Abstract Introduction Hyaluronidase-facilitated subcutaneous immunoglobulin 10% (fSCIG 10%) is a unique and effective treatment for primary immunodeficiency disease (PID), allowing for less frequent administration than conventional subcutaneous immunoglobulin therapies. Methods The pharmacokinetics (PK) of fSCIG 10% in pediatric patients (aged 2 to 16 years at screening) with PID was assessed in a prospective, phase 3, open-label, multicenter, clinical trial conducted in the USA. Patients previously treated with intravenous or conventional subcutaneous immunoglobulin therapy (consistent dose for ≥3 months) received fSCIG 10% via a dose ramp-up schedule for ≤6 weeks (Epoch 1), then at full target dose every 3–4 weeks for ≤3 years (Epoch 2). Serum total immunoglobulin G (IgG) trough levels were reported throughout Epoch 2 across pediatric age groups (2 to 6, 6 to 12, and 12 to ≤16 years); serial PK were characterized at the Month 6 infusion. In total, 44 patients (mean age: 9.0 years; 59% male and 91% White) were eligible for the study. Results Mean total IgG trough levels during Epoch 2 were similar across age groups. Geometric mean area under the IgG concentration–time curve per week ranged from 63.4 to 76.8 g·day/L, and body weight-adjusted apparent clearance ranged from 1.5 to 1.9 ml/day/kg. Conclusion This study showed that serum total IgG trough levels were effectively maintained in pediatric patients with PID treated with fSCIG 10%, regardless of age. The dosing strategy for pediatric patients should be informed by assessing individual IgG levels and clinical status as for adults. Clinical trials registration The study is registered with the ClinicalTrials.gov registry at https://clinicaltrials.gov/ct2/study/NCT03277313 (ClinicalTrials.gov Identifier: NCT03277313).
Li et al. (Wed,) studied this question.