An Extension Study of TAK-664 for Japanese People With Primary Immunodeficiency Disease

TEAEs were defined as adverse events (AEs) with onset after date-time of first dose of study drug (intravenous immunoglobulin [IGIV] or IGSC), or medical conditions present prior to the start of study drug (IGIV or IGSC) but increased in severity or relationship after date-time of first dose of study drug (IGIV or IGSC). A serious TEAE was an AE that resulted in any of the following outcomes: death; life threatening; persistent/significant disability/incapacity; initial or prolonged inpatient hospitalization; congenital anomaly/birth defect or was otherwise considered medically important.

TEAEs were defined as adverse events (AEs) with onset after date-time of first dose of study drug (intravenous immunoglobulin [IGIV] or IGSC), or medical conditions present prior to the start of study drug (IGIV or IGSC) but increased in severity or relationship after date-time of first dose of study drug (IGIV or IGSC). Any TEAE that was recorded by the investigator as "probably related" or "possibly related" to study drug was considered as study drug related AE, and any AE recorded as "unlikely related" or "not related" was considered as unrelated AE.

A severe TEAE was an AE that caused considerable interference with the participant's usual activities. Local TEAEs were defined as AEs that were included in the MedDRA Higher Level Group Term "administration site reactions" or contained the phrase "injection site" or "infusion site". Systemic TEAEs were defined as AEs that were not included in the Medical Dictionary for Regulatory Activities (MedDRA) Higher Level Group Term "administration site reactions" and did not contain the phrase "injection site" or "infusion site".

Infusion associated TEAEs were defined as any TEAE that began during study drug infusion or within 72 hours of completion of study drug infusion. TEAEs leading to premature discontinuation from study and infusion-associated TEAEs were reported.

Serum trough levels of total IgG and IgG1, IgG2, IgG3, IgG4 antibodies subclasses were determined by using standard assay methods.

Serum trough levels of IgG and IgG1, IgG2, IgG3, IgG4 antibodies subclasses were determined by using standard assay methods.

The ASBI rate was calculated as the mean number of acute serious bacterial infections per participants per year. Annual rate of validated acute serious bacterial infections per participant was assessed. Reported timeframe included timeframe of core study TAK-664-3001 (NCT04346108) (Max approximately 1.5 year) and of current extension study (Max approximately 3 years) as data of this outcome measure was collected from first dose of core study to end of current extension study and the data is presented for participants who entered in current study from core study as per plan.

The annual rate of infections was calculated as the mean number of infections per participant per year. Reported timeframe included timeframe of core study TAK-664-3001 (NCT04346108) (Max approximately 1.5 year) and of current extension study (Max approximately 3 years) as data of this outcome measure was collected from first dose of core study to end of current extension study and the data is presented for participants who entered in current study from core study as per plan.

Number of days not able to attend school or work to perform normal daily activities due to illness/infection are standardized per year (365.25 days). Reported timeframe included timeframe of core study TAK-664-3001 (NCT04346108) (Max approximately 1.5 year) and of current extension study (Max approximately 3 years) as data of this outcome measure was collected from first dose of core study to end of current extension study and the data is presented for participants who entered in current study from core study as per plan.

Number of days on antibiotics was defined as the number of days those antibiotics were taken as concomitant medications and was standardized to per year (365.25 days). Number of days participants on antibiotics were reported. Reported timeframe included timeframe of core study TAK-664-3001 (NCT04346108) (Max approximately 1.5 year) and of current extension study (Max approximately 3 years) as data of this outcome measure was collected from first dose of core study to end of current extension study and the data is presented for participants who entered in current study from core study as per plan.

Number of hospitalizations were standardized to per year (365.25 days). Hospitalizations were measured by asking participants to report the number of nights they have stayed overnight in the hospital during the year, for something related to their own health. Number of hospitalizations due to illness or infection were reported. Reported timeframe included timeframe of core study TAK-664-3001 (NCT04346108) (Max approximately 1.5 year) and of current extension study (Max approximately 3 years) as data of this outcome measure was collected from first dose of core study to end of current extension study and the data is presented for participants who entered in current study from core study as per plan.

Length of hospital stay per stay was standardized to per year (365.25 days). Number of days due to illness or infection were reported. Reported timeframe included timeframe of core study TAK-664-3001 (NCT04346108) (Max approximately 1.5 year) and of current extension study (Max approximately 3 years) as data of this outcome measure was collected from first dose of core study to end of current extension study and the data is presented for participants who entered in current study from core study as per plan.

Number of acute physician visits is standardized to per year (365.25 days). Number of acute (urgent or unscheduled) physician visits due to illness/infection were reported. Reported timeframe included timeframe of core study TAK-664-3001 (NCT04346108) (Max approximately 1.5 year) and of current extension study (Max approximately 3 years) as data of this outcome measure was collected from first dose of core study to end of current extension study and the data is presented for participants who entered in current study from core study as per plan.

Treatment preference questionnaire is a self-administered questionnaire developed to assess participant's preference towards the administration of new IGSC therapy. There are 4-items on the questionnaire, which investigate a participant's preference on the clinic/hospital/home setting of receiving the immunoglobulin therapy, the participant's rating on the frequency and method of administration, and the participant's preference to continue receiving the IGSC treatment. For First question "Before participation in the trial(s), where did you receive your immunoglobulin therapy" participants were allowed to select multiple answers for options ("At the hospital"; "At home"; "Other") for their treatment. As a result, the sum of responders in the arm "IGSC, 20%: >=14 Years" for the first question were higher than the total number of participants analyzed in the category.

An infusion was considered tolerable if the infusion rate was not reduced, or the infusion was not interrupted or stopped, due to a TEAE related to study drug infusion. A tolerability event was considered to have occurred if an infusion was not tolerable.