The Effect of Tafamidis on Transthyretin Stabilization, Safety, Tolerability and Efficacy in Transthyretin Amyloid Polyneuropathy Patients

Inclusion Criteria:

• Participants are eligible to be included in the study only if all of the following criteriaapply: Age and Sex:

1. Male or female participants between the ages of 18 and 80 years. Type of Participant and Disease Characteristics:
2. Participants who are willing and able to comply with all scheduled visits, treatmentplan, laboratory tests, lifestyle considerations and other study procedures.
3. Participants have amyloid documented by biopsy in accordance with institutional sitestandard of care (Biopsy must have been performed within 5 years of enrollment).
4. Participants must have a TTR mutation that is associated with ATTR-PN. (See Section 8.2.6.3 for further details).
5. Participants have peripheral and/or autonomic neuropathy with a Karnofsky PerformanceStatus ≥50 (refer to Appendix 5).
6. Stages of disease according to symptom severity-stage I. Informed Consent:
7. Capable of giving signed informed consent as described in Appendix 1, which includescompliance with the requirements and restrictions listed in the informed consentdocument (ICD) and in this protocol.

Exclusion Criteria:

• Participants are excluded from the study if any of the following criteria apply: Medical Conditions:

1. Other acute or chronic medical or psychiatric condition including recent (within thepast year) or active suicidal ideation or behavior or laboratory abnormality that mayincrease the risk associated with study participation or investigational productadministration or may interfere with the interpretation of study results and, in thejudgment of the investigator, would make the participant inappropriate for entry intothis study. Prior/Concomitant Therapy:
2. Chronic use of non-protocol approved non-steroidal anti-inflammatory drugs (NSAIDs),defined as greater than 3-4 times/month. The following NSAID are allowed:acetylsalicylic acid, etodolac, ibuprofen, indomethacin, ketoprofen, nabumetone,naproxen, nimesulide, piroxicam, and sulindac.
3. Use of diflunisal, tauroursodeoxycholate, doxycycline or a TTR stabilizing agent, orother experimental interventions for familial amyloidosis within 30 days prior to thestudy entry and/or during study participation. Participants who are taking or who havepreviously taken tafamidis.
4. Previous administration with an investigational drug within 30 days or 5 half-livespreceding the first dose of investigational product used in this study (whichever islonger). Diagnostic Assessments:
5. Participant has primary (light chain) or secondary amyloidosis.
6. If female, participant is pregnant or breast feeding, or plans to be pregnant orbreast feeding in the next 18 months.
7. Participant has received prior liver or any other organ except cornea transplantation.
8. Participant has no recordable sensory threshold for vibration perception in both feet,as measured by CASE IV or participant requires significant assistance with ambulationor is wheel chair bound.
9. Participants with positive results for hepatitis B surface antigen (HBsAg),anti-hepatitis C virus (HCV), and/or human immunodeficiency virus (HIV).
10. Participant has liver function test abnormalities: alanine transaminases (ALT) and/oraspartate transaminases (AST) >2 times upper limit of normal (ULN) that in the medicaljudgment of the investigator are due to reduced liver function or active liverdisease.
11. Participants with cardiomyopathy specific TTR mutations (Val122Ile, Leu111Met,Ile68Leu).
12. Participant has a co-morbidity anticipated to limit survival to less than 18 months.
13. Participant has other causes of sensorimotor neuropathy (B12 deficiency, DiabetesMellitus, HIV treated with retroviral medications, thyroid disorders, alcohol abuse,Fabry disease, Lyme disease, sarcoidosis, Sjogren's Syndrome, Systemic LupusErythematosus, alcohol dependency, celiac disease, Chronic Inflammatory DemyelinatingPolyneuropathy, and chronic inflammatory diseases). Other Exclusions:
14. Investigator site staff members directly involved in the conduct of the study andtheir family members, site staff members otherwise supervised by the investigator, orPfizer employees, including their family members, directly involved in the conduct ofthe study.