Recent advances in the treatment of familial amyloid polyneuropathy

Abstract

The treatment of familial amyloid polyneuropathy (FAP) requires a multidisciplinary approach, mainly neurological and cardiological. It includes specific treatments to stop the progression of systemic amyloidogenesis, the symptomatic treatment of the peripheral and autonomic neuropathy and the treatment of organs severely involved by amyloidosis (heart, eyes, kidneys). First-line specific treatment of met30 transthyretin (TTR) FAP is liver transplantation, which allows suppression of the main source of mutant TTR, to stop the progression of the neuropathy in 70% of cases in the long term and to double the median survival. In cases of severe renal or cardiac insufficiency, a combined kidney-liver or heart-liver transplantation can be discussed. Tafamidis (Vyndaqel) is a novel specific stabilizer of TTR which, in the very early stages of met30 TTR FAP, slows the progress of peripheral neuropathy. This drug should be proposed in cases of stage 1 symptomatic polyneuropathy. Other innovative medicines have been developed by biopharmaceutical companies to block the hepatic production of mutant and wild type TTR which are harmful in late-onset FAP (> 50 years old), including RNA interference therapeutics and antisense oligonucleotides, and to remove the amyloid deposits (monoclonal antibody antiserum amyloid P). Clinical trials should first assess patients with late onset FAP or non-met30 TTR FAP who are less responsive to liver transplantation or in case of significant progression of the neuropathy with Vyndaqel. Initial cardiac assessment and periodic cardiac investigations are important for patients with FAP because of the frequency of cardiac impairment, which is responsible for the high rate of mortality. Prophylactic pacemaker treatment should be discussed. Symptomatic treatments are required to improve patients' quality of life. Familial screening of people with TTR mutation and regular follow up are essential. Appropriate clinical examination and complementary investigations are vital for the early detection of disease onset and to start specific therapy as soon as possible.