Phase III APeX-2 trial of BCX 7353 reported data for treatment of hereditary angioedema

BioCryst Pharmaceuticals, Inc. announced that the randomized (n=121), double-blind, placebo-controlled, Phase III APeX-2 trial of once-daily, oral BCX 7353 for the prevention of hereditary angioedema (HAE) attacks achieved its primary endpoint for both dose levels (110 mg and 150 mg), with the 150 mg dose reducing the attack rate in HAE patients by 44 percent (p<0.001) compared to placebo.

Fifty percent of patients receiving 150 mg BCX 7353 in APeX-2 had a greater than 70 percent reduction in their HAE attack rate compared to baseline, compared to 15 percent of placebo patients (p=0.002). In patients on the 150 mg dose with a baseline attack rate of < 2 attacks per month, BCX 7353 reduced the HAE attack rate by 66 percent compared to placebo (p=0.009). In patients with a baseline attack rate of more than 2 attacks per month, the attack rate was reduced by 40 percent (p=0.005). Of 108 patients who completed 24 weeks of study drug treatment, 100 percent continued into the ongoing 48 week extension phase of the trial.

In APeX-2, both the 110 mg and 150 mg dose levels of once-daily oral BCX 7353 were generally safe and well-tolerated. No drug-related serious adverse events were reported. The most common drug-related adverse events reported in at least five percent of patients in APeX-2 were: nausea (9.8% 110 mg, 7.5% 150 mg, 15.4% placebo), dyspepsia (9.8% 110 mg, 7.5% 150 mg, 5.1% placebo) and diarrhea (7.3% 110 mg, 10% 150 mg, 0% placebo).

Comment: Reception by investors of the results of the trial accepted that the drug significantly outperformed placebo but the reductions in attack rates fell well short of similar results from competing drugs as well as prior Phase II data of the drug.