Pharmacokinetics of a New Intravenous Immunoglobulin (IVIg) 10% (KIg10) in Primary Immunodeficiency (PI) Patients

Intravenous immunoglobulin (IVIg) therapy is commonly used in the treatment of primary immunodeficiency (PI) disorders.

This open-label, prospective, single-arm, multicenter phase III study in adult PI patients (KIG10_US3_PID01; NCT01581593) investigated efficacy, safety, and pharmacokinetics (PK) of a new 10% IVIg product (KIg10), given 200 to 800 mg/kg every 21 or 28 days for 48 weeks.

Primary PK endpoints included total IgG levels, IgG subclasses levels, selected specific antibody levels, and PK parameters of total and baseline-corrected IgG.

PK assessments were performed in 23 adult patients, and blood samples from them were taken for PK parameters’ analysis before and after the 5th infusion for the 28-day infusion schedule or the 7th infusion for the 21-day infusion schedule and at protocol prespecified time points.

The estimated mean serum half-life (T1/2) for uncorrected total IgG was 24.5 days (587 h) and 37.3 days (896 h) for patients on 21- and 28-day schedule, respectively. The total serum IgG PK profiles were comparable between the two dosing schedules, with a numerically higher exposure for the 21-day schedule. All the mean values of IgG subclasses were maintained within the reference ranges following IV infusion of KIg10. All anti-tetanus toxoid antibody levels, mean values of anti-pneumococcal capsular polysaccharide antibodies, and mean levels of anti-Haemophilus influenzae type b antibodies were maintained above protective levels.

In study KIG10_US3_PID01, measured PK parameters for KIg10 in adult patients with PID were considered comparable with previously published data for other IVIg treatments.