A Study About the Long-Term Safety of TAK-881 in People With Primary Immunodeficiency Diseases

Inclusion Criteria

Participants who meet ALL of the following criteria are eligible for this study:

• Participant must have completed Study TAK-881-3001 (NCT05755035).

• Participant/Participant's parent(s)/legal guardian(s) is/are willing and able to comply with the requirements of the protocol.

• Participant/Participant's parent(s)/legal guardian(s) has/have provided informed consent/assent (if applicable), including providing consent for use of the investigational medical device, prior to the initiation of any study procedures.

Exclusion Criteria

• Participant has a serious medical condition such that the participant's safety or medical care would be impacted by participation in this long-term follow-up study.

• New medical condition that developed during participation in Study TAK-881-3001 (NCT05755035), that, in the judgment of the investigator, could increase risk to the participant or interfere with the evaluation of TAK-881 and/or conduct of the study.

• Participant has participated in another clinical study involving an investigational product (IP) or investigational device within 30 days prior to screening (with the exception of Study TAK-881-3001 [NCT05755035]).

• Participant is scheduled to participate in another clinical study involving an IP or investigational device during the course of this study.

• Participant is a family member or employee of the investigator or the investigator's site staff.

• Women of childbearing potential who meet any one of the following criteria:-

1. Participant has a positive pregnancy test.

2. Participant does not agree to employ a highly effective form of contraception for the duration of the study.

• If female, participant is pregnant or lactating at the time of screening or intends to become pregnant or begin lactating during the study.