Bayer’s oral FXIa inhibitor asundexian has significantly reduced the risk of stroke in a phase 3 trial, giving a boost to a potentially blockbuster mechanism that has suffered setbacks over the past two years.
Germany’s Bayer stopped a phase 3 trial of asundexian in patients with atrial fibrillation two years ago after an interim look at the data suggested the molecule was less effective than Bristol Myers Squibb and Pfizer’s Eliquis. Earlier this month, BMS and Johnson & Johnson took a similar action, stopping a phase 3 trial of their rival oral FXIa inhibitor in acute coronary syndrome patients early for futility.
Bayer broke the losing streak Sunday, reporting that a phase 3 trial of asundexian for secondary stroke prevention (SSP) met its primary efficacy and safety endpoints. The trial randomized patients who had experienced a non-cardioembolic ischemic stroke or high-risk ischemic attack to receive asundexian or placebo, both in combination with antiplatelet therapy.
The risk of stroke was significantly lower on asundexian than on placebo, achieving the study’s primary efficacy endpoint. Asundexian reduced the stroke rate without increasing the risk of major bleeding, the trial’s primary safety endpoint. Bayer plans to talk to regulators in preparation for seeking approval of the drug candidate. Shares in Bayer climbed 10% to 30.28 euros ($34.91) in early trading in Germany.
Related
The potential for FXIa inhibitors to stop the formation of clots without raising the risk of bleeding is key to the pitch for the mechanism. Bayer and BMS have bet big on the idea that disentangling thrombosis from hemostasis can match or beat the efficacy of existing drugs while improving the safety profile. Delivering that profile could mitigate the arrival of off-patent rivals to Bayer’s Xarelto and BMS’ Eliquis.
Guggenheim analysts said in a note to investors early this month that they had “limited enthusiasm” for Bayer’s stroke readout. But, with Bayer bucking the trend and racking up a phase 3 win, BMO Capital Markets analysts said Sunday that the data “provide new confidence that FXIa inhibition can lead to meaningful improvements in anticoagulation without sacrificing safety risks through increased bleeding.”
Bayer is yet to share any numbers from the stroke trial. BMO analysts flagged “the relative contribution of treatment and the degree to which treatment benefit is clinically meaningful” as factors to look out for when Bayer presents the full data.
The analysts said Bayer’s data are positive for BMS and J&J’s rival FXIa agent milvexian. While milvexian recently failed one trial, BMS and J&J are continuing to study the asset in SSP and afib. BMS has named afib as the big commercial opportunity. While Bayer has already fallen short in afib, the phase 3 SSP win gives it a shot at sparking growth at a pharma unit that currently has stagnant sales.