The Effect of Omalizumab on Responses to Cat Allergen Challenge

Allergic Rhinitis Clinical Trial

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

Status Completed

Clinical Trial 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.

Clinical Trial 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. ;

Related Conditions & MeSH terms

• Allergic Rhinitis
• Rhinitis
• Rhinitis, Allergic

• NCT number: NCT00604786
• Study type: Interventional
• Source: Johns Hopkins University
• Status: Completed
• Phase: N/A
• Start date: July 2007
• Completion date: January 2009