Efficacy and safety of ClairYg, a ready-to-use intravenous immunoglobulin, in adult patients with primary immune thrombocytopenia.

Purpose: The present study was designed to assess the efficacy and safety of IGNG that is a new liquid, saccharose and maltose-free highly purified ready-to-use 5% intravenous immunoglobulin (IVIg), in primary immune thrombocytopenic patients with severe thrombocytopenia.

Methods: Nineteen adults with a platelet count ≤ 25 × 10/L received a single dose of IGNG (1 g/kg) on Day 1, with a second identical dose on Day 3 if needed. Patients were followed for 30 days. Primary endpoint was the response rate, defined as the proportion of patients with a platelet count ≥ 50 × 10/L within 96 hours after the first IGNG dose.

Results: All but one of the 17 evaluable patients for efficacy responded with an overall response rate of 94.1% (95% CI 71.3%-99.9%). Response was observed after only one infusion (1 g/kg boby weight) in 11 patients (59%) and the others required a second dose. Mean time to response was 2.2 days. Maximum platelet count was reached within 1 week after the first dose and lasted for approximately 2 weeks. Patients requiring a second dose had lower platelet counts at baseline than patients requiring a single dose. In the 19 evaluable patients for safety, IGNG demonstrated good safety, good hepatic and renal tolerance, and did not induce hemolysis. This trial was registered at the French Medical Agency (AFSSAPS) as #DI n°060735.