The drug, known by the code GG-167, does not kill the virus but stops it spreading around the body. This should make it easier for the body's immune system to mop up the infection before it can take hold.
The pharmaceutical giant Glaxo has embarked on the second of three trials being held to test the drug, and establish how best to administer it. The company's chief executive, Richard Sykes, is reported to have given the project top priority. Trials were delayed last year because there were not enough flu patients to act as guinea-pigs.
The initial trial - launched in 1993 and involving 160 volunteers - showed that flu patients who took GG-167 recovered more quickly than those who did not. Glaxo has started recruiting 1,500 flu volunteers in the US and Europe, including the UK, for a much bigger trial.
The company expects to apply for a licence to market the drug in about a year's time. If approved, GG-167 may be on sale from about 1998.
Flu kills an average 3,000 to 4,000 people in Britain each winter, mostly affecting the elderly, and people with respiratory problems or weak immune systems.
A Glaxo spokesman, Martin Sutton, said: "It is too early to really tell if this drug can save lives ... It looks promising, but we have to complete the clinical trials and find out which people would be most appropriate to benefit from it."
The drug was developed using powerful computer programmes which can produce graphics showing the structure of complex molecules in 3-D. GG- 167 works by blocking the action of an enzyme called neuraminidase, which allows the virus to escape from infected cells and spread throughout the body. Scientists designed new molecules which bind to the enzyme and jam it, in the same way that a key jams in a lock.
The drug was first discovered by an Australian scientist and has been developed, with financial backing from Glaxo, by the small Australian company, Biota.
An American team of scientists based at Alabama University is reported to be working along similar lines, but has not progressed as far.Reuse content