German pharmaceutical giant Bayer has halted a study on the anti-coagulant Asundexian early after data showed poor performance.
The drug had been seen as a promising potential treatment from Bayer and was viewed as the likely successor to Xarelto, the brand name of Bayer’s Rivaroxaban medication which is widely prescribed by doctors to prevent and treat blood clots.
Asundexian was in relatively advanced stage III trials, and there were expectations at Bayer that Asundexian could eventually generate billions of dollars in annual revenue for Bayer.
There is a large and booming market for anticoagulants, which are often prescribed for older patients to reduce the risk of strokes.
But early data from the study indicated that it was less effective than the standard treatment, the company said on Monday. Bayer said it will continue to analyse the data.
The company had only recently extended the phase III study programme for Asundexian. Medications that clear a stage III trial and relatively close to regulatory approval.
Xarelto has been one of Bayer’s most lucrative pharmaceutical products, generating ?3 billion ($3.3 billion) in sales over the first nine months of 2023. That accounted for about a quarter of all revenue in the pharmaceutical division.
However, Bayer’s lucrative patent protections for Xarelto will gradually expire over the coming years.
Far cheaper generic competitors are already available in Brazil, and should arrive on other markets as the company’s patents expire.
Xarelto sales were down 8.4% over the first nine months of 2023, which the company attributed to growing price pressure from other drugs.
Bayer management had highlighted Asundexian as an improvement over Xarelto. In the annual report for 2022 published in February, the drug was cited as a key example of innovative products and called the development effort “one of the largest Phase III projects [Bayer has] undertaken to date.”
Investors reacted negatively to Bayer’s announcement on Monday, with shares losing about a quarter of their value in trading by early Monday afternoon.
The announcement came on top of more bad news for Bayer’s troubled agrochemical business, which has been plagued by costly lawsuits over the health effects of the glyphosate-based weedkiller Roundup.
A federal jury in the US state of Missouri on Friday ordered Bayer to pay more than $1.5 billion to three people who blamed the weedkiller for cancer.
Bayer expressed confidence that the massive verdict would be overturned or reduced on appeal. Roundup was long a best-selling product for US agrichemical giant Monsanto, which Bayer acquired in 2018 for more than $60 billion.