Key Inclusion Criteria:

1. Signed informed consent form (ICF) and assent form (where applicable) obtained from the participant/legal representative before study participation. If a minor participant reaches the age of legal majority (as defined by local law), they must be re-consented at the next study visit
2. Participants have completed the treatment period in any ligelizumab Phase III studies in food allergy
3. Participants who are willing to adhere to the study visits and procedures, including receiving injections (study treatment) and participating in the OL-OFC (open label oral food challenge)
4. Participants who agree to continue avoiding exposure to allergens (per core study) and any other foods they are allergic to throughout this study
5. Participants who are able to safely continue into the study as judged by the investigator

Key Exclusion Criteria:

1. Development of a severe or life-threatening episode of an allergic reaction that required intubation and/or ICU admission during the core studies
2. Development of a serious adverse event which is suspected to be related to the study treatment judged by the investigator during the core study
3. Development of uncontrolled asthma during the core study that could compromise the safety of the participants judged by the investigator
4. Development of clinically significant cardiovascular, neurological, and or psychiatric conditions during the core study that could interfere with or compromise the safety of the participants, interfere with evaluation or interpretation of the study results or preclude completion of the study judged by the investigator
5. Participants who failed to comply with the protocol requirements and procedures during the core study, and in the Investigator's opinion they should not participate in this extension study
6. Platelets <75,000/ul at end of treatment of the core study

Other protocol defined inclusion/exclusion criteria may apply