12-Week Safety and Efficacy Study of BCX4161 as an Oral Prophylaxis Against HAE Attacks (OPuS-2)

November 3, 2025 updated by: BioCryst Pharmaceuticals

OPuS-2: A Multicenter, Randomized, Double-blind, Placebo-controlled, Parallel Group Study to Evaluate the Efficacy and Safety of Two Dose Levels of BCX4161 for 12 Weeks as an Oral Prophylaxis Treatment for Attacks of Hereditary Angioedema

This study will evaluate the safety and efficacy of an oral treatment, BCX4161, in preventing acute attacks in participants with hereditary angioedema (HAE). Eligible participants will be randomized to receive one of two doses of BCX4161 or placebo for 12 weeks. The study will compare the number of acute attacks in each treatment group, as well as a number of other clinical outcomes, and the safety and tolerability of each dose of BCX4161 compared to placebo.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
110

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 2
  • Phase 3

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Belgium
      • Leuven, Belgium
  • Canada
      • Ottawa, Canada
  • France
      • Grenoble, France
      • Lille, France
      • Paris, France
  • Germany
      • Berlin, Germany
      • Frankfurt, Germany
      • Mörfelden-Walldorf, Germany
  • Hungary
      • Budapest, Hungary
  • Italy
      • Milan, Italy
  • United Kingdom
      • Birmingham, United Kingdom
      • Bristol, United Kingdom
      • Cardiff, United Kingdom
      • London, United Kingdom
      • Manchester, United Kingdom
  • United States
    • Alabama
      • Birmingham, Alabama, United States, 35209
    • Arizona
      • Scottsdale, Arizona, United States, 85251
    • California
      • Granada Hills, California, United States, 91344
      • San Diego, California, United States, 92093
      • San Diego, California, United States, 92112
      • Walnut Creek, California, United States, 94598
    • Colorado
      • Colorado Springs, Colorado, United States, 80907
    • Louisiana
      • Shreveport, Louisiana, United States, 71106
    • Maryland
      • Chevy Chase, Maryland, United States, 20815
    • Massachusetts
      • Boston, Massachusetts, United States, 02114
    • Minnesota
      • Plymouth, Minnesota, United States, 55446
    • Missouri
      • St Louis, Missouri, United States, 63141
    • New York
      • New York, New York, United States, 10029
    • North Carolina
      • Charlotte, North Carolina, United States, 28277
    • Ohio
      • Cincinnati, Ohio, United States, 45267
    • Oklahoma
      • Oklahoma City, Oklahoma, United States, 73131
      • Tulsa, Oklahoma, United States, 74133
    • Oregon
      • Lake Oswego, Oregon, United States, 97035
    • Pennsylvania
      • Hershey, Pennsylvania, United States, 17033
      • Pittsburgh, Pennsylvania, United States, 15241
    • Texas
      • Dallas, Texas, United States, 75231
      • Galveston, Texas, United States, 77555
    • Virginia
      • Fairfax, Virginia, United States, 63141
    • Washington
      • Spokane, Washington, United States, 99204
      • Tacoma, Washington, United States, 98405

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Key Inclusion Criteria:

  1. A clinical diagnosis of HAE type I or II
  2. Documented HAE attacks within a defined calendar period; in the absence of documented HAE attacks, participants will be required to enter a run-in period to document attacks
  3. Access to acute attack medications
  4. Sexually active women of child-bearing potential and sexually active men must utilize highly effective contraception

Key Exclusion Criteria:

  1. Women who are pregnant or breast-feeding
  2. Any clinical condition or medical history that would interfere with the subject's safety or ability to participate in the study
  3. Use of C1INH or tranexamic acid for prophylaxis of HAE attacks
  4. Current participation in any other investigational drug study or within the last 30 days
  5. History of or current alcohol or drug abuse
  6. Infection with hepatitis B, hepatitis C or HIV

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Prevention
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: BCX4161 300 mg three times daily
Three BCX4161 capsules (100 mg) and two placebo capsules to be taken three times daily by mouth
Drug: Placebo
Drug: BCX4161
Experimental: BCX4161 500 mg three times daily
Five BCX4161 capsules (100 mg) to be taken three times daily by mouth
Drug: BCX4161
Placebo Comparator: Placebo three times daily
Five placebo capsules to be taken three times daily by mouth
Drug: Placebo

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
The Mean Acute Angioedema Attack Rate
Time Frame: 12 weeks
An angioedema attack was defined as swelling at any location reported by participant, which had no swelling earlier. Total number of confirmed attacks during the treatment period standardized to a weekly attack-rate to adjust for the total duration of treatment. The attack rate was derived for each participant by treatment period. The weekly attack rate was equal to the total number of confirmed attacks during a treatment period divided by the duration of the treatment (in days) times 7 days.
12 weeks

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Number of Attack-free Days
Time Frame: 12 weeks
The number of attack free days was the sum of the days during the treatment period for which participants reported no attacks.
12 weeks
Number of Participants Who Are Attack-free
Time Frame: 12 weeks
The number of participants who reported no attacks during the 12-week treatment period.
12 weeks
Disease Activity, as Measured by the 84-day Angioedema Activity Score
Time Frame: 12 weeks
Angioedema Activity Score (AAS) consists of 5 questions (period in which swelling occurred, physical discomfort, daily activity restriction, cosmetic disfigurement, and overall severity) to be answered for each day during which a subject experiences an HAE attack. A score between 0 (no symptoms) and 3 (Severe symptoms) was assigned to the responses for each question and the total daily score will be derived as the sum of the 5 question scores for each day during which the subject experiences a confirmed attack. Daily AAS ranged from 0 to 15 with higher scores indicating the greater disease severity. For participants who completed the study, the 84-day AAS was obtained by sum of AAS score during the treatment period and ranged from 0 (best) to 1,260 (worst).For participants who discontinued the study prematurely the 84-day AAS was obtained using the formula: Sum of AAS score of each day on treatment ∗ 84/Number of days on treatment.
12 weeks
Change From Baseline at Week 12, in Quality of Life as Measured by the Angioedema Quality of Life Questionnaire
Time Frame: Baseline (Day 1) and Week 12
Angioedema Quality of Life questionnaire (AE-QoL) consisted of 4 domains (i.e., functioning, fatigue/mood, fear/shame, and nutrition) and a total score based on a total of 17 possible responses. The results of all the responses are summed up and transformed to a scale ranging from 0 (best) to 100 (worst).
Baseline (Day 1) and Week 12
Number of Participants With Treatment Emergent Adverse Events
Time Frame: From first dose up to 14 weeks
An adverse event (AE) is any untoward medical occurrence in a clinical study participant. No causal relationship with study drug or with the clinical study itself is implied. An AE could be an unfavorable and unintended sign, symptom (including an abnormal laboratory finding), syndrome, or illness that developed or worsened during the clinical study. A serious adverse event (SAE) is any untoward medical occurrence resulting in death, is life-threatening, requires inpatient hospitalization or prolongation of existing hospitalization, results in persistent or significant disability/incapacity, results in a congenital anomaly/birth defect, or other medically important event. Any graded abnormality that occurred following the initiation of study drug and up to 30 days after the last dose of study drug, and represented at least a 1-grade increase from the baseline assessment, was defined as treatment emergent.
From first dose up to 14 weeks
Change From Baseline at Week 12 in Quality of Life, as Measured by the EuroQoL Five-dimensional, 5-level Questionnaire
Time Frame: Baseline (Day 1) and Week 12
The EuroQoL five-dimensional, 5-level (EQ-5D-5L) was used to assess overall wellbeing and comprised the following five domains: mobility, self-care, usual activities, pain/discomfort and anxiety/depression. Each domain has 5 response levels: no problems, slight problems, moderate problems, severe problems, and extreme problems. It included the EQ Visual Analogue scale (EQ VAS) to rate overall health on a scale of 0 (worst health) to 100 (best health).
Baseline (Day 1) and Week 12

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
BioCryst Pharmaceuticals

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Marc Riedl, MD MS, UCSD

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
December 17, 2014

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
January 1, 2016

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
January 1, 2016

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
November 24, 2014

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
November 25, 2014

First Posted (Estimated)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
December 1, 2014

Study Record Updates

Last Update Posted (Estimated)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
November 17, 2025

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
November 3, 2025

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
November 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • BCX4161-301

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Clinical Trials on Hereditary Angioedema

Clinical Trials on Placebo

Search Similar Trials

Sponsors and Collaborators

Medical Conditions

Drug Interventions

Conditions

Rare Diseases

Drug Interventions

Dietary Supplements

Sponsor/Collaborators

Locations

Cookie Settings

We use cookies to ensure that we give you the best experience on our website. For more details carefully read our Privacy and Cookies Policy. ...>>>You can change your preferences or withdraw your consent at any time by deleting the cookies from your website or computer as described in the policy. Please accept it and choose your preferences by ticking the corresponding boxes in the "Manage Settings" section below. Please carefully read our Terms of Service before you proceed with using any part of this website.
«Manage Settings