BioCryst Hereditary Angioedema Phase II Trial Meets Expectations

BioCryst Pharmaceuticals has announced that its hereditary angioedema, or HAE, drug, met the company’s primary efficacy endpoint, along with several of its secondary endpoints in its Phase 2a clinical trial. The drug, called BCX4161, is a selective inhibitor of plasma kallikrein, indicated to prevent the attacks characteristic of hereditary angioedema (HAE).

HAE is a rare condition, however is potentially deadly for those that suffer from the disease. HAE causes swelling of the face and airways as well as abdominal cramping. It is extremely debilitating and only occurs in about 1 to 10,000 to 1 to 50,000 people, being passed down genetically between families. The condition is caused by low levels of the C1 inhibitor proteins, and swelling attacks can cause airway blockage or abdominal cramping that needs immediate medical attention. The BCX4161 drug prevents HAE attacks by suppressing the body’s bradykinin production. Bradykinin plays a key role in HAE’s acute swelling.

In the Phase 2a trial, 24 patients received the drug, and researchers found a statistically significant reduction in the number of HAE swelling attacks in patients treated with BCX4161 compared to the placebo. The average attach rate per week was 0.82 for those on the drug, compared to 1.27 for those taking the placebo. The researchers also found that the drug was generally well tolerated, with only one adverse event reported.

Marcus Maurer, MD and Professor of Dermatology and Allergy at the Charité-Universitätsmedizin in Berlin and principal investigator for the study, commented on the results. “OPuS-1 represents a milestone study in establishing the proof of concept that prophylaxis with an oral kallikrein inhibitor can effectively reduce attacks for patients living with HAE,” said Maurer. “Existing therapies for prophylaxis of attacks in patients with HAE require frequent i.v. infusions, or the use of oral androgens that have significant long term side effects. The OPuS-1 results open up the possibility of an exciting new treatment option for this challenging disease.”

The announcement last Tuesday of the HAE drug’s successful trial helped to improve the company’s stock, which was up by more than 11 percent.