AstraZeneca's Brilinta has been hit with another setback after failing to show superiority over veteran bloodthinner clopidogrel (Sanofi's Plavix) in patients with peripheral arterial disease (PAD).

Top-line results from the EUCLID study show that Brilinta (ticagrelor) failed to demonstrate a benefit over clopidogrel in a symptomatic PAD patient population and therefore did not meet the primary endpoint of the trial.

The firm said it is disappointed with the outcome, and that a fuller set of results will be presented next month at the American Heart Association Scientific Sessions.

Brilinta/Brilique is a direct-acting P2Y12 receptor antagonist that works by inhibiting platelet activation, which has been shown to reduce the rate of thrombotic cardiovascular events, such as heart attack or CV death, in patients with Acute Coronary Syndrome (ACS).

The drug is approved to reduce the rate of thrombotic CV events in patients with ACS, non–ST-elevation myocardial infarction (NSTEMI), or ST-elevation myocardial infarction (STEMI), as well as for the treatment of patients who have suffered a heart attack at least one year prior and are at high risk of developing a further atherothrombotic event.

The firm has been seeking to expand Brilinta's scope, but the drug also missed its targets in a different Phase III trial earlier this year, failing to increasing the time to first occurrence of stroke (ischaemic or haemorrhagic), myocardial infarction or death compared to aspirin.

On the back of these failures the drugs giant is now having to face trimming its sales prediction for the drug.

"We don't believe the goal of $3.5 billion is attainable. I think it would be unrealistic to believe that," Ludovic Helfgott, head of the firm's Brilinta line, told Reuters.

Aralez deal

Meanwhile, AZ also announced that it has entered into an agreement with Aralez Pharmaceuticals for rights to branded and authorised generic Toprol-XL (metoprolol succinate) in the US.

The drug is a beta-blocker medicine for the control of hypertension (high blood pressure), angina (chest pain) and heart failure.

Under the terms, Aralez will pay AZ $175 million to acquire the rights, and up to $48 million in milestone and sales-related payments, as well as mid-teen percentage royalties on sales.