautionary measures to be ready to deal with a potential smallpox outbreak.

About ACAM2000

- ACAM2000 is a live, vaccinia virus smallpox vaccine indicated for active immunization against smallpox disease for persons determined to be at high risk for smallpox infection.

- It is a single-dose vaccine administered percutaneously.

- It was derived by plaque purification from Dryvax(R), the licensed calf lymph-produced vaccine that was extensively used in the smallpox eradication program.

- ACAM2000 is manufactured in Vero cells using modern cell-culture techniques designed to comply with current Good Manufacturing Practice standards.

- Acambis has supplied more than 200 million doses of ACAM2000 under an FDA Investigational New Drug application to 15 governments around the world, including the US.

Notes and references (1) WHO: http://www.who.int/mediacentre/factsheets/smallpox/en/ [1] (2) CDC: http://www.bt.cdc.gov/agent/smallpox/overview/disease-facts.asp [2] About Acambis

Acambis is a leading vaccine company developing novel vaccines that address significant unmet medical needs or substantially improve standards of care. ChimeriVax(TM)-JE, Acambis' most advanced vaccine candidate in its non-biodefense pipeline, has completed Phase 3 trials, and is currently undergoing pediatric trials in India. It is partnered with sanofi pasteur and Bharat Biotech. Acambis' proprietary ChimeriVax technology, developed in association with St Louis University, has also been used to develop Acambis' ChimeriVax-West Nile vaccine candidate, which is undergoing Phase 2 clinical testing, making it the most advanced investigational vaccine against the West Nile virus. Acambis also has the only vaccine in development against Clostridium difficile bacteria, a leading cause of hospital-acquired infections. Acambis' influenza program aims to develop a universal vaccine against influenza, for which a universal 'A' strain vaccine, ACAM-FLU-A(TM), is currently being tested in a Phase 1 trial, and also includes various further vaccine candidates in the research and pre-clinical stages.

Recognised internationally as the leading producer of smallpox vaccines, Acambis manufactured its smallpox vaccine, ACAM2000, for emergency-use stockpiles held by the US Government and 14 others governments around the world under a US FDA IND application. ACAM2000 is licensed for active immunization of persons determined to be at high risk for smallpox infection.

Acambis is based in Cambridge, UK and Cambridge, Massachusetts, US, and is listed on the London Stock Exchange (ACM). More information is available at http://www.acambis.com [3].

"Safe Harbor" statement under the Private Securities Litigation Reform Act of 1995:

The statements in the news release that are not historical facts are forward-looking statements that involve risks and uncertainties, including the timing and results of clinical trials, product development, manufacturing and commercialisation risks, the risks of satisfying the regulatory approval process in a timely manner, and the need for and the availability of additional capital. For a discussion of these and other risks and uncertainties, see the relevant risk sections in the Company's latest Annual Report, in addition to those detailed on the Company's website and in the Company's filing made with the Securities and Exchange Commission prior to Acambis' deregistration. These forward-looking statements are based on estimates and assumptions made by the management of Acambis and are believed to be reasonable, though are inherently uncertain and difficult to predict. Actual results or experience could differ materially from the forward-looking statements.

Acambis plc
CONTACT: Enquiries: Acambis, Ian Garland, Chief Executive Officer,Elizabeth Brown, Acting Chief Financial Officer, Lyndsay Wright, VP,Communications and IR, Tel: +44-(0)-1223-275-300; Brunswick (financialpress enquiries), Jon Coles / Justine McIlroy / Margherita Lupi, Tel:+44-(0)-20-7404-5959; Northbank Communications (trade press enquiries),Lorna Cuddon, Gemma Price, Katie Odgaard, Tel: +44-(0)-20-7268-3002, Email:g.price@northbankcommunications.com