BCX4161 (plasma kallikrein inhibitor)
BCX4161 is being developed as an oral prophylactic treatment for patients suffering from Hereditary Angioedema (HAE). BCX4161 inhibits plasma kallikrein and suppresses bradykinin production. Bradykinin is the mediator of acute swelling attacks in HAE patients.
In July 2013, BioCryst successfully completed a randomized, placebo-controlled, Phase 1 clinical trial of orally-administered BCX4161 in healthy volunteers. The safety, tolerability, drug exposure and on-target kallikrein inhibition results of this trial strongly supported advancing the development program into a Phase 2a trial in high-attack frequency HAE patients.
In November 2013, the OPuS-1 (Oral ProphylaxiS-1) Phase 2a proof of concept clinical trial enrolled its first subject and enrolled 24 HAE patients with a history of HAE attack frequency of 1 per week. On May 27, 2014 BioCryst announced that OPuS-1 met the primary efficacy endpoint, several secondary endpoints and all other objectives established for the trial. Treatment with BCX4161 demonstrated a statistically significant mean attack rate reduction of 0.45 attacks per week versus placebo, p<0.001. The mean attack rate per week was 0.82 on BCX4161 treatment, compared to 1.27 on placebo.
In December 2014, BioCryst initiated enrollment in OPuS-2 (Oral ProphylaxiS-1). OPuS-2 is a 12-week, three-arm, parallel cohort design trial to evaluate the efficacy and safety of two different dose regimens of BCX4161 administered three-times daily, 300 mg and 500 mg, compared with placebo. The trial is being conducted in the U.S. and selected European countries, and is expected to enroll approximately 100 HAE patients with a history of moderately frequent to very frequent attacks. The primary efficacy endpoint for the trial will be the mean angioedema attack rate for each BCX4161 dose group compared to placebo.
Second Generation plasma kallikrein inhibitors
In December 2013, BioCryst selected two optimized next generation kallikrein inhibitors to advance into preclinical development for the treatment of HAE. Its scientists are moving forward based on evidence of superior bioavailability and selectivity, as well as comparable or better potency compared to BCX4161. BioCryst plans to begin human testing of one or more of the second generation kallikrein inhibitors during the second quarter of 2015.
About Hereditary Angioedema (HAE)
HAE is a rare, severely debilitating and potentially fatal genetic condition that occurs in about 1 in 10,000 to 1 in 50,000 people. HAE symptoms include recurrent episodes of edema in various body parts including the hands, feet, face, genitalia and airway. In addition, patients often have bouts of excruciating abdominal pain, nausea and vomiting that is caused by swelling in the intestinal wall. Airway swelling is particularly dangerous and can lead to death by asphyxiation. Current treatments include potentially toxic oral anabolic steroids for prophylaxis or medicines that are delivered by injection or infusion to either prevent or treat acute attacks. Daily, oral administration of a safe and efficacious prophylactic drug would revolutionize treatment for patients suffering from this serious condition.
For more information on hereditary angioedema, please visit the following websites: