Study to Evaluate Safety and Efficacy of Benralizumab in Subjects With Hypereosinophilic Syndrome

Phase 2

Conditions: Hypereosinophilia
Anti-Asthmatic Agents
Hematologic Diseases
Respiratory System Agents
Leukocyte Disorders

Interventions: Other: Placebo
Drug: benralizumab

Registration Number: NCT02130882

Lead Sponsor: National Institute of Allergy and Infectious Diseases (NIAID)

Brief Summary: Background:

- Eosinophils are white blood cells that help fight infections. High eosinophil levels can damage people s organs, causing hypereosinophilic syndrome (HES). Researchers want to study if the drug benralizumab can help people with HES.

Objective:

- To test if benralizumab can safely decrease eosinophils in people with HES.

Eligibility:

- Adults age 18-65 who have been on stable HES therapy for at least 1 month but still have symptoms and high eosinophil levels.

Design:

* Participants will be screened with medical history, physical exam, and urine and blood tests. They will take simple heart and lung tests.

* Participants will also have a bone marrow biopsy. A numbing medicine is injected into the outer covering of the bone. Then a needle is inserted into the bone. A fast suction movement takes bone marrow cells.

* Phase 1: Participants will randomly receive either the study drug or placebo as an injection.

* They will have daily visits for the next 3 days, then 4 weekly visits, and then 4 biweekly visits. Each time, they will have medical history, physical exam, blood tests, and a check of side effects.

* They will receive another dose of the study drug or placebo at 1 month and 2 months after the first injection.

* Phase 2 repeats the Phase 1 schedule. All participants will receive the study drug.

* At 1 visit, participants will also receive a vaccine. At 4 visits, they will repeat the heart and lung tests. They will also have one other bone marrow biopsy.

* After week 24, participants will receive the study drug either 6 times over 6 months or twice over 6 months.

Detailed Description: Hypereosinophilic syndrome (HES) is a rare group of heterogeneous disorders characterized by marked peripheral eosinophilia (\>1500/(micro)L) and evidence of eosinophil-associated tissue damage. Although a high proportion of patients respond initially to corticosteroid therapy, high doses are often necessary to control the eosinophilia and clinical symptoms, and many patients become relatively refractory to therapy and/or develop serious side effects. IL-5 receptor alpha expression in humans is restricted to eosinophils, basophils, mast cells and their precursors and is, therefore, an ideal target for the therapy of HES. To date, there have been no safety concerns with benralizumab (anti-IL-5 receptor alpha) in phase 1, 2 and 3 trials in asthma and efficacy data is promising. In order to explore the safety and efficacy of benralizumab in the treatment of HES, 20 adults (men and non-pregnant women, 18-75 years of age) with HES who are symptomatic with absolute eosinophil count \>1000/(micro)L on stable HES therapy for at least 1 month will be recruited for this randomized, placebo-controlled, double-blind phase 2 trial. Benralizumab (30 mg) or placebo will be administered sc at weeks 0, 4, and 8. Eosinophil counts will be blinded for a subject and background HES therapy will not be tapered until that subject has been on study for 13 weeks. At weeks 12, 16, and 20, all subjects will receive a sc injection of benralizumab. Subjects demonstrating a response at the 24 week visit (eosinophil count \<1000/(alpha) L and stable or improved clinical symptoms without an increase in background HES therapy) will continue to receive additional 30 mg sc injections every 4 weeks. Following the initial dose of benralizumab or placebo and the first open-label dose of benralizumab, subjects will be followed daily for 3 days, weekly for 4 weeks, and every 2 weeks for 8 weeks. Subsequent visits will be at 4 weeks intervals for responders and 12 weeks intervals for non-responders for a minimum of two years. Subjects with stable and complete response for greater than or equal to 2 years may be eligible to receive benralizumab at a dosing interval of every 8 weeks. Subjects will receive diphtheria-tetanus-acellular pertussis (TdaP) booster immunization at the 22 week visit. Titers will be measured 6 weeks after immunization.The primary endpoint of the study is a 50% reduction in peripheral blood eosinophilia on stable background therapy at 12 weeks post-initiation of study drug. Secondary endpoints will include absolute eosinophil count, the frequency and severity of adverse events, reduction in signs and symptoms of HES, tissue eosinophilia, numbers of eosinophils, mast cells and their precursors in bone marrow, levels of markers of eosinophil and mast cell activation, eosinophil count and background HES therapy at 1 year, pharmacokinetics and anti-drug antibody (ADA) levels and eosinophil count after 24 weeks of every 8 week dosing. Exploratory endpoints will address predictors of response to benralizumab and the impact of eosinophil depletion on vaccine responses and glucose homeostasis. Subjects who complete the study and for whom benralizumab provides sustained clinical benefit, may be eligible to receive drug on an open-label extension protocol until regulatory approval and commercial availability of the marketed drug to prescribing physicians (for any indication), or until development of benralizumab is discontinued by MedImmune.

Recruitment & Eligibility

Status: UNKNOWN

Sex: All

Target Recruitment: 20

Inclusion Criteria

Not provided

Exclusion Criteria

Not provided

Study & Design

Study Type: INTERVENTIONAL

Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Placebo	Placebo	Placebo will be administered sc every 4 weeks for 3 doses (at weeks 0, 4 and 8). Eosinophil counts will be blinded during this time and background HES therapy will not be tapered.
Drug	benralizumab	Benralizumab (30mg) will be administered sc every 4 weeks for 3 doses (at weeks 0, 4 and 8). Eosinophil counts will be blinded during this time and background hypereosinophilic syndrome (HES) therapy will not be tapered.

Primary Outcome Measures

Name	Time	Method
Number of Participants With 50% Reduction in Peripheral Blood Eosinophilia	3 months	50% reduction in peripheral blood eosinophilia on stable HES background therapy at 12 weeks post-initiation of study drug

Secondary Outcome Measures