Ongoing Clinical Trials for Hypereosinophilic Syndrome
Currently, there are 4 clinical trials investigating new treatments for Hypereosinophilic Syndrome, a rare blood disorder characterized by abnormally high levels of eosinophils. These trials are testing three different investigational medications—depemokimab, mepolizumab, and benralizumab—across multiple European countries including Germany, Italy, Spain, Poland, France, Belgium, Netherlands, Denmark, Austria, Greece, Czechia, and Romania.
Clinical trial locations
- Austria
- Belgium
- Czechia
- Denmark
- France
- Germany
- Greece
- Italy
- Netherlands
- Poland
- Romania
- Spain
A Study of Depemokimab and Prednisolone in Adults with Hypereosinophilic Syndrome (HES)
This trial is investigating depemokimab, a new investigational medication given as an injection under the skin, in combination with standard treatments for adults with Hypereosinophilic Syndrome. The study aims to determine whether depemokimab can effectively control the condition and prevent disease flares when compared to placebo.
Inclusion criteria: Participants must be at least 18 years old and weigh at least 40 kilograms. They must have a confirmed diagnosis with blood tests showing more than 1,500 eosinophils per microliter on at least two occasions, taken at least one month apart, along with signs of organ problems related to high eosinophil levels. Participants must have experienced at least 2 disease flares in the past 12 months, where symptoms worsened or eosinophil counts increased requiring stronger treatment. Women of childbearing potential must use highly effective birth control and must not be pregnant or breastfeeding.
Exclusion criteria: The trial excludes people with current parasitic infections, a history of cancer within the past 5 years (except certain skin cancers or cervical cancer in situ), active infections requiring treatment, severe allergic reactions to biological medications, significant heart conditions, severe liver or kidney disease, recent substance abuse, or mental health conditions that could interfere with study participation.
Study focus: The trial will last 52 weeks, during which participants will receive either depemokimab or placebo injections while continuing their standard care medications. The medical team will monitor for HES flares, track blood eosinophil levels, assess fatigue using questionnaires, and evaluate overall health throughout the study period.
Investigational drug: Depemokimab is a novel biological medication administered through subcutaneous injections that works by modulating specific components of the immune system to reduce elevated levels of eosinophils. It is being studied as an add-on therapy to standard treatments.
Access to Mepolizumab for Patients with Hypereosinophilic Syndrome
This expanded access program provides mepolizumab treatment to patients with Hypereosinophilic Syndrome who have a significant medical need and for whom the potential benefits of treatment outweigh the risks. Mepolizumab is administered as a solution for injection under the skin and is designed to reduce the number of eosinophils in the body.
Inclusion criteria: Participants must be at least 12 years old and provide written informed consent. They must have a diagnosis of Hypereosinophilic Syndrome, meaning a high eosinophil count (more than 1,500 cells per microliter) for at least 6 months along with symptoms affecting organs, with no other known causes. For those with high eosinophil counts for less than 6 months, there must be clear signs of eosinophils affecting tissues. The condition must be serious or life-threatening, there must be no other good treatment options (meaning at least three standard treatments were tried without success), and there must be a belief that the benefits outweigh the risks.
Exclusion criteria: There are no specific exclusion criteria listed for this trial.
Study focus: The program provides access to mepolizumab with monitoring of the patient’s response to treatment and any side effects. The investigator determines the dosage and frequency of administration based on clinical judgment and the patient’s specific needs. The focus is on assessing serious and non-serious adverse events related to the medication.
Investigational drug: Mepolizumab works by targeting and blocking interleukin-5, a protein that plays a key role in the growth and activity of eosinophils, thereby reducing their numbers and activity. It is classified as a monoclonal antibody with anti-inflammatory effects.
Study of benralizumab compared to placebo for treatment of patients with Hypereosinophilic Syndrome (HES)
This study tests benralizumab, a medication given as an injection under the skin using a pre-filled syringe, to see if it can help control symptoms and prevent disease flares in patients with Hypereosinophilic Syndrome. The research compares benralizumab to placebo over 24 weeks, with an opportunity to continue in an open-label extension phase where all participants receive the active medication.
Inclusion criteria: Participants must be at least 12 years old and have a confirmed diagnosis with blood tests showing high eosinophil levels (more than 1,500 cells/μL) on two separate occasions at least one month apart, along with evidence of organ problems. They must test negative for the FIP1L1-PDGFRA genetic mutation, be on stable treatment for at least 4 weeks before the first study visit, and have either current signs of worsening or a history of at least 2 flares in the past 12 months requiring increased treatment. The eosinophil count must be at least 1,000 cells/μL at the first visit, and participants must respond to corticosteroid treatment. Women of childbearing potential must use effective birth control and have a negative pregnancy test.
Exclusion criteria: The trial excludes those under 12 years old, people with known allergic reactions to benralizumab or similar medications, pregnant or breastfeeding women, those with active or untreated parasitic infections, recent participation in other clinical trials, severe liver or kidney disease, active cancer or ongoing cancer treatment, uncontrolled heart conditions, severe allergic reaction history, recent major surgery, active infections requiring antibiotics, use of other biological treatments in the past 4 months, mental conditions interfering with study procedures, and drug or alcohol abuse within the past year.
Study focus: The trial monitors participants for signs of disease worsening or flares over 24 weeks. Regular blood tests measure eosinophil counts, fatigue levels are assessed using standardized questionnaires, and overall health and quality of life are evaluated. Safety monitoring includes checks of vital signs and laboratory tests throughout the study.
Investigational drug: Benralizumab is a biological medication that targets and binds to the interleukin-5 receptor on eosinophils, leading to their reduction in the bloodstream. It represents a targeted therapeutic approach offering a treatment option by modulating the immune system’s response and reducing inflammation caused by elevated eosinophil levels.
Study on Mepolizumab for Children and Teens with Hypereosinophilic Syndrome
This clinical trial evaluates the effectiveness and safety of mepolizumab specifically for children and teenagers aged 6 to 17 years with Hypereosinophilic Syndrome. The medication is given as an injection under the skin every four weeks over a period of 52 weeks.
Inclusion criteria: Participants must be between 6 and 17 years old and have been diagnosed with Hypereosinophilic Syndrome for at least 6 months. They must have experienced 2 or more disease flares in the past 12 months and have a blood eosinophil count of 1,000 cells per microliter or more at the start of the study. Participants must be on a stable dose of treatment for 4 weeks before the first dose of study medication. Female participants who can have children must use acceptable contraception during the study and for 16 weeks after the last dose, and a pregnancy test is required. Written consent from a legal guardian is required, along with the participant’s agreement if able to understand and sign. A legal guardian or primary caregiver must be available to help with study visits and provide information.
Exclusion criteria: The trial excludes participants who are not between 6 to 17 years old, those who do not have Hypereosinophilic Syndrome, those unable to receive injections under the skin every 4 weeks, those unable to follow study procedures or attend required visits, and those with any other medical condition that might interfere with the study or pose a health risk.
Study focus: The study monitors the frequency of disease flare-ups throughout the 52-week treatment period. It tracks changes in the use of other medications, particularly oral corticosteroids, with a focus on reducing dosage over time. Fatigue levels are assessed using specific questionnaires, and blood tests monitor eosinophil levels and other health indicators at regular follow-up visits every 4 weeks.
Investigational drug: Mepolizumab works by targeting and inhibiting interleukin-5, a protein that plays a key role in the growth and activation of eosinophils. It is classified as a monoclonal antibody and is used to reduce the number of eosinophils in the blood, thereby alleviating symptoms.
Summary
The four ongoing clinical trials for Hypereosinophilic Syndrome demonstrate a focused effort to develop targeted biological therapies for this rare blood disorder. Three distinct investigational medications are being tested: depemokimab, mepolizumab, and benralizumab, all administered as subcutaneous injections and all working through similar mechanisms to reduce elevated eosinophil levels.
Geographically, the trials show broad European coverage, with Poland, Spain, Belgium, Germany, Italy, and Denmark each hosting multiple studies. This distribution provides opportunities for patients across many countries to access these investigational treatments. Notably, one trial specifically focuses on children and teenagers aged 6 to 17 years, addressing the need for pediatric treatment options.
All trials share common inclusion requirements, including confirmed diagnosis with elevated eosinophil counts and a history of disease flares. The studies typically exclude patients with active infections, parasitic infections, severe organ disease, or recent cancer. Treatment durations range from 24 to 52 weeks, with some trials offering open-label extension phases where all participants receive active medication after the initial blinded period.
One notable program provides expanded access to mepolizumab for patients with significant medical need who have exhausted other treatment options, offering an alternative pathway to treatment outside of traditional clinical trials. This compassionate use program operates in Poland and reflects the urgent need for effective therapies in this patient population.
