Participants will receive up to 3 years treatment with ligelizumab after which they will enter a follow-up period for 16 weeks. During the study, participants will undergo allergy testing by a Skin Prick Test and Oral Food challenge to test if the treatment is working or not. Accordingly, this study will generate data that should provide guidance relative to the long-term (chronic) use of ligelizumab in food allergic patients in terms of safety, efficacy, pharmaco-dynamics, biomarkers and Qualify of Life, and potential discontinuation from treatment.~During the study, treatment will be administered every 4 weeks and while this can take place in the hospital clinic, some participants will be trained to administer study treatment at home by either the participant or parent/caregiver. Participants at home will record administration of the study treatment on a dosing log and return this to the clinic for review.
This is an extension study to evaluate the long-term safety and efficacy of ligelizumab in particiants who have completed a ligelizumab Phase III study in food allergy.