Study: Bioavailability similar among four subcutaneous IgG preparations

Data presented by CSL Behring today suggest that the bioavailability of immunoglobulin G (IgG) therapies is consistent when patients with primary immunodeficiencies switch from one IgG product to another by the subcutaneous route. The analysis, which was presented at the 2012 American Academy of Allergy, Asthma and Immunology annual meeting, was a joint effort between CSL Behring and physicians at University Hospital of Wales, Cardiff, UK and University of South Florida, St. Petersburg, USA.

Based on an analysis of published data, the study found that bioavailability – the percentage of unchanged drug that reaches the circulation – was similar among four subcutaneous IgG (SCIg) preparations and all fell within the range of 66.7+2.7 percent as compared to intravenous IgG. In the United States study, mean serum IgG level following SCIg administration did not differ significantly between Hizentra® (Immune Globulin Subcutaneous [Human]) and Vivaglobin® at the recommended dose dosages (1139+249 mg/dl and 1158+311 mg/dl, respectively). In the European Union, mean serum IgG levels were not significantly different between all tested SCIg products and Hizentra when the same doses were administered (843+138mg/dl and 833+125mg/dl, respectively).

"Maintaining a consistent level of IgG in the blood is important for patients with primary immunodeficiencies in order to prevent infections," said John W. Sleasman, MD, Chief of the Division of Pediatric Allergy, Immunology and Rheumatology at the University of South Florida. "This analysis provides reassurance that regardless of current treatment – intravenous or subcutaneous – patients can switch IgG products without undue concern about dosing or therapeutic IgG levels."   

"This analysis furthers the understanding of bioavailability among Ig therapy options, an important consideration for patients and physicians as they evaluate which product is best suited to an individual patient's therapeutic and lifestyle needs," said Dr. Mel Berger, Senior Medical Director, Immunology Research and Development at CSL Behring. "CSL Behring will continue to advance research on how best to use innovative SCIg treatments such as Hizentra to ensure patients can achieve steady-state serum IgG levels and consistent symptom control with Ig therapy that fits into their lives."