P69 | REAL-WORLD USAGE OF HYALURONIDASE-FACILITATED SUBCUTANEOUS IMMUNOGLOBULIN 10% IN PATIENTS WITH MULTIPLE MYELOMA DIAGNOSED WITH SECONDARY IMMUNODEFICIENCY: AN INTERIM ANALYSIS

Patients with multiple myeloma (MM) are susceptible to secondary immunodeficiency (SID) owing to both their underlying disease and/or immunosuppressive therapy. HyMMy (NCT05879757) is an ongoing, prospective, non-interventional, observational study of hyaluronidase-facilitated subcutaneous immunoglobulin (fSCIG) 10% in adult patients with MM and SID across 25 centres in Europe. This interim analysis evaluated fSCIG 10% use and associated outcomes at 3-month follow up. Enrolled patients had a diagnosis of MM and met criteria for SID, defined as severe, recurrent or persistent infection(s) despite appropriate anti-infective treatment, and proven specific antibody failure or a serum IgG trough level of < 4 g/L (excluding paraprotein). The primary objective was to assess real-world infusion parameters of fSCIG 10%. Secondary objectives included healthcare resource utilization, MM disease status and adverse events (AEs). Statistical analysis was descriptive. As of 5 May 2025, 67 patients were enrolled; of these, 43 had completed 3 months of follow up. The mean (standard deviation [SD]) age was 64.9 (11.26) years and 53.7% were female. At baseline (enrolment), patients with MM had bone lesions (82.4%), anaemia (49.0%), renal insufficiency (27.5%) or hypercalcemia (13.7%). At baseline, patients received steroids (61.2%), anti-plasma cell monoclonal antibodies (49.3%), immunomodulatory drugs (46.3%), proteasome inhibitors (28.4%) and bispecific antibodies (14.9%). The median (interquartile range [IQR]) time from MM to SID diagnosis was 30 (8.0–67.0) months and the time from SID diagnosis to fSCIG 10% initiation was 2 (0.0–6.0) months. At baseline, 41.6% (57/137) of fSCIG 10% infusions were received every 4 weeks; this increased to 82.2% (97/118) of infusions at 3 months. The mean (SD) dose was 0.36 (0.225) g/kg at baseline and 0.37 (0.319) g/kg at 3 months. At baseline and at 3 months, median (IQR) total infusion volume was 200 (100–250) mL and 300 (210–400) mL, respectively; infusion rate was 133.3 (100–250) mL/h and 210.5 (165–224) mL/h; maximum infusion rate was 240 (240–250) mL/h and 300 (245–300) mL/h; infusion duration was 80 (60–120) minutes and 95 (80–110) minutes; and number of infusion sites was 2 (1–3) and 2.5 (2–3). The shorter infusion duration and fewer infusion sites at baseline were related potentially to dose ramp-up. At baseline and at 3 months, 91.1% (123/135) and 92.2% (129/119) of infusions were in the abdomen, respectively. At baseline, 90.5% (124/137) of infusions occurred in the hospital and 8.8% (12/137) at home; at 3 months, 66.1% (78/118) occurred in hospital and 33.9% (40/118) at home. No infusions were discontinued, slowed or interrupted. Four patients discontinued treatment owing to lack of effectiveness (n = 1) or because they enrolled in another study (n = 3). At 3 months, all treatment-related AEs were mild (1.5%) to moderate (3.0%) in severity, with no serious treatment-related AEs reported (Table). One patient died (2.2%) from an infection unrelated to treatment. This interim analysis shows the feasibility of using fSCIG 10% as a treatment option for patients with MM and SID in real-world setting, potentially offering the flexibility of home infusions with a favourable safety profile. Final study data from up to 12 months of follow-up are needed to confirm these findings. Takeda Development Center Americas, Inc. funded this study. Takeda Pharmaceuticals International AG funded writing support.