AstraZeneca has raised fresh fears over its threadbare development pipeline of new drugs, admitting that its heart drug AGI-1067 is a "very high-risk project".

"We have a low probability of success from our perspective," said the chief executive, David Brennan, in an interview with the Times today.

AGI-1067 is an anti-inflammatory treatment for reducing atherosclerosis, the build-up of plaque inside arteries that can lead to heart attacks and stroke. If successful, it is a potential blockbuster drug capable of generating billions of dollars a year in revenues.

"We believe there is a possibility that it could work, based on the Phase II data," Mr Brennan said. "It's the same reasons we went forward with NXY [a stroke drug that failed in trials in October]."

He added: "If we get it, it will be significant. If we don't, we have three other products in our pipeline that we are moving along in Phase II - two oncology products and a platelet inhibitor - and we are actively looking for others."

After a string of drug failures, AstraZeneca, Britain's second biggest pharmaceuticals firm, has few treatments left in the late stages of development.

Its shares crashed in October when it admitted that its stroke treatment NXY-059 did not work.

AGI-1067 could hit the market in 2008 if late-stage clinical trials show it is effective.

But City analysts are sceptical: while they believe the drug could generate peak sales of up to $5bn (£2.55bn) a year, they have adjusted their forecasts to $500m to $1bn to reflect the high risk that it could not work.

AstraZeneca signed a $50m licensing deal for the rights to AGI-1067 with a US firm, Athero-Genics, last year.

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