Acambis has had its smallpox vaccine approved by the US, coming one step closer to closing another supply contract for the US Strategic National Stockpile.
The UK-based vaccine company has developed ACAM2000 (smallpox Vaccinia vaccine, live) under contracts with the US Centres for Disease Control and Prevention (CDC), totalling $505m (€370.5m), and has already supplied 192.5 million doses of the vaccine to the US Strategic National Stockpile since November 2001.
The approval of ACAM2000 by the US Food and Drug Administration (FDA) is a precursor to being able to win a second supply contract with the CDC for warm-base manufacturing, where Acambis would maintain a constant state of production through annual manufacturing runs.
"The licensure of ACAM2000 is a significant milestone not only for Acambis but also for the US Government in its effort to ensure a state of preparedness against the threat of smallpox," Acambis chief executive Ian Garland said in a statement
"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."
Details of the warm-base manufacturing contract were still being negotiated but analysts were estimating revenues of $30m (€22m) a year for between five and 10 years.
An Acambis spokeswoman told in-PharmaTechnologist.com there was no specified time-frame for when the new contract would be finalised, but the company hoped it would be during the fourth quarter of this year.
Part of the new contract would be to establish all vaccine production on US soil, which reflects the US Government's preparedness activities should it need to close its borders in the event of an outbreak to ensure supply of vaccine.
Acambis plans to transfer its bulk material production capabilities from Austria to the company's facility in Canton, Massachusetts, where purification work was previously done.
The company is also establishing a lyophilisation (freeze-drying) and fill/finish capability in Rockville, Maryland.
The contract would also address licence maintenance activities including the follow-up work specified by the FDA to explore the myocarditis, inflammation of the heart muscle, which was seen in ACAM2000 and the old vaccine in Phase III trials.
Despite the World Health Organization (WHO) declaring the disease eradicated worldwide in 1980, with the last case of smallpox occurring in the US in 1949, there are concerns that should the virus get into the hands of terrorists, it could be used as a biological weapon with potentially devastating consequences.
It is a highly contagious disease, killing about one-third of the people it infects. There is no treatment and the only prevention is vaccination.
ACAM2000, a live vaccinia virus smallpox vaccine indicated for the active immunisation against smallpox for persons determined to be at high risk of infection, is a single-dose vaccine administered percutaneously.
It is derived by plaque purification from Dryvax, the licensed calf lymph-produced vaccine that was extensively used in the smallpox eradication programme.
ACAM2000 is a second-generation vaccine produced in bioreactors on vero cells, where first-generation vaccines were produced using animals. Production of first-generation vaccines ceased in the early 1980s.
To make ACAM2000 reproducible in vero cells, it is a clonal vaccine produced from a single strain of vaccinia derived from a first-generation vaccine.
ACAM2000 is the only licensed second-generation smallpox vaccine and the first biodefense vaccine approved as part of the US response to the 2001 bioterrorism attacks.
Another smallpox vaccine Acambis was developing, MVA-3000, reached Phase II but was thrown out loosing out to a more "competitive" version by Novo Nordisk.
Danish biopharma Bavarian Nordic scooped a five year contract worth $500m in June to supply an additional 20 million doses of a different smallpox vaccine to the US stockpile for immuno-compromised people.