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). HizentraA (R), 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 HizentraA (R) 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 HizentraA (R) at the end of the study. In conclusion, the IBIS study provided real-world evidence on the efficacy of biweekly HizentraA (R) in patients with PIDs, thus verifying the data generated by the pharmacometric modeling and simulation study in a normal clinical setting.