Biweekly Hizentra® in Primary Immunodeficiency: a Multicenter, Observational Cohort Study (IBIS)

Immunoglobulin G (IgG) replacement therapy is a standard treatment for patients with primary immunodeficiency diseases (PIDs). Hizentra®, a 20% human subcutaneous IgG (SCIG), is approved for biweekly administration for PIDs. The aim of the multicenter IBIS study was to prospectively investigate the efficacy of biweekly Hizentra® compared with previous IVIG or SCIG treatment regimens in patients with PIDs. The study consisted of a 12-month retrospective period followed by 12-month prospective observational period. The main endpoints included pre-infusion IgG concentrations, proportion of patients with serious bacterial infections (SBIs), other infections, hospitalizations due to PID-related illnesses, and days with antibiotics during the study periods. Of the 36 patients enrolled in the study, 35 patients continued the study (mean age 26.1 ± 14.4 years; 68.6% male). The mean pre-infusion IgG levels for prior immunoglobulin regimens during the retrospective period (7.84 ± 2.09 g/L) and the prospective period (8.55 ± 1.76 g/L) did not show any significant variations (p = 0.4964). The mean annual rate of SBIs/patient was 0.063 ± 0.246 for both prospective and retrospective periods. No hospitalizations related to PIDs were reported during the prospective period versus one in the retrospective period. All patients were either very (76.5%) or quite (23.5%) satisfied with biweekly Hizentra® at the end of the study. In conclusion, the IBIS study provided real-world evidence on the efficacy of biweekly Hizentra® in patients with PIDs, thus verifying the data generated by the pharmacometric modeling and simulation study in a normal clinical setting

Pediatric subset of primary immunodeficiency patients treated with SCIG: post hoc analysis of SHIFT and IBIS pooled data

Background Primary immunodeficiencies (PID) constitute a heterogeneous group of more than 350 monogenetic diseases. PID patients with antibody impairment require lifelong administration of immunoglobulin G replacement therapy, administered either intravenously (IVIG) or subcutaneously (SCIG). Although the effectiveness of weekly and biweekly (every other week) SCIG administration has been shown in several trials, data on the viability of these two regimens in pediatric PID patients are sparse. Methods Data on the pediatric subsets of PID patients enrolled in SHIFT (weekly) and IBIS (biweekly) studies were pooled and analyzed to indirectly compare two different 20%-concentrated SCIG (Hizentra(R)) regimens. The primary endpoints were to evaluate trough IgG levels and cumulative monthly doses; the secondary endpoint was to analyze incidence of infections. Results Fifteen and 13 children from the SHIFT and IBIS studies were included, respectively. Cumulative 20%-concentrated SCIG monthly dose was slight lower for the biweekly regimen (Delta = - 2.04, 90% CI - 8.3 to 4.23). However, the trough IgG levels were similar between the two groups (Delta = 0.28, 90% CI - 0.51 to 1.07) and constantly above the threshold of 5 g/L. After adjusting for potential confounders, the annualized rate of infections was similar between SHIFT and IBIS patients (incidence rate ratio = 1.09, 90% CI 0.72-1.67); only 1 serious bacterial infection was experienced by a patient in the IBIS group. Conclusion In pediatric PID patients, weekly and biweekly Hizentra(R)administrations appeared equally effective treatment options