• Incidence of patients experiencing treatment-emergent adverse events [ Time Frame: 12 months ] [ Designated as safety issue: Yes ]
• Incidence of patients experiencing treatment-emergent >/= Grade 3 adverse events [ Time Frame: 12 months ] [ Designated as safety issue: Yes ]
• Incidence of patients with treatment-emergent echocardiography findings considered by the Investigator to be clinically significant [ Time Frame: 12 months ] [ Designated as safety issue: Yes ]
• Incidence of patients with treatment-emergent electrocardiogram (ECG) findings considered by the Investigator to be clinically significant [ Time Frame: 12 months ] [ Designated as safety issue: Yes ]
• Incidence of patients with treatment-emergent Holter monitoring findings considered by the Investigator to be clinically significant [ Time Frame: 12 months ] [ Designated as safety issue: Yes ]
• Incidence of patients discontinuing from the study because of clinical or laboratory adverse events [ Time Frame: 12 months ] [ Designated as safety issue: Yes ]
• Change from Baseline in the Neuropathy Impairment Score (NIS) and NIS-Lower Limb (LL) scores [ Time Frame: 6 and 12 months ] [ Designated as safety issue: No ]
• Response to treatment (change from Baseline in the NIS-LL of < 2) [ Time Frame: 6 and 12 months ] [ Designated as safety issue: No ]
• Change from Baseline in the total quality of life and five individual domain scores of the Norfolk Quality of Life-Diabetic Neuropathy (QOL-DN) [ Time Frame: 6 and 12 months ] [ Designated as safety issue: No ]
• Change from Baseline in nerve conduction studies (NCS) [ Time Frame: 6 and 12 months ] [ Designated as safety issue: No ]
• Change from Baseline in heart rate response to deep breathing (HRDB) [ Time Frame: 6 and 12 months ] [ Designated as safety issue: No ]
• Change from Baseline in modified body mass index (mBMI) [ Time Frame: 6 and 12 months ] [ Designated as safety issue: No ]
• Change from Baseline in overall quality of life and individual domains of the SF-36 [ Time Frame: 6 and 12 months ] [ Designated as safety issue: No ]
• Change from Baseline in echocardiography parameters [ Time Frame: 6 and 12 months ] [ Designated as safety issue: No ]
• Change from Baseline in NT-pro-BNP and troponin I levels [ Time Frame: 6 weeks, 3, 6, and 12 months ] [ Designated as safety issue: No ]
• Change from Baseline in Karnofsky score [ Time Frame: 6 and 12 months ] [ Designated as safety issue: No ]

This is an open-label, multicenter, international study designed to determine TTR stabilization as well as Fx-1006A safety and tolerability, and its effects on clinical outcomes in patients with non-V30M TTR amyloidosis.

Strong pre-clinical and clinical evidence support a daily dose of 20 mg of Fx-1006A to be the optimum dose to achieve stabilization of tetrameric TTR in ATTR-PN patients. Since disease presentation is similar between V30M and non-V30M TTR mutations associated with ATTR-PN and Fx-1006A has been shown to stabilize wild-type and V30M TTR in vitro and ex vivo, the present study is being conducted to determine the effects of Fx-1006A on TTR stabilization in ATTR-PN patients with TTR mutations other than V30M. Safety and exploratory efficacy of Fx-1006A administered once daily for 12 months will also be evaluated in this patient population.

This is an open-label, multicenter, international study designed to determine TTR stabilization as well as Fx-1006A safety and tolerability, and its effects on clinical outcomes in patients with non-V30M TTR amyloidosis. The study will be conducted in two parts. Part 1 will include a six-week dosing period during which all enrolled patients will receive oral Fx-1006A 20 mg soft gelatin capsules once daily for six weeks. At Week 6, blood samples will be collected from each patient to determine TTR stabilization. Patients who complete the Week 6 visit will continue receiving daily oral Fx-1006A 20 mg for up to a total of 12 months during Part 2 of this study. If it is determined that a patient is not stabilized at Week 6, the patient will be discontinued from the study.

During Part 2, clinical outcomes will be measured at Months 6 and 12, based on NIS, Norfolk QOL-DN, mBMI, NCS, HRDB, SF-36, Karnofsky score, and echocardiography; NT-pro-BNP and troponin I levels will be measured at Baseline, Weeks 2 and 6, and Months 3, 6, and 12.

Pharmacokinetic measurements will be made using samples collected at Baseline, Week 6, and Months 6 and 12.

Safety and tolerability will be assessed throughout the study based on vital signs, physical examinations, ECG, echocardiography, 24-hour Holter monitoring, clinical laboratory tests (hematology, serum chemistry, and urinalysis), and monitoring adverse events and concomitant medication use.

Day 1 will be defined as administration of the first dose of study drug. Clinic Visits will be conducted during Screening (Days -30 to -1) and at Baseline (Day 0), and Week 2, and Week 6, and Months 3, 6, and 12 (± 2 weeks of the scheduled date for post-Baseline visits). Monthly telephone contacts (+ 1 week of the scheduled date) will be made during months in which no investigative site visits are scheduled (Months 4, 5, 7, 8, 9, 10, and 11) for assessment of adverse events and concomitant medications. A final telephone contact to assess adverse events and concomitant medication usage will be made 30 days after the last dose of study drug.

Patients who discontinue from the study at any time following enrollment will have a final visit performed, including all safety assessments, at the time of discontinuation. Any patient discontinuing after the Month 6 visit will also have all exploratory assessments performed.

Inclusion Criteria:

1. Patient has amyloid documented by biopsy (in accordance with institutional site standard of care).
2. Patient has documentation of one of the following targeted TTR mutations: Ser77Tyr, Thr60Ala, Tyr114Cys, Leu58His, Glu89Gln, Ser77Phe, Thr49Ala, Ile107Val, Val30Ala, Gly47Ala, Gly47Glu, Leu55Arg, Lys70Asn, Ile84Thr, Ile107Met. Patients with mutations other than those listed may be enrolled only after approval by the Sponsor.
3. Patient has peripheral and/or autonomic neuropathy and/or cardiomyopathy with a Karnofsky Performance Status ≥ 50.
4. Patient is aged ≥18 to 75 years, inclusive.
5. If female, patient is post-menopausal, surgically sterilized, or willing to use two acceptable methods of birth control (i.e., a hormonal contraceptive, intra-uterine device, diaphragm with spermicide, condom with spermicide) throughout the study and for 3 months from the end of the study. (A condom alone is not considered an acceptable method of birth control.) If male with a female partner of childbearing potential, willing to use two acceptable methods of birth control for the duration of the study. For both females and males, acceptable birth control must be used for at least 3 months after the last dose of study medication.
6. Patient is, in the opinion of the investigator, willing and able to comply with the study medication regimen and all other study requirements.

Exclusion Criteria:

1. Chronic use of non-steroidal anti-inflammatory drugs (NSAIDs), defined as greater than 3-4 times/month (ibuprofen and nimesulide will be permitted).
2. Patient has primary or secondary amyloidosis.
3. Patient has TTR-associated amyloidosis with V30M mutation.
4. If female, patient is pregnant or breast feeding.
5. Patient has received prior liver transplantation.
6. Patient is expected to undergo liver transplantation within 12 months after enrollment.
7. Patient with positive results for hepatitis B surface antigen (HBsAg), anti-hepatitis C virus (HCV), and/or human immunodeficiency virus (HIV).
8. Patient has renal insufficiency (creatinine clearance < 30 ml/min).
9. Patient has liver function test abnormalities: alanine transaminases (ALT) and/or aspartate transaminases (AST) > 2 times upper limit of normal (ULN) that in the medical judgment of the investigator are due to reduced liver function or active liver disease.
10. Patient has a New York Heart Association (NYHA) Functional Classification ≥ III.
11. Patient has other causes of sensorimotor neuropathy (B12 deficiency, Diabetes Mellitus, HIV treated with retroviral medications, thyroid disorders, alcohol abuse, and chronic inflammatory diseases).
12. Patient has prior non-amyloid cardiac disease such as: myocardial infarction due to obstructive coronary artery disease, active non-amyloid cardiomyopathy (e.g., symptomatic left ventricular dysfunction from any cause other than amyloid, patients with a primary diagnosis of symptomatic valvular heart disease)
13. Patient has a co-morbidity anticipated to limit survival to less than 12 months.
14. Patient has received an investigational drug/device and/or participated in another clinical investigational study within 60 days before Baseline (Day 0).