Omalizumab may benefit children with severe asthma, comorbid food allergy

Key takeaways:

• Mean serum total IgE levels began at 2,158 kU/L before increasing to 3,237 kU/L at 1 year and falling to 2,313 kU/L at year 2.
• All seven patients were desensitized to their food allergen at year 2.

Children with severe allergic asthma and serum total IgE levels between 1,500 kU/L and 3,300 kU/L as well as food allergy benefitted from omalizumab, according to a study published in Pediatric Allergy and Immunology.

Treatment did not lead to any severe adverse events, Giulio Dinardo, student, department of woman, child and general and specialized surgery, University of Campania Luigi Vanvitelli, and colleagues wrote.

Omalizumab (Xolair; Genentech, Novartis) is recommended for patients with asthma whose IgE levels do not exceed 1,500 kU/L, with adverse events reported for patients with higher totals, the researchers said.

Omalizumab may reduce levels of free circulating IgE and thereby increase the formation of immune complexes that may deposit in various tissues, cause inflammation and tissue damage, and induce serum sickness, the researchers said.

However, they continued, omalizumab also may remain effective in patients whose serum total IgE levels exceed 1,500 UI/L without significant side effects, based on postmarketing observational studies.

Between September 2019 and June 2021, seven patients (four males) aged 7 to 18 years (mean age, 145 ± 61 months) with severe persistent asthma due to perennial allergens and other atopic comorbidities were treated with omalizumab. All seven patients had total IgE levels exceeding 1,500 kU/L.

All seven patients experienced improvements in Asthma Control Test scores from baseline through 2 years, including increases of nine points for four patients, eight points for one patient and seven points for two patients.

FEV₁ percentages also improved from baseline to 2 years for all seven patients, including increases from 76% to 95%, 82% to 99%, 74% to 94%, 82% to 98%, 75% to 96%, 73% to 97% and 78% to 99%.

Four patients saw their use of fluticasone maintenance treatment fall from 400 µg per day to 200 mcg, and three saw their use of budesonide maintenance treatment fall from 840 mcg per day to 320 mcg per day as well.

None of the patients experienced any asthma exacerbations or needed emergency care during the 2-year follow-up, and no cases of severe adverse events or severe injection site reactions were reported either.

One patient developed a headache and fever 24 hours after receiving omalizumab, but the patient continued treatment with no further adverse events.

Mean serum total IgE levels included 2,158 kU/L (range, 1,699-3,307) before treatment, 3,237 kU/L (range, 1,657-5,614) during the first year and 2,313 kU/L (range, 945-3,771) during the second year.

Mean plasma creatinine values included 0.6 mg/dL (range, 0.33-0.81) at baseline, 0.63 mg/dL (range, 0.4-0.77) at year 1 and 0.62 mg/dL (range, 0.37-0.75) at year 2, indicating stability and safety in regard to renal function, the researchers said.

Mean estimated glomerular filtration rates included 112 mL/min/1.73 m² (range, 93-156) at baseline, 105 mL/min/1.73 m² (range, 90-132) at year 1 and 107 mL/min/1.73 m² (range, 90-142) at year 2, which the researchers classified as within the normal range and consistent with the patients’ growth during follow-up.

IgE-mediated food allergies included cow’s milk for five patients, egg for five patients, and peanut for two patients, with an initial mean threshold of reactivity of 21.72 mg ± 11.92 mg of food protein.

When patients experienced periods of sustained asthma control, they participated in oral food challenges. Mean thresholds of reactivity increased to 355 mg ± 3,195 mg at year 1 and 4,505 mg ± 3,117 mg of food protein at year 2.

Four of the patients with milk allergy and three of the patients with egg allergy achieved food desensitization at year 1, and all the patients had achieved food desensitization at year 2, based on their OFC results.

These OFC results confirm omalizumab’s potential for a protective effect and improved outcomes for patients with IgE-mediated food allergies, the researchers said, indicating possible applications for therapy beyond allergic asthma.

Overall, the researchers said, these findings indicate omalizumab’s potential for children with asthma whose serum total IgE levels exceed the current 1,500 kU/L cutoff, with desensitization possible for those who also have a comorbid food allergy as well.