There are several neurological diseases with unmet medical needs in which a single dose of IdeS treatment may be beneficial. Guillian-Barré syndrome is the lead clinical indication in neurology.
Guillain-Barré Syndrome (GBS)
The acute immune-mediated polyneuropathies are classified under the eponym Guillain-Barré syndrome after the authors of early descriptions of the disease. GBS is an autoimmune disease, resulting from the generation of autoimmune antibodies and inflammatory cells that cross-react with epitopes on peripheral nerves and roots, leading to demyelination, axonal damage or both. Pathogenesis of GBS is not yet fully understood, but the disease is often triggered by a preceding bacterial or viral infection. In particular, one potential trigger of GBS is infection caused by campylobacter. GBS is a heterogeneous disorder, and several variants of the disease have been identified. Variants are often categorized as demyelinating and axonal. Most often, GBS presents as an acute monophasic paralyzing illness.
The cardinal clinical features of GBS are rapidly progressive, symmetrical weakness of the extremities accompanied by absent or depressed deep tendon reflexes. The weakness reaches its highest severity in 4 weeks followed by a plateau phase and then recovery. The weakness can vary from mild difficulty with walking to nearly complete paralysis of all extremity, facial, respiratory, and bulbar muscles.
The standard first line treatment of GBS is either IVIg or plasma exchange (PE), although 30 –50 percent do not respond satisfactory to this treatment. There is a high unmet need as 5 percent of patients are dying and many of the surviving patients are left with physical disability and pain. Overall, the disease is associated with diminished life quality and high costs for society in terms of treatment and reduced work capacity. The incidence of GBS is estimated at 1:100,000. An increase in the occurrence of GBS of 20 peercent is seen with every 10-year rise in age after the first decade of life. The addressable patient population with GBS is estimated to be in the range of 4,200 –13,800.
There is evidence of pathogenic role of IgG in axonal variants of GBS, and most researchers and clinicians believe IgG to play a significant role in demyelinating variants as well.