Investigational BCX7353 Delivered to First Patient in APeX-2 Trial

A Phase 3 trial testing BCX7353, an inhibitor of plasma kallikrein for the prevention of swelling attacks in hereditary angioedema (HAE) patients, has dosed its first participant, BioCryst Pharmaceuticals announced.

The trial, APeX-2, will include roughly 100 patients with type 1 and type 2 hereditary angioedema in several centers in the United States, Canada, and Europe. Participants will randomly receive one of two BCX7353 doses – 110 mg or 150 mg – or a placebo. BCX7353 is delivered orally, once a day.

The trial’s primary goal is to determine BCX7353’s ability to reduce the frequency of angioedema attacks after 24 weeks of treatment.

“The ability to safely prevent attacks of angioedema with an oral medicine has been a dream for many HAE  patients. Today marks a significant milestone toward the realization of that dream,” Bruce Zuraw, MD and principal investigator of the APeX-2 trial, said in a press release.

“I am excited to be able to participate in this important trial, which we believe will lead to an effective oral prophylactic treatment offering HAE patients the opportunity to lead a normal life,” he added.

In hereditary angioedema, mutations in the C1 inhibitor protein lead to excessive bradykinin production. This inflammatory mediator causes vasodilatation, vascular leakage, and subsequent angioedema and pain.

BCX735, an oral inhibitor of plasma kallikrein, is believed to reduce the amount of bradykinin in these patients. This would make it a promising approach for treating and preventing angioedema attacks.

BioCryst recently initiated the APeX-S trial, a long-term study designed to the safety of BCX7353 and its effect on quality of life when given for 48 weeks for the prevention of angioedema attacks. The company also is conducting the ZENITH-1 Phase 2 trial, a proof-of-concept study testing BCX7353 as an oral liquid.

“Beginning dosing in the APeX-2 pivotal trial of BCX7353 brings us one step closer to providing a once-daily, oral prophylactic treatment to HAE patients. Our entire organization is encouraged and excited by this important milestone, largely because both physicians and patients have told us they are waiting for a convenient and efficacious HAE treatment that allows patients to lead a more normal life,” said Jon Stonehouse, CEO of BioCryst.

“We look forward to reporting top-line results from the APeX-2 Phase 3 trial in the first half of 2019,” he said.