A Randomized, Double-Blind, Placebo-Controlled Study of Omalizumab for Idiopathic Anaphylaxis



Status:Active, not recruiting
Conditions:Skin and Soft Tissue Infections, Cardiology, Hospital, Pulmonary
Therapuetic Areas:Cardiology / Vascular Diseases, Dermatology / Plastic Surgery, Pulmonary / Respiratory Diseases, Other
Healthy:No
Age Range:18 - 70
Updated:9/9/2018
Start Date:April 27, 2009
End Date:May 31, 2019

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A Randomized Double-Blinded, Placebo-Controlled Study of Omalizumab for Idiopathic Anaphylaxis

Background:

- Omalizumab is an approved drug for the treatment of asthma by the Food and Drug
Administration.

- Researchers are now studying this drug in a double-blind placebo-controlled manner to
assess efficacy in patients with idiopathic anaphylaxis (recurrent hypersensitive
allergic episodes for which a cause is not identified).

- The study will improve understanding of the mechanisms involved in anaphylactic
reactions as a response to the downregulation (a decrease in the number of receptors on
the surface of cells) in mast cell (a resident cell with several types of tissues)
activation, and lead to the development of strategies to better prevent or treat
anaphylaxis.

Objectives:

- To determine whether treatment with omalizumab will reduce or prevent episodes of
unprovoked anaphylaxis (an acute allergic reaction) in subjects with a history of
idiopathic anaphylaxis.

- To assess pharmacodynamics (physiological effects of a drug) and identify patients with
undiagnosed mastocytosis (rare disorders caused by too many mast cells).

- To investigate cellular and molecular mechanisms of signaling and the effect of
omalizumab on mast cells or basophils (a cell in the leukocyte family that releases
histamine, which affects allergic response) and explore other regulatory pathways that
may be involved with modulation of mast cell degranulation.

Eligibility:

- Patients between 18 and 70 years of age who have been diagnosed with idiopathic
anaphylaxis, a diagnosis that is made only after other causes of anaphylaxis have been
considered.

- Patients with documented anaphylaxis episodes (mild to severe) at least six times within
the past 1 year period, at least once within the last 4 months, and with at least one of
the following:

- Elevated serum tryptase above baseline within 2 hours of the event.

- Emergency room visit with documented anaphylaxis without a known cause established
by the acute onset of an illness (minutes to several hours) with involvement of the
skin, mucosal tissue, or both (generalized hives, itching or flushing, swollen
lips-tongue-throat) and at least one of the following: (1) respiratory compromise
or gastrointestinal involvement (shortness of breath, wheeze-bronchospasm, throat
tightness, low oxygen levels, nausea, vomiting, or abdominal pain); or (2) reduced
blood pressure or associated symptoms of end-organ dysfunction (collapse, loss of
consciousness, or loss of bladder or bowel control).

- Hospitalization for anaphylaxis.

- Patients must provide a letter of referral, with copies of pertinent medical history and
laboratory tests, from the prospective participant s local physician, and have the
ability to give informed consent.

- Women with childbearing potential must have a negative pregnancy test, and must agree to
practice abstinence or effective birth control from the start of the protocol and for 3
months following the last injection of the study drug.

Design:

- Participants will undergo a clinical evaluation, blood tests, and a bone marrow biopsy
and aspirate.

- Participants will be randomized to either drug or placebo and will receive two doses of
omalizumab or a matched placebo while hospitalized, followed by continued outpatient
therapy, every 2 to 4 weeks, for up to 6 months.

- Participants will remain on the assigned regimen for 6 months or until they have
experienced new onset of severe adverse event on one occasion within 24 hours of study
medication that are related to the study drug, whichever comes first. At that time, the
participant will be discontinued from drug administration.

Anaphylaxis is a severe systemic reaction caused by release of mediators from mast cells and
basophils. Manifestations include cutaneous, respiratory, cardiovascular, or gastrointestinal
signs and symptoms. Although anaphylaxis is frequently attributed to exposure to specific
foods, drugs, and insect venoms in sensitive individuals, a causative factor is not
identified in 30% to 50% of patients with recurrent anaphylactic episodes (idiopathic
anaphylaxis).

Currently, therapeutic options for the treatment of idiopathic anaphylaxis are limited with
variable efficacy. This pilot study will examine the hypothesis that omalizumab (Xolair )
will decrease episodes of unexplained anaphylaxis in patients with idiopathic anaphylaxis.
Omalizumab is approved for use in asthma. We will examine the safety profile and efficacy of
omalizumab in patients with anaphylaxis. In addition, the study will investigate whether
patients with anaphylaxis have unique molecular and cellular defects in mast cells that
result in these cells being more susceptible to degranulation.

The study will enroll patients with idiopathic anaphylaxis. Patients will undergo a clinical
evaluation, blood tests, and a bone marrow biopsy and aspirate. Patients will be randomized
to either drug or placebo and will receive, in a double-blind placebo-controlled approach, 2
doses of omalizumab or a matched placebo while hospitalized, followed by continued outpatient
therapy, every 2 to 4 weeks, for up to 6 months. Patients will remain on the assigned regimen
if they have experienced anaphylactic events (post 24-hr window) determined to be unrelated
to study drug or have been followed for 6 months, whichever comes first. These unrelated
events would be determined by the PI not to jeopardize patient safety or restrict the use of
additional therapy such as corticosteroids to control symptoms. After this point, the patient
may be discontinued from drug administration until unblinding. This design ensures that no
patient will have anaphylactic episodes while on placebo if other therapy is medically
indicated. Research studies will be conducted to elucidate other markers or pathways of mast
cell regulation.

The primary outcome will be a reduction in the number and timing of anaphylactic events
during the randomized phase. Secondary outcomes will include a reduction in surface IgE
receptors on basophils, identification of mutations in c-kit, and evaluation of the efficacy
of omalizumab on other mediator-induced symptoms associated with anaphylaxis. The study will
improve the understanding of the mechanisms involved in anaphylactic reactions as a response
to the downregulation of mechanisms involved in mast cell activation that could, in turn,
lead to development of strategies to better prevent or treat anaphylaxis.

- INCLUSION CRITERIA:

Volunteers must satisfy all of the following inclusion criteria to be eligible for this
study.

Subject must be at least 18 years of age and no older than 70 years of age.

Diagnosis of idiopathic anaphylaxis, a diagnosis of exclusion, assigned after other causes
of anaphylaxis and other diseases in the differential diagnoses have been considered.

Anaphylaxis episodes (mild-severe) at least 6 times within the past 1 year period,
documented according to medical records physician report, or patient report and 1 episode
within the last 4 months, and with at least 1 of the following:

1. Elevated serum tryptase above baseline within 2 hours of the event.

2. Emergency room visit with documented anaphylaxis without an etiology established by
the acute onset of an illness (minutes to several hours) with involvement of the skin,
mucosal tissue, or both (e.g., generalized hives, pruritus or flushing, swollen
lips-tongue-uvula) [Grade 1]* and at least 1 of the following:

1. Respiratory compromise or gastrointestinal involvement (e.g., dyspnea,
wheeze-bronchospasm, stridor, reduced peak expiratory flow, hypoxemia, nausea,
vomiting, or abdominal pain [Grade 2]*).

2. Reduced blood pressure or associated symptoms of end-organ dysfunction (e.g.,
hypotonia [collapse], syncope, or incontinence [Grade 3]*).

3. Hospitalization for anaphylaxis: hospital records with documented anaphylaxis without
known cause established by the acute onset of an illness (minutes to several hours)
with involvement of the skin, mucosal tissue, or both (e.g., generalized hives,
pruritus or flushing, swollen lips-tongue-uvula) [Grade 1]*) and at least one of the
following:

1. Respiratory compromise or gastrointestinal involvement (e.g., dyspnea,
wheeze-bronchospasm, stridor, reduced peak expiratory flow, hypoxemia, nausea,
vomiting, or abdominal pain [Grade 2]*).

2. Reduced blood pressure or associated symptoms of end-organ dysfunction (e.g.,
hypotonia [collapse], syncope, or incontinence [Grade 3]*).

4. Letter of referral, with copies of pertinent medical history and laboratory tests,
from prospective study participant s local physician.

5. Ability to give informed consent.

6. Women of childbearing potential must have a negative beta-HCG serum or urine pregnancy
test prior to each injection, and must agree to practice abstinence or effective
contraception from initiation of the protocol and for 3 months following the last
infusion of the study agent (effective contraception methods include abstinence;
surgical sterilization of either partner, barrier methods such as diaphragm, condom,
cap, or sponge; or hormonal contraception).

- Severity grading of anaphylaxis

EXCLUSION CRITERIA:

A volunteer who satisfies any of the following exclusion criteria will be ineligible to
participate in this study.

1. Presence of conditions which, in the judgment of the investigator or the referring
physician, may put the subject at undue risk for study participation or travel (such
as an acute infection, severe thrombocytopenia, coronary artery disease, uncontrolled
hypertension, congestive heart failure, chronic beta blocker therapy such as atenolol
or metoprolol, or myeloproliferative disease).

2. History of malignancy

3. Known cause for anaphylaxis or flushing

4. Diagnosis of mastocytosis

5. Inability to provide informed consent

6. Inability or refusal to undergo a bone marrow biopsy and aspirate

7. HIV positive or other known immunodeficiency

8. Active or chronic hepatitis

9. Use of any other investigational agent within 30 days of the study

10. Current use of chronic-oral corticosteroids or other immunosuppressant medications

11. Pregnant or nursing women

12. Positive pregnancy test

13. IgE levels and subject s weight that cause dosing to be above dosing guidelines.
We found this trial at
1
site
9000 Rockville Pike
Bethesda, Maryland 20892
Phone: 800-411-1222
?
mi
from
Bethesda, MD
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