MEDICS have raised concerns over a drug taken by millions to prevent heart attacks and strokes, claiming key safety data was “misreported”; by its manufacturer AstraZeneca.
Anti-clotting pill ticagrelor has been available on the NHS in 2011, after trials appeared to show it could prevent one in five deaths after a heart attack.
But an investigation published in the BMJ cast doubt “over the integrity of the clinical trials that underpinned its approval”;.
Ticagrelor is an antiplatelet that prevents blood cells from sticking together and .
The twice-daily pill is prescribed to patients with acute coronary syndrome who are at greater risk of blood clots due to a history of , or – often in combination with a low dose of .
In the UK, the drug is prescribed around 45,000 times per month on the NHS.
Now, experts claim to have uncovered “evidence of serious misreporting”; in two clinical trials that were pivotal to the drug’s approval in the UK and US.
These findings raise “doubts over the approval and decade long use of ticagrelor”;, sold as Brilique in the UK, the report authors wrote in the BMJ.
In response, an spokesperson told Sun Health: “We are confident in the integrity of the trials and its evidence in support for Brilique.”;
Two AstraZeneca studies, known as ONSET/OFFSET and RESPOND, were published in the leading journalCirculation, reporting the drug’s effects on platelet function.
The ONSET/OFFSET trial involved 123 patients and found that ticagrelor was faster and better at preventing clots than a competitor drug.
Similar results were published in RESPOND, which involved 98 patients.
But the report authors claimed claimed ‘primary endpoint’ results in the two key trials – which were pivotal in determining the treatment’s effectiveness – were inaccurately reported in Circulation.
“We found evidence that the trials were inaccurately reported,”; they said.
“In one instance, AstraZeneca’s trial failed to show statistical significance, but was published in a leading cardiology journal as significant.”;
It also said around a quarter of the readings from machines used in the trials were not included in the data sets, the US medicine’s regulator, the Food and Drug Administration (FDA) used to approve the drug.
In order for ticagrelor to get approved, clinical trials had to prove that it was a better drug than competitors in a phase 3 trial.
After phase 3 and drug approval, the FDA and MHRA in the UK, continues monitoring it in phase 4 trials, to see if there are any additional problems with the drug.
But the BMJ analysis of two phase 2 trial results found there were instances of patients whose blood “platelet aggregation dramatically increased”;.
This is when blood cells stick together to form clumps, which can lead to blood clots – exactly what the drug aims to prevent.
This is “an improbable effect for an anti-platelet drug”; and “suggests an incorrect laboratory reading”;, the BMJ said.
Assessing the readings from platelet machines used at the two trial sites, led by cardiologist Dr Paul Gurbel, investigators also found more than 60 of the 282 readings were not included in datasets submitted to the FDA.
“The platelet activity levels not entered were significantly higher than those used in the Circulation papers and FDA datasets,”; they claimed.
“It is unclear whose blood was sampled, and why those measurements did not contribute to data in either trial.”;
The report authors conducted their investigation through with trial investigators and platelet experts and access to the underlying trial data submitted to regulators.
They also said that principal investigators involved in ticagrelor trials “were unreachable or declined to be interviewed”;.
“The findings raise even deeper questions over the approval and decade long use of the drug,”; the authors claimed.
Dr Victor Serebruany, an expert in cardiovascular pharmacology at Johns Hopkins University in Maryland, who has been critical of the drug for over a decade said: “It’s been obvious for years that there is something wrong with the data.
“That the FDA’s leadership could look past all these problems- on top of the many problems their own reviewers identified and are now being discovered by The BMJ – is unconscionable.
“We all need to know how and why that happened.
“If doctors had known what happened in these trials, they would never have started using ticagrelor.”;
But a spokesperson for the Sinai Center for Thrombosis Research and Drug Development, which Dr Gurbel leads, told MailOnline: “Any allegations of any research misconduct in the two studies are baseless and erroneous.”;
Sun has also contacted Circulation for comment. The journal did not respond to the BMJ.
