Efficacy and safety of a new 10% intravenous immunoglobulin (IVIG) in Chinese patients with primary immune thrombocytopenia (ITP): a multicenter, single-arm, phase III trial.

A novel, highly purified 10% intravenous immunoglobulin (IVIG) formulation was evaluated for both therapeutic efficacy and safety profile in adult patients diagnosed with persistent or chronic primary immune thrombocytopenia (ITP). This phase III, multicenter, open-label, single-arm clinical trial enrolled Chinese adult patients diagnosed with persistent or chronic ITP presenting with baseline platelet counts below 30 × 10⁹/L. Participants received intravenous administration of 10% IVIG at a standardized dosage of 1 g/kg/day for two consecutive days. The primary efficacy endpoint was defined as the proportion of subjects achieving both a platelet count elevation to ≥ 30 × 10⁹/L and a minimum two-fold increase from baseline values within a 7-day post-treatment observation period following the first dose administration. Seventy-two patients were enrolled and sixty patients completed the study. 52 (72.2%; 95% CI: 60.4, 82.1) patients achieved platelet count ≥ 30 × 10⁹/L and experienced a ≥ twofold increase from baseline within 7 days, and 52 (72.2%; 95% CI: 60.4, 82.1) patients achieved complete response (CR) or response (R) within 7 days. 64 patients (88.9%; 95% CI: 79.3, 95.1) achieved platelet count ≥ 50 × 10⁹/L within 7 days with a median time of 3 days. 71 patients completed the ITP bleeding scale assessment after 7 days, showing a decrease of 0.6 ± 1.07 from baseline. A total of 66 patients (91.7%) reported treatment-emergent adverse events (TEAEs) during the study, and 37 patients (51.4%) reported adverse drug reactions (ADRs). The most prevalent ADRs with an incidence exceeding 5% included headache (n = 12, 16.7%), fever (n = 10, 13.9%), decreased white blood cell count (n = 5, 6.9%), and nausea (n = 5, 6.9%). The therapeutic regimen of 10% IVIG administered at a dosage of 1 g/kg/day for two consecutive days demonstrated both favorable safety profiles and clinical efficacy. These robust findings provide substantial evidence supporting the clinical application of this novel 10% IVIG formulation in the management of adult patients with ITP.