Integrity Concerns in Ticagrelor Trials Challenge Clinical Confidence

As generic versions of AstraZeneca’s blockbuster drug ticagrelor prepare to enter the market, The BMJ raises fresh concerns over the integrity of the clinical trials that underpinned its approval. | Image Credit: Peera | stock.adobe.com

New scrutiny has emerged over the trial data supporting ticagrelor (Brilinta; AstraZeneca), after a BMJ investigation revealed inaccuracies in 2 foundational studies that assessed platelet inhibition efficacy. These trials were critical in establishing the drug’s clinical profile. However, BMJ reports that more than 60 of 282 platelet aggregation values were omitted from data submitted to the FDA, despite being included in the published versions of the trials and used to justify statistical significance of the drug’s effects.¹

Ticagrelor is an antiplatelet medication indicated to prevent blood clots and reduce the risk of cardiovascular events such as heart attack or stroke. This includes in individuals with acute coronary syndrome or past heart attack, coronary artery disease at high risk of a cardiovascular event, or those with recent ischemic stroke or at high risk of a transient ischemic attack.^1-3

The omission of key data points has raised alarms about the credibility of these early studies, which were integral in the FDA’s initial evaluation and subsequent approval of ticagrelor. Investigators also flagged that these inconsistencies were not disclosed in the publications, contributing to an inflated perception of the drug’s benefits compared to clopidogrel (Plavix; Sanofi).¹

Safety Considerations and Risk of Rebound Events

In response to the BMJ findings, Victor Serebruany, MD, PhD, a cardiologist at Johns Hopkins University, raised safety concerns, particularly about ticagrelor’s reversible binding and its effects on platelet reactivity. He warned that overstated inhibition could increase risks for rebound thrombotic events or bleeding when the drug is discontinued.

“If doctors had known this data was faulty, they would never have started using ticagrelor,” he said in an interview with SciTechDaily.²

Pharmacists should therefore take special care when counseling patients about stopping or restarting ticagrelor. Clear education on the importance of adherence, signs of adverse events, and appropriate transitions is critical for minimizing harm.²

Pharmacist Responsibilities in Monitoring and Counseling

As trusted medication experts, pharmacists are well positioned to mitigate risks posed by uncertainty in ticagrelor’s clinical data. This includes close monitoring of patients, especially those with comorbidities or at high risk for bleeding and engaging in conversations with prescribers about the comparative benefits and risks of other antiplatelet agents.³

Additionally, as generic versions of ticagrelor become available, pharmacists will likely encounter questions about substitutions. It is important to reassure patients that these generics are bioequivalent to Brilinta. However, pharmacists should also be transparent in noting that concerns relate to the integrity of early clinical trials, not the quality of generic formulations themselves.³

References

1. Doshi P. Ticagrelor doubts: inaccuracies uncovered in key studies for AstraZeneca’s billion dollar drug. BMJ. 2025;389:r1201. https://www.bmj.com/content/389/bmj.r1201

2. Scientists Uncover New Concerns About Billion-Dollar Heart Drug. SciTechDaily. June 29, 2025. Accessed June 30, 2025. https://scitechdaily.com/scientists-uncover-new-concerns-about-billion-dollar-heart-drug/

3. Marley Drug. What is Ticagrelor? Uses, Side Effects & FAQs. Accessed June 30, 2025. https://www.marleydrug.com/blog/ticagrelor