ASTRAZENECA’S new chief executive admitted for the first time yesterday that Exanta, once one of its most promising medicines, would never make it on to US pharmacy shelves.

Speaking exclusively to The Times, David Brennan conceded that the blood-thinning drug, which was unexpectedly blocked by US regulators in late 2004, would never see the light of day. “We don’t see any way forward in the US for Exanta right now, especially given what work we’ve done in the clinic and what the regulators want to see from us.”

Mr Brennan said that the company’s research effort into the medicine would not go to waste: “We’re still interested in the market but, from a commercial expectation, this isn’t something that has tremendous opportunity.”

Under its previous chief, Sir Tom McKillop, the company had vowed to persuade US authorities to approve the drug.

Mr Brennan, in defiant mood as the market reacted badly to another set of record quarterly results — the sixth in a row — also vowed to fight generic competitors. He specifically ruled out settlement talks with copycat manufacturers trying to undermine three of its biggest-selling medicines.

“Nobody likes uncertainty but our assets are our patents and we would have to think very carefully before giving up any aspect of them,” he said.

The chief executive reported a 30 per cent jump in fourth-quarter profits to $1.6 billion (£900 million). Meanwhile, full-year profits jumped 38 per cent to $6.66 billion, bolstered by strong sales from ten leading treatments that now enjoy billion-dollar plus, or blockbuster, status.

But it was the performance of the group’s “fabulous five” drugs — Nexium, Seroquel, Crestor, Armidex and Symbicort — that fuelled the profit growth, generating between them $10.8 billion worth of sales during the year, almost one third higher than last time.

However, shares in the company fell 3 per cent to £26.38 as the Anglo-Swedish drugs group conceded that profits growth for the current financial year would depend almost entirely on the drugs maker clinging on to the licensing rights to Toprol XL, a top-selling heart drug.

Mr Brennan said that earnings per share for 2006 would be between $3.40 and $3.60. However, he cautioned that the bullish forecasts, up from $2.91 this year, included revenues of about 45 cents a share from Toprol. The estimates assume that a US court judgment that the Toprol patents are no longer valid can be overturned.

A further two top-selling drugs, Nexium, an anti-ulcer treatment, and Seroquel, a medicine for schizophrenia, also face crucial patent challenges in the coming months, underlining a paucity of new prospects in the company’s pipeline.

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