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Long-term Safety Study of KVD900 for Treating Angioedema Attacks in Adolescents and Adults with Hereditary Angioedema Type I or II

Verified siteInvestigationalNo placebo
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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 the long-term safety of a medication called KVD900 for treating attacks in patients with Hereditary Angioedema (HAE) Type I or II. Hereditary Angioedema is a rare genetic condition that causes sudden swelling in various parts of the body, such as the face, hands, and feet. The medication being tested, KVD900, is taken as a film-coated tablet and works as an oral plasma kallikrein inhibitor, which means it helps to prevent the swelling attacks by blocking a specific protein in the blood.

The purpose of this study is to evaluate if KVD900 is safe and effective for long-term use in adolescents and adults who experience these swelling attacks. Participants in the study will take KVD900 as needed when they feel an attack coming on. The study will monitor the safety of the medication over time by checking for any side effects and observing how well the medication works in reducing the symptoms of the attacks.

Throughout the study, participants will have regular check-ups to assess their health and the effects of the medication. This includes monitoring any changes in their condition and ensuring that the medication is working as intended. The study aims to provide valuable information on the long-term use of KVD900 for managing Hereditary Angioedema attacks, helping to improve treatment options for those affected by this 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

    Enrollment

    The patient joins the study after providing signed informed consent. If applicable, a parent or legally authorized representative must also provide consent.

    The patient must have a confirmed diagnosis of hereditary angioedema (HAE) type I or II and have experienced at least two documented HAE attacks within three months prior to enrollment.

    The patient must be 12 years of age or older and able to swallow tablets whole.

  2. Step 2

    Treatment administration

    The patient receives KVD900, an oral plasma kallikrein inhibitor, in the form of a film-coated tablet.

    The medication is taken on-demand to treat angioedema attacks. The specific dosage and frequency are determined by the study protocol and the patient's needs.

  3. Step 3

    Monitoring and assessment

    The patient is monitored for any adverse events (AEs) and serious adverse events (SAEs) that may occur within two days of taking the medication.

    Regular assessments are conducted to check for normal or abnormal laboratory results and vital signs at each scheduled visit.

  4. Step 4

    Symptom relief evaluation

    The time to the beginning of symptom relief is evaluated, defined as at least 'a little better' within 12 hours of the initial dose.

    The time to the resolution of the HAE attack is also assessed, defined as 'none' within 24 hours of the initial dose.

  5. Step 5

    Study duration

    The study is estimated to continue until March 9, 2026.

    The patient's participation involves adhering to all protocol requirements and completing an electronic diary (eDiary) to document their experiences and any symptoms.

Who can join the trial?

10 criteria

  • Patients may continue from a previous study called KVD900-301.
  • Patient must provide signed informed consent, which means they agree to participate after understanding the study. If the patient is underage, a parent or legal representative must also sign.
  • Patient must have a confirmed diagnosis of **Hereditary Angioedema (HAE) Type I or II**, which is a genetic condition that can cause swelling.
  • Patient must have experienced at least 2 documented HAE attacks in the 3 months before joining the study.
  • If the patient is on long-term preventive treatment allowed by the study, they must have been on a stable dose for at least 3 months before joining.
  • Patient must be male or female and at least 12 years old.
  • Patient must meet the study's contraception requirements to prevent pregnancy during the trial.
  • Patient must be able to swallow the trial tablets whole.
  • Patient must be able to properly receive and store the study medication, and be able to read, understand, and complete an electronic diary (eDiary).
  • The study doctor must believe that the patient is willing and able to follow all study requirements.

Who cannot join the trial?

4 criteria

  • Patients who do not have **Hereditary Angioedema Type I or II** cannot participate. This is a genetic condition that causes sudden swelling in different parts of the body.
  • Patients who are not in the age range specified for the study cannot participate. The study includes certain age groups, so if you are outside these groups, you cannot join.
  • Patients who are not willing or able to follow the study procedures cannot participate. This means if you cannot or do not want to follow the rules and steps of the study, you cannot be part of it.
  • Patients who are part of a vulnerable population that the study does not include cannot participate. Vulnerable populations might include groups like pregnant women or people with certain health conditions.
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Investigated drugs

KVD900 is an oral medication being studied for its ability to treat angioedema attacks in patients with hereditary angioedema (HAE) type I or II. It works by inhibiting plasma kallikrein, an enzyme involved in the process that leads to swelling during an angioedema attack. This trial aims to evaluate the long-term safety of using KVD900 for on-demand treatment, meaning it is taken when an attack occurs, rather than on a regular schedule.

What is already known about the treatment

KVD900 – KVD900 is an oral medication designed to treat hereditary angioedema (HAE) types I and II, a condition characterized by sudden swelling attacks. It is currently being studied in clinical trials to evaluate its long-term safety for on-demand use in adolescents and adults. The drug works by inhibiting plasma kallikrein, an enzyme involved in the production of bradykinin, which is responsible for the swelling in HAE. KVD900 belongs to the pharmacological class of kallikrein inhibitors, aiming to prevent or reduce the severity of angioedema attacks.

Investigated diseases

Hereditary Angioedema Type I or II – Hereditary Angioedema (HAE) is a genetic disorder characterized by recurrent episodes of severe swelling. This swelling can occur in various parts of the body, including the hands, feet, face, and airway, and can also affect the intestinal walls, leading to abdominal pain. Type I is the most common form and is caused by low levels of a protein called C1 inhibitor, while Type II is due to dysfunctional C1 inhibitor. These episodes of swelling can be triggered by stress, trauma, or even spontaneously without a clear cause. The condition is inherited in an autosomal dominant pattern, meaning a single copy of the altered gene in each cell is sufficient to cause the disorder. Symptoms typically begin in childhood or adolescence and can vary in frequency and severity among individuals.
Trial detailsLast updated 7 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2023-505904-41-00Protocol codeKVD900-302Estimated enrolment150 patientsSponsorKalvista Pharmaceuticals Limited

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