P1505: TOLERABILITY AND SAFETY OF INTRAVENOUS IMMUNOGLOBULINS (5% AND 10%) FOR THE TREATMENT OF PATIENTS WITH SECONDARY IMMUNODEFICIENCIES – FINAL SUBGROUP RESULTS OF A NON-INTERVENTIONAL SAFETY STUDY

Abstract Topic: 30. Infections in hematology (incl. supportive care/therapy)

Background: Hematological diseases and/or its immunosuppressive treatments can cause secondary immunodeficiencies (SID). In case of recurrent infections and hypogammaglobulinemia, replacement therapy with intravenous immunoglobulins (IVIG) may be prescribed to reduce the risk of infections and irreversible complications. In addition to efficacy, the tolerability of IVIG is of particular importance in patients with SID.

Aims: A subgroup analysis of SID patients who received intravenous immunoglobulin therapy in routine clinical practice was performed. The treatment parameters as well as the tolerability and efficacy were analyzed and compared between a 5% and 10% IVIG-preparation.

Methods: From 2014 to 2019 a multicenter, non-interventional safety study was performed in 229 in- and outpatient centers throughout Germany to evaluate the efficacy and tolerability of two IVIG-products (5% and 10%).

Results: In this subgroup analysis a total of 3,846 patients with SID were analyzed who received 69,320 IVIG-infusions. The most common diseases within the SID group included chronic lymphocytic leukemia (CLL, 36.1%), non-hodgkin lymphoma (NHL, 21.9%) and multiple myeloma (MM, 12.8%). Further 20.7% received a stem cell transplantation (BMT) in the past.

Of these patients, 1,927 were treated with IVIG 5%, 1,749 with IVIG 10% and 170 received either both products in the same treatment cycle or changed the used product during the study.

The mean dose per treatment cycle was 0.23 g/kg body weight (BW) and 0.25 g/kg BW when being treated with IVIG-products 5% and 10%, respectively. The median treatment interval was 4.1 (IVIG 5%) and 4.4 (IVIG 10%) weeks. The patients received a mean number of 16.2 treatment cycles with IVIG 5% and 17.4 with IVIG 10%.

Efficacy was assessed by analyzing IgG-levels and infections before and during IVIG-therapy. Mean IgG-levels increased within the first three months from 7.2 g/l at baseline up to 7.9 g/l (IVIG 5%) and from 5.4 g/l up to 6.7 g/l (IVIG 10%).

The number of SID patients with infections decreased from 66.9% to 40.8% during treatment and 40.2% at the last follow-up documentation. Respiratory infections were the most common infections and the percentage of patients with any kind of respiratory infection decreased from 50.4% to 32.0% during treatment und 30.1% at the last follow-up documentation. The efficacy of both products in the reduction of infections is comparable.

In total, adverse drug reactions (ADR) were reported in 419 out of 69,320 infusions (0.60%) in 9.4% of the SID patients. Slight differences between IVIG 5% and IVIG 10% were observed: 7.5% of the patients treated with IVIG 5% and 11.5% treated with IVIG 10% experienced at least one ADR. Serious ADRs were rare and reported for 0.9% (IVIG 5%) and 1.5% (IVIG 10%) of the patients. The most frequent ADRs in patients treated with IVIG 5% were chills, back pain and pruritus and with IVIG 10% chills, nausea, pyrexia and rash.

Summary/Conclusion: This subgroup analysis shows that both IVIG-products (5% and 10%) are well tolerated and effective in patients with hematological malignancies associated with SID.

Keywords: Immunoglobulin, Safety, Immunodeficiency, IVIg