First patient receives BCX7353 dosing in BioCryst’s Phase II trial for HAE


US-based BioCryst Pharmaceuticals has started dosing patients in the Phase II ZENITH-1 exploratory clinical trial of BCX7353 to treat patients with hereditary angioedema (HAE).

BCX7353 is a once-daily selective inhibitor of plasma kallikrein currently being developed to prevent angioedema attacks.

The randomised, double-blind, placebo-controlled, adaptive dose-ranging Phase II trial is designed to evaluate the safety and tolerability of BCX7353 for acute treatment of the attacks in 60 patients.

During the trial, 250mg, 500mg and 750mg dosage strengths of the product candidate will be given as an oral liquid for up to three attacks in each patient.

Each subject is scheduled to be administered with BCX7353 for two attacks and placebo for one attack in a randomised pattern.

BioCryst Pharmaceuticals CEO Jon Stonehouse said: “Based upon pharmacokinetic and pharmacodynamic properties of BCX7353, we believe it could be an efficacious and convenient oral alternative to parenteral treatments of acute angioedema attacks in patients with HAE.

"A liquid formulation of BCX7353 would be a strong complement to our prophylactic treatment programme."

“A liquid formulation of BCX7353 would be a strong complement to our prophylactic treatment programme.”

Efficacy measurements in the trial will be performed using patient-reported composite visual analogue scale (VAS) scores, patient global assessment, change in symptoms and rescue medication.

The trial will compare the proportion of 750mg BCX7353-treated attacks that have stable or improved composite VAS approximately four hours after dosing with that of the placebo.

The cohort for 500mg dose level will be initiated only after demonstration of a treatment effect in the 750mg arm, while a subsequent 250mg cohort will be commenced if the effect at 500mg is similar to 750mg.

In clinical pharmacology studies conducted with healthy volunteers and in an ongoing Phase II trial, BCX7353 was reported to be safe and well-tolerated.