Researchers Evaluate Infusion Parameters for IgPro20

Two studies discussed the feasibility of different parameters for the infusion of a product for patients with primary immunodeficiency disorder (PID) in abstracts prepared for the American Academy of Allergy, Asthma & Immunology 2020 Annual Meeting.

The first study evaluated high infusion parameters for pump-assisted and manual push 20% subcutaneous immunoglobulin (SCIg), or IgPro20. Sold under the name Hizentra, IgPro20 was first approved for the treatment of PID and is also approved for chronic inflammatory demyelinating polyneuropathy. HILO was the first multicenter, open‑label, parallel‑arm, nonrandomized study (NCT03033745), in which patients received weekly IgPro20 infusions at a constant dose using forced upward titration design.

Researchers evaluated patients who received pump-assisted IgPro20 administration. Eligible patients were experienced with pump-assisted infusions at the highest approved IgPro20 infusion parameters.

Responders were defined as the percentage of patients who successfully completed at least 75% of planned infusions. Researchers evaluated responder rates in the pump-assisted volume cohort (n = 15; 25-50 mL per injection site) and in the pump-assisted flow rate cohort (n = 18; 25-100 mL/h per injection site), as well as adherence rates and serum immunoglobulin G (IgG) trough levels.

In the volume and flow rate groups, responder rates were 86.7% (25 mL), 73.3% (40 and 50 mL), 77.8% (25 and 50 mL/h), 66.7% (75 mL/h), and 61.1% (100 mL/h) respectively. Dose and volume adherence rates were 90% or higher in all patients of the volume cohort and in 83.3% of patients in the flow rate cohort (<90% in 3 patients).

Mean (SD) IgG trough levels (g/L) were similar between day 1 and the end of the study in both the volume (10.19 [2.35] vs 10.96 [2.42]) and flow rate (10.40 [2.06] vs 10.62 [1.87]) cohorts.

Pump-assisted IgPro20 infusions are feasible at high infusion parameters in most patients, allowing shorter infusion times and thereby improved administration convenience, despite decreasing responder rates, the study said.

In a second study, another HILO analysis looked at the manual push flow rate cohort (n = 16), which included patients experienced with frequent IgPro20 infusions (2-7 infusions/week) at the highest flow rate approved for pump-assisted infusions (~25 mL/h or ~0.5 mL/min).

High infusion flow rates including 0.5, 1, and 2 mL/min were evaluated, while weekly IgPro20 dose, dosing frequency, and infusion volume remained constant during the study period (16 weeks).

Responder rates were defined at the percentage of of patients completing at least 60% of infusions at each flow rate and completing the full dose per scheduled infusion without interruptions for any reason. Researchers assessed compliance rates and serum immunoglobulin G (IgG) trough levels.

Responder rates were 100%, 100%, and 87.5% at 0.5 mL/min, 1 mL/min, and 2 mL/min, respectively, with 98.5% to 100% of infusions completed per planned schedule.

Dose compliance rate was 90% or higher in 15/16 patients. Mean IgG trough levels were similar between day 1 (9.36 [2.53] g/L) and the end of study (9.58 [2.12] g/L).

Manual IgPro20 push infusions at high flow rate of up to 2 mL/min are feasible in most patients with PID, the researchers said.