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

Open to people ages 2 years and up

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

• Participant must have completed Study TAK-881-3001 (NCT05755035).
• Participant or, in the case of minors, legally designated representative(s) is/are willing and able to comply with the requirements of the protocol.
• Participant or, in the case of minors, legally designated representative(s) has/have provided informed consent/assent (if applicable), including providing consent for use of the investigational medical device (in US sites only), prior to the initiation of any study procedures.

• 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 was enrolled 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.
• Participants with potential to become pregnant 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 participant is pregnant or lactating at the time of screening or intends to become pregnant or begin lactating during the study.