Omalizumab Linked to 0 Epinephrine Use in Alpha-Gal Syndrome

Among 64 patients with alpha-gal syndrome (AGS) treated with omalizumab (Xolair), none required epinephrine for a food-triggered reaction during therapy, according to a retrospective cohort analysis presented at the American College of Allergy, Asthma and Immunology (ACAAI) 2026 Annual Scientific Meeting in Phoenix, Arizona.¹

Despite strict avoidance of mammalian-derived foods and products, patients with AGS remain vulnerable to accidental exposures and recurrent anaphylaxis requiring epinephrine.¹ Real-world evidence on how omalizumab, an anti-immunoglobulin E (IgE) monoclonal antibody, affects severe allergic outcomes in this population has been limited.¹

“These findings suggest that omalizumab may offer an additional layer of protection for patients living with alpha-gal syndrome,” said Collette Tilly, MD, lead author of the study and allergy & immunology fellow-in-training at the University of North Carolina at Chapel Hill, in a statement.

Omalizumab Efficacy in Alpha-Gal Syndrome: Epinephrine Use and Anaphylaxis Burden

Tilly and colleagues conducted a retrospective cohort analysis of 64 patients with confirmed AGS treated with omalizumab between April 2022 and November 2025.¹ Inclusion required a compatible clinical history, positive alpha-gal-specific IgE, and at least 3 months of follow-up. The primary endpoint was food-related epinephrine utilization during therapy.¹

The median patient age was 55 years (range, 20-89 years), and 56% of patients were female.¹ The cohort carried substantial baseline risk: 81% had documented anaphylaxis, and 53% had required epinephrine before starting omalizumab.¹

Across a median treatment duration of 23 months (range, 3-83 months), no patients required epinephrine for a food-triggered reaction.¹ The investigators described the finding as complete elimination of food-related epinephrine utilization in a high-risk cohort with substantial baseline anaphylaxis.¹

Mammalian Product Reintroduction and Omalizumab Safety in AGS

Nearly all patients reported benefit on the secondary outcome of reaction burden. A patient-defined, clinically meaningful reduction in reaction frequency or severity was reported by 95% of the cohort.¹

Reintroduction of mammalian foods and/or products was achieved in 31% of patients. This included full reintroduction in 13% and partial reintroduction in 19%.¹

Adverse events were infrequent and predominantly mild, with arthralgias reported most commonly. Only 3% of patients discontinued omalizumab because of adverse events, and the investigators characterized the agent’s tolerability as favorable.¹

Omalizumab is produced in Chinese hamster ovary cells, which may variably express alpha-gal.3 Prior HCPLive coverage noted this creates a theoretical anaphylaxis risk warranting appropriate precautions at initiation in patients with AGS.

References

1. Tilly C, Commins S. Omalizumab eliminates epinephrine use and reduces anaphylaxis burden in alpha-gal syndrome. Abstract A025. Presented at: American College of Allergy, Asthma and Immunology 2026 Annual Scientific Meeting; November 12-16, 2026; Phoenix, AZ.

2. Patients with meat allergy who take omalizumab may see improvement of symptoms. American College of Allergy, Asthma and Immunology. Published November 12, 2026. Accessed November 13, 2026. https://annualmeeting.acaai.org/patients-meat-allergy.cfm?utm_source=Registrants&utm_campaign=3937e8f549-EMAIL_CAMPAIGN_2020_11_03_09_12_COPY_01&utm_medium=email&utm_term=0_bfcb93257f-3937e8f549-142668538

3. Alpha-gal syndrome: closing an underrecognized allergy diagnostic gap. HCPLive. https://www.hcplive.com/view/alpha-gal-syndrome-closing-underrecognized-allergy-diagnostic-gap. Published September 4, 2026. Accessed November 13, 2026.