Evaluate the impact on circulating protein biomarkers in response to patisiran treatment in patients with hATTR amyloidosis with polyneuropathy.

Hereditary transthyretin-mediated (hATTR) amyloidosis is a rare, rapidly progressing, life-threatening disease caused by deposition of aggregated TTR amyloid in organs and tissues. The majority of patients develop a mixed phenotype that includes polyneuropathy and cardiomyopathy. Since TTR amyloid accumulates over time in nerves and other tissues, it is likely that tissue damage occurs prior to overt symptomology. Clinically validated and non-invasive plasma biomarkers proximal to the neuropathology may facilitate earlier diagnosis and treatment initiation, as well as aid in monitoring disease progression/regression.