Real-World Effectiveness, Safety, and Tolerability of Facilitated Subcutaneous Immunoglobulin 10% in Secondary Immunodeficiency Disease: A Systematic Literature Review

Background: Secondary immunodeficiency disease (SID) is a complex, heterogeneous condition that occurs when extrinsic factors weaken the immune system. Expert consensus guidelines recommend immunoglobulin replacement therapy to manage immunoglobulin G (IgG) levels and mitigate severe, recurrent, and persistent infections. Hyaluronidase-facilitated subcutaneous immunoglobulin (fSCIG) 10% is a dual-vial unit of IgG and recombinant human hyaluronidase; the latter enables absorption of higher volumes of IgG than conventional subcutaneous therapies. Methods: For this systematic literature review, Embase, MEDLINE®, and the Cochrane Library were searched on 9 August 2023, with supplemental congress searches. Results: Eight studies fulfilled the inclusion criteria, reporting real-world evidence of the clinical effectiveness, safety, and tolerability of fSCIG 10% in 183 patients with SID in Europe from September 2014 to August 2021. The potential causes of SID were primarily hematological malignancies, most commonly chronic lymphocytic leukemia. Treatment was typically administered at 4-week or 3-week intervals, with doses of approximately 0.4 g/kg/month. Infections were rare during follow-up, with numerical reductions observed after fSCIG 10% treatment initiation compared with the period before initiation. Adverse reactions, including local infusion site reactions, and tolerability events were uncommon. Conclusions: Given the recency of fSCIG 10% use in patients with SID, there are opportunities for future research to better understand survival and patient-reported outcomes after receiving this treatment. Despite SID heterogeneity, this study demonstrates the feasibility of fSCIG 10% treatment for this condition.