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The Effect of Omalizumab on Responses to Cat Allergen Challenge

Pilot Study of the Effect of Omalizumab on Basophil and Mast Responses to Intranasal Cat Allergen Challenge

Status
Completed
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT00604786
Enrollment
18
Registered
2008-01-30
Start date
2007-07-31
Completion date
2009-01-31
Last updated
2017-05-10

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Allergic Rhinitis

Keywords

Basophils, Mast Cells, IgE, IgE receptors, omalizumab

Brief summary

This research is being done to study the effects of the drug omalizumab (Xolair) in people with cat allergies. The investigators will use omalizumab to study changes in the cells in the nose, skin and blood that cause allergies. The investigators predict that cells in the blood will be effected before cells in the nose or skin.

Detailed description

Omalizumab is a monoclonal antibody directed against Immunoglobulin E (IgE) and is FDA-approved for use in allergic asthma, though its clinical role is not precisely defined. It binds IgE on the same site of the Fc domain as the high affinity IgE receptor (FcεRI), and therefore, blocks the interaction between IgE and mast cells or basophils. It, therefore, may be used as a mechanistic tool in the study of IgE. As IgE levels are reduced with omalizumab, FcεRI expression on human basophils is reduced. This reduction of basophil receptors and allergen induced activation is pronounced within 7 days of the initial administration and is reversible once omalizumab administration is discontinued. The omalizumab-induced reductions in mast cell FcεRI expression and function is unchanged at day 7 and significantly reduced by day 70. These changes were based upon intravenously administered omalizumab at a dose of 0.03 mg/kg/IU IgE/mL in a total of three subjects. We propose to exploit the kinetics of faster omalizumab effects on circulating basophils relative to tissue mast cells to elucidate the role of the basophil versus mast cell activation in nasal airway allergen challenge, which has not been studied to date.

Interventions

DRUGomalizumab

Dosing is based on IgE level and weight given every 2 or 4 weeks

DRUGplacebo

Dosing is based on IgE level and weight given every 2 or 4 weeks

Sponsors

National Institute of Allergy and Infectious Diseases (NIAID)
CollaboratorNIH
Johns Hopkins University
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
BASIC_SCIENCE
Masking
DOUBLE (Subject, Investigator)

Eligibility

Sex/Gender
ALL
Age
18 Years to 50 Years
Healthy volunteers
No

Inclusion criteria

* Ability to understand and provide informed consent * Male or Female (non-pregnant), age 18-50 * Females must be: Surgically sterile (hysterectomy, bilateral oophorectomy, bilateral tubal ligation), OR postmenopausal (at least 1 year since last menses), OR using a medically acceptable form of birth control throughout the duration of the study. * Clinical history of seasonal or perennial allergic rhinitis for at least two years, with or without mild persistent asthma * Positive puncture skin test greater than or equal to 5 mm diluent control * Positive Immunocap to Fel d 1 \> 0.35 kallikrein unit/L * Positive intranasal cat allergen challenge as defined by \> 5 sneezes or a tripling of measured nasal lavage mediators * In vitro assay of basophil responsiveness to cat allergen with greater than 20% histamine release * The use of antihistamines, cromolyn, leukotriene modifiers and other non-steroid (astelin and topical decongestants), nasal medications will be allowed, but they will be withheld for 5 days prior to each nasal allergen provocation session. Inhaled corticosteroids for mild asthma will be permissible. * No known contraindications to therapy with omalizumab

Exclusion criteria

* Asthma with forced expiratory volume at one second (FEV1) \< 80%, moderate to severe asthma classification per National Asthma Education and Prevention Program Expert Panel (NAEP) Standards (1997 National Asthma Education and Prevention Program Expert Panel Report II guidelines) * Serum IgE levels less than 30 IU/mL or greater than 700 IU/mL at the time of enrollment will be excluded * Unexplained elevation of erythrocyte sedimentation rate (ESR), hematocrit \< 32%, white blood cell (WBC) count 2400/microliter lower limit of normal, platelet \< 75000/microliter, creatinine \> 141.4 micromolar/L, or aspartate aminotransferase (AST) \> 100 IU/L * Body weight less than 30 kg or greater than 150 kg will be excluded. * Plans to become pregnant or breastfeed will be excluded from the study * A perforated nasal septum, structural nasal defect, large nasal polyps causing obstruction, evidence of acute or chronic sinusitis * A life expectancy less than 6 months * A terminal illness as determined by the investigator * A history of malignancy, anaphylaxis or bleeding disorder are also exclusion illnesses. * Mental illness or history of drug or alcohol abuse that, in the opinion of the investigator, would interfere with the participant's ability to comply with study requirements. * Inability or unwillingness of a participant to give written informed consent or comply with study protocol * Use of any investigational drugs within 8 weeks of participation * Contraindications to omalizumab include patients with a previous hypersensitivity to omalizumab * Recent recipient of any licensed or investigational live attenuated vaccine(s) within two months of study initiation such as flu mist. * Prior use of omalizumab * Frequent sinusitis (\>2/ documented episodes per year) or active sinusitis within 2 weeks of enrollment * Use of immunotherapy within the last 5 years

Design outcomes

Primary

MeasureTime frameDescription
Change in Basophil Surface IgEChange from baseline to 3.5 monthsFlow cytometry in mean fluorescence units. 100%\*\[(3.5 month value minus baseline value)/baseline value\]

Countries

United States

Participant flow

Participants by arm

ArmCount
Active Treatment
This arm will receive treatment with omalizumab at the dose FDA-approved for the treatment of allergic asthma. omalizumab: IgE 30-100 int. units/mL: 30-90 kg: 150 mg every 4 weeks \>90-150 kg: 300 mg every 4 weeks IgE \>100-200 int. units/mL: 30-90 kg: 300 mg every 4 weeks \>90-150 kg: 225 mg every 2 weeks IgE \>200-300 int. units/mL: 30-60 kg: 300 mg every 4 weeks \>60-90 kg: 225 mg every 2 weeks \>90-150 kg: 300 mg every 2 weeks IgE \>300-400 int. units/mL: 30-70 kg: 225 mg every 2 weeks \>70-90 kg: 300 mg every 2 weeks \>90 kg: Do not administer dose IgE \>400-500 int. units/mL: 30-70 kg: 300 mg every 2 weeks \>70-90 kg: 375 mg every 2 weeks \>90 kg: Do not administer dose IgE \>500-600 int. units/mL: 30-60 kg: 300 mg every 2 weeks \>60-70 kg: 375 mg every 2 weeks \>70 kg: Do not administer dose IgE \>600-700 int. units/mL: 30-60 kg: 375 mg every 2 weeks \>60 kg: Do not administer dose
14
Placebo
placebo: IgE 30-100 int. units/mL: 30-90 kg: placebo every 4 weeks \>90-150 kg: placebo every 4 weeks IgE \>100-200 int. units/mL: 30-90 kg: placebo every 4 weeks \>90-150 kg: placebo every 2 weeks IgE \>200-300 int. units/mL: 30-60 kg: placebo every 4 weeks \>60-90 kg: placebo every 2 weeks \>90-150 kg: placebo every 2 weeks IgE \>300-400 int. units/mL: 30-70 kg: placebo every 2 weeks \>70-90 kg: placebo every 2 weeks \>90 kg: Do not administer dose IgE \>400-500 int. units/mL: 30-70 kg: placebo every 2 weeks \>70-90 kg: placebo every 2 weeks \>90 kg: Do not administer dose IgE \>500-600 int. units/mL: 30-60 kg: placebo every 2 weeks \>60-70 kg: placebo every 2 weeks \>70 kg: Do not administer dose IgE \>600-700 int. units/mL: 30-60 kg: placebo every 2 weeks \>60 kg: Do not administer dose
4
Total18

Withdrawals & dropouts

PeriodReasonFG000FG001
Overall StudyLost to Follow-up20

Baseline characteristics

CharacteristicPlaceboActive TreatmentTotal
Age, Categorical
<=18 years
0 Participants0 Participants0 Participants
Age, Categorical
>=65 years
0 Participants0 Participants0 Participants
Age, Categorical
Between 18 and 65 years
4 Participants14 Participants18 Participants
Age, Continuous32.3 years30.6 years31 years
Region of Enrollment
United States
4 participants14 participants18 participants
Sex: Female, Male
Female
3 Participants9 Participants12 Participants
Sex: Female, Male
Male
1 Participants5 Participants6 Participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
deaths
Total, all-cause mortality
— / —— / —
other
Total, other adverse events
2 / 140 / 4
serious
Total, serious adverse events
0 / 140 / 4

Outcome results

Primary

Change in Basophil Surface IgE

Flow cytometry in mean fluorescence units. 100%\*\[(3.5 month value minus baseline value)/baseline value\]

Time frame: Change from baseline to 3.5 months

Population: 2 participants on the Omalizumab subcutaneous group moved and were therefore lost to follow-up.

ArmMeasureValue (MEAN)Dispersion
Omalizumab SubcutaneousChange in Basophil Surface IgE-95 percentage of basophil surface IgEStandard Deviation 3
Placebo SubcutaneousChange in Basophil Surface IgE-10 percentage of basophil surface IgEStandard Deviation 4

Source: ClinicalTrials.gov · Data processed: Mar 29, 2026