a study about the long-term safety of tak-881 in people with primary immunodeficiency diseases

Conditions: Primary Immunodeficiency Diseases (PID)

Summary: the main aim of this study is to learn if tak-881 is safe and well tolerated during long-term use in adults and children with pidd who are eligible and completed study tak-881-3001 (nct05755035). the participants will receive the first dose of tak-881 immunoglobulin (igg) infusion at the same dosage as the last dose administered in study tak-881-3001 (nct05755035). after the first tak-881 infusion in study tak-881-3002, the dosing interval (can be adjusted by participant/caregiver) and/or the dose of tak-881 can be adjusted by the study doctor to every 2, 3 or 4 weeks at scheduled site visits. participants will visit the clinic every 12 weeks until the end of study (eos) visit.

the study consists of two epochs: epoch 1 and epoch 2. in epoch 1 eligible participants will have the opportunity to receive tak-881 for a minimum of 6 months. after 6 months in study tak-881-3002, the results of the anti-rhuph20 binding antibody assay from either study tak-881-3001 (nct05755035) or study tak-881-3002 (epoch 1) will be used to determine the next steps in the study: * epoch 1: participants with an anti-rhuph20 antibody titer less than \[\<\] 1:160 will complete the eos visit on the day of the first non-investigational product (ip) infusion following study visit week 25. * epoch 2: participants with an anti-rhuph20 antibody titer greater than or equal to \[\>=\] 1:160 at any time point during study tak-881-3001 (nct05755035) and/or study tak-881-3002 (epoch 1), will continue with an additional two years of tak-881 treatment and undergo safety follow-up and will complete the eos visit on the day of the first non-ip infusion following study visit week 121.

Eligibility criteria:
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.