British drugmaker AstraZeneca has placed a lot of faith—and money—in its wide-ranging R&D program for aging blood thinner Brilinta in hopes of major label expansions. So far, those results have been mixed, but AstraZeneca’s drug may be looking at a win in stroke patients.
A combination of Brilinta and aspirin cut stroke patients’ risk of having another stroke or dying after 30 days of treatment, according to data from the phase 3 Thales study released Thursday.
The Brilinta-aspirin combo reduced the risk of those events by 17% over aspirin alone in patients who had previously had a stroke or mini-stroke caused by clotting in blood vessels running to the brain. The combo was especially significant in preventing stroke, with a 21% risk reduction over aspirin, AstraZeneca said.
The full data release comes just days after the FDA accepted Brilinta for priority review to reduce the risk of stroke or death in prior stroke patients. Stroke is the second-leading cause of death worldwide, with about 2.7 million deaths per year tied to brain-related strokes, AstraZeneca said.
The Thales study is AstraZeneca’s latest attempt to bolster Brilinta’s label through an expansive R&D effort that has turned out mixed results in recent years.
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As of January, AstraZeneca had spent an estimated $5.4 billion on R&D for Brilinta despite an unlikely chance the drug will ever return on that investment with generics on the way in 2024, Evaluate Pharma predicted.
Much of that R&D expense has been tied to AstraZeneca’s Parthenon program, Evaluate reported, which has churned out a suite of trial data, including the newest results from the phase 3 Thales study.
Parthenon—and its six outcomes trials for Brilinta—has already swallowed $3.7 billion in R&D costs with an additional $1.7 billion tied up in more than 80 investigator-sponsored trials, Evaluate said. Of the six Parthenon studies, three have led to label updates, while another two were called “clear failures” by Evaluate.
In June, the FDA approved Brilinta to reduce the risk of a first heart attack or stroke in patients with coronary artery disease and Type 2 diabetes, AstraZeneca said. The approval was based on the phase 3 Themis study.
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Evaluate’s report came just days after AstraZeneca reported top-line results from the Thales study, and the analysts targeted the drug combo’s bleeding rates as another weak point on Brilinta’s record.
The Brilinta-aspirin combo showed severe bleeding in 0.5% of patients in the Thales study compared with 0.1% of those on aspirin alone, AstraZeneca said.
Those results were in line with previous Brilinta studies, the company said, but Evaluate noted that physicians would likely have to make a tradeoff between the combo’s efficacy and safety issues if Brilinta wins an expanded label.
