Inclusion Criteria:  Male or female participants between the ages of 18 and 80 years. Participants have amyloid documented by biopsy Participants must have a TTR mutation that is associated with ATTR-PN. Participants have peripheral and/or autonomic neuropathy Stages of disease according to symptom severity-stage I.  Exclusion Criteria:  Other acute or chronic medical or psychiatric condition including recent or active suicidal ideation or behavior or laboratory abnormality, in the judgment of the investigator, would make the participant inappropriate for entry into this study. Chronic use of non-protocol approved non-steroidal anti-inflammatory drugs.  Use of diflunisal, tauroursodeoxycholate, doxycycline, inotersen, patisiran or any other TTR stabilizing agent, or experimental interventions for familial amyloidosis within 30 days prior to the study entry and/or during study participation. Participants who are taking or who have previously taken tafamidis.  Prior/Concurrent Clinical Study Experience:  Previous administration with an investigational drug within 30 days or 5 half lives preceding the first dose of investigational product used in this study (whichever is longer). Participant has primary (light chain) or secondary amyloidosis. If female, participant is pregnant or breast feeding, or plans to be pregnant or breast feeding in the next 18 months. Participant has received prior liver or any other organ except cornea transplantation. Participant requires significant assistance with ambulation or is wheel chair bound. Participants with cardiomyopathy specific TTR mutations. Participant has other causes of sensorimotor neuropathy.