D2.465 - Omalizumab Enhances Safety and Supports Completion of Oral Immunotherapy in High-Risk Patients

Omalizumab, an anti-IgE monoclonal antibody, may enhance the safety of oral immunotherapy (OIT) and facilitate reaching the target maintenance dose. This study aimed to evaluate the safety of OIT combined with omalizumab and the success of achieving full milk dose in high-risk children with cow’s milk protein allergy (CMPA).

Six children diagnosed with CMPA, with a history of milk-induced anaphylaxis and high milk- and casein-specific IgE levels, were included. Omalizumab was initiated prior to OIT and continued throughout treatment. OIT was administered in a stepwise manner with incremental milk doses, aiming for a target maintenance dose of 200 mL per day. Dose escalations were performed in the hospital, while maintenance doses were given at home.

The median age at CMPA diagnosis was 6 months (25–75p: 3.8–6), and the median age at OIT initiation was 4.9 years (25–75p: 4.3–6.6). All patients had coexisting food and/or inhalant allergies. Pre-omalizumab median milk- and casein-specific IgE levels were 82.8 kU/L (25–75p: 52.1–100) and 42.8 kU/L (25–75p: 22.9–100), respectively. All patients had a history of milk-induced anaphylaxis. Omalizumab (150 mg) was administered biweekly for eight doses, and OIT was started with the ninth dose. During the initial escalation phase, patients were monitored in the hospital and reached 49 mL of milk over 20 days. Subsequently, doses were increased by 15–20% every two weeks in the hospital, with continued biweekly omalizumab. All patients reached the target maintenance dose of 200 mL milk. The median time from OIT initiation to target dose was 4.1 months (25–75p: 4.0–4.6). Two-weekly increments of yogurt, cheese, and ice cream were then added. After a median of 5.6 months (25–75p: 5.5–6.1) from OIT initiation, patients transitioned to a free diet while maintaining daily 200 mL milk intake. No allergic reactions or clinically significant adverse events occurred during dose escalation or maintenance.

Milk OIT is an established treatment; however, its use in children with severe and multiple food allergies is often limited by safety concerns. Our study demonstrates that OIT combined with omalizumab enables high-risk children to rapidly reach the full milk dose without allergic reactions during escalation or maintenance, providing a safer and more predictable treatment process for both clinicians and patients.