Dyax, an integrated biopharmaceutical company, has decided to discontinue its Phase 2 trial of ecallantide for acute treatment of angiotensin converting enzyme (ACE) inhibitor-induced angioedema, based on the data from an interim analysis.
The double-blind, placebo-controlled study was planned to evaluate the efficacy and safety of ecallantide (10, 30, or 60mg subcutaneous doses) compared to the placebo.
The proportion of patients meeting a set of criteria indicating eligibility for discharge from the emergency department within six hours after study drug administration was the primary endpoint of the randomised, dose-ranging tests.
Dyax president and chief executive officer Gustav Christensen said that the company would continue to actively investigate novel therapeutic approaches for angioedema disorders, including next generation therapies and testing.
"These results, while unanticipated, provide us with further evidence and understanding of the biology of angioedema, supporting our efforts to address these disorders and to remain at the forefront of therapeutic innovation," Christensen added.
An independent Data Safety Monitoring Board, which reviewed blinded safety data for the first 25% of patients in the trial, did not spot any safety concerns or recommended any changes to the conduct of the study.
Although the data from the first 72 patients treated in the trial suggested a trend favouring a treatment with ecallantide over a placebo, it was not statistically significant.
The study was determined to be poorly powered to detect a statistically significant difference between ecallantide and the placebo, as the observed response rate to the placebo was substantially higher than originally anticipated; in addition, the enrolled population does not appear to reproduce the high morbidity described in previous medical literature.
Dyax chief medical officer Burt Adelman added: "These results have no bearing on the use of Kalbitor (ecallantide) to treat patients during an acute attack of HAE."