Subcutaneous immunoglobulin replacement therapy in patients with primary immunodeficiency in routine clinical...

Subcutaneous immunoglobulin (SCIG) therapy is becoming increasingly popular as self-administration is possible because intravenous access is unnecessary, and there is a lower frequency of systemic adverse events. The aim of this study was to evaluate the shifting from intravenous immunoglobulins (IVIGs) replacement therapy to SCIG in patients with primary immunodeficiency (PID) in a routine real-life situation.

In a multicenter prospective observational study, we enrolled 50 patients suffering from PID who were monitored for 24 months; 44 patients switched from IVIG and six from different SCIG preparations. The study preparation (human IgG 16 %, Vivaglobin(®), CSL Behring GmbH, Germany) was subcutaneously infused weekly (maximum volume 15 mL/site; maximum infusion rate 22 mL/h). The study endpoints were: annual rate of severe bacterial infections (SBIs), local adverse reactions, quality of life, days off school/work, and days of hospitalization.

Thirty-three of 39 (84.6 %) patients who completed the study experienced an infection or signs thereof. Only five SBIs were observed, corresponding to an annual rate of 0.056 episodes per patient in 44 subjects [intention-to-treat (ITT) population]. A significant decrease in both days of hospitalization (1.93 ± 4.08 vs. 0.64 ± 2.94) and days off school/work (15.27 ± 23.17 vs. 2.26 ± 4.45) was recorded at 24 months. Local reactions were observed in 14/50 (28 %) patients, mainly consisting of skin manifestations at the injection site. Only three (6.8 %) patients discontinued due to infusion site reactions. In patients shifting from IVIG to SCIG, the total mean score of Life Quality Index (LQI) improved from 76.9 ± 16.8 to 90.7 ± 11.6 (P < 0.01) at 6 months; there was an improvement also in the overall patients' evaluation.

A total of 93.2 % patients tolerated the new route of administration and reported a significant improvement in their LQI. Our results from a routine clinical practice in a real-life population are consistent with those of phase III clinical studies.