The full prescribing information for Xolair ( Omalizumab ) includes a new boxed WARNING, updated Warnings, Precautions, and Adverse Reactions.
A New Medication Guide about the risk of anaphylaxis following administration of Xolair is to be distributed with each dose of Xolair. The treatment with Xolair is associated with risk of anaphylaxis.

Xolair is approved to treat adults and adolescents ( 12 years of age and above ) with moderate to severe persistent asthma who have a positive skin test or in vitro reactivity to a perennial aeroallergen and whose symptoms are inadequately controlled with inhaled corticosteroids.

Anaphylaxis, presenting as bronchospasm, hypotension, syncope, urticaria, and/or angioedema of the throat or tongue has been reported to occur after administration of Xolair.

Anaphylaxis has occurred as early as after the first dose of Xolair, but also has occurred beyond one year after beginning regular treatment with Xolair.
Due to the risk of anaphylaxis, Xolair should only be administered to patients in a healthcare setting under direct medical supervision.

Three cases of anaphylaxis were identified among the 3,507 subjects exposed to Xolair in premarketing clinical trials. Reports of anaphylaxis were based on investigator judgment in relationship to the study drug. The time to onset of anaphylaxis after administration of Xolair in these three patients was: 90 minutes in two patients, 2 hours in one patient.

In addition to these three cases, there were two cases of dyspnea and/or wheezing with urticaria that were not reported as anaphylaxis, but met the diagnostic criteria for anaphylaxis that were used to define the postmarketing cases. One of these patients developed localized urticaria, dyspnea, coughing, and wheezing after receiving the first dose of Xolair. The second patient experienced urticaria, dyspnea, and hot flushes the day after receiving the third dose of Xolair.

Based on a review of 124 spontaneous case reports and an estimated exposure of about 57,300 patients from June 2003 to December 2006, the frequency of anaphylaxis attributed to Xolair use was estimated to be at least 0.2% of treated patients. Because adverse reactions are reported voluntarily, the actual frequency of anaphylaxis and percent of patients with onset during specific time periods after administration of Xolair may differ from these estimates and this case series. The case definition of anaphylaxis used for this review included either skin or mucosal tissue involvement, and, either airway compromise, and/or reduced blood pressure with or without associated symptoms; and a temporal relationship with Xolair administration with no other identifiable cause.

Symptoms and signs of anaphylaxis in these reported cases included bronchospasm, hypotension, syncope, urticaria, angioedema of the throat or tongue, dyspnea, cough, chest tightness, cutaneous angioedema, and generalized pruritus. Some patients required Oxygen and parenteral medications. Pulmonary involvement, including bronchospasm, dyspnea, cough, or chest tightness, was reported in 89% of the cases. Hypotension or syncope was reported in 14% of cases. Fifteen percent of patients required hospitalization. A previous history of anaphylaxis unrelated to Xolair was reported in 24% of the cases.

Of the reported cases of anaphylaxis, 39% occurred after the first dose of Xolair, 19% occurred with the second dose, 10% occurred with the third dose, and the rest after subsequent doses. One case occurred after 39 doses ( after 19 months of continuous therapy, anaphylaxis occurred when treatment was restarted following a 3 month gap ). Twenty-three patients who experienced anaphylaxis were re-challenged with Xolair; among them, 18 had a recurrence of similar symptoms of anaphylaxis. Four patients who experienced urticaria and not anaphylaxis were re-challenged with Xolair and developed anaphylaxis upon re-challenge.

Source: FDA, 2007

XagenaMedicine2007


Link: Xapedia - Medical Encyclopedia