As human normal immunoglobulin has been used to treat these diseases for many years, in accordance with current guidelines, two small studies and an analysis of scientific literature were needed to establish the effectiveness and safety of Hizentra in patients.

In the first study, Hizentra was investigated in 51 patients with PID who had already received human immunoglobulin by injection into a vein for at least six months. The patients received Hizentra for 28 weeks and the lowest IgG levels during treatment with Hizentra (average level of 8.1 g per litre) were comparable to those seen during previous immunoglobulin treatment. In addition, no infections occurred during the study period.

In the second study Hizentra was studied in 172 patients with CIDP who had previously received human immunoglobulin treatment by injection into a vein. Patients received Hizentra or placebo (a dummy treatment) for 13 weeks and the study measured the proportion of patients in whom the disease came back within 13 weeks. For patients on placebo, the disease came back in about 63% of patients; for patients on Hizentra, the disease came back in 33 and 39% of patients, depending on the dose used.

The scientific literature analysis involved seven studies comparing the use of Hizentra in patients with SID with other subcutaneous infusion or intravenous (injected directly into a vein) immunoglobulin treatments. All studies showed increases in antibody levels and/or a reduction in infection rates after receiving Hizentra or another subcutaneous immunoglobulin treatment; the effects were comparable to those seen with intravenous immunoglobulin treatment.