Shares of Allakos (ALLK) are lower after Regeneron Pharmaceuticals (REGN) announced yesterday that Part A of a Phase 3 trial evaluating Dupixent in patients 12 years and older with eosinophilic esophagitis met both of its co-primary endpoints as well as all key secondary endpoints.

Dupixent is the "first and only biologic to show positive and clinically-meaningful results in this population as part of a Phase 3 trial," Regeneron said in a statement. T

he drug showed a 69% reduction in disease symptoms compared to 32% for placebo and a 60% reduction in esophageal eosinophilic count to a normal range compared to 5% for placebo. Allakos is developing antolimab for the treatment of eosinophil and mast cell related diseases and has a Phase 2/3 study in eosinophilic esophagitis.

"These data don't leave much room for Allakos to win with antolimab," STAT's Adam Feuerstein tweeted. Shares of Allakos are down 10%, or $7.41, to $69.15 in midday trading.