The committee stated that there was not enough evidence supporting efficacy of the drug, and requested additional clinical trials.In August 2018, the FDA approved patisiran, an siRNA-based treatment, at an expected cost of up to $450,000 per year.In August 2021 six patients with hereditary ATTR amyloidosis with polyneuropathy were given doses of NTLA-2001, based on a CRISPR gene editing system. Researchers reported mild adverse events and decreases in serum misfolded transthyretin protein concentrations through targeted knockout. Prognosis
In the absence of a liver transplant, FAP is invariably fatal, usually within a decade. The disadvantage of liver transplantation is that approximately 10% of the subjects die from the procedure or complications resulting from the procedure, which is a form of gene therapy wherein the liver expressing wild type and mutant TTR is replaced by a liver only expressing wild type TTR. Moreover, transplanted patients must take immune suppressants (medications) for the remainder of their life, which can lead to additional complications. In late 2011, the European Medicines Agency approved the transthyretin kinetic stabilizer Tafamidis or Vyndaqel discovered by Jeffery W. Kelly and developed by FoldRx pharmaceuticals (acquired by Pfizer in 2010) for the treatment of FAP based on clinical trial data. Tafamidis (20 mg once daily) slowed the progression of FAP over a 36-month period and importantly reversed the weight loss and muscle wasting associated with disease progression.
Epidemiology
This disease is endemic in Portuguese locations Póvoa de Varzim and Vila do Conde (Caxinas), with more than 1000 affected people, coming from about 500 families, where 70% of the people develop the illness. ll the analysed Portuguese families presented the same haplotype (haplotype I) associated with the Met 30 mutation. In northern Sweden, more specifically  Skellefteå (it is locally called "Skelleftesjukan", the Skellefteå disease), 1.5% of the population has the mutated gene. There are many other populations in the world who exhibit the illness after having developed it independently. References
External links

GeneReviews/NIH/NCBI/UW entry on Familial Transthyretin Amyloidosis