Socrates: Minor Setback for Brilinta Development

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On March 23rd, AstraZeneca announced that Brilinta/Brilique (ticagrelor) had failed to meet the primary end point in the SOCRATES trial. This trial assessed the efficacy of Brilinta90mg tablets twice daily, when compared to aspirin 100mg once daily, in patients with acute ischaemic stroke or transient ischaemic attack. While this result is a blow to AstraZeneca’s hopes of significantly increasing future sales of the drug, we at DRG believe that the SOCRATES trial represented only a small fraction of the potential revenue growth forecast for Brilinta’s PARTHENON programme.

The primary efficacy end point in the SOCRATES trial was time to first occurrence of any event from the composite of stroke (ischaemic or hemorrhagic), myocardial infarction (MI), and death. Despite fewer events occurring in the Brilinta arm in the overall trial population, the trend did not reach statistical significance. Preliminary analyses suggested safety data were consistent with the known safety profile of Brilinta and full analysis of the trial results will be presented at the European Stroke Organisation conference in Barcelona in May.

While Brilinta revenue has not been at the level that AstraZeneca would have wanted, they remain hopeful that label extensions will lead to significant growth over the coming years. Brilinta already successfully expanded its label in late 2015 on the back of the PEGASUS trial for long term treatment in post-MI patients. Results from EUCLID, in peripheral arterial disease (PAD) patients, and from THEMIS, in patients with type 2 diabetes (T2D) at high risk of cardiovascular events, are expected in late 2016 and early 2018, respectively.

When we analyse the details of these trials and compare them to SOCRATES, we see that any potential revenue from SOCRATES would likely have been curtailed by two central issues: firstly, the narrow treatment window of 90 days. By comparison, patients in EUCLID will be assessed after 40 months of treatment, and those in THEMIS after 48 months.

Secondly, when we assess 2015 epidemiology in the G7 (United States, France, Germany, Italy, Spain, United Kingdom, and Japan) for the potential treatment populations from each trial, we see that:

  • The number of diagnosed acute ischemic stroke events totalled approximately 1.3 million.
  • The diagnosed prevalence of PAD was approximately 12 million.
  • The diagnosed prevalence of T2D at high risk of CV events was approximately 40 million.

In conclusion, when we take the potential duration of treatment and the magnitude of the treatment populations into account, we can see the SOCRATES trial failure represents but a minor percentage of the potential revenue from the PARTHENON programme. Conversely, we also see the significant opportunity for increased revenue that rests on the successful completion of EUCLID and THEMIS.