For hereditary angioedema (HAE) patients, this cascade of protein malfunction results in recurrent episodes or “attacks” of swelling (edema) in different parts of the body, including the hands, feet, face, and airway. Airway swelling can cause asphyxiation, which is why HAE can be deadly. HAE attacks can also occur in the intestinal wall, which causes patients to experience severe bouts of abdominal pain, nausea, and vomiting.
The Biocryst Phase 3 study, called APeX-2, evaluated two doses of BCX7353, a pill taken once per day, compared against a placebo. More than 120 patients with HAE were enrolled. The primary endpoint of the study was the rate of HAE attacks over 24 weeks, confirmed by the participating doctors.
The results: The lower dose of BCX7353 reduced the HAE attack rate by 30% compared to a placebo. The higher dose of BCX7353 also worked, cutting the HAE attack rate by 44% relative to placebo. Both results were statistically significant, which means the clinical trial achieved its primary endpoint. There were no worrisome safety issues reported in the clinical trial.
However, HAE patients already have effective treatment options available. Takhzyro, marketed by Takeda (formerly Shire) is the preventive HAE therapy that serves as the best comparable to Biocryst’s BCX7353. Both drugs work by suppressing the same misbehaving protein. Takhzyro is administered via an injection under the skin. It was approved last August and has launched very strongly.