Wyeth has won approval in Europe for a first-in-class antibiotic – Tygacil – expected to become an important new treatment option for resistant bacterial infections with sales potential of $1 billion or more.

Tygacil (tigecycline) has been approved by the European Medicines Agency for use in complicated infections of the skin and soft tissue and complicated intra-abdominal infections acquired either in the hospital or in the community. Critically, because the agent has a broad spectrum of activity, it can be used in the first 24 or 48 hours after the infection emerges, even before the organism causing it is identified.

Wyeth says Tygacil is the first glycylcycline in Europe, offspring of the tetracycline family of antibiotics that gets around some of the resistant mechanisms that bacteria have evolved to handle its parents. This profile means it is effective against some of the most notorious ‘superbugs’, including methicillin-resistant Staphlococcus aureus and vancomycin-resistant enterococci.

The drug is one of only a handful of antibiotics that can cover Gram-positive organisms, Gram-negative organisms, anaerobes and atypical bacteria.

Wyeth is also testing Tygacil in other infections, and has said it plans to file for approval to use Tygacil in community- and hospital-acquired pneumonia and for resistant pathogens during 2007.

Tygacil will be launched in individual EU countries during 2006 and 2007, beginning with Germany and Austria, said Wyeth. Aside from the USA, it has been approved in a number of countries in Latin America and the Middle East and the Philippines.

Tygacil is a key element in Wyeth’s strategy to extend its antibiotic franchise, which also includes Zosyn/Tazocin (piperacillin/tazobactam), the world’s top-selling intravenous hospital antibiotic with sales of $890 million last year - a rise of more than 17% year-on-year, although the US patent on the drug is due to expire next year. $460 million of the drug’s sales come from the US market.

A Wyeth spokesman reported last month that Tygacil brought in around $10 million in sales between its launch in July 2005 and the end of the year. Analysts noted that new antibiotics for resistant infections tend to grow slowly shortly after launch, as their use tends to be reserved for last-resort treatment of problem cases.

It is estimated that there have been three million hospital-acquired infections per year in the extended EU, resulting in an alarming 50,000 deaths. About 70% of hospital infections are resistant to at least one class of antibiotics, according to data supplied by the US Centers for Disease Control.