Evaluating dose ratio of subcutaneous to intravenous immunoglobulin therapy among patients with primary immunodeficiency disease switching to 20% subcutaneous immunoglobulin therapy.

Background: Current prescribing information recommends that physicians apply a dose ratio of 1.37:1 (1.53:1 prior to January 2015) in the United States (US) when switching patients with primary immunodeficiency disease (PI) from intravenous (IVIG) therapy to most subcutaneous therapy ([SCIG], except the 10% SCIG human hyaluronidase and immune globulin).