Shares of the biotechnology company AtheroGenics fell sharply yesterday after its lead experimental heart disease drug failed a late-stage clinical trial.

The drug, AGI-1067, which is being developed in partnership with the drug maker AstraZeneca, failed to meet the goal of a closely watched 6,100-patient trial, which combined a group of measures into a composite benchmark for success or failure.

Those measures included rates of death, heart attack, stroke, bypass surgery, angioplasty and chest pain requiring hospitalization.

AGI-1067 is considered pivotal to the future of AtheroGenics, based in Alpharetta, Ga., which has no other products on the market. AstraZeneca, which is based in London, has been working with AtheroGenics to develop the drug and had agreed to pay up to $1 billion for an exclusive worldwide license.

AtheroGenics shares were down $4.74, or 60.5 percent, to $3.09, on Nasdaq yesterday, after trading as low as $2.90.

AGI-1067 is one of a group of experimental drugs aimed at reducing the buildup of plaque inside arteries by addressing the inflammation behind heart disease.

Had it been successful, the drug could have generated peak sales of as much as $5 billion a year. But analysts were already skeptical, as developing drugs that reduce plaque, as opposed to slowing its buildup, has proved an elusive goal for drug companies.

The drug was important to AstraZeneca, which is seeking to replenish a pipeline that has become depleted since the failure of its stroke treatment, NXY-069, in October.

Many AtheroGenics investors had already bet against the data, as 51 percent of the company’s 39.5 million shares were sold short, according to recent Nasdaq data.