Estimation of the latent therapeutic demand for immunoglobulin therapies in autoimmune neuropathies in the United States

Abstract

Background and Objectives The use of immunoglobulin (IG) solutions as an immunomodulatory therapy in certain neurological conditions has become an established modality and represents a significant proportion of total IG use. The estimation of the evidence‐based potential demand designated as the latent therapeutic demand (LTD) for IG in these diseases is required for adequate planning of the plasma supply required to manufacture the product. Materials and Methods The diseases studied included chronic inflammatory demyelinating polyneuropathy (CIDP), Guillain–Barré syndrome (GBS) and multifocal motor neuropathy (MMN). The LTD for IG was assessed using a decision analysis model, using Microsoft Excel. The model analysed the epidemiological and clinical factors contributing to IG usage. One‐way sensitivity analysis and probabilistic sensitivity analysis derived the LTD in grams per 1000 inhabitants. The key variables included the treatment schedule and the prevalence of the disease. Results The model estimates that an average annual IG demand and standard deviation for CIDP, GBS and MMN in the United States is 83.05 ± 24.5, 6.1 ± 3.2 and 36.1 ± 25.5 g/1000 inhabitants, respectively. Conclusion Together with previous work on the LTD for IG in immunodeficiencies, these results indicate that current IG usage reflects the estimated LTD for the main indications for IG in the United States The wide range of LTD found in all these studies emphasizes the need for more precise assessment of the underlying variables, particularly disease prevalence and dosage. Further studies on other indications such as secondary immunodeficiencies will augment these results and will assist in guiding demand planning for IG use and plasma collection in the United States and inform blood policy in other countries.

Intravenous Immunoglobulin: Mechanism of Action in Autoimmune and Inflammatory Conditions

“…IVIG has been consistently and successfully used for numerous conditions, including Immune thrombocytopenic purpura (ITP), Kawasaki Disease (KD), Guillain-Barré syndrome, chronic inflammatory demyelinating polyneuropathy (CIDP), systemic lupus erythematosus, dermatomyositis, and other autoimmune and neurologic disorders 4 . Indeed, the number of conditions for which IVIG is used "off label" outnumbers those that have regulatory approval 5,6 .…”

Reply to Farrugia: Appropriately specifying the quality of plasma for fractionation

“…There is no doubt that immunoglobulins (IgG) are one of the main drivers for plasma procurement globally [ 2 ] as emphasized by Farrugia. However, plasma fractionation is a complex procedure by which a variety of therapeutic proteins are separated.…”