Skip to content
Clinical Trials – home

Rare diseases

Investigational molecules

Locations

Our offerNewsroom

RecruitingRare disease

Study on C1 Esterase Inhibitor for Treating and Preventing Hereditary Angioedema Attacks in Patients with C1-INH Deficiency

Verified siteRegistered drug
Clinical Trials Concierge

Prefer not to search? Our Concierge searches the trials for you.

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, which is a rare genetic disorder that causes sudden swelling in various parts of the body, such as the face, hands, and feet. The study is testing a treatment called C1-esterase inhibitor, which is derived from human plasma and is designed to help prevent and treat these swelling attacks. The treatment is given through an intravenous injection, meaning it is administered directly into a vein.

The purpose of the study is to determine if the C1-esterase inhibitor is more effective than a placebo in relieving the symptoms of an acute attack in people with hereditary angioedema. Participants in the study will receive either the treatment or a placebo, and neither the participants nor the researchers will know which one is being administered, a method known as a double-blind study. The study will monitor how quickly participants experience relief from their symptoms after receiving the injection.

Participants will be involved in the study for a period of time during which they will receive the treatment or placebo and be observed for any changes in their condition. The study aims to provide valuable information on the safety and effectiveness of the C1-esterase inhibitor in managing hereditary angioedema attacks, potentially leading to improved treatment options for those affected by this condition.

The research process

The trial runs in 6 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, eligibility is confirmed based on age, diagnosis of hereditary angioedema (HAE), and history of attacks.

    Informed consent is required, and a negative pregnancy test is necessary for participants of childbearing potential.

  2. Step 2

    Treatment administration

    The study involves the administration of a C1 esterase inhibitor through intravenous injection or infusion.

    The medication is given to relieve symptoms of acute hereditary angioedema attacks.

  3. Step 3

    Symptom monitoring

    Symptom relief is monitored every 15 minutes for 4 hours after the injection.

    Participants rate their symptom relief at the site of swelling or pain.

  4. Step 4

    Evaluation of treatment response

    The primary goal is to measure the time to the beginning of symptom relief at the attack site.

    Secondary evaluations include the percentage of participants responding to treatment and changes in symptom severity.

  5. Step 5

    Follow-up and additional assessments

    Follow-up includes monitoring for any adverse events and changes in quality of life.

    Additional assessments involve physical examinations, vital signs, and laboratory tests.

  6. Step 6

    End of study

    The study is estimated to conclude by December 31, 2025.

    Final evaluations compare the end-of-study results with baseline measurements.

Who can join the trial?

7 criteria

  • The participant must be at least 18 years old for the first phase of the study or at least 2 years old for the second phase.
  • The participant must have a confirmed diagnosis of **HAE type I or II**. **HAE** stands for **Hereditary Angioedema**, a condition that causes sudden swelling.
  • The participant must have experienced at least 3 moderate or severe **HAE attacks** (excluding attacks on the arms or legs) in the last 3 months before the screening visit. For participants aged 2 to 12 years, they must have had at least 1 moderate or severe attack in the last 6 months before the screening visit.
  • The participant must have a documented **C1-INH functional activity** of less than 50%. **C1-INH** is a protein in the blood, and low levels can lead to swelling. The participant may or may not have a deficiency of this protein, and their **C4 antigen level** must be below the normal range.
  • The participant or their legally authorized representative must have signed an informed consent form, which is a document explaining the study and confirming their agreement to participate. If the participant is capable, they must also agree to participate.
  • The participant must be willing to follow all study procedures and be available for the entire duration of the study.
  • If the participant is capable of becoming pregnant, they must have a negative pregnancy test and use a highly effective method of birth control. They must continue using birth control until at least 2 weeks after their last dose of the study medication. Participants not capable of becoming pregnant include those who have had certain surgeries (like removal of the uterus or ovaries) or those who are postmenopausal, meaning they have not had a menstrual period for 12 months without another medical reason.

Who cannot join the trial?

4 criteria

  • Participants who are not experiencing an acute hereditary angioedema attack. This is a sudden swelling that can occur in different parts of the body.
  • Individuals who are younger than 12 years old or older than 18 years old.
  • Participants who are not willing to receive treatment through an IV injection. This means medicine is given directly into a vein.
  • Individuals who are part of a vulnerable population, which means they might need special protection or care.
Clinical Trials Concierge

Prefer not to search? Our Concierge searches the trials for you.

Tell us about your condition – we search every trial in Europe and connect you with the right site.

We usually reply within a few days

Verified sites

All sites with verified contact details – recruitment status may not be available; ask directly

Trial locations

Where you can join this trial

Countries are shaded by recruitment status. Click a recruiting country to ask about joining there.

RecruitingNot recruiting
Not finding your country?

Not sure what to do next?

Joining a clinical trial can seem overwhelming. We guide you step by step, so you know exactly what to expect and how we support you through the process.

See the full process and FAQ

Investigated drugs

OCTA-C1-INH is an intravenous medication derived from human plasma. It is used in this clinical trial to treat and prevent acute attacks of hereditary angioedema (HAE) in patients with a deficiency of C1 esterase inhibitor. The medication works by replacing the missing or malfunctioning C1 inhibitor in the blood, helping to control swelling and other symptoms associated with HAE attacks.

What is already known about the treatment

OCTA-C1-INH – This medication is administered intravenously and is used to treat acute hereditary angioedema attacks. It is currently being studied in a phase 3 clinical trial to confirm its effectiveness and safety compared to a placebo. The main therapeutic indication is for individuals with congenital C1-INH deficiency, aiming to relieve symptoms during acute attacks. At the molecular level, it works by supplementing the deficient C1 esterase inhibitor, which helps regulate the complement and contact systems involved in inflammation and swelling. It is classified pharmacologically as a human plasma-derived C1 esterase inhibitor concentrate.

Investigated diseases

Acute Hereditary Angioedema Attacks – This condition is characterized by sudden episodes of swelling in various parts of the body, including the skin, gastrointestinal tract, and airways. It is a genetic disorder caused by a deficiency or dysfunction of the C1 inhibitor protein, which normally helps regulate inflammation. During an attack, patients may experience painful swelling, abdominal pain, nausea, and difficulty breathing if the airways are affected. The attacks can occur spontaneously or be triggered by stress, trauma, or certain medications. The frequency and severity of attacks can vary widely among individuals. Managing the condition involves understanding triggers and monitoring symptoms to prevent complications.
Trial detailsLast updated 7 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2023-503507-29-00Protocol codeCONE-02Estimated enrolment124 patientsSponsorOctapharma Pharmazeutika Produktionsgesellschaft mbH

sourced from the EU Clinical Trials Register and site verification

Want to learn more about this trial or check if you can participate?

Clinical Trials Concierge

Prefer not to search? Our Concierge searches the trials for you.

Tell us about your condition – we search every trial in Europe and connect you with the right site.