The anticipated positive decision for AstraZeneca’s anticlotting drug Brilinta (ticagrelor) in the USA has not materialised after regulators announced they wanted more information. 

The setback is not the first, as the US Food and Drug Administration has already put off making a decision on the drug, rival to blockbuster Plavix (clopidogrel), back in September when it wanted more time to consider the evidence. 

A thumbs up in the USA had been anticipated yesterday following a marketing approval win in Europe earlier this month. However, the FDA has requested additional analyses of the PLATO data used in the submission, though this does not include additional clinical studies. 

The PLATO study, which compared Brilinta with Plavix in more than 18,000 patients, showed that treating 54 acute coronary syndrome patients with ticagrelor instead of clopidogrel for one year prevented one atherothrombotic event and treating 91 patients prevented one cardiovascular death, with no increase in overall major/fatal bleeding over the course of one year of treatment. 

While these results suggest Brilinta is more effective than Plavix, there have been concerns there are variations in drug efficacy between countries, with a lack of benefit in the North American subgroup. Analysts expect this to be the reason behind the FDA’s delay.  

AstraZeneca is evaluating the complete response letter and said it will respond to the agency’s request for additional analyses of the PLATO data as soon as possible. The firm added it remains confident in the submission for the drug and in its ability to respond to the agency’s questions.