Efficacy, safety and pharmacokinetics of a new 10% normal human immunoglobulin for intravenous infusion, BT595, in children and adults with primary immunodeficiency disease

Background and objectives: To evaluate the efficacy, safety and pharmacokinetics of a new, highly purified 10% IVIg (BT595, Yimmugo®) administered in children and adults with Primary immunodeficiency diseases (PID).

Materials and methods: Prospective, uncontrolled, multicentre Phase III trial. Patients aged 2 to <76 years with PID were switched from their pre-trial IVIg replacement therapy to BT595. In all, 67 patients (49 adults, 18 children) received doses between 0.2 and 0.8 g/kg body weight for approximately 12 months at intervals of 3 or 4 weeks. Dosing and dosing intervals were based on each patient's pre-trial infusion schedule. The primary end point was the rate of acute serious bacterial infections (SBIs); secondary efficacy, safety and pharmacokinetic outcomes were also evaluated.

Results: The primary efficacy end point was met, and the unadjusted SBI rate was 0.01 per subject-year (adjusted SBI rate 0.015 per subject-year, with an upper limit of the one-sided 99% confidence interval of 0.151). A single adult patient experienced one event classified as an SBI. All secondary end points, including those related to infections, supported the efficacy. Infusion rates were increased up to 8 ml/kg/h. Overall, 8% of infusions were associated with ≥1 infusional adverse event (AE) (start during or within 72 h post-infusion), comprising mainly headache (2.4%), fatigue (0.9%) and nausea (0.5%). There were no infusional AEs at infusion rates of >4.0 ml/kg/h, and only one patient required a single premedication. The observed patterns, severity and frequency of treatment-emergent adverse events are consistent with the established safety profile for IVIgs and did not show clinically relevant differences between all age groups.

Conclusion: BT595 is effective, safe and well tolerated for treating patients with PID.