European Agency Issues Positive Opinion on Orphan Drug Status for BXC7353 to Treat HAE

The European Medicines Agency issued a positive opinion on BioCryst Pharmaceuticals’ application for orphan drug status of BCX7353 to treat hereditary angioedema (HAE).

The European Commission is expected to adopt the recommendation from the EMA’s Committee for Orphan Medicinal Products in the next 30 days. With orphan drug designation, BCX7353 will receive 10 years of market exclusivity in Europe as well as other incentives.

Additionally, in the U.K, the Medicines and Healthcare Products Regulatory Agency granted a promising innovative medicine (PIM) designation to the therapy candidate.

A PIM designation is an early indication that a certain product might be a candidate for the early access to medicines scheme, which supports products intended to address an unmet need in the treatment, diagnosis, or prevention of a  life-threatening disease.

“We are pleased to receive these important regulatory designations granted to BCX7353. These provide further support for the potential for BCX7353 to address a clear unmet medical need with an oral treatment for patients with HAE,” Jon P. Stonehouse, president and CEO of BioCryst Pharmaceuticals, said in a press release.

BCX7353 is an oral antagonist of plasma kallikrein, a precursor of bradykinin. In HAE, mutations in the C1 inhibitor (a protein involved in immune response) lead to excessive production of bradykinin. This inflammatory mediator regulates blood pressure and inflammation by encouraging small blood vessels to dilate. When the body produces too much bradykinin, however, patients experience angioedema and pain.

BCX7353 is designed to inhibit plasma kallikrein to reduce the amount of bradykinin in HAE patients, potentially treating and preventing angioedema attacks.

In the now-completed Phase 2 APeX-1 clinical trial (NCT02870972), the treatment candidate was found to be generally safe and well-tolerated by participants.

A Phase 3 APeX-2 clinical trial (NCT03485911), which is recruiting up to 96 participants, will investigate the long-term safety of two dosage strengths of BCX7353 administered orally once a day. In this trial, the therapy will be administered as a preventive treatment to reduce the frequency of HAE attacks.

BioCryst is also evaluating BCX7353 in the ZENITH-1 study, a Phase 2 proof-of-concept clinical trial (NCT03240133) designed to evaluate an oral liquid formulation of BCX7353 for acute angioedema attacks.

The study is recruiting up to 60 participants with HAE types 1 or 2. In each of the study’s three parts, two of the patients’ angioedema attacks will be treated with BCX7353 while one will be treated with a placebo in a randomly allocated order.

In part one, a 750 mg dose will be evaluated relative to placebo in up to 36 patients. If this shows signs of effectiveness, 12 additional patients will be enrolled at 500 mg, followed by another 12, if effective, at 250 mg. The progressive decrease aims to identify the minimum effective dose of BCX7353 when compared with placebo for the treatment of HAE attacks.

The first patient in the ZENITH-1 study has already been dosed. Enrollment will continue throughout 11 European countries, and the trial is expected to be completed in November 2018.

BCX7353 previously received orphan drug status from the U.S. Food and Drug Administration.