BioCryst, Torii Partner to Commercialize BCX7353 in Japan to Prevent HAE Attacks

BioCryst Pharmaceuticals has licensed rights to Torii Pharmaceutical for the commercialization of BCX7353 — an oral, once-daily investigational therapy for the prevention of hereditary angioedema (HAE) attacks — in Japan, pending the treatment’s approval.

The plan is for BioCryst to submit a Japanese new drug application (JNDA) in the first quarter of 2020 to the Pharmaceuticals and Medical Devices Agency (PMDA), the regulatory agency for medicines in Japan.

The deal between the two pharmaceuticals includes a $22 million upfront payment to BioCryst, which could increase to $42 million with potential milestone payments, plus royalties on net sales.

“We are excited to partner with Torii to accelerate access for Japanese patients to BCX7353,” Jon Stonehouse, BioCryst’s president and CEO, said in a press release.

“With no approved treatments in Japan for the prevention of HAE attacks, there is a significant unmet need today,” said Beverley Yamamoto, president of the Japanese Hereditary Angioedema Patient Association.

“A safe, effective oral prophylactic therapy would offer tremendous benefit to Japanese HAE patients and their families,” Yamamoto said.

BCX7353 is an investigational treatment, given as a once-daily capsule, for preventing acute angioedema, or swelling attacks in patients with HAE. The compound is an oral inhibitor of plasma kallikrein, a precursor of bradykinin, which is overproduced in people with HAE, leading to the signs and symptoms of the disease.

Bradykinin is an inflammatory molecule that regulates blood pressure and inflammation by causing small blood vessels to dilate or widen. Excessive bradykinin leads to angioedema and pain.

By inhibiting kallikrein, BCX7353 is thought to reduce the amount of bradykinin in HAE patients, potentially preventing angioedema attacks.

The compound was granted fast track designation by the U.S. Food and Drug Administration (FDA) and recommended for orphan drug status by the European Medicines Agency (EMA) in 2018. It also received Sakigake designation in Japan, which promotes the development of innovative medicines.

BioCryst started its Phase 3 clinical trial APeX-2 (NCT03485911) in 2018 to test BCX7353’s efficacy and safety versus a placebo in people with type 1 and type 2 HAE. The study showed that 110 mg or 150 mg daily doses of the medicine provided a significant benefit by decreasing HAE attacks by 30% in type 1 and 44% in type 2, compared with placebo. BCX7353 was well-tolerated by the study’s participants.

That Phase 3 study came after the successful completion of the APeX-1 Phase 2 trial (NCT02870972), in which BCX7353 reduced by more than 70% the rate of angioedema attacks in people with HAE.

BioCryst also is currently running the ApeX-S Phase 2/3 trial (NCT03472040). That study, which is currently recruiting, is testing the long-term safety of the two doses of BCX7353 as a preventive treatment for HAE patients.

Based on the positive results of the APeX-2 trial, BioCryst shared its plans to submit a new drug application to the FDA toward the end of this year. The company also intends to submit a marketing authorization application to EMA in the first quarter of 2020.