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Study on Oral PHA-022121 for Preventing Angioedema Attacks in Patients with Hereditary Angioedema

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What is this trial about?

A plain-language summary of the goals, design and what participants do

This clinical trial is focused on studying a condition known as hereditary angioedema (HAE), which is a rare genetic disorder that causes sudden swelling in various parts of the body, such as the face, hands, and feet. The swelling is due to a deficiency in a protein called C1-Inhibitor. The study is testing a new treatment called PHA-022121, which is taken as a soft capsule by mouth. This medication is designed to prevent the swelling attacks associated with HAE by blocking a specific receptor in the body known as the bradykinin B2 receptor.

The purpose of the study is to evaluate the safety and effectiveness of PHA-022121 in preventing HAE attacks. Participants in the study will be randomly assigned to receive either the new medication or a placebo, which looks like the medication but does not contain the active ingredient. The study is conducted in two parts. In the first part, different doses of the medication will be tested to find the most effective dose. In the second part, the long-term safety of the medication will be assessed. Participants will take the medication over a period of time and will be monitored for any changes in the frequency and severity of their HAE attacks.

Throughout the study, participants will have regular check-ups to ensure their safety and to track the effectiveness of the treatment. The study aims to provide valuable information on whether PHA-022121 can be a safe and effective option for people with hereditary angioedema, potentially offering a new way to manage this challenging condition.

The research process

The trial runs in 5 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Joining the study

    Upon joining the study, the patient will be randomly assigned to receive either the medication PHA-022121 or a placebo. This process is double-blind, meaning neither the patient nor the researchers know which treatment the patient is receiving.

  2. Step 2

    Treatment period part 1

    The patient will begin the treatment period, which lasts for 84 days. During this time, the patient will take the assigned treatment orally in the form of a soft capsule.

    The primary goal during this period is to evaluate the safety and effectiveness of two different dose regimens of PHA-022121 in preventing angioedema attacks.

  3. Step 3

    Monitoring and reporting

    Throughout the treatment period, the patient will be required to report any angioedema attacks. This includes the number of attacks, their severity, and whether they required acute treatment.

    The patient will also document any symptoms experienced and the number of days with symptoms.

  4. Step 4

    Treatment period part 2

    After completing the initial 84-day period, the patient may continue into a second phase of treatment. This phase involves long-term use of PHA-022121 to further assess its safety and effectiveness.

    The patient will continue to take the medication orally and report any angioedema attacks and symptoms as before.

  5. Step 5

    End of study

    The study is expected to conclude by February 2026. At the end of the study, the collected data will be analyzed to determine the overall safety and effectiveness of PHA-022121 in preventing angioedema attacks.

Who can join the trial?

15 criteria

  • Patients must be between 18 and 75 years old.
  • Must have a diagnosis of **Hereditary Angioedema (HAE)**, which is a condition that causes swelling, based on specific criteria:
    • A history of swelling under the skin or in mucous membranes without hives.
    • At least one of the following:
      • First symptoms of swelling appeared at or before 30 years old.
      • Family history of HAE.
      • Normal levels of a protein called **C1q**.
      • Test results showing low levels of a protein called **C1-INH** (less than 50% of normal).
      • Must have had at least 3 HAE attacks in the last 3 months before the study starts. If not, they must have at least 2 attacks during the screening period.
      • Must be able to access and use standard treatments for sudden HAE attacks.
      • Must weigh at least 40 kg (about 88 pounds).
      • Must be willing and able to follow all study requirements, including using an electronic tool to report outcomes.
      • Female patients who can have children must agree to pregnancy testing and use birth control or abstain from heterosexual intercourse during the study and for 30 days after the last treatment. Acceptable methods include:
        • Male condom, with or without spermicide.
        • Cervical cap, diaphragm, or sponge with spermicide.
        • Hormonal methods (oral, injectable, or implantable).
        • Intrauterine device (IUD) or hormone-releasing systems (IUS).
        • Must provide informed consent, meaning they agree to participate after understanding the study details.

Who cannot join the trial?

10 criteria

  • Patients with any other serious health condition that could interfere with the study.
  • Patients who are pregnant or breastfeeding.
  • Patients who have participated in another clinical trial recently.
  • Patients with a history of drug or alcohol abuse.
  • Patients who are unable to follow the study procedures.
  • Patients with known allergies to the study medication.
  • Patients who have had a recent infection or illness.
  • Patients with a history of heart problems.
  • Patients who are taking medications that might interfere with the study drug.
  • Patients with a history of cancer.
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Investigated drugs

PHA-022121 is an experimental medication being tested for its ability to prevent angioedema attacks in patients with hereditary angioedema, a condition caused by a deficiency in C1-Inhibitor. This medication is taken orally and is being studied to determine its safety and effectiveness when used regularly to prevent these attacks. The trial is exploring different dosing regimens to find the most effective and safe way to use this medication for long-term prevention of angioedema episodes.

What is already known about the treatment

PHA-022121 – This medication is administered orally and is currently being studied in clinical trials for its safety and effectiveness in preventing angioedema attacks in patients with hereditary angioedema due to C1-Inhibitor Deficiency (Type I or Type II). It is in the experimental phase, with ongoing research to determine its potential as a long-term preventive treatment. The main therapeutic indication is to reduce the frequency and severity of angioedema attacks. At the molecular level, PHA-022121 works by modulating pathways involved in the regulation of inflammation and vascular permeability, which are key factors in angioedema. It is classified pharmacologically as a prophylactic agent for hereditary angioedema.

Investigated diseases

Hereditary Angioedema due to C1-Inhibitor Deficiency (Type I or Type II) – This is a genetic disorder characterized by recurrent episodes of severe swelling, known as angioedema. The swelling can affect various parts of the body, including the face, extremities, gastrointestinal tract, and airway. It is caused by a deficiency or dysfunction of the C1 inhibitor protein, which plays a role in regulating inflammation and swelling. The episodes of swelling can be triggered by stress, trauma, or other factors, but they often occur without a clear cause. The condition is typically inherited in an autosomal dominant pattern, meaning a single copy of the altered gene in each cell is sufficient to cause the disorder. Symptoms usually begin in childhood or adolescence and can vary in frequency and severity among individuals.
Trial detailsLast updated 7 Oct 2026
Age18+ yearsPhasePhase IITrial ID2023-505549-18-00Protocol codePHA022121-C301Estimated enrolment34 patientsSponsorPharvaris Netherlands B.V.

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