AstraZeneca has dumped billions into Brilinta R&D, but will it ever pay off?

AstraZeneca's Parthenon program for Brilinta has been a hit-and-miss affair despite $3.7 billion in R&D costs. (AstraZeneca)

With a series of late-stage trial readouts in the past few years, AstraZeneca has invested heavily in outcomes R&D for its stalwart clotbuster Brilinta. But there's big problem with that approach, which was once one of CEO Pascal Soriot's pet projects.

AstraZeneca may never see a return on investment for the billions it's dumped into the drug.

With an estimated $5.4 billion in sunk costs in Brilinta, AstraZeneca will likely never turn a profit on the blood thinner with generics expected to hit the market in 2024 and marketing costs swallowing up any increase in the drug's already disappointing sales, EvaluatePharma said Tuesday. 

Much of that R&D expense has been tied to AstraZeneca's Parthenon program, Evaluate reported, which has turned out a suite of trial data, including top-line results from the phase 3 Thales study released Monday. 

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, two have led to label updates, while another two were called "clear failures" by Evaluate. 

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"Companies risk these sums for the rewards of owning a life-saving drug, but it is hard to argue that in this case the spend was worth it," Evaluate said. 

In the most recent Parthenon trial––phase 3 Thales–– twice-daily Brilinta on top of aspirin significantly cut the risk of stroke or death over aspirin alone in patients who had suffered a stroke or transient ischemic attack and began treatment within 24 hours, according to top-line data released Monday.