Latent Therapeutic Demand of Immunoglobulin therapies in neuropathies – chronic inflammatory demyelinating polyneuropathy (CIDP), Guillain–Barré syndrome (GBS) and multifocal motor neuropathy (MMN) in the United States

Abstract

AbstractChronic inflammatory demyelinating polyneuropathy (CIDP) is a neurological disorder characterized by progressive weakness and impaired sensory function in the legs and arms. Guillain-Barré syndrome is a disorder in which the body’s immune system attacks part of the peripheral nervous system. The first symptoms of this disorder include varying degrees of weakness or tingling sensations in the legs (NIH). Multifocal motor neuropathy is a progressive muscle disorder characterized by muscle weakness in the hands, with differences from one side of the body to the other in the specific muscles involved (NIH). We have modeled a latent therapeutic demand (LTD) of IVIg for CIDP and similar neuropathies in the US. We used the decision analysis methodology similar to the methods used by Stonebraker et al1 for modeling LTD of IVIg. The model is based on the relationships of the epidemiological and clinical factors. Most of the usage patterns and dosage level of albumin are according to the epidemiological studies and clinical trials. The model is built in Microsoft Excel. The analysis is conducted based on oneway sensitivity analysis and probabilistic sensitivity analysis. The demand in terms of grams per 1,000 inhabitants is calculated depending on the treatment schedule and the prevalence of the disease. The model for CIDP has eight variables including prevalence of CIDP, patients using IVIg, dosage and treatment patterns. The annual demand of IVIg is based on initial treatment of 24 weeks followed by a maintenance period, with lower dosage and frequency of treatment for another 24 weeks2. The model for GBS has eight variables with a loading dose for 3-6 days followed by a second dose in case of relapse. The model for MMN has nine variables. It has a loading dose followed by maintenance dose every 1-6 weeks depending on the clinical factors of the patient. On an average, IVIg use was calculated as 100 gms, 5.6 gms and 35 gms per 1,000 inhabitants for CIDP, GBS and MMN, respectively, in the US annually.